WO2010105045A2

WO2010105045A2 - Method and apparatus for fall prevention and monitoring

Info

Publication number: WO2010105045A2
Application number: PCT/US2010/026967
Authority: WO
Inventors: Imad Libbus; Yatheendhar D. Manicka; Badri Amurthur
Original assignee: Corventis, Inc.
Priority date: 2009-03-11
Filing date: 2010-03-11
Publication date: 2010-09-16
Also published as: WO2010105045A3

Abstract

Devices, systems, and methods for fall prevention and/or fall detection can include an adherent support configured to adhere to a skin of the patient, an accelerometer coupled with the support, and a processor coupled with the accelerometer and configured to detect a fall of the patient, an orientation of the patient, an orientation-restriction violation, and/or a movement-restriction violation. A restriction can be dynamically imposed or adjusted in response to detected patient conditions. The disclosed devices, systems, and related methods can provide notification of a patient fall and patient data useful in evaluating the severity and/or cause of the fall.

Description

METHOD AND APPARATUS FOR FALL PREVENTION AND

MONITORING

CROSS-REFERENCES TO RELATED APPLICATIONS

[0001] The present application claims priority to U.S. Application No. 61/209,937, filed on March 11 , 2009 (Attorney Docket No. 026843-03700US), the full disclosures of which are incorporated herein by reference.

BACKGROUND

[0002] 1. Field of the Invention. The present invention relates to patient monitoring. Although embodiments make specific reference to monitoring patient orientation, movement, impedance and electrocardiogram signals with an adherent patch device, the system methods and device described herein may be applicable to many applications in which physiological monitoring is used, for example wireless physiological monitoring for extended periods.

[0003] Patients with a compromised status (e.g., due to old age, injury, and/or illness) can be susceptible to collateral injury due to experiencing a fall. According the United States

Centers for Disease Control and Prevention (CDC), falls may be the leading cause of nonfatal medically-attended injuries in the United States. Fall related injuries can be especially prevalent among older adults (65 and older). According to the CDC, falls may be a cause of injury deaths in the United States of older adults, and more than a third of older adults may experience at least one fall each year. For example, in 2005 alone, falls appear to have accounted for a significant amount of injury among older adults, as approximately 15,800 older adults may have died from fall related injuries, and approximately 1.8 million older adults may have received emergency room treatment for fall related injuries, in which more than 433,000 of these patients may have been hospitalized. [0004] Falls can be associated with a range of serious consequences. Physical injuries associated with falling may include factures, contusions, and lacerations. Among older adults, hip and lower extremity fractures can be especially debilitating. Older adults injured during a fall may not return to their pre-fall level of physical functioning, in at least some instances. [0005] Work in relation to embodiments of the present invention suggests that known methods and apparatus for treating and/or preventing falls may be less than ideal. Many falls are associated with one or more underlying physiological causes. As such, identification and treatment of the underlying cause(s) may help to prevent falls. For example, a patient may report symptoms (e.g., fainting or dizziness) that require diagnosis to determine the underlying cause. Although patient monitoring can provide useful information as to the physiologic status of the patient so as to aid in the diagnosis of the underlying cause, many of the known methods and devices are less than ideal. For example, a patient may require care and/or monitoring after release from the hospital, and many of the current treatments can be less than ideal. For example, the Holter monitor, or ambulatory electrocardiography device, may provide patient measurements of electrocardiogram signals that are less than ideal for fall prevention and monitoring. Although transthoracic impedance measurements may be used to measure hydration and respiration, at least some of the known devices can be somewhat uncomfortable and/or cumbersome for the patient to wear. In at least some instances, electrodes that are held against the skin of the patient can become detached and/or dehydrated, such that the electrodes must be replaced. Replacement of electrodes can be uncomfortable for the patient and may result in a change in the orientation of the electrodes that may affect the measured signal in at least some instances. Examples of physiological measurements that may be affected by electrode placement include electrocardiogram signals and tissue impedance signals to measure hydration and/or respiration of a patient. Therefore, a need exists to improve the quality of long term patient measurements with external devices, for example those worn by the patient.

[0006] Although implantable devices may be used in some instances, many of these devices can be invasive and/or costly, and may suffer at least some of the shortcomings of known wearable devices.

[0007] Therefore, a need exists for improved patient monitoring, especially with regard to monitoring that may help to reduce the occurrences of fall related injury. Ideally, such improved patient monitoring would avoid at least some of the short-comings of the present methods and devices. For example, long-term fall prevention and monitoring with a device that is comfortable for the patient to wear and easy to use would be desirable. Also, it would be helpful to detect subtle changes in patient physiology, for example based on subtle changes in electrocardiogram signals and/or patient hydration signals, such that the cause of a fall can be detected. It would also be helpful to detect subtle changes in physiology such that falls can be prevented. At least some of these improvements are achieved by the embodiments of the present invention described herein.

[0008] 2. Description of the Background Art. The following US Patents and Publications may describe background art: 4,121,573; 4,478,223; 4,850,370; 4,955,381; 4,981,139; 5,080,099; 5,125,412; 5,331,966; 5,353,793; 5,511,553; 5,544,661; 5,558,638; 5,724,025; 5,772,586; 5,862,802; 5,970,986; 5,987,352; 6,047,203; 6,052,615; 6,117,077; 6,129,744; 6,225,901; 6,385,473; 6,416,471; 6,454,707; 6,480,733; 6,496,715; 6,527,711; 6,527,729; 6,551,252; 6,595,927; 6,595,929; 6,605,038; 6,611,705; 6,645,153; 6,699,200; 6,821,249; 6,912,414; 6,881,191; 6,972,683; 6,980,851; 7,020,508; 7,054,679; 7,127,370; 7,153,262; 7,206,630; 7,319,386; 7,423,537; 7,443,302; 7,450,024; 2002/0045836; 2003/0092975;

2003/0149349; 2005/0065445; 2005/0113703; 2005/0131288; 2005/0267381; 2006/0010090; 2006/0031102; 2006/0089679; 2006/0116592; 2006/0122474; 2006/0155183; 2006/0253044; 2006/0224051; 2006/0264730; 2007/0016089; 2007/0021678; 2007/0038038; 2007/0073132; 2007/0142715; 2007/0167849; 2007/0167850; 2007/0208233; and 2008/0058614. SUMMARY

[0009] Embodiments of the present invention comprise devices, systems, and methods for patient monitoring that may be used to detect, even prevent, patient falls in a variety of ways. In many embodiments, an adherent monitoring device is used to monitor the patient to detect falls rapidly and restrict patient movement. The rapid fall detection and notification can help to ensure that the patient receives immediate assistance if necessary. The monitoring device may comprise a support that can be adhered to the skin of the patient so as to provide non- obtrusive patient monitoring that minimizes patient discomfort. The adherent device may comprise a processor and a sensor, such as an accelerometer, coupled to the support to support the processor and the sensor with the skin of the patient, such that patient movement and orientation can be detected quickly and accurately. The processor may be configured to detect a patient fall, such that the fall can be detected quickly, and appropriate action taken, for example a notification of the fall can be provided. In many embodiments, patient data related to the fall is recorded, processed, and/or communicated in response to the detected fall. Alternatively or in combination, at least one of a patient's orientation or movement can be monitored with the processor and the sensor to detect when the patient violates at least one of an orientation restriction or a movement restriction. Patient orientation and/or movement monitoring can help to reduce patient falls by providing the patient and/or a monitoring caregiver or professional with increased awareness of patient actions that may lead to an increased risk of falling. Such increased awareness may result in the patient avoiding the risky behavior and/or may result in actions by the people monitoring the patient, so as to reduce the risk of falling (e.g., by discouraging the patient from violating the restrictions, by helping the patient, etc.). Recorded patient data can be used to diagnose the cause of the patient fall. Such diagnosis can enable treatment, which may minimize recurring falls and can result in improved patient therapy, for example when the fall is caused by patient syncope. For example, patient data relating to the state of the patient's cardiovascular and/or respiratory system near the time of the fall can be recorded for evaluation in response to the detected fall. Such data can also be used to dynamically adjust restriction levels. For example, patient data indicative of patient distress can be used to impose and/or lower an existing orientation restriction and/or movement restriction, thereby helping to make the patient aware of his or her current condition and limitations, which may help the patient avoid falling based on the patient's current capabilities.

[0010] In a first aspect, a device for monitoring a patient is provided. The device comprises an adherent support configured to adhere to a skin of the patient, an accelerometer coupled with the support to support the accelerometer when the support is adhered to the skin of the patient, and a processor coupled with the accelerometer. The processor comprises a tangle medium and is configured to detect at least one of a fall of the patient or an orientation of the patient. [0011] In many embodiments, the accelerometer can comprise one or more measurement axes, for example three measurement axes. Each axis of the accelerometer can be sensitive to an acceleration of the patient along the axis. The processor can be configured to detect the patient fall in response to measured patient accelerations, such as patient accelerations measured along one or more of the accelerometer axes. The accelerometer can comprise three measurement axes and be configured to measure each axis to detect the patient fall. The processor can be configured to measure an acceleration profile (i.e., a series of acceleration values) along each axis and detect the patient fall in response to the acceleration profiles. Each axis of the accelerometer can be sensitive to gravity to detect an orientation of the patient. The processor can be configured to detect the patient fall in response to an abrupt change in an orientation of the patient. An abrupt change in the orientation of the patient can comprise a change in orientation of each axis of the accelerometer over a period of time from about 0.1 to about 1 second. [0012] In many embodiments, the processor can be configured to digitize an acceleration signal for each axis over a period of time with a sampling frequency to measure an acceleration profile for the axis. The processor can be configured to store each acceleration profile in a circular buffer and detect the patient fall in response to the acceleration profiles stored in the circular buffers. The processor may be coupled to electrocardiogram circuitry to measure an electrocardiogram signal and impedance circuitry to measure a respiration signal of the patient, and the processor can be configured to store each of the electrocardiogram signal and the respiration signal in a circular buffer. Each of the circular buffers may correspond to a period of time extending from before the detected fall to after the detected fall, and the processor may be configured to transmit the data stored in the circular buffers with wireless transmission circuitry in response to the detected fall.

[0013] In many embodiments, the processor can be configured to detect the patient fall initially in response to a large amplitude signal corresponding to at least about 0.7 G-force of patient acceleration and corroborate the patient fall in response to ringing from at least one axis of the accelerometer. The ringing can comprise oscillations indicative of an impact event. For example, the ringing can comprise a damped substantially periodic oscillation.

[0014] In many embodiments, the device can comprise sensors to measure at least one of an electrocardiogram or a respiratory rate. The processor can be configured to detect the patient fall in response to a signal from the accelerometer and the at least one of the electrocardiogram or the respiratory rate. The processor can be configured to detect a syncope of the patient in response to the electrocardiogram and the signal from the accelerometer. In many embodiments, the electrocardiogram can be processed to identify an arrhythmia. The processor can be configured to detect the patient fall in response to the arrhythmia and the accelerometer signal. The arrhythmia can comprise at least one of a heart-rate variability, a heart-rate turbulence, a tachycardia, a bradycardia, or a non-sustained ventricular tachycardia. The processor can be configured to detect the patient fall in response to the at least one of the heart-rate variability, the heart-rate turbulence, the tachycardia, the bradycardia, or the non-sustained ventricular tachycardia.

[0015] In many embodiments, the device can further comprise at least two electrodes coupled with electrocardiogram circuitry to measure electrocardiogram data of the patient. The at least two electrodes and the electrocardiogram circuitry can be coupled with the support to support the at least two electrodes and the electrocardiogram circuitry when the support is adhered to the skin of the patient. The processor can be configured to at least one of store, transmit or analyze the electrocardiogram data in response to detection of the patient fall. The processor can be coupled with the electrocardiogram circuitry to store the electrocardiogram data in a buffer of the processor. The electrocardiogram data stored in the buffer can correspond to a period of time preceding detection of the patient fall. The period of time preceding the patient fall can correspond to at least about 15 seconds of electrocardiogram data. The processor can be configured to store the at least about 15 second of electrocardiogram data preceding the patient fall in response to detection of the patient fall. The processor may be configured to store electrocardiogram data corresponding to a period of time after detection of the patient fall, in which the period of time after the patient fall corresponds to at least about 15 seconds of electrocardiogram data. The processor can be configured to store and transmit the at least about 15 seconds of electrocardiogram data after the patient fall in response to detection of the patient fall. The electrocardiogram data can comprise a digitized electrocardiogram signal. The processor can be configured to transmit at least about 15 seconds of the digitized electrocardiogram signal measured before detection of the patient fall. The processor can be configured to sample the electrocardiogram data at a rate of at least about 50 Hz, for example, at a nominal sampling rate of approximately 100 Hz. The processor can be configured to store the digitized electrocardiogram signal continuously in a circular buffer such that the digitized electrocardiogram data corresponding to the period of time is stored in the circular buffer when the patient fall is detected. The processor can be configured to transmit the electrocardiogram data in response to detection of the patient fall. The processor can be configured to determine a heart rate from the electrocardiogram data. The processor can be configured to transmit the heart rate in response to detection of the patient fall. [0016] In many embodiments, the device further comprises impedance circuitry supported with the support to measure a respiration data of the patient in response to impedance of the patient. The processor can be coupled with the impedance circuitry. The processor can be configured to at least one of store, transmit or analyze the respiration data in response to detection of the patient fall. The processor can be configured to store respiration data corresponding to a period of time preceding detection of the patient fall. The period of time preceding the patient fall can correspond to at least about 15 second of respiration data. The processor can be configured to store the at least about 15 seconds of respiration data preceding the patient fall in response to detection of the patient fall. The processor can be configured to store respiration data corresponding to a period of time after detection of the patient fall, and the period of time after the patient fall may correspond to at least about 15 seconds of respiration data. The processor can be configured to store and transmit the at least about 15 seconds of respiration data after the patient fall in response to detection of the patient fall.

[0017] The respiration data can be measured in many ways and may comprise at least one of an impedance, an impedance magnitude, a resistance or a respiration rate of the patient. The processor can be coupled with the impedance circuitry. The processor can be configured to transmit the respiration data in response to detection of the patient fall. The at least two electrodes can comprise at least four electrodes. The impedance circuitry can comprise drive circuitry to drive a current through a first two of the at least four electrodes. The impedance circuitry can comprise measurement circuitry to measure a voltage across a second two of the at least four electrodes in response to the current.

[0018] In many embodiments, the processor is configured to measure patient movement in response to detection of the patient fall. The processor can be configured to activate an alarm in response to a low amount of patient movement after detection of the patient fall. The processor can be coupled with the support to support the processor when the support is adhered to the skin of the patient. The device can further comprise wireless communication circuitry coupled with the support to support the wireless communication circuitry when the support is adhered to the skin of the patient. The wireless communication circuitry can be configured to transmit patient data. The support can be configured to stretch with the skin of the patient such that the support is configured to continuously adhere to the skin of the patient for an extended period of at least one week.

[0019] In another aspect, a system for monitoring a patient is provided. The system comprises an adherent monitoring device configured to adhere to a skin of the patient, a gateway, and a server communicatively coupled with the gateway. The monitoring device comprises an adherent support configured to adhere to a skin of the patient, a plurality of sensors coupled with the support and configured to measure patient data. The plurality of sensors comprises an accelerometer. The monitoring device further comprises a processor coupled with the support and the accelerometer, and wireless communication circuitry coupled with the support and the processor. The processor comprises a tangible medium and is configured to detect at least one of a patient fall or a patient orientation and transmit the patient data. The wireless communication circuitry is configured to transmit the patient data. The gateway is configured to communicate with the wireless communication circuitry. The server is configured to receive the patient data from the gateway in response to at least one of the detection of the patient fall or the detection of the patient orientation. The processor can be configured to transmit the patient data in response to the detection of the patient fall.

[0020] In many embodiments, the system for monitoring the patient comprise a processor system. The processor system can comprise at least one of the processor of the adherent monitoring device, a processor of the gateway, or a processor of the server. The processor system can be configured to measure a patient acceleration profile and process the patient acceleration profile to detect the patient fall.

[0021] The processor system can be configured in many ways to measure the patient acceleration profile and detect the patient fall. The processor of the adherent device comprising the tangible medium may have instructions of a computer program embodied thereon such that the processor is configured to measure patient data from the sensors adhered to the patient and detect the fall of the patient. The gateway may comprise a gateway processor having a gateway tangible medium having instructions of a gateway computer program embodied thereon such that the gateway is configured to transmit the patient data from the patch device to the server in response to the detected fall. The server may comprise a server processor having a server tangible medium having instructions of a server program embodied thereon such that the server is configured to transmit the patient data to a display device in response to the fall.

[0022] In many embodiments, the processor system is configured to detect the patient fall in response to an initial detection of the patient fall and a subsequent corroboration of the patient fall. The processor of the adherent monitoring device can be configured to detect the patient fall initially in response to a patient acceleration magnitude that exceeds an impact acceleration threshold, and at least one of the server or the gateway can be configured to corroborate the fall.

[0023] In many embodiments, the processor system is configured to detect the patient fall in response to a patient acceleration magnitude that exceeds an impact acceleration threshold. The fall detection by the processor system can be made in response to ringing in the patient acceleration profile. The detected ringing can comprise oscillations indicative of an impact event. For example, the detected ringing can comprise a damped substantially periodic oscillation.

[0024] In many embodiments, the processor system is configured to detect a patient fall in response to identifying a falling event that is followed by an impact event. An acceleration magnitude profile can be generated from the patient acceleration profile. Identification of the falling event can comprise determining that the acceleration magnitude profile exceeds a falling event acceleration threshold during the falling event. Identification of the impact event can comprise determining that an acceleration magnitude exceeds an impact acceleration threshold. [0025] In many embodiments, the tangible medium of the processor comprises a memory, and the processor can be configured to store an acceleration based data profile for the patient in the memory. For example, the acceleration based data can be stored in a circular memory buffer.

[0026] In many embodiments, the processor system is configured to detect the patient fall in response to identifying a falling event that is followed by a post-impact event. A velocity- magnitude profile can be generated from the acceleration based data profile. Identification of the falling event can comprise determining that during the falling event the velocity- magnitude profile exhibits increasing magnitudes and a velocity magnitude exceeds a falling velocity magnitude threshold. Identification of the post-impact event can comprise determining that during the post-impact event the velocity-magnitude profile exhibits decreasing magnitudes.

[0027] In many embodiments, the processor of the monitoring device is configured to detect the patient fall using addition approaches. For example, the processor can be configured to detect the patient fall in response to an abrupt change in an orientation of the patient.

[0028] In many embodiments, the processor can is configured to detect the patient fall in response to a concomitant change in a patient activity level. The processor can be configured to generate a patient acceleration profile and generate an activity-level profile for the patient by processing the patient acceleration profile. The processor can be configured to generate a high-pass filtered acceleration profile by applying a high-pass filter to the patient acceleration profile to filter out gravity-induced accelerations. The processor can be configured to generate the activity-level profile by processing the high-pass filtered acceleration profile. The processor can be configured to generate the activity-level profile by smoothing the high- pass filtered profile. The smoothing can comprise applying a moving-median filter and/or a moving-average filter. The generation of an activity-level profile can comprise the use of an accelerometer comprising two or more measurement axes. The processor can be configured to generate an acceleration profile along each axis, generate a high-pass filtered acceleration profile along each axis by applying a high-pass filter to each axis acceleration profile, generate a power- sum acceleration profile by taking the power- sum of the high-pass filter acceleration profiles, and generate the activity-level profile by processing the power-sum acceleration profile values that exceed a designated threshold. The designated threshold can be selected to substantially remove device noise contributions to the generated activity-level profile.

[0029] In many embodiments, the monitoring device comprises wireless communication circuitry. The wireless communication circuitry can be configured to transmit patient data.

[0030] In another aspect, a method for monitoring a patient is provided. The method comprises adhering an adherent monitoring device on a skin of the patient. The monitoring device comprises an accelerometer and a processor coupled with the accelerometer. The processor generates an acceleration profile for the patient and detects at least one of a patient fall or a patient orientation in response to the acceleration profile. In many embodiments, a notification can be sent in response to the detection of the at least one of the patient fall or the patient orientation.

[0031] In many embodiments, the accelerometer comprises at least three measurement axes. Each axis can be sensitive to an acceleration of the patient along the axis and sensitive to gravity along the axis. A violation of at least one of an orientation restriction or a movement restriction can be detected in response to acceleration profiles generated for the three axes. A notification can be provided for at least one of the orientation-restriction violation or the movement-restriction violation in response to detection of the patient violation of the at least one of the orientation restriction or the movement restriction. The monitoring device can be adhered to the patient's torso. The orientation restriction can comprise at least one of a torso-inclination restriction or a torso-rotation restriction. The method can further comprise selecting the at least one of the orientation restriction or the movement restriction. The method can further comprise transferring the at least one of the orientation restriction or the movement restriction to the monitoring device. Transferring of the at least one of the orientation restriction or the movement restriction can comprise wirelessly transmitting the at least one of the orientation restriction or the movement restriction to the monitoring device. The movement restriction can comprise restricting the patient from leaving a bed. [0032] In many embodiments, the method comprises receiving notification of an activity- level violation. The processor can be configured to process at least one axis acceleration profile to generate an activity-level profile for the patient and provide a notification of the activity-level violation in response to detecting an activity level of the patient that exceed an activity-level restriction. The method can further comprise selecting the activity-level restriction. The method can further comprise transferring the activity-level restriction to the monitoring device. Transferring the activity-level restriction can comprise wirelessly transmitting the activity-level restriction to the monitoring device.

[0033] In another aspect, a device for use in monitoring a patient is provided. The device comprises an adherent support configured to adhere to a skin of the patient, an accelerometer coupled with the support to support the accelerometer when the support is adhered to the skin of the patient, and a processor coupled with the support and the accelerometer. The processor comprises a tangible medium and is configured to process signals from the accelerometer to detect when the patient violates at least one of an orientation restriction or a movement restriction. [0034] In many embodiments, the device comprises sensors to measure at least one of an electrocardiogram of the patient or a respiratory rate of the patient. The processor can be configured to at least one of impose or adjust the at least one of the orientation restriction or the movement restriction in response to the at least one of the electrocardiogram or the respiratory rate. The processor can be configured to detect a syncope of the patient in response to the electrocardiogram and the signal from the accelerometer. The processor can be configured to detect whether an arrhythmia is present in the electrocardiogram. The processor can be configured to at least one of impose or adjust the at least one of the orientation restriction or the movement restriction in response to detection of the arrhythmia. The detected arrhythmia can comprise at least one of a heart-rate variability, a heart-rate turbulence, a tachycardia, a bradycardia, or a non-sustained ventricular tachycardia. The processor can be configured to at least one of impose or adjust the at least one of the orientation restriction or the movement restriction in response to the at least one of the heart- rate variability, the heart-rate turbulence, the tachycardia, the bradycardia, or the non- sustained ventricular tachycardia.

[0035] In many embodiments, the device comprises at least two electrodes coupled with electrocardiogram circuitry to measure electrocardiogram data of the patient. The at least two electrodes and electrocardiogram circuitry can be coupled with the support to support the at least two electrodes and electrocardiogram circuitry when the support is adhered to the skin of the patient. The processor can be configured to at least one of store, transmit or analyze the electrocardiogram data in response to detection of the restriction violation. The processor can be coupled with the electrocardiogram circuitry to store the electrocardiogram data in a buffer of the processor. The electrocardiogram data stored in the buffer can correspond to a period of time preceding detection of the restriction violation. The period of time preceding the restriction violation can correspond to at least about 15 seconds of electrocardiogram data. The processor can be configured to store the at least about 15 seconds of electrocardiogram data preceding the restriction violation in response to detection of the restriction violation. The electrocardiogram data can comprise a digitized electrocardiogram signal. The processor can be configured to transmit at least about 15 seconds of the digitized electrocardiogram signal measured before detection of the restriction violation. The processor can be configured to sample the electrocardiogram data at a rate of at least about 50 Hz (e.g., at a nominal sampling rate of approximately 100 Hz) and store the digitized electrocardiogram signal continuously in a circular buffer such that the digitized electrocardiogram data corresponding to the period of time is stored in the circular buffer when the restriction violation is detected. The processor can be configured to transmit the electrocardiogram data in response to detection of the restriction violation. The processor can be configured to determine a heart rate from the electrocardiogram data. The processor can be configured to transmit the heart rate in response to detection of the restriction violation.

[0036] In many embodiments, the device can comprises impedance circuitry supported with the support to measure a respiration data of the patient in response to an impedance of the patient. The processor can be coupled with the impedance circuitry and configured to at least one of store, transmit or analyze the respiration data in response to detection of the restriction violation. The processor can be configured to store the respiration data corresponding to a period of time preceding detection of the restriction violation. The period of time preceding the restriction violation can correspond to at least about 15 seconds of respiration data. The processor can be configured to store the at least about 15 seconds of respiration data preceding the restriction violation in response to detection of the restriction violation. The respiration data can comprise at least one of an impedance, an impedance magnitude, a resistance or a respiration rate of the patient. The processor can be configured to transmit the respiration data in response to detection of the restriction violation. The at least two electrodes can comprise at least four electrodes. The impedance circuitry can comprise drive circuitry to drive a current through a first two of the at least four electrodes and measurement circuitry to measure a voltage across a second two of the at least four electrodes in response to the current.

[0037] In another aspect, a system for monitoring a patient is provided. The system comprises an adherent monitoring device configured to adhere to a skin of the patient, a gateway, and a server communicatively coupled with the gateway. The monitoring device comprises an adherent support configured to adhere to a skin of the patient, a plurality of sensors coupled with the support and configured to measure patient data, a processor coupled with the support, and wireless communication circuitry coupled with the support and the processor. The plurality of sensors comprises an accelerometer. The processor is coupled with the accelerometer. The processor comprises a tangible medium and is configured to process signals from the accelerometer to detect when a patient violates at least one of an orientation restriction or a movement restriction. The wireless communication circuitry is configured to transmit the patient data. The gateway is configured to communicate with the wireless communication circuitry. The server is configured to receive the patient data transmitted in response to the detection of the violation of the at least one of the orientation restriction or the movement restriction.

[0038] In many embodiments, the monitoring device is configured for placement on a patient's torso. The orientation restriction can comprise at least one of a torso-inclination restriction or a torso-rotation restriction.

[0039] In many embodiments, the accelerometer comprises three measurement axes. Each measurement axis can be sensitive to gravity to detect an orientation of the patient.

[0040] In many embodiments, the system comprises a processor system, in which the processor system comprises at least one of a processor of the monitoring device, a processor of the gateway, or a processor of the server. The processor system can be configured to detect when the patient violates the at least one of the orientation restriction or the movement restriction. The gateway and the server may each comprise a processor having a tangible medium and the tangible medium of at least one processor of the processor system can be configured to measure and store an acceleration profile along each axis. The processor system can be configured to measure and store in the memory an acceleration profile along each axis. The processor system can be configured to generate a low-pass filtered acceleration profile along each axis by applying a low-pass filter to each of the acceleration profiles. The processor can be configured to determine an orientation of the patient by processing a low-pass filtered acceleration value for each axis.

[0041] In many embodiments, the server is configured to receive at least one of a user- selected orientation restriction or a user-selected movement restriction and the system can be configured to transfer the at least one of the user-selected orientation restriction or the user- selected movement restriction from the server to the monitoring device.

[0042] In many embodiments, the system comprises a processor system. The processor system can comprise at least one of the processor of the monitoring device, a processor of the gateway, or a processor of the server. The processor system can be configured to detect when the patient violates the at least one of the orientation restriction or the movement restriction. The movement restriction can comprise an activity-level restriction. The processor system can be configured to generate an acceleration profile for the patient. The processor system can be configured to generate an activity- level profile by processing the acceleration profile. The processor system can be configured to generate a high-pass filter acceleration profile by applying a high-pass filter to the acceleration profile to filter out gravity induced accelerations. The processor system can be configured to generate an activity-level profile by processing the high-pass filtered acceleration profile. The processor system can be configured to generate the activity-level profile by smoothing the high-pass filtered acceleration profile. The smoothing can comprise applying at least one of a moving-median filter or a moving-average filter. The accelerometer can comprise two or more measurement axes. The processor system can be configured to generate an acceleration profile along each axis. The processor system can be configured to generate a high-pass filtered acceleration profile along each axis by applying a high-pass filter to each axis acceleration profile. The processor system can be configured to generate a power-sum acceleration profile by taking the power-sum of the high-pass filtered acceleration profiles. The processor system can be configured to generate an activity-level profile by processing the power-sum acceleration- profile values that exceed an activity-level threshold. The activity-level threshold can substantially remove device-noise contributions to the activity-level profile. The processor system can be configured to process the activity-level profile to detect when the patient violates an activity-level restriction. The server can be configured to receive the patient data transmitted in response to the detection of the activity-level restriction. The server can be configured to accept a user-input activity level restriction. The system can be configured to transfer the user-input activity-level restriction to the monitoring device. The plurality of sensors can comprise sensors to measure at least one of an electrocardiogram or a respiratory rate. The processor system can be configured to at least one of impose or adjust the at least one of the orientation restriction or the movement restriction in response to the at least one of the electrocardiogram or the respiratory rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure IA shows a patient and a monitoring system comprising an adherent device, according to embodiments of the present invention;

[0044] Figure IB shows a bottom view of the adherent device as in Figure IA comprising an adherent patch; [0045] Figure 1C shows a top view of the adherent patch, as in Figure IB;

[0046] Figure ID shows a printed circuit boards and electronic components over the adherent patch, as in Figure 1C;

[0047] Figure IDl shows an equivalent circuit that can be used to determine optimal frequencies for determining patient hydration, according to embodiments of the present invention;

[0048] Figure 1D2 shows an adherent devices as in Figs. 1A-1D positioned on a patient to determine orientation of the adherent patch on the patient, according to embodiments of the present invention;

[0049] Figure 1D3 shows vectors from a 3D accelerometer to determine orientation of the measurement axis of the patch adhered on the patient, according to embodiments of the present invention;

[0050] Figure IE shows batteries positioned over the printed circuit board and electronic components as in Figure ID;

[0051] Figure IF shows a top view of an electronics housing and a breathable cover over the batteries, electronic components and printed circuit board as in Figure IE; [0052] Figure IG shows a side view of the adherent device as in Figures IA to IF;

[0053] Figure IH shown a bottom isometric view of the adherent device as in Figures IA to IG;

[0054] Figures II and IJ show a side cross-sectional view and an exploded view, respectively, of the adherent device as in Figures IA to IH;

[0055] Figure IK shows at least one electrode configured to electrically couple with a skin of the patient through a breathable tape, according to embodiments of the present invention;

[0056] Figures 2A to 2C show a system to monitor a patient for an extended period comprising a reusable electronic component and a plurality of disposable patch components, according to embodiments of the present invention;

[0057] Figure 2D shows a method of using the system as in Figures 2A to 2C;

[0058] Figures 3 A to 3D show a method of monitoring a patient for an extended period with an adherent patch with adherent patches alternatively adhered to the right side or the left side of the patient; [0059] Figure 4 A shows a method of monitoring a patient, according to embodiments of the present invention;

[0060] Figure 5 shows a method for monitoring a patient, according to embodiments of the present invention;

[0061] Figure 6 A is a plot of a three-axis acceleration profile for a patient showing corresponding gravity-induced acceleration profiles, according to embodiments of the present invention;

[0062] Figure 6B is the plot of Figure 6A, showing two detected fall events, according to embodiments of the present invention;

[0063] Figure 6C is a plot of a patient high-frequency acceleration components for the acceleration profile of Figure 6 A, according to embodiments of the present invention;

[0064] Figure 6D is a plot of an acceleration magnitude profile for the acceleration profile of Figure 6 A, according to embodiments of the present invention;

[0065] Figure 6E is the plot of Figure 6D, showing two detected fall events, according to embodiments of the present invention; [0066] Figure 6F is a plot of a velocity profile for the acceleration profile of Figure 6A, according to embodiments of the present invention;

[0067] Figure 6G is a plot of a velocity magnitude profile for the acceleration profile of Figure 6 A, according to embodiments of the present invention; [0068] Figure 7A is a plot of a three-axis acceleration profile showing corresponding gravity-induced acceleration profiles, according to embodiments of the present invention;

[0069] Figure 7B is a plot of a patient inclination-angle profile and a patient rotation-angle profile for the acceleration profile of Figure 7A, according to embodiments of the present invention; [0070] Figure 8 A is a plot of a patient inclination-angle profile and a patient rotation-angle profile for another acceleration profile, according to embodiments of the present invention; and

[0071] Figure 8B is a plot of a patient high-frequency acceleration magnitudes corresponding to the profiles of Figure 8 A, and a corresponding activity-level profile, according to embodiments of the present invention.

DETAILED DESCRIPTION

[0072] Embodiments of the present invention relate to patient fall prevention and monitoring. Although embodiments make specific reference to monitoring impedance, accelerometer and electrocardiogram signals with an adherent patch device, the systems, methods and devices described herein may be applicable to any application in which physiological monitoring is used, for example wireless physiological monitoring for extended periods.

[0073] U.S. App. No. 12/209,265 makes references to improved patient measurements with an adherent patch device used to improve patient measurements, which represents a significant advance in patient measurements with adherent devices used for an extended period. Although some embodiments of the present invention may utilize methods and apparatus similar to the embodiments described therein, the embodiments of the present invention described herein can be used to improve the care and monitoring of patients who are at risk of falling. [0074] Embodiments of the present invention comprise an adherent monitoring system that can be configured for in-hospital or at-home fall prevention and detection. The system comprises an adherent device configured to adhere to the skin of the patient to monitor posture and activity, and issues an alarm if the patient violates movement restrictions or experiences a fall. The adherent device comprises an accelerometer, for example a 3-axis accelerometer, for monitoring the patient's posture and activity level with respect to 3 axes of the patient. The adherent device communicates, via a wireless gateway, to a server configured with a physician/nurse/caregiver interface. The interface allows the physician/nurse/caregiver to place restrictions on the patient's posture and movement. For example, the patient may be prohibited from rising from a recumbent posture without assistance. The adherent accelerometer device can monitor the patient's posture and movement, and issue an alarm if the patient violates the imposed restrictions. For example, the patient may be permitted to sit up in bed, and prohibited from moving from the bed. The adherent device may also issue an alarm based on fall detection, which may be based on the following characteristics of the accelerometer signal: 1) an abrupt change in posture; 2) a large amplitude followed by oscillation in the accelerometer signal; 3) concomitant changes in heart rate and respiratory rate as measured by additional physiological sensors.

[0075] The adherent device, gateway and server may comprise a stand-alone product, or may by integrated into a multi-sensor patient monitoring system with additional sensors to monitor patient physiology, for example electrocardiogram circuitry and impedance circuitry to measure hydration.

[0076] Patient Monitoring Using Advanced Adherent Devices

[0077] In many embodiments, an adherent device comprises an adhesive patch with at least two electrodes and an accelerometer. The accelerometer can be used to determine an orientation of the at least two measurement electrodes on a patient, for example a measurement axis defined by the at least two electrodes. This use of the accelerometer and the at least two measurement electrodes can be particularly advantageous with patient monitoring for an extended period, for example when it is desirable to detect subtle changes in patient physiology and the adherent patch with electrodes is replaced. By determining the orientation of the electrodes of the patch on the patient, physiologic measurements with the at least two electrodes can be adjusted and/or corrected in response to the orientation of the patch on the patient. In many embodiments, the accelerometer may be oriented with respect to an electrode measurement axis in a predetermined configuration, which can facilitate determination of the electrode measurement axis in response to the accelerometer signal. In many embodiments, the adherent patch and/or electrodes are replaced with a second adherent patch and/or electrodes, and the orientation of the second adherent patch and/or electrodes determined with the accelerometer or a second accelerometer. The determined orientation of the second patch and/or electrodes on the patient can be used to correct measurements made with the second adherent patch and/or electrodes, such that errors associated with the alignment of the first and second patch on the patient can be minimized, even inhibited.

[0078] As used herein, an adhesive patch encompasses a piece of soft material with an adhesive that can cover a part of the body.

[0079] In many embodiments, the adherent devices described herein may be used for 90 day monitoring, or more, and may comprise completely disposable components and/or reusable components, and can provide reliable data acquisition and transfer. In many embodiments, the patch is configured for patient comfort, such that the patch can be worn and/or tolerated by the patient for extended periods, for example 90 days or more. In many embodiments, the adherent patch comprises a tape, which comprises a material, preferably breathable, with an adhesive, such that trauma to the patient skin can be minimized while the patch is worn for the extended period. In many embodiments, the printed circuit board comprises a flex printed circuit board that can flex with the patient to provide improved patient comfort.

[0080] Figure IA shows a patient P and a monitoring system 10. Patient P comprises a midline M, a first side Sl, for example a right side, and a second side S2, for example a left side. Monitoring system 10 comprises an adherent device 100. Adherent device 100 can be adhered to a patient P at many locations, for example thorax T of patient P. In many embodiments, the adherent device may adhere to one side of the patient, from which side data can be collected. Work in relation with embodiments of the present invention suggests that location on a side of the patient can provide comfort for the patient while the device is adhered to the patient.

[0081] Adherent device 100 can be aligned and/or oriented with respect to axes of patient P. Orientation of adherent device 100 can comprise orientation of device 100 with a patient coordinate system IOOP aligned with axes of the patient. Patient P comprises a horizontal axis Px that extends laterally from one side of the patient to the other, for example from side Sl to side Sl across midline M. Patient P comprises an anterior posterior axis Py that extends from the front, or anterior, of the patient to the back, or posterior of the patient. Patient P comprises a vertical axis Pz that extends vertically along the patient, for example vertically along the midline of the patient from the feet of the patient toward the head of the patient. In many embodiments, horizontal axis Px, anterior posterior axis Py and vertical axis Pz may comprise a right handed triple of orthogonal coordinate references.

[0082] Adherent device 100 may comprise a 3D coordinate reference system 112XYZ. Device 100 may comprise an X-axis 112X for alignment with horizontal axis Px of the patient, a Y-axis for alignment with anterior posterior axis Py of the patient and a Z axis for alignment with vertical axis Pz of the patient. Coordinate reference system 112XYZ may comprise X-axis 112X, Y-axis 112Y and Z-axis 112Z. Coordinate reference system 112XYZ may comprise a right handed triple, although other non-orthogonal and orthogonal reference systems may be used.

[0083] Adherent device 100 may comprise indicia for alignment with an axis of the patient. The indicia can be used to align at least one axis of device 100 with at least one axis of the patient. The indicia can be positioned on at least one of the adherent patch, a cover, or an electronics module. The indicia can be visible to the patient and/or a care provider to adhere device 100 to the patient in alignment with at least one axis of the patient. A vertical line along Z-axis 112Z can indicate vertical axis 112Z to the patient and/or care provider, and a horizontal line along X-axis 112X can indicate horizontal X-axis 112X to the patient and/or care provider. A name, logo and/or trademark can be visible the outside of device 100 to indicate that device 100 correctly oriented, and arrows can also be used, for example a vertical arrow pointing up and a horizontal arrow pointing to the right.

[0084] Monitoring system 10 includes components to transmit data to a remote center 106. Remote center 106 can be located in a different building from the patient, for example in the same town as the patient, and can be located as far from the patient as a separate continent from the patient, for example the patient located on a first continent and the remote center located on a second continent. Adherent device 100 can communicate wirelessly to an intermediate device 102, for example with a single wireless hop from the adherent device on the patient to the intermediate device. Intermediate device 102 can communicate with remote center 106 in many ways, for example with an internet connection and/or with a cellular connection. In many embodiments, monitoring system 10 comprises a distributed processing system with at least one processor comprising a tangible medium of device 100, at least one processor 102P of intermediate device 102, and at least one processor 106P at remote center 106, each of which processors can be in electronic communication with the other processors. At least one processor 102P comprises a tangible medium 102T, and at least one processor 106P comprises a tangible medium 106T. Remote processor 106P may comprise a backend server located at the remote center. Remote center 106 can be in communication with a health care provider 108 A with a communication system 107A, such as the Internet, an intranet, phone lines, wireless and/or satellite phone. Health care provider 108 A, for example a family member, can be in communication with patient P with a communication, for example with a two way communication system, as indicated by arrow 109A, for example by cell phone, email, landline. Remote center 106 can be in communication with a health care professional, for example a physician 108B, with a communication system 107B, such as the Internet, an intranet, phone lines, wireless and/or satellite phone. Physician 108B can be in communication with patient P with a communication, for example with a two way communication system, as indicated by arrow 109B, for example by cell phone, email, landline. Remote center 106 can be in communication with an emergency responder 108C, for example a 911 operator and/or paramedic, with a communication system 107C, such as the Internet, an intranet, phone lines, wireless and/or satellite phone. Emergency responder 108C can travel to the patient as indicated by arrow 109C. Thus, in many embodiments, monitoring system 10 comprises a closed loop system in which patient care can be monitored and implemented from the remote center in response to signals from the adherent device.

[0085] In many embodiments, the adherent device may continuously monitor physiological parameters, communicate wirelessly with a remote center, and provide alerts when necessary. The system may comprise an adherent patch, which attaches to the patient's thorax and contains sensing electrodes, battery, memory, logic, and wireless communication capabilities. In some embodiments, the patch can communicate with the remote center, via the intermediate device in the patient's home. In some embodiments, remote center 106 receives the patient data and applies a patient evaluation algorithm, for example an algorithm to calculate the apnea hypopnea index. When a flag is raised, the center may communicate with the patient, hospital, nurse, and/or physician to allow for therapeutic intervention.

[0086] The adherent device may be affixed and/or adhered to the body in many ways. For example, with at least one of the following: an adhesive tape, a constant- force spring, suspenders around shoulders, a screw-in microneedle electrode, a pre-shaped electronics module to shape fabric to a thorax, a pinch onto roll of skin, or transcutaneous anchoring. Patch and/or device replacement may occur with a keyed patch (e.g., two-part patch), an outline or anatomical mark, a low-adhesive guide (place guide | remove old patch | place new patch I remove guide), or a keyed attachment for chatter reduction. The patch and/or device may comprise an adhesiveless embodiment (e.g., chest strap), and/or a low-irritation adhesive for sensitive skin. The adherent patch and/or device can comprise many shapes, for example at least one of a dogbone, an hourglass, an oblong, a circular or an oval shape.

[0087] In many embodiments, the adherent device may comprise a reusable electronics module with replaceable patches, and each of the replaceable patches may include a battery. The module may collect cumulative data for approximately 90 days and/or the entire adherent component (electronics + patch) may be disposable. In a completely disposable embodiment, a "baton" mechanism may be used for data transfer and retention, for example baton transfer may include baseline information. In some embodiments, the device may have a rechargeable module, and may use dual battery and/or electronics modules, wherein one module 101 A can be recharged using a charging station 103 while the other module 10 IB is placed on the adherent patch with connectors. In some embodiments, the intermediate device 102 may comprise the charging module, data transfer, storage and/or transmission, such that one of the electronics modules can be placed in the intermediate device for charging and/or data transfer while the other electronics module is worn by the patient. [0088] System 10 can perform the following functions: initiation, programming, measuring, storing, analyzing, communicating, predicting, and displaying. The adherent device may contain a subset of the following physiological sensors: bioimpedance, respiration, respiration rate variability, heart rate (ave, min, max), heart rhythm, hear rate variability (HRV), heart rate turbulence (HRT), heart sounds (e.g., S3), respiratory sounds, blood pressure, activity, posture, wake/sleep, orthopnea, temperature/heat flux, and weight. The activity sensor may comprise one or more of the following: ball switch, accelerometer, minute ventilation, HR, bioimpedance noise, skin temperature/heat flux, BP, muscle noise, posture.

[0089] The adherent device can wirelessly communicate with remote center 106. The communication may occur directly (via a cellular or Wi-Fi network), or indirectly through intermediate device 102. Intermediate device 102 may consist of multiple devices, which can communicate wired or wirelessly to relay data to remote center 106. [0090] In many embodiments, instructions are transmitted from remote site 106 to a processor supported with the adherent patch on the patient, and the processor supported with the patient can receive updated instructions for the patient treatment and/or monitoring, for example while worn by the patient. [0091] Figure IB shows a bottom view of adherent device 100 as in Figure IA comprising an adherent patch 110. Adherent patch 110 comprises a first side, or a lower side HOA, that is oriented toward the skin of the patient when placed on the patient. In many embodiments, adherent patch 110 comprises a tape HOT which is a material, preferably breathable, with an adhesive 116A. Patient side 11OA comprises adhesive 116A to adhere the patch 110 and adherent device 100 to patient P. Electrodes 112 A, 112B, 112C and 112D are affixed to adherent patch 110. In many embodiments, at least four electrodes are attached to the patch, for example six electrodes. In some embodiments the patch comprises two electrodes, for example two electrodes to measure the electrocardiogram (ECG) of the patient. Gel 114 A, gel 114B, gel 114C and gel 114D can each be positioned over electrodes 112A, 112B, 112C and 112D, respectively, to provide electrical conductivity between the electrodes and the skin of the patient. In many embodiments, the electrodes can be affixed to the patch 110, for example with known methods and structures such as rivets, adhesive, stitches, etc. In many embodiments, patch 110 comprises a breathable material to permit air and/or vapor to flow to and from the surface of the skin. [0092] Electrodes 112A, 112B, 112C and 112D extend substantially along a horizontal measurement axis that corresponds to X axis-112X of the measurement device. Electrodes 112, 112B, 112C and 112D can be affixed to adherent patch 11OA, such that the positions of electrodes 112 A, 112B, 112C and 112D comprise predetermined positions on adherent patch 11OA. Z-axis 112Z can extend perpendicular to the electrode measurement axis, for example vertically and perpendicular to X-axis 112 when adhered on the patient. X-axis 112X and Z- axis 112Z can extend along an adhesive surface of adherent patch 11OA, and a Y-axis 112Y can extend away from the adhesive surface of adherent device 11OA.

[0093] Figure 1C shows a top view of the adherent patch 100, as in Figure IB. Adherent patch 100 comprises a second side, or upper side HOB. In many embodiments, electrodes 112 A, 112B, 112C and 112D extend from lower side 11OA through adherent patch 110 to upper side HOB. An adhesive 116B can be applied to upper side 11OB to adhere structures, for example a breathable cover, to the patch such that the patch can support the electronics and other structures when the patch is adhered to the patient. The PCB may comprise completely flex PCB, rigid PCB, rigid PCB combined flex PCB and/or rigid PCB boards connected by cable.

[0094] Figure ID shows a printed circuit boards and electronic components over adherent patch 110, as in Figure IA to 1C. In some embodiments, a printed circuit board (PCB), for example flex printed circuit boardl20, may be connected to electrodes 112A, 112B, 112C and 112D with connectors 122A, 122B, 122C and 122D. Flex printed circuit board 120 can include traces 123A, 123B, 123C and 123D that extend to connectors 122A, 122B, 122C and 122D, respectively, on the flex PCB. Connectors 122A, 122B, 122C and 122D can be positioned on flex printed circuit board 120 in alignment with electrodes 112 A, 112B, 112C and 112D so as to electrically couple the flex PCB with the electrodes. For example, connectors 122 A and 122D may comprise a flexible polyester film coated with conductive silver ink. In some embodiments, connectors 122A, 122B, 122C and 122D may comprise insulated wires and/or a film with conductive ink that provide strain relief between the PCB and the electrodes. In some embodiments, additional PCB's, for example rigid PCB's 120A, 120B, 120C and 120D, can be connected to flex printed circuit board 120. Electronic components 130 can be connected to flex printed circuit board 120 and/or mounted thereon. In some embodiments, electronic components 130 can be mounted on the additional PCB's.

[0095] Electronic components 130 comprise components to take physiologic measurements, transmit data to remote center 106 and receive commands from remote center 106. In many embodiments, electronics components 130 may comprise known low power circuitry, for example complementary metal oxide semiconductor (CMOS) circuitry components. Electronics components 130 comprise an activity sensor and activity circuitry 134, impedance circuitry 136 and electrocardiogram circuitry, for example ECG circuitry 136. In some embodiments, electronics circuitry 130 may comprise a microphone and microphone circuitry 142 to detect an audio signal from within the patient, and the audio signal may comprise a heart sound and/or a respiratory sound, for example an S3 heart sound and a respiratory sound with rales and/or crackles.

[0096] Electronics circuitry 130 may comprise a temperature sensor, for example a thermistor in contact with the skin of the patient, and temperature sensor circuitry 144 to measure a temperature of the patient, for example a temperature of the skin of the patient. A temperature sensor may be used to determine the sleep and wake state of the patient. The temperature of the patient can decrease as the patient goes to sleep and increase when the patient wakes up.

[0097] Work in relation to embodiments of the present invention suggests that skin temperature may effect impedance and/or hydration measurements, and that skin temperature measurements may be used to correct impedance and/or hydration measurements. In some embodiments, increase in skin temperature or heat flux can be associated with increased vaso-dilation near the skin surface, such that measured impedance measurement decreased, even through the hydration of the patient in deeper tissues under the skin remains substantially unchanged. Thus, use of the temperature sensor can allow for correction of the hydration signals to more accurately assess the hydration, for example extra cellular hydration, of deeper tissues of the patient, for example deeper tissues in the thorax.

[0098] Electronics circuitry 130 may comprise a processor 146. Processor 146 comprises a tangible medium, for example read only memory (ROM), electrically erasable programmable read only memory (EEPROM) and/or random access memory (RAM). Processor 146 may comprise many known processors with real time clock and frequency generator circuitry, for example the PIC series of processors available from Microchip, of Chandler AZ.. In some embodiments, processor 136 may comprise the frequency generator and real time clock. The processor can be configured to control a collection and transmission of data from the impedance circuitry electrocardiogram circuitry and the accelerometer. In many embodiments, device 100 comprise a distributed processor system, for example with multiple processors on device 100.

[0099] In many embodiments, electronics components 130 comprise wireless communications circuitry 132 to communicate with remote center 106. The wireless communication circuitry can be coupled to the impedance circuitry, the electrocardiogram circuitry and the accelerometer to transmit to a remote center with a communication protocol at least one of the hydration signal, the electrocardiogram signal or the inclination signal. In specific embodiments, wireless communication circuitry is configured to transmit the hydration signal, the electrocardiogram signal and the inclination signal to the remote center with a single wireless hop, for example from wireless communication circuitry 132 to intermediate device 102. The communication protocol comprises at least one of Bluetooth, Zigbee, WiFi, WiMax, IR, amplitude modulation or frequency modulation. In many embodiments, the communications protocol comprises a two way protocol such that the remote center is capable of issuing commands to control data collection.

[0100] Intermediate device 102 may comprise a data collection system to collect and store data from the wireless transmitter. The data collection system can be configured to communicate periodically with the remote center. The data collection system can transmit data in response to commands from remote center 106 and/or in response to commands from the adherent device.

[0101] Activity sensor and activity circuitry 134 can comprise many known activity sensors and circuitry. In many embodiments, the accelerometer comprises at least one of a piezoelectric accelerometer, capacitive accelerometer or electromechanical accelerometer. The accelerometer may comprise a 3 -axis accelerometer to measure at least one of an inclination, a position, an orientation or acceleration of the patient in three dimensions. Work in relation to embodiments of the present invention suggests that three dimensional orientation of the patient and associated positions, for example sitting, standing, lying down, can be very useful when combined with data from other sensors, for example ECG data and/or bioimpedance data, for example a respiration rate of the patient.

[0102] Activity sensor 134 may comprise an accelerometer with at least one measurement axis, for example two or more measurement axes. In some embodiments, activity sensor 134 comprises three axis accelerometer 134A. Three axis accelerometer 134A may comprise an X-axis 134X, a Y-axis 134Y and a Z-axis 134Z with each axis sensitive to gravity such that the orientation of the accelerometer can be determined in relation to gravity. Three axis accelerometer 134A can be aligned with electrodes of adherent patch 11OA. X-axis 134X can be aligned with X-axis 112X of adherent patch 110. Y-axis 134Y can be aligned with Y- axis 112Y of adherent patch 110. Z-axis 134Z can be aligned with Z-axis 112Z of adherent patch 110. Axes of accelerometer 134A can be aligned with axes of patch 11OA, for example with connectors 122A, 122B, 122C and 122D, such that the axes of the accelerometer are aligned with adherent patch and/or the electrodes in a predetermined configuration. Although the axes of the patch and accelerometer are shown substantially parallel, the axes of the patch can be aligned with the axes of the accelerometer in a non-parallel configuration, for example an oblique configuration with oblique angles between axes of the accelerometer and axes of the adherent patch and/or electrodes. [0103] Impedance circuitry 136 can generate both hydration data and respiration data. In many embodiments, impedance circuitry 136 is electrically connected to electrodes 112A, 112B, 112C and 112D in a four pole configuration, such that electrodes 112A and 112D comprise outer electrodes that are driven with a current and comprise force electrodes that force the current through the tissue. The current delivered between electrodes 112A and 112D generates a measurable voltage between electrodes 112B and 112C, such that electrodes 112B and 112C comprise inner, sense, electrodes that sense and/or measure the voltage in response to the current from the force electrodes. In some embodiments, electrodes 112B and 112C may comprise force electrodes and electrodes 112A and 112B may comprise sense electrodes. The voltage measured by the sense electrodes can be used to measure the impedance of the patient and determine the respiration rate and/or hydration of the patient.

[0104] Figure IDl shows an equivalent circuit 152 that can be used to determine optimal frequencies for measuring patient hydration. Work in relation to embodiments of the present invention indicates that the frequency of the current and/or voltage at the force electrodes can be selected so as to provide impedance signals related to the extracellular and/or intracellular hydration of the patient tissue. Equivalent circuit 152 comprises an intracellular resistance 156, or R(ICW) in series with a capacitor 154, and an extracellular resistance 158, or R(ECW). Extracellular resistance 158 is in parallel with intracellular resistance 156 and capacitor 154 related to capacitance of cell membranes. In many embodiments, impedances can be measured and provide useful information over a wide range of frequencies, for example from about 0.5 kHz to about 200 KHz. Work in relation to embodiments of the present invention suggests that extracellular resistance 158 can be significantly related extracellular fluid and to cardiac decompensation, and that extracellular resistance 158 and extracellular fluid can be effectively measured with frequencies in a range from about 0.5 kHz to about 20 kHz, for example from about 1 kHz to about 10 kHz. In some embodiments, a single frequency can be used to determine the extracellular resistance and/or fluid. As sample frequencies increase from about 10 kHz to about 20 kHz, capacitance related to cell membranes decrease the impedance, such that the intracellular fluid contributes to the impedance and/or hydration measurements. Thus, many embodiments of the present invention measure hydration with frequencies from about 0.5 kHz to about 20 kHz to determine patient hydration. [0105] In many embodiments, impedance circuitry 136 can be configured to determine respiration of the patient. In specific embodiments, the impedance circuitry can measure the hydration at 25 Hz intervals, for example at 25 Hz intervals using impedance measurements with a frequency from about 0.5 kHz to about 20 kHz. [0106] ECG circuitry 138 can generate electrocardiogram signals and data from two or more of electrodes 112A, 112B, 112C and 112D in many ways. In some embodiments, ECG circuitry 138 is connected to inner electrodes 112B and 122C, which may comprise sense electrodes of the impedance circuitry as described above. In some embodiments, ECG circuitry 138 can be connected to electrodes 112A and 112D so as to increase spacing of the electrodes. The inner electrodes may be positioned near the outer electrodes to increase the voltage of the ECG signal measured by ECG circuitry 138. In many embodiments, the ECG circuitry may measure the ECG signal from electrodes 112A and 112D when current is not passed through electrodes 112A and 112D.

[0107] ECG circuitry 138 can be coupled to the electrodes in many ways to define an electrocardiogram vector. For example electrode 112A can be coupled to a positive amplifier terminal of ECG circuitry 138 and electrode 112D can be coupled to a negative amplifier terminal of ECG circuitry 138 to define an orientation of an electrocardiogram vector along the electrode measurement axis. To define an electrocardiogram vector with an opposite orientation electrode 112D can be couple to the positive amplifier terminal of ECG circuitry 138 and electrode 112A can be coupled to the negative amplifier terminal of ECG circuitry

138. The ECG circuitry may be coupled to the inner electrodes so as to define an ECG vector along a measurement axis of the inner electrodes.

[0108] Figure 1D2 shows adherent device 100 positioned on patient P to determine orientation of the adherent patch. X-axis 112X of device 100 is inclined at an angle α to horizontal axis Px of patient P. Z-axis 112Z of device 100 is inclined at angle α to vertical axis Pz of patient P. Y-axis 112Y may be inclined at a second angle, for example β, to anterior posterior axis Py and vertical axis Pz. As the accelerometer of adherent device 100 can be sensitive to gravity, inclination of the patch relative to axis of the patient can be measured, for example when the patient stands. [0109] Figure 1D3 shows vectors from a 3D accelerometer to determine orientation of the measurement axis of the patch adhered on the patient. A Z-axis vector 112ZV can be measured along vertical axis 112Z with an accelerometer signal from axis 134Z of accelerometer 134A. An X-axis vector 112XV can be measured along horizontal axis 112X with an accelerometer signal from axis 134X of accelerometer 134A. Inclination angle α can be determined in response to X-axis vector 112XV and Z-axis vector 112ZV, for example with vector addition of X-axis vector 112XV and Z-axis vector 112ZV. An inclination angle β for the patch along the Y and Z axes can be similarly obtained an accelerometer signal from axis 134Y of accelerometer 134A and vector 112ZV.

[0110] Figure IE shows batteries 150 positioned over the flex printed circuit board and electronic components as in Figure ID. Batteries 150 may comprise rechargeable batteries that can be removed and/or recharged. In some embodiments, batteries 150 can be removed from the adherent patch and recharged and/or replaced.

[0111] Figure IF shows a top view of a cover 162 over the batteries, electronic components and flex printed circuit board as in Figures IA to IE. In many embodiments, an electronics housing 160 may be disposed under cover 162 to protect the electronic components, and in some embodiments electronics housing 160 may comprise an encapsulant over the electronic components and PCB. In some embodiments, cover 162 can be adhered to adherent patch 110 with an adhesive 164 on an underside of cover 162. In many embodiments, electronics housing 160 may comprise a water proof material, for example a sealant adhesive such as epoxy or silicone coated over the electronics components and/or PCB. In some embodiments, electronics housing 160 may comprise metal and/or plastic. Metal or plastic may be potted with a material such as epoxy or silicone.

[0112] Cover 162 may comprise many known biocompatible cover, casing and/or housing materials, such as elastomers, for example silicone. The elastomer may be fenestrated to improve breathability. In some embodiments, cover 162 may comprise many known breathable materials, for example polyester, polyamide, and/or elastane (Spandex). The breathable fabric may be coated to make it water resistant, waterproof, and/or to aid in wicking moisture away from the patch.

[0113] Figure IG shows a side view of adherent device 100 as in Figures IA to IF. Adherent device 100 comprises a maximum dimension, for example a length 170 from about 2 to 10 inches (from about 50 mm to about 250 mm), for example from about 4 to 6 inches (from about 100 mm to about 150 mm). In some embodiments, length 170 may be no more than about 6 inches (no more than about 150 mm). Adherent device 100 comprises a thickness 172. Thickness 172 may comprise a maximum thickness along a profile of the device. Thickness 172 can be from about 0.1 inches to about 0.4 inches (from about 5 mm to about 10 mm), for example about 0.3 inches (about 7.5 mm) .

[0114] Figure IH shown a bottom isometric view of adherent device 100 as in Figures IA to IG. Adherent device 100 comprises a width 174, for example a maximum width along a width profile of adherent device 100. Width 174 can be from about 1 to about 4 inches (from about 25 mm to 100 mm), for example about 2 inches (about 50 mm).

[0115] Figures II and IJ show a side cross-sectional view and an exploded view, respectively, of adherent device 100 as in Figures IA to IH. Device 100 comprises several layers. Gel 114A, or gel layer, is positioned on electrode 112A to provide electrical conductivity between the electrode and the skin. Electrode 112A may comprise an electrode layer. Adhesive patch 110 may comprise a layer of breathable tape HOT, for example a known breathable tape, such as tricot-knit polyester fabric. An adhesive 116 A, for example a layer of acrylate pressure sensitive adhesive, can be disposed on underside HOA of adherent patch 110. A gel cover 180, or gel cover layer, for example a polyurethane non-woven tape, can be positioned over patch 110 comprising the breathable tape. A PCB layer, for example flex printed circuit board 120, or flex PCB layer, can be positioned over gel cover 180 with electronic components 130 connected and/or mounted to flex printed circuit board 120, for example mounted on flex PCB so as to comprise an electronics layer disposed on the flex PCB layer. In many embodiments, the adherent device may comprise a segmented inner component, for example the PCB may be segmented to provide at least some flexibility. In many embodiments, the electronics layer may be encapsulated in electronics housing 160 which may comprise a waterproof material, for example silicone or epoxy. In many embodiments, the electrodes are connected to the PCB with a flex connection, for example trace 123 A of flex printed circuit board 120, so as to provide strain relive between the electrodes 112A, 112B, 112C and 112D and the PCB. Gel cover 180 can inhibit flow of gel 114A and liquid. In many embodiments, gel cover 180 can inhibit gel 114A from seeping through breathable tape 11OT to maintain gel integrity over time. Gel cover 180 can also keep external moisture, for example liquid water, from penetrating though the gel cover into gel 114A while allowing moisture vapor from the gel, for example moisture vapor from the skin, to transmit through the gel cover. In many embodiments, cover 162 can encase the flex PCB and/or electronics and can be adhered to at least one of the electronics, the flex PCB or adherent patch 110, so as to protect at least the electronics components and the PCB. Cover 162 can attach to adhesive patch 110 with adhesive 116B. Cover 162 can comprise many known biocompatible cover materials, for example silicone. Cover 162 can comprise an outer polymer cover to provide smooth contour without limiting flexibility. In many embodiments, cover 162 may comprise a breathable fabric. Cover 162 may comprise many known breathable fabrics, for example breathable fabrics as described above. In some embodiments, the breathable cover may comprise a breathable water resistant cover. In some embodiments, the breathable fabric may comprise polyester, nylon, polyamide, and/or elastane (Spandex) to allow the breathable fabric to stretch with body movement. In some embodiments, the breathable tape may contain and elute a pharmaceutical agent, such as an antibiotic, anti-inflammatory or antifungal agent, when the adherent device is placed on the patient.

[0116] The breathable cover 162 and adherent patch 110 comprises breathable tape can be configured to couple continuously for at least one week the at least one electrode to the skin so as to measure breathing of the patient. The breathable tape may comprise the stretchable breathable material with the adhesive and the breathable cover may comprises a stretchable water resistant material connected to the breathable tape, as described above, such that both the adherent patch and cover can stretch with the skin of the patient. Arrows 182 show stretching of adherent patch 110, and the stretching of adherent patch can be at least two dimensional along the surface of the skin of the patient. As noted above, connectors 122 A, 122B, 122C and 122D between PCB 130 and electrodes 112A, 112B, 112C and 112D may comprise insulated wires that provide strain relief between the PCB and the electrodes, such that the electrodes can move with the adherent patch as the adherent patch comprising breathable tape stretches. Arrows 184 show stretching of cover 162, and the stretching of the cover can be at least two dimensional along the surface of the skin of the patient. Cover 162 can be attached to adherent patch 110 with adhesive 116B such that cover 162 stretches and/or retracts when adherent patch 110 stretches and/or retracts with the skin of the patient. For example, cover 162 and adhesive patch 110 can stretch in two dimensions along length 170 and width 174 with the skin of the patient, and stretching along length 170 can increase spacing between electrodes. Stretching of the cover and adhesive patch 110, for example in two dimensions, can extend the time the patch is adhered to the skin as the patch can move with the skin such that the patch remains adhered to the skin. Cover 162 can be attached to adherent patch 110 with adhesive 116B such that cover 162 stretches and/or retracts when adherent patch 110 stretches and/or retracts with the skin of the patient, for example along two dimensions comprising length 170 and width 174. Electronics housing 160 can be smooth and allow breathable cover 162 to slide over electronics housing 160, such that motion and/or stretching of cover 162 is slidably coupled with housing 160. The printed circuit board can be slidably coupled with adherent patch 110 that comprises breathable tape HOT, such that the breathable tape can stretch with the skin of the patient when the breathable tape is adhered to the skin of the patient. Electronics components 130 can be affixed to printed circuit board 120, for example with solder, and the electronics housing can be affixed over the PCB and electronics components, for example with dip coating, such that electronics components 130, printed circuit board 120 and electronics housing 160 are coupled together. Electronics components 130, printed circuit board 120, and electronics housing 160 are disposed between the stretchable breathable material of adherent patch 110 and the stretchable water resistant material of cover 160 so as to allow the adherent patch 110 and cover 160 to stretch together while electronics components 130, printed circuit board 120, and electronics housing 160 do not stretch substantially, if at all. This decoupling of electronics housing 160, printed circuit board 120 and electronic components 130 can allow the adherent patch 110 comprising breathable tape to move with the skin of the patient, such that the adherent patch can remain adhered to the skin for an extended time of at least one week, for example two or more weeks.

[0117] An air gap 169 may extend from adherent patch 110 to the electronics module and/or PCB, so as to provide patient comfort. Air gap 169 allows adherent patch 110 and breathable tape 11OT to remain supple and move, for example bend, with the skin of the patient with minimal flexing and/or bending of printed circuit board 120 and electronic components 130, as indicated by arrows 186. Printed circuit board 120 and electronics components 130 that are separated from the breathable tape HOT with air gap 169 can allow the skin to release moisture as water vapor through the breathable tape, gel cover, and breathable cover. This release of moisture from the skin through the air gap can minimize, and even avoid, excess moisture, for example when the patient sweats and/or showers.

[0118] The breathable tape of adhesive patch 110 may comprise a first mesh with a first porosity and gel cover 180 may comprise a breathable tape with a second porosity, in which the second porosity is less than the first porosity to minimize, and even inhibit, flow of the gel through the breathable tape. The gel cover may comprise a polyurethane film with the second porosity. [0119] In many embodiments, the adherent device comprises a patch component and at least one electronics module. The patch component may comprise adhesive patch 110 comprising the breathable tape with adhesive coating 116A, at least one electrode, for example electrode 114A and gel 114. The at least one electronics module can be separable from the patch component. In many embodiments, the at least one electronics module comprises the flex printed circuit board 120, electronic components 130, electronics housing 160 and cover 162, such that the flex printed circuit board, electronic components, electronics housing and cover are reusable and/or removable for recharging and data transfer, for example as described above. In many embodiments, adhesive 116B is coated on upper side HOA of adhesive patch HOB, such that the electronics module can be adhered to and/or separated from the adhesive component. In specific embodiments, the electronic module can be adhered to the patch component with a releasable connection, for example with Velcro™, a known hook and loop connection, and/or snap directly to the electrodes. Two electronics modules can be provided, such that one electronics module can be worn by the patient while the other is charged, as described above. Monitoring with multiple adherent patches for an extended period is described in U.S. Pat. App. No. 60/972,537, the full disclosure of which is incorporated herein by reference and may be suitable for combination with some embodiments of the present invention. Many patch components can be provided for monitoring over the extended period. For example, about 12 patches can be used to monitor the patient for at least 90 days with at least one electronics module, for example with two reusable electronics modules.

[0120] At least one electrode 112A can extend through at least one aperture 180A in the breathable tape 110 and gel cover 180.

[0121] In some embodiments, the adhesive patch may comprise a medicated patch that releases a medicament, such as antibiotic, beta-blocker, ACE inhibitor, diuretic, or steroid to reduce skin irritation. The adhesive patch may comprise a thin, flexible, breathable patch with a polymer grid for stiffening. This grid may be anisotropic, may use electronic components to act as a stiffener, may use electronics-enhanced adhesive elution, and may use an alternating elution of adhesive and steroid. [0122] Figure IK shows at least one electrode 190 configured to electrically couple to a skin of the patient through a breathable tape 192. In many embodiments, at least one electrode 190 and breathable tape 192 comprise electrodes and materials similar to those described above. Electrode 190 and breathable tape 192 can be incorporated into adherent devices as described above, so as to provide electrical coupling between the skin and electrode through the breathable tape, for example with the gel.

[0123] Figures 2A to 2C show a schematic illustration of a system 200 to monitor a patient for an extended period.

[0124] Figure 2A shows a schematic illustration of system 200 comprising a reusable electronics module 210 and a plurality of disposable patch components. Figure 2B shows a schematic illustration of a side cross-sectional view of reusable electronics module 210. System 200 may comprise a first disposable patch component 220A, a second disposable patch component 220B, a third disposable patch component 220C and a fourth disposable patch component 220D. Although four patch components a shown the plurality may comprise as few as two patch component and as many as three or more patch components, for example 25 patch components.

[0125] Reusable electronics module 210 may comprise a connector 219 adapted to connect to each of the disposable patch components, sequentially, for example one disposable patch component at a time. Connector 219 can be formed in many ways, and may comprise known connectors as described above, for example a snap. In some embodiments, the connectors on the electronics module and adhesive component can be disposed at several locations on the reusable electronics module and disposable patch component, for example near each electrode, such that each electrode can couple directly to a corresponding location on the flex PCB of the reusable electronics component.

[0126] Reusable electronics module 210 may comprise additional reusable electronics modules, for example two or more rechargeable electronics modules each with a 3D accelerometer, such that the first module comprising a first 3D accelerometer can be recharged while the second module comprising a second 3D accelerometer is worn by the patient. The second module can be recharged and connected to a third adhesive patch when the first adhesive patch is removed from the patient. The second module comprising the second accelerometer can be removably coupled to the adhesive patch such that the second accelerometer can be recharged and connected to a fourth adhesive patch when the second adhesive patch is removed from the patient.

[0127] Reusable electronics module 210 may comprises many of the structures described above that may comprise the electronics module. In many embodiments, reusable electronics module 210 comprises a PCB, for example a flex PCB 212, electronics components 214, batteries 216, and a cover 217, for example as described above. In some embodiments, reusable electronics module 210 may comprise an electronics housing over the electronics components and/or PCB as described above. The electronics components may comprise circuitry and/or sensors for measuring ECG signals, hydration impedance signals, respiration impedance signals and accelerometer signals, for example as described above.

[0128] Electronics components 214 may comprise an accelerometer 214A. Accelerometer 214A may comprise a three axis accelerometer, for example as described above. Accelerometer 214A may comprise an X-axis 234X, a Y-axis 234Y and a Z-axis 234Z with each axis sensitive to gravity such that the orientation of the accelerometer, for example 3D orientation, can be determined in relation to gravity, as described above. Alignment of the accelerometer, for example the axes of the accelerometer 214A, can be aligned with the axes of the adherent patches using the connectors. For example connector 219 can connect with at least one of connector 229A, connector 229B, connector 229C and connector 229D to align the respective patch with accelerometer 214 A.

[0129] First disposable patch component 220A comprises a connector 229A to mate with connector 219 on reusable electronics module 210 such that the first disposable patch component 220A is aligned with the reusable electronics module with a predetermined orientation. First disposable patch component 220A comprises a first axis 220AX substantially aligned with electrodes 222A. A second axis 220AZ corresponds to vertical on the patient when first disposable patch component 220A is adhered to the patient. Connector 229A is configured to mate with connector 219 such that axis 234X is aligned with first axis 220AX and axis 234Z is aligned with axis 220AZ.

[0130] Second disposable patch component 220B comprises a connector 229B to mate with connector 219 on reusable electronics module 210 such that the second disposable patch component 220B is aligned with the reusable electronics module with the predetermined orientation similar to first disposable patch component 220A. Second disposable patch component 220B comprises a first axis 220BX substantially aligned with electrodes 222B. A second axis 220BZ corresponds to vertical on the patient when second disposable patch component 220B is adhered to the patient. Connector 229B is configured to mate with connector 219 such that axis 234X is aligned with first axis 220BX and axis 234Z is aligned with axis 220BZ. [0131] Third disposable patch component 220C comprises a connector 229C to mate with connector 219 on reusable electronics module 210 such that the third disposable patch component 220C is aligned with the reusable electronics module with the predetermined orientation similar to second disposable patch component 220B. Third disposable patch component 220C comprises a first axis 220CX substantially aligned with electrodes 222C. A second axis 220CZ corresponds to vertical on the patient when second disposable patch component 220C is adhered to the patient. Connector 229C is configured to mate with connector 219 such that axis 234X is aligned with first axis 220CX and axis 234Z is aligned with axis 220CZ. [0132] Fourth disposable patch component 220D comprises a connector 229D to mate with connector 219 on reusable electronics module 210 such that the fourth disposable patch component 220D is aligned with the reusable electronics module with the predetermined orientation similar to third disposable patch component 220C. Fourth disposable patch component 220D comprises a first axis 220DX substantially aligned with electrodes 222D. A second axis 220DZ corresponds to vertical on the patient when second disposable patch component 220D is adhered to the patient. Connector 229D is configured to mate with connector 219 such that axis 234X is aligned with first axis 220DX and axis 234Z is aligned with axis 220DZ.

[0133] Figure 2C shows a schematic illustration first disposable patch component 220A of the plurality of disposable patch components that is similar to the other disposable patch components, for example second disposable patch component 220B, third disposable patch component 220C and fourth disposable patch component 220C. The disposable patch component comprises a breathable tape 221 A, an adhesive 226A on an underside of breathable tape 227 A to adhere to the skin of the patient, and at least four electrodes 222 A. The at least four electrodes 224A are configured to couple to the skin of a patient, for example with a gel 226A, in some embodiments the electrodes may extend through the breathable tape to couple directly to the skin of the patient with aid form the gel. In some embodiments, the at least four electrodes may be indirectly coupled to the skin through a gel and/or the breathable tape, for example as described above. A connector 229A on the upper side of the disposable adhesive component can be configured for attachment to connector 219 on reusable electronics module 210 so as to electrically couple the electrodes with the electronics module. The upper side of the disposable patch component may comprise an adhesive 224 A to adhere the disposable patch component to the reusable electronics module. The reusable electronics module can be adhered to the patch component with many additional known ways to adhere components, for example with Velcro™ comprising hooks and loops, snaps, a snap fit, a lock and key mechanisms, magnets, detents and the like.

[0134] Figure 2D shows a method 250 of using system 200, as in Figures 2A to 2C. A step 252 adheres electronics module 210 to first disposable adherent patch component 220A of the plurality of adherent patch components and adheres the first disposable patch component to the skin of the patient, for example with the first adherent patch component adhered to the reusable electronics module. The orientation on the patient of first disposable patch component 220A is determined with the accelerometer, for example as described above, when the first disposable patch component is adhered to the patient. Patient measurements can be taken with the electronics module and/or adjusted in response to the orientation of the first patch on the patient. A step 254 removes the first disposable adherent patch from the patient and separates first disposable adherent patch component 220A from reusable electronics module 210. [0135] A step 256 adheres electronics module 210 to second disposable adherent patch component 220B and adheres the second disposable patch component to the skin of the patient, for example with the second adherent patch component adhered to the reusable electronics module. The orientation on the patient of second disposable patch component 220B is determined with the accelerometer, for example as described above, when the second disposable patch component is adhered to the patient. Patient measurements can be taken with the electronics module and/or adjusted in response to the orientation of the second patch on the patient. A step 258 removes the second disposable adherent patch from the patient and separates second disposable adherent patch component 220B from reusable electronics module 210. [0136] A step 260 adheres electronics module 210 to third disposable adherent patch component 220C and adheres the third disposable patch component to the skin of the patient, for example with the third adherent patch component adhered to the reusable electronics module. The orientation on the patient of third disposable patch component 220C is determined with the accelerometer, for example as described above, when the third disposable patch component is adhered to the patient. Patient measurements can be taken with the electronics module and/or adjusted in response to the orientation of the third patch on the patient. A step 262 removes the third disposable adherent patch from the patient and separates third disposable adherent patch component 220C from reusable electronics module 210.

[0137] A step 264 adheres electronics module 210 to fourth disposable adherent patch component 220D and adheres the fourth disposable patch component to the skin of the patient, for example with the third adherent patch component adhered to the reusable electronics module. The orientation on the patient of fourth disposable patch component 220D is determined with the accelerometer, for example as described above, when the fourth disposable patch component is adhered to the patient. Patient measurements can be taken with the electronics module and/or adjusted in response to the orientation of the fourth patch on the patient. A step 268 removes the fourth disposable adherent patch from the patient and separates fourth disposable adherent patch component 220D from reusable electronics module 210.

[0138] In many embodiments, physiologic signals, for example ECG, hydration impedance, respiration impedance and accelerometer impedance are measured when the adherent patch component is adhered to the patient, for example when any of the first, second, third or fourth disposable adherent patches is adhered to the patient.

[0139] Figures 3A to 3D show a method 300 of monitoring a patient for an extended period with adherent patches alternatively adhered to a right side 302 and a left side 304 of the patient. Work in relation to embodiments of the present invention suggests that repeated positioning of a patch at the same location can irritate the skin and may cause patient discomfort. This can be minimized, even avoided, by alternating the patch placement between left and right sides of the patient, often a front left and a front right side of the patient where the patient can reach easily to replace the patch. In some embodiments, the patch location can be alternated on the same side of the patient, for example higher and/or lower on the same side of the patient without substantial overlap to allow the skin to recover and/or heal. In many embodiments, the patch can be symmetrically positioned on an opposite side such that signals may be similar to a previous position of the patch symmetrically disposed on an opposite side of the patient. In many embodiments, the duration between removal of one patch and placement of the other patch can be short, such that any differences between the signals may be assumed to be related to placement of the patch, and these differences can be removed with signal processing. [0140] In many embodiments each patch comprises at least four electrodes configured to measure an ECG signal and impedance, for example hydration and/or respiration impedance. In many embodiments, the patient comprises a midline 306, with first side, for example right side 302, and second side, for example left side 304, symmetrically disposed about the midline. A step 310 adheres a first adherent patch 312 to at a first location 314 on a first side 302 of the patient for a first period of time, for example about 1 week. When the adherent patch 312 is position at first location 314 on the first side of the patient, the accelerometer signals are measured to determine the orientation of the patch and the electrodes of the patch are coupled to the skin of the patient to measure the ECG signal and impedance signals. [0141] A step 320 removes patch 312 and adheres a second adherent patch 322 at a second location 324 on a second side 206 of the patient for a second period of time, for example about 1 week. In many embodiments, second location 324 can be symmetrically disposed opposite first location 314 across midline 304, for example so as to minimize changes in the sequential impedance signals measured from the second side and first side. When adherent patch 322 is position at second location 324 on the second side of the patient, the orientation of the patch can be measured with the accelerometer and the electrodes of the patch are coupled to the skin of the patient to measure the ECG signal and impedance signals. In many embodiments, while adherent patch 322 is positioned at second location 324, skin at first location 314 can heal and recover from adherent coverage of the first patch. In many embodiments, second location 324 is symmetrically disposed opposite first location 314 across midline 304, for example so as to minimize changes in the impedance signals measured between the first side and second side. In many embodiments, the duration between removal of one patch and placement of the other patch can be short, such that any differences between the signals may be determined to be related to orientation of the patch, and these differences can be corrected in response to the measured orientation of the patch on the patient.

[0142] A step 330 removes second patch 322 and adheres a third adherent patch 332 at a third location 334 on the first side, for example right side 302, of the patient for a third period of time, for example about 1 week. In many embodiments, third location 334 can be symmetrically disposed opposite second location 324 across midline 304, for example so as to minimize changes in the sequential impedance signals measured from the third side and second side. In many embodiments, third location 334 substantially overlaps with first location 314, so as to minimize differences in measurements between the first adherent patch and third adherent patch that may be due to patch location. When adherent patch 332 is positioned at third location 334 on the first side of the patient, the orientation of the patch is measured with the accelerometer and the electrodes of the patch are coupled to the skin of the patient to measure the ECG signal and impedance signals. In many embodiments, while adherent patch 332 is positioned at third location 334, skin at second location 324 can heal and recover from adherent coverage of the second patch. In many embodiments, the duration between removal of one patch and placement of the other patch can be short, such that differences between the signals may be determined to be related to orientation of the patch, and these differences can be corrected in response to the measured orientation of the patch on the patient.

[0143] A step 340 removes third patch 332 and adheres a fourth adherent patch 342 at a fourth location 344 on the second side, for example left side 306, of the patient for a fourth period of time, for example about 1 week. In many embodiments, fourth location 344 can be symmetrically disposed opposite third location 334 across midline 304, for example so as to minimize changes in the sequential impedance signal measured from the fourth side and third side. In many embodiments, fourth location 344 substantially overlaps with second location 324, so as to minimize differences in measurements between the second adherent patch and fourth adherent patch that may be due to patch location. When adherent patch 342 is positioned at fourth location 344 on the second side of the patient, the orientation of patch is measured with the accelerometer and the electrodes of the patch are coupled to the skin of the patient to measure the ECG signal and impedance signals. In many embodiments, while adherent patch 342 is positioned at fourth location 324, skin at third location 334 can heal and recover from adherent coverage of the third patch. In many embodiments, the duration between removal of one patch and placement of the other patch can be short, such that differences between the signals may be determined to be related to orientation of the patch, and these differences can be corrected in response to the measured orientation of the patch on the patient.

[0144] The accelerometer signal measured to determine the orientation on the patient for each of adherent patch 312, adherent patch 322, adherent patch 332 or adherent patch 342 can be measured with a reusable accelerometer of a reusable electronics module, for example as described above, or measured with a disposable accelerometer affixed to each patch and disposed of with the patch after the patch is removed from the patient. [0145] It should be appreciated that the specific steps illustrated in Figures 3A to 3D provide a particular method of monitoring a patient for an extended period, according to an embodiment of the present invention. Other sequences of steps may also be performed according to alternative embodiments. For example, alternative embodiments of the present invention may perform the steps outlined above in a different order. Moreover, the individual steps illustrated in Figures 3A to 3D may include multiple sub-steps that may be performed in various sequences as appropriate to the individual step. Furthermore, additional steps may be added or removed depending on the particular applications. One of ordinary skill in the art would recognize many variations, modifications, and alternatives. [0146] Figure 4A shows a method 400 of monitoring a patient. A step 405 adheres a first adherent patch to the patient, for example an adherent patch as described above. The first adherent patch may comprise a first patch that is separable from an electronics module, as described above. The first adherent patch may comprise a first patch of a first device with the electronics module fixed to the adherent patch, for example disposable electronics with a disposable patch.

[0147] A step 410A measures a first accelerometer signal along a first axis, for example an X-axis of a 3D accelerometer responsive to gravity as described above. A step 410B measures a first accelerometer signal along a second axis, for example a y-axis of a 3D accelerometer as described above. A step 410C measures a first accelerometer signal along a third axis, for example a Z-axis of a 3D accelerometer as described above. Measurement of the accelerometer signal with step 410A, step410B and step 41C, which may comprise sub- steps, can be performed with the patient in a known and/or determined position. The patient may be asked to stand and/or sit upright in a chair and the first signal measured. In some embodiments, the 3D accelerometer signal can be analyzed to determine that the patient is standing, walking and the first signal determined from a plurality of measurements to indicate that the patient is upright for the measurement of the first signal.

[0148] A step 415 determines an orientation of the first patch on the patient. The accelerometer can be coupled to the patch with a pre-determined orientation, for example with connectors as described above, such that the orientation of the patch can be determined from the accelerometer signal and the orientation of the 3D accelerometer on the adherent patch and the orientation of the patient. [0149] A step 420 measures a first ECG signal. The first ECG signal can be measured with the electrodes attached to the patient when the patch comprises the first orientation. The ECG signal can be measured with electronics components and electrodes, as described above.

[0150] A step 425 determines a first orientation of an electrode measurement axis on the patient. The electrode measurement axis may correspond to one of the measurement axes of the 3D accelerometer, for example an X-axis of the accelerometer as described above. However, the orientation of the electrode measurement axis can be aligned in relation to the axes of the accelerometer in many ways, for example at oblique angles, such that the alignment of the accelerometer with the electrode measurement axis is known and the signal from the accelerometer can be used to determine the alignment of the electrode measurement axis.

[0151] A step 430 determines a first orientation of the ECG vector. The orientation of the ECG vector can be determined in response to the polarity of the measurement electrodes and orientation of the electrode measurement axis, as described above. [0152] A step 435 rotates a first ECG vector. The first ECG vector orientation of the ECG vector can be used to rotate the ECG vector onto a desired axis, for example an X-axis of the patient in response to the first orientation of the ECG vector and the accelerometer signal. For example, if the first measurement axis of the first ECG vector is rotated five degrees based on the accelerometer signal, the first ECG vector can be rotated by five degrees so as to align the first ECG vector with the patient axis.

[0153] A step 440 measures a first patient temperature. The first temperature of the patient can be measured with electronics of the adherent device, as described above.

[0154] A step 445 measures a first patient impedance. The first patient impedance may comprise a four pole impedance measurement, as described above. The first patient impedance can be used to determine respiration of the patient and/or hydration of the patient.

[0155] A step 450 adheres a second patch to the patient. The second patch may comprise a second patch connected to a reusable electronics module, for example a reusable electronics module connected to the first patch for the first patient measurements above. The second patch may comprise a second patch of a second adherent device comprising a second electronics module in which the second patch and second electronics module comprise a disposable second adherent device and the first adherent patch and first electronics module comprise a first disposable adherent device.

[0156] A step 455 A measures a second accelerometer signal along a first axis, for example an x-axis of the accelerometer as described above. The first axis may comprise the first axis of the first accelerometer as described above, for example the X-axis of the accelerometer used to measure the X-axis signal with the first measurement. In some embodiments, the second accelerometer signal along the first axis may comprise an X-axis of a second accelerometer, for example a second disposable electronics module, aligned with an electrode measurement axis as described above. [0157] A step 455B measures a second accelerometer signal along a second axis. The second axis may comprise the second axis of the first accelerometer as described above, for example the Y-axis of the accelerometer used to measure the Y-axis signal with the first measurement. In some embodiments, the second accelerometer signal along the second axis may comprise a Y-axis of a second accelerometer, for example a second disposable electronics module, aligned with an electrode measurement axis as described above.

[0158] A step 455C measures a second accelerometer signal along a third axis. The third axis may comprise the third axis of the first accelerometer as described above, for example the Z-axis of the accelerometer used to measure the Z-axis signal with the first measurement. In some embodiments, the second accelerometer signal along the third axis may comprise a Z-axis of a second accelerometer, for example a second disposable electronics module, aligned with an electrode measurement axis as described above.

[0159] A step 460 determines an orientation of the second patch on the patient. The accelerometer can be coupled to the second patch with a pre-determined orientation, for example with connectors as described above, such that the orientation of the second patch can be determined from the second accelerometer signal and the orientation of the 3D accelerometer on the adherent patch and the orientation of the patient.

[0160] A step 465 measures a second ECG signal. The second ECG signal can be measured with the electrodes attached to the patient when the second patch comprises the second orientation, for example after the first patch has been removed and the second patch has been positioned on the patient as described above. The ECG signal can be measured with electronics components and electrodes, as described above. [0161] A step 470 determines a second orientation of the electrode measurement axis on the patient. The second orientation of the electrode measurement axis may comprise orientation of an axis of a second set of electrodes, for example a second set of electrodes disposed along an axis of the second patch. The second orientation of the electrode measurement axis may correspond to one of the measurement axes of the 3D accelerometer, for example an X-axis of the accelerometer as described above. However, the second orientation of the electrode measurement axis can be aligned in relation to the axes of the accelerometer in many ways, for example at oblique angles, such that the alignment of the accelerometer with the second electrode measurement axis is known and the signal from the accelerometer can be used to determine the alignment of the electrode measurement axis.

[0162] A step 475 determines a second orientation of the ECG vector. The second orientation of the ECG vector can be determined in response to the polarity of the second measurement electrodes and second orientation of the electrode measurement axis, for example second measurement electrodes on the second adherent patch that extend along the electrode measurement axis of the second adherent patch.

[0163] A step 480 rotates a second ECG vector. The second ECG vector orientation of the second ECG vector can be used to rotate the second ECG vector onto the desired axis, for example the X-axis of the patient in response to the first orientation of the ECG vector and the accelerometer signal. For example, if the first measurement axis of the first ECG vector is rotated five degrees from the X-axis based on the accelerometer signal, the first ECG vector can be rotated by five degrees so as to align the first ECG vector with the X-axis of the patient, for example the horizontal axis of the patient.

[0164] A step 485 measures a second patient temperature. The second temperature of the patient can be measured with electronics of the adherent device, as described above. [0165] A step 490 measures a second patient impedance. The second patient impedance may comprise a four pole impedance measurement, as described above. The second patient impedance can be used to determine respiration of the patient and/or hydration of the patient.

[0166] A step 495 repeats the above steps. The above steps can be repeated to provide longitudinal monitoring of the patient with differential measurement of patient status. The monitoring of the patient may comprise a comparison of baseline patient data with subsequent patient date. [0167] Many of the steps of method 400 can be performed with the processor system, as described above.

[0168] It should be appreciated that the specific steps illustrated in Figure 4 A provides a particular method of monitoring a patient, according to an embodiment of the present invention. Other sequences of steps may also be performed according to alternative embodiments. For example, alternative embodiments of the present invention may perform the steps outlined above in a different order. Moreover, the individual steps illustrated in Figure 4A may include multiple sub-steps that may be performed in various sequences as appropriate to the individual step. Furthermore, additional steps may be added or removed depending on the particular applications. One of ordinary skill in the art would recognize many variations, modifications, and alternatives.

[0169] Patient Monitoring For Fall Prevention and Fall Detection

Adherent monitoring devices, systems and methods for fall prevention and fall detection are provided. Such monitoring devices, systems and methods can be used to reduce the risk that a patient will experience a fall, as well as to detect when the patient experiences a fall. These monitoring devices, systems and methods can incorporate the above described devices, systems, and/or methods in whole or in part.

[0170] Figure 5 shows a method 500 of monitoring a patient for fall prevention and detection. The above described methods, devices and systems can be configured for use in practicing method 500. For example, method 500 may comprise method 400, described above. In step 505, one or more process parameters, orientation restrictions, and/or movement restrictions can be input by a user of a patient monitoring system comprising a processor system, as described above. The one or more process parameters can include any parameter used in the method 500. For example, a user-defined impact-acceleration threshold can be input. The impact-acceleration threshold can be used to detect when a patient acceleration exceeds the impact-acceleration threshold. As another example, a user- defined falling-velocity magnitude threshold can be input. The falling-velocity magnitude threshold can be used to detect when a patient velocity exceeds the falling-velocity threshold. User-defined process parameters can be used in place of default process parameters. Additionally, a user may select from one or more patient profiles that contain default process parameters that can be used for a patient, such as a patient with a compromised state similar to the compromised state corresponding the selected patient profile. [0171] User-defined orientation restrictions and/or movement restrictions can also be input. Orientation restrictions can include a designation of permissible ranges of orientations for the patient, such as permissible orientations for a portion of the patient having an adherent monitoring device adhered thereto (e.g., the patient's torso, arm, leg, head, etc.). Alternatively, an orientation restriction can include a designation of restricted ranges of orientations for the patient, or combinations of permissible and restricted ranges. A movement restriction can include a designation of permissible movements and/or a designation of restricted movements. A movement restriction can include an activity-level restriction. Additionally, a user may select from one or more patient profiles that contain orientation restrictions and/or movement restrictions that can be used for a patient, such as a patient with a compromised state similar to the compromised state corresponding the selected patient profile. For example, a patient profile can contain orientation restrictions and/or movement restrictions that can be used for patients that are restricted to bed rest so as to permit the patient to sit up in the bed while restricting the patient from leaving the bed. [0172] In step 510, one or more accelerations for the patient is measured. A series of accelerations can be used to form an acceleration profile. An acceleration profile can include a series of acceleration values for the patient as measured along a measurement axis. Acceleration profiles for one or more measurement axes can be measured. An accelerometer on the adherent device can be used to measure the acceleration(s). Each axis of the accelerometer can be sensitive to gravity so that the measured accelerations can be used to determine an orientation of the accelerometer axis. As described above, the relationship between the orientation of the accelerometer and the orientation of the patient can be determined. Accordingly, the orientation of the patient can be derived from the orientation of the accelerometer. In embodiments, the monitoring device can include an accelerometer with three orthogonal measurement axis, which can be used to generate three orthogonal accelerations for the patient. By measuring three orthogonal accelerations for the patient, an orientation for the accelerometer can be fully determined. A fully determined accelerometer orientation can be used to generate a fully determined orientation for the part of the patient to which the monitoring device is adhered (e.g., the patient's torso, arm, leg, head, etc.). More than one monitoring device can be adhered with more than one part of the patient and thereby provide orientations for the more than one part of the patient. The accelerations can be stored in a circular memory buffer as they are measured so that patient accelerations for the preceding period of time are available for further processing. [0173] In step 515, patient physiological data is measured. Measured patient physiological data can include an electrocardiogram and respiration data. The measured patient physiological data can be stored for subsequent processing. For example, the measured physiological data can be stored in a circular buffer so that data for the preceding period is available for processing and/or transmission for evaluation and/or processing elsewhere.

[0174] In step 520, one or more process parameter(s), orientation restriction(s), and/or movement restriction(s) can be imposed or adjusted based upon the measured patient physiological data. The measured physiological data can be processed to determine whether the patient is experiencing any physical distress (e.g., cardiovascular distress, respiratory distress). For example, if the patient's electrocardiogram indicates that the patient is experiencing arrhythmia, one or more of the process parameter(s), orientation restriction(s), and/or movement restriction(s) can be imposed or adjusted to reflect the current cardiovascular status of the patient. Likewise, if the measured respiration data for the patient indicates that the patient is experiencing respiratory distress (e.g., hyperventilation, hypoventilation, tachypnea), one or more of the process parameter(s), orientation restriction(s), and/or movement restriction(s) can be imposed or adjusted to reflect the current respiratory status of the patient. The above described imposition and/or adjustment of process parameter(s) and/or restriction(s) provides the ability to monitor the patient using a dynamic approach that may better reflect the current status of the patient. [0175] In step 525, low-frequency accelerations for the patient are generated. The measured patient accelerations can be processed to remove high-frequency acceleration components, which are typically not a function of the orientation of the accelerometer but may be a function of vibration and/or device noise. The resulting low- frequency accelerations contain the low-frequency acceleration components, which are typically a function of the orientation of the accelerometer when the accelerometer is sensitive to gravity. The low- frequency accelerations can be generated by applying a low-pass filter to a series of measured patient accelerations (i.e., a patient acceleration profile).

[0176] In step 530, one or more patient orientations or movements are generated. A patient movement along a direction in the form of a velocity magnitude (in the direction) can be generated by integrating patient accelerations in the direction. A known or assumed velocity magnitude along the direction for a known point in time can be used to solve for the constant of integration. Likewise, a patient movement along a direction in the form of a displacement (in the direction) can be generated by integrating patient velocity magnitudes in the direction. A known or assumed displacement along the direction for a known point in time can be used to solve for the constant of integration.

[0177] A patient orientation can be generated by processing one or more patient low- frequency accelerations. A single patient low- frequency acceleration along a direction, that includes a gravity-induced component, can be processed to determine a relative angle between the direction of the acceleration measurement and the direction of gravity (i.e., down). Three orthogonal patient low- frequency accelerations can be processed to provide additional orientation information. For example, a patient orientation in the form of the inclination angle of the patient's torso can be generated by processing three orthogonal low- pass filtered acceleration profiles for patient relative x, y, and z directions (Ax, Ay, and Az). In this example, the patient relative x direction is oriented from the patient's head toward the patient's foot, the patient relative y direction is oriented fore/aft and points away from the patient's chest, and the patient relative z direction is oriented parallel to the ground when the patient is standing vertical and points to the patient's right. The patient's torso-inclination angle (90 degrees = vertical; 0 degrees = supine) can be found for any point in time with equation (1).

(1)

[0178] Likewise, the patient's torso-rotation angle (90 degrees = one side; -90 degrees = other side) can be found for any point in time with equation (2).

θ_Rot = (2)

[0179] In step 535, high-frequency accelerations for the patient are generated. The generation of the high-frequency accelerations involves removal of the low-frequency acceleration components, such as gravity-induced accelerations. The resulting high- frequency accelerations contain patient-relative accelerations, which can be processed to generate additional patient-relative data, such patient-relative velocities, patient-relative velocity magnitudes, and patient activity levels. The high-frequency accelerations can be generated by applying a high-pass filter to a series of measured patient accelerations (i.e., a patient acceleration profile). The high-frequency accelerations can be generated for one or more measurement axes by processing patient accelerations measured along the one or more measurement axes.

[0180] In step 540, one or more patient activity levels are generated. As discussed above, an adherent device can include an activity sensor. The activity sensor can comprise one or more of the following: ball switch, accelerometer, minute ventilation, HR, bioimpedance, noise, skin temperature/heat flux, BP, muscle noise, posture. Signals from the activity sensor can be processed to provide a corresponding patient activity level. For example, patient activity levels can be generated by processing accelerometer based data, such as the above discussed high-frequency accelerations for the patient. In embodiments, patient activity levels are generated by smoothing a series of patient high-frequency accelerations. The resulting activity levels reflect lower- frequency variations in the amplitude of the high- frequency accelerations. Such smoothing can be accomplished using various approaches. For example, the smoothing can be accomplished by applying a moving-median filter and/or a moving-average filter to a series of high-frequency accelerations for the patient. An acceleration-based activity level can be generated from accelerations measured along one or more axis. When accelerations along two or more axes are used, a series of acceleration magnitudes can be generated from the acceleration components. The series of acceleration magnitudes can then be used to generate the patient activity levels, such as by smoothing the series of acceleration magnitudes as discussed above. [0181] In step 545, one or more restriction violations are detected. The one or more restriction violations can include one or more orientation-restriction violations and/or movement-restriction violations. A movement-restriction violation can include an activity- level violation, such as an acceleration based activity-level violation. A restriction violation can be detected by comparing a generated patient orientation, movement, and/or activity level to a corresponding restriction, such as the above discussed restrictions.

[0182] In step 550, one or more restriction violations are communicated. If the restriction violation is detected by an above described adherent monitoring device, the monitoring device can wirelessly transmit a notification of the restriction violation to the gateway. The gateway can subsequently transfer the notification to the server. The transfer of the restriction violation to the server can be used to inform a monitoring caregiver and/or healthcare professional of the restriction violation. [0183] In step 555, one or more patient acceleration magnitudes are generated. The one or more acceleration magnitudes can be generated by processing one or more patient accelerations measured about one or more measurement axes. For example, a patient acceleration magnitude can be generated by determining the magnitude of an patient acceleration vector defined by three orthogonal acceleration vector components by taking the square root of the sum of the squares of the components. Although the one or more patient acceleration magnitudes can be generated using patient accelerations that include gravity induced accelerations, the use of the above discussed patient high-frequency accelerations can help to simplify subsequent processing steps by eliminating the need to account for gravity-induced accelerations.

[0184] In step 560, one or more acceleration threshold violations are detected. For example, a patient acceleration magnitude can be compared against an acceleration threshold to determine whether the acceleration magnitude exceeds the threshold. The acceleration threshold used can be a default or user-defined threshold, such as the impact-acceleration threshold discussed above. A fall can be detected in response to determining that an acceleration threshold violation exists. An acceleration threshold violation can also be used to identify an incident that can be further evaluated before a determination is made that the patient has experienced a fall. Acceleration data preceding and/or following the acceleration threshold violation can be further evaluated so as to corroborate the violation. Following the further evaluation, a fall can be detected in response to an affirmative corroboration.

[0185] In step 565, one or more patient velocity magnitudes are generated. The measured patient accelerations can be integrated to generate patient velocities. Where the measured patient accelerations include gravity-induced accelerations, the influence of gravity induced accelerations can be accounted for, such as by removing the gravity-induced accelerations prior to integration. Conveniently, the patient velocities can be generated by integrating the patient high-frequency accelerations, which do not include gravity-induced accelerations. The constant of integration can be determined using a known or assumed velocity magnitude for a point in time. The one or more patient velocity magnitudes can be generated by processing one or more patient velocities along one or more axes. For example, a patient velocity magnitude can be generated by determining the magnitude of a patient velocity vector defined by three orthogonal velocity vector components by taking the square root of the sum of the squares of the components. A patient velocity magnitude can also be generated for a particular direction by determining the component of the patient velocity along the particular direction using know methods, such as trigonometry and/or linear algebra.

[0186] In step 570, one or more falls are detected. A fall detection can include a determination that one or more fall indications has occurred. Various fall indicators can be considered. For example, a fall indicator can include a patient acceleration that exceeds an impact-acceleration threshold (e.g., an acceleration that exceeds 0.7 G-force); an abrupt change in a patient orientation; "ringing" (oscillations characteristic of an impact, for example a damped substantially periodic oscillation, the presence of which can be determined with a software program written by a person of ordinary skill in the art based on the teachings described herein) from at least one axis of the accelerometer; a concomitant change in a patient's activity level (e.g., an activity level below a threshold such a low level of movement); a concomitant change in a patients cardiovascular and/or respiratory functioning (e.g., heart rate, electrocardiogram data for the patient indicative of syncope or arrhythmia, respiration rate, etc.); a falling event where a patient's acceleration magnitude exceeds a falling-event acceleration threshold during the falling event; and a falling event where a patient's velocity magnitude increases followed by a post-impact event where the patient's velocity magnitude decreases. One or more fall indicators can be evaluated and a fall detected in response to the one or more fall indicators.

[0187] In step 575, one or more detected falls are communicated. Where a fall is detected by an adherent monitoring device, the monitoring device can communicate the detection to the gateway and/or directly to the server. The gateway can communicate the fall detection to the server and/or further process any received patient data before or after communicating the fall detection to the server. The server can also further process any received patient data.

[0188] In step 580, patient data and/or condition(s) are communicated. Patient data (e.g., patient accelerations, velocities, acceleration and/or velocity magnitudes, physiological data, etc.) measured before and/or after the fall can be communicated to the gateway and/or server.

Where the monitoring device has measured patient data and has identified one or more patient conditions, the one or more patient conditions can also be communicated. The gateway and/or server can also process patient data so as to identify patient conditions. The monitoring device, gateway, and/or server can communicate the detection to the patient and/or others. The communication can be made in a variety of ways, such as using known audio-visual based notifications, displays, etc. [0189] Patient data and conditions that can be measured, determined, and/or communicated can include information to assist in the determination of the severity and/or cause of a fall. For example, the patient data can include electrocardiogram data, respiratory data, and/or acceleration data. The electrocardiogram and acceleration data can be evaluated to identify a syncope of the patient. The electrocardiogram data can be evaluated to identify arrhythmia (e.g. , heart-rate variability, heart-rate turbulence, tachycardia, bradycardia, non-sustained ventricular tachycardia, etc.). The respiratory data can be measured through the use of impedance circuitry and used to identify patient respiratory distress (e.g., hyperventilation, hypoventilation, tachypnea). The adherent monitoring device, gateway, and/or server can be configured to identify patient conditions by processing the patient data. The patient data, and/or any system identified patient conditions, can be communicated to the server for access by a monitoring person. The monitoring person can then make an informed decision as to what course of action to pursue, as well as making an informed decision as to the level of urgency associated with the situation. [0190] It should be appreciated that the specific operations illustrated in Figure 5 provides a particular method of monitoring a patient, according to an embodiment of the present invention. Other sequences of operations may also be performed according to alternative embodiments. For example, alternative embodiments of the present invention may perform the operations outlined above in a different order. Moreover, the individual operations illustrated in Figure 5 may include multiple sub-operations that may be performed in various sequences as appropriate to the individual operation. Furthermore, additional operations may be added or removed depending on the particular applications. One of ordinary skill in the art would recognize many variations, modifications, and alternatives.

[0191] Figures 6A, 6B, 6C, 6D, 6E, 6F, and 6G illustrate the use of measured patient accelerations for fall detection. These figures use "arbitrary units" (A. U.). The arbitrary units may comprise at least one of bit levels, G's, m/sec, or normalized values. Figure 6A shows measured patient acceleration components for three orthogonal measurement axes (X, Y, and Z directions). In this example, the patient relative x direction is oriented from the patient's head toward the patient's foot, the patient relative y direction is oriented fore/aft and points away from the patient's chest, and the patient relative z direction is oriented parallel to the ground when the patient is standing vertical and points to the patient's right. The data shown in Figure 6A includes both low-frequency accelerations, which include gravity- induced accelerations, and high-frequency accelerations. Traces showing the low-frequency accelerations are shown superimposed on the measured acceleration data.

[0192] Figure 6B shows the data of Figure 6 A, and further shows two detected falls corresponding to spikes in the measured accelerations. The first detected fall occurred at approximately time period 30, and the second detected fall occurred at approximately time period 41. The detection of these two falls is discussed in more detail below with reference to Figures 6C, 6D, 6E, 6F, and 6G.

[0193] Figure 6C shows patient high-frequency acceleration components generated from the patient accelerations of Figure 6A. The high-frequency accelerations shown where generated by applying a high-pass filter to the accelerations of Figure 6A. The application of the high-pass filter removes the low- frequency acceleration components (i.e., the gravity- induced accelerations), thereby leaving the high-frequency accelerations (e.g., patient-relative accelerations, accelerations due to device noise, etc.).

[0194] Figure 6D shows patient acceleration magnitudes generated from the high- frequency accelerations of Figure 6C. A magnitude value for a point in time can be generated by taking the square root of the sum of the squares of the separate components (e.g., X, Y, and Z components).

[0195] Figure 6E shows the patient acceleration magnitudes of Figure 6D, and further shows the two detected falls corresponding to spikes in the acceleration magnitudes. The two detected falls have peak acceleration magnitudes that exceed an impact-acceleration threshold, which in this example corresponds to approximately 0.7G-force of acceleration.

[0196] Figure 6F shows patient velocity components generated from the high-frequency acceleration components of Figure 6C. The velocity components shown can be obtained by integration of the high-frequency acceleration components. Also shown are the two detected falls.

[0197] Figure 6G shows patient velocity magnitudes generated from the patient velocity components of Figure 6F. The magnitudes shown exhibit rising patient velocity magnitudes just prior to the detected falls and decreasing patient velocity magnitudes following the detected falls. The rising patient velocity magnitudes are consistent with a potential falling event and the decreasing patient velocity magnitudes are consistent with a post-impact event. Such consistency can be used to provide fall detection and/or corroboration. [0198] Figures 7 A and 7B illustrate the generation of patient orientations from measured patient acceleration components. Figure 7 A shows measured patient acceleration components (X, Y, and Z directional components) for a 24 hour period. The acceleration components shown include gravity-induced acceleration components. Figure 7A includes traces of corresponding low-frequency acceleration components. These low- frequency components can be generated by applying a low-pass filter to the measured acceleration components.

[0199] Figure 7B shows patient orientations generated from the low-frequency acceleration components of Figure 7A. The patient orientations shown include torso inclination and torso rotation. The orientations shown can be generated using the methods shown above with reference Figure 5, operation 530. As described above, a torso-inclination of 90 degrees corresponds to a vertical torso inclination and a torso-inclination of 0 degrees corresponds to a horizontal torso inclination. The torso-rotation values can vary from +90 degrees to -90 degrees. Torso-rotation may be best visualized during periods when the torso-inclination is closer to horizontal (i.e., when the patient is lying down), which occurs between about hour 12 through hour 20 in the data shown. The torso-rotation values during this time show the rotary position of the patient (e.g., laying on one side, laying on the opposite side, laying facing up, etc.).

[0200] Figures 8 A and 8B illustrate the generation of activity levels for a patient from measured accelerations. Acceleration-based activity levels can be generated so as to discount acceleration values that arise due to vibration and/or device noise. Vibration and/or device noise can cause high-frequency acceleration values to exist even during times of patient inactivity, such as during periods when the patient is asleep. Figure 8 A shows a period of time when the patient's torso-inclination angle is less than 20 degrees (from about hour 11 through hour 17.5). Figure 8B shows high-frequency acceleration magnitudes corresponding the orientations of Figure 8 A. Figure 8B also shows activity levels generated from the high- frequency acceleration magnitudes. The activity levels were generated by smoothing the acceleration magnitudes that exceeded a threshold (in this example a 50 mG threshold). The resulting activity levels indicate zero activity for the time when the patient is laying down. Various approaches can be used to smooth the acceleration magnitudes that exceed a threshold, such as by applying a moving-median filter and/or a moving-average filter to the acceleration magnitudes that exceed the selected threshold. [0201] While the exemplary embodiments have been described in some detail, by way of example and for clarity of understanding, those of skill in the art will recognize that a variety of modifications, adaptations, and changes may be employed. Hence, the scope of the present invention should be limited solely by the appended claims.

Claims

WHAT IS CLAIMED IS:

1. A device for monitoring a patient, the device comprising: an adherent support configured to adhere to a skin of the patient; an accelerometer coupled with the support to support the accelerometer when the support is adhered the skin of the patient; and a processor coupled with the accelerometer, the processor comprising a tangible medium and configured to detect at least one of a fall of the patient or an orientation of the patient.

2. The device of claim 1, wherein the accelerometer comprises a plurality of measurement axes, each axis of the accelerometer being sensitive to an acceleration of the patient along the axis, and wherein the processor is configured to detect the patient fall in response to measured patient accelerations.

3. The device of claim 2, wherein the accelerometer comprises three measurement axes and wherein the processor is configured to measure each axis to detect the patient fall.

4. The device of claim 3, wherein the processor is configured to measure an acceleration profile along each axis and detect the patient fall in response to the acceleration profiles.

5. The device of claim 3, wherein each axis of the accelerometer is sensitive to gravity to detect the orientation of the patient, and wherein the processor is configured to detect the patient fall in response to an abrupt change in the orientation of the patient.

6. The device of claim 5, wherein the abrupt change in the orientation of the patient comprises a change in orientation of each axis of the accelerometer over a period of time from about 0.1 to about 1 second.

7. The device of claim 1 , wherein the processor is configured to digitize an acceleration signal for each axis over a period of time with a sampling frequency to measure the acceleration profile for the axis.

8. The device of claim 7, wherein the processor is configured to store each acceleration profile in a circular buffer and detect the patient fall in response to the acceleration profiles stored in the circular buffers.

9. The device of claim 8, wherein the processor is coupled to electrocardiogram circuitry to measure an electrocardiogram signal and impedance circuitry to measure a respiration signal of the patient and wherein the processor is configured to store each of the electrocardiogram signal and the respiration signal in a circular buffer, and wherein each of the circular buffers corresponds to a period of time extending from before the detected fall to after the detected fall and wherein the processor is configured to transmit the data stored in the circular buffers with wireless transmission circuitry in response to the detected fall.

10. The device of claim 1 , wherein the processor is configured to detect the patient fall initially in response to a large amplitude signal corresponding to at least about 0.7 G-force of patient relative acceleration and corroborate the patient fall in response to ringing from at least one axis of the accelerometer.

11. The device of claim 10, wherein the ringing comprises a damped substantially periodic oscillation.

12. The device of claim 1, further comprising sensors to measure at least one of an electrocardiogram or a respiratory rate and wherein the processor is configured to detect the patient fall in response to a signal from the accelerometer and the at least one of the electrocardiogram or the respiratory rate.

13. The device of claim 12, wherein the processor is configured to detect a syncope of the patient in response to the electrocardiogram and the signal from the accelerometer.

14. The device of claim 12, wherein the electrocardiogram comprises an arrhythmia and the processor is configured to detect the patient fall in response to the arrhythmia and the accelerometer signal.

15. The device of claim 14, wherein the arrhythmia comprises at least one of a heart rate variability, a heart rate turbulence, a tachycardia, a bradycardia, or a non- sustained ventricular tachycardia and wherein the processor is configured to detect the patient fall in response to the at least one of the heart rate variability, the heart rate turbulence, the tachycardia, the bradycardia, or the non-sustained ventricular tachycardia.

16. The device of claim 1, further comprising at least two electrodes coupled with electrocardiogram circuitry to measure electrocardiogram data of the patient, the at least two electrodes and electrocardiogram circuitry being coupled with the support to support the at least two electrodes and the electrocardiogram circuitry when the support is adhered to the skin of the patient and wherein the processor is configured to at least one of store, transmit or analyze the electrocardiogram data in response to detection of the patient fall.

17. The device of claim 16, wherein the processor is coupled with the electrocardiogram circuitry to store the electrocardiogram data in a buffer of the processor and wherein the electrocardiogram data stored in the buffer correspond to a period of time preceding detection of the patient fall.

18. The device of claim 17, wherein the period of time preceding the patient fall corresponds to at least about 15 seconds of electrocardiogram data and wherein the processor is configured to store the at least about 15 seconds of electrocardiogram data preceding the patient fall in response to detection of the patient fall.

19. The device of claim 18, wherein the processor is configured to store electrocardiogram data corresponding to a period of time after detection of the patient fall and wherein the period of time after the patient fall corresponds to at least about 15 seconds of electrocardiogram data and wherein the processor is configured to store and transmit the at least about 15 seconds of electrocardiogram data after the patient fall in response to detection of the patient fall.

20. The device of claim 18, wherein the electrocardiogram data comprise a digitized electrocardiogram signal and wherein the processor is configured to transmit at least about 15 seconds of the digitized electrocardiogram signal measured before detection of the patient fall.

21. The device of claim 20, wherein the processor is configured to sample the electrocardiogram data at a rate of at least about 50 Hz and store the digitized electrocardiogram signal continuously in a circular buffer such that the digitized electrocardiogram data corresponding to the period of time is stored in the circular buffer when the patient fall is detected.

22. The device of claim 16, wherein the processor is configured to transmit the electrocardiogram data in response to detection of the patient fall.

23. The device of claim 16, wherein the processor is configured to determine a heart rate from the electrocardiogram data and transmit the heart rate in response to detection of the patient fall.

24. The device of claim 16, further comprising impedance circuitry supported with the support to measure a respiration data of the patient in response to impedance of the patient and wherein the processor is coupled with the impedance circuitry and configured to at least one of store, transmit or analyze the respiration data in response to detection of the patient fall.

25. The device of claim 24, wherein the processor is configured to store respiration data corresponding to a period of time preceding detection of the patient fall.

26. The device of claim 25, wherein the period of time preceding the patient fall corresponds to at least about 15 seconds of respiration data and wherein the processor is configured to store the at least about 15 seconds of respiration data preceding the patient fall in response to detection of the patient fall.

27. The device of claim 25, wherein the processor is configured to store respiration data corresponding to a period of time after detection of the patient fall and wherein the period of time after the patient fall corresponds to at least about 15 seconds of respiration data and wherein the processor is configured to store and transmit the at least about 15 seconds of respiration data after the patient fall in response to detection of the patient fall.

28. The device of claim 24, wherein the respiration data comprise at least one of an impedance, an impedance magnitude, a resistance or a respiration rate of the patient.

29. The device of claim 24, wherein the processor is coupled with the impedance circuitry and configured to transmit the respiration data in response to detection of the patient fall.

30. The device of claim 24, wherein the at least two electrodes comprise at least four electrodes and wherein the impedance circuitry comprises drive circuitry to drive a current through a first two of the at least four electrodes and measurement circuitry to measure a voltage across a second two of the at least four electrodes in response to the current.

31. The device of claim 1 , wherein the processor is configured to measure patient movement in response to detection of the patient fall and activate an alarm in response to a low amount of patient movement after detection of the patient fall.

32. The device of claim 1 , wherein the processor is coupled with the support to support the processor with the support when the support is adhered to the skin of the patient.

33. The device of claim 1 , further comprising wireless communication circuitry coupled with the support to support the wireless communication circuitry when the support is adhered to the skin of the patient and wherein the wireless communication circuitry is configured to transmit patient data.

34. The device of claim 1 , wherein the support is configured to stretch with the skin of the patient such that the support is configured to adhere continuously to the skin of the patient for an extended period of at least one week.

35. A system for monitoring a patient, the system comprising: an adherent monitoring device configured to adhere to a skin of the patient, the monitoring device comprising, an adherent support configured to adhere to a skin of the patient, a plurality of sensors coupled with the support and configured to measure patient data, the plurality of sensors comprising an accelerometer, a processor coupled with the support and the accelerometer, the processor comprising a tangible medium and configured to detect at least one of a patient fall or a patient orientation, and transmit the patient data, and wireless communication circuitry coupled with the support and the processor, the wireless communication circuitry configured to transmit the patient data; a gateway configured to communicate with the wireless communication circuitry; and a server configured to couple with the gateway to receive the patient data from the gateway in response to the at least one of the detection of the patient fall or the detection of the patient orientation.

36. The system of claim 35, wherein the processor is configured to transmit the patient data in response to the detection of the patient fall.

37. The system of claim 35, further comprising a processor system, the processor system comprising at least one of the processor of the adherent monitoring device, a processor of the gateway, or a processor of the server, wherein the processor system is configured to measure a patient acceleration profile and to process the patient acceleration profile to detect the patient fall.

38. The system of claim 37, wherein the processor of the adherent device comprising the tangible medium has instructions of a computer program embodied thereon such that the processor is configured to measure patient data from the sensors adhered to the patient and detect the fall of the patient and wherein the gateway comprises a gateway processor comprising a gateway tangible medium having instructions of a gateway computer program embodied thereon such that the gateway is configured to transmit the patient data from the patch device to the server in response to the detected fall and wherein the server comprises a server processor comprising a server tangible medium having instructions of a server program embodied thereon such that the server is configured to transmit the patient data to a display device in response to the fall.

39. The system of claim 37, wherein the processor system is configured detect the patient fall in response to an initial detection of the patient fall and a subsequent corroboration of the patient fall and wherein the processor of the adherent monitoring device is configured to detect the patient fall initially in response to a patient acceleration magnitude that exceeds an impact acceleration threshold and wherein at least one of the server or the gateway is configured to corroborate the fall.

40. The system of claim 37, wherein the processor system is configured to detect the patient fall in response to a patient acceleration magnitude that exceeds an impact acceleration threshold, wherein the fall detection of the processor system comprises at least one of an initial detection of the patient fall or a corroboration of the patient fall.

41. The system of claim 40, wherein the fall detection by the processor system is in response to ringing in the patient acceleration profile.

42. The system of claim 41 , wherein the ringing comprises a damped substantially periodic oscillation.

43. The system of claim 37, wherein the processor system is configured to detect a patient fall in response to identifying a falling event that is followed by an impact event, wherein an acceleration magnitude profile is generated from the patient acceleration profile, wherein identification of the falling event comprises determining that the acceleration magnitude profile exceeds a falling event acceleration threshold during the falling event, and wherein identification of the impact event comprises determining that an acceleration magnitude exceeds an impact acceleration threshold.

44. The system of claim 37, wherein the tangible medium of the processor comprises a memory, and the processor is configured to store an acceleration based data profile for the patient in the memory.

45. The system of claim 44, wherein the acceleration based data profile is stored in a circular memory buffer.

46. The system of claim 44, wherein the processor system is configured to detect a patient fall in response to identifying a falling event that is followed by a post-impact event, wherein a velocity-magnitude profile is generated from the acceleration based data profile, wherein identification of the falling event comprises determining that during the falling event the velocity-magnitude profile exhibits increasing magnitudes and a velocity magnitude exceeds a falling velocity magnitude threshold, and wherein identification of the post-impact event comprises determining that during the post-impact event the velocity- magnitude profile exhibits decreasing magnitudes.

47. The system of claim 35, wherein the processor is configured to detect the patient fall in response to an abrupt change in patient orientation.

48. The system of claim 35, wherein the processor is configured to detect the patient fall in response to a concomitant change in a patient activity level.

49. The system of claim 48, wherein the processor is configured to: generate a patient acceleration profile; and generate an activity-level profile for the patient by processing the patient acceleration profile.

50. The system of claim 49, wherein the processor is configured to: generate a high-pass filtered acceleration profile by applying a high-pass filter to the patient acceleration profile to filter out gravity induced accelerations; and generate the activity-level profile by processing the high-pass filtered acceleration profile.

51. The system of claim 50, wherein the processor is configured to generate the activity-level profile by smoothing the high-pass filtered acceleration profile.

52. The system of claim 51 , wherein the smoothing comprises applying a moving-median filter and a moving-average filter.

53. The system of claim 48, wherein: the accelerometer comprises two or more measurement axes; and the processor is configured to generate an acceleration profile along each axis, generate a high-pass filtered acceleration profile along each axis by applying a high-pass filter to each axis acceleration profile, generate a power-sum acceleration profile by taking the power-sum of the high-pass filtered acceleration profiles, and generate an activity-level profile by processing the power-sum acceleration profile values that exceed a designated threshold.

54. The system of claim 53, wherein the designated threshold is selected to substantially remove device noise contributions to the generated activity-level profile.

55. The system of claim 35, wherein the monitoring device comprises wireless communication circuitry, and wherein the wireless communication circuitry is configured to transmit patient data.

56. A method of monitoring a patient, the method comprising: adhering an adherent monitoring device on a skin of the patient, the monitoring device comprising an accelerometer and a processor coupled with the accelerometer, wherein the processor generates an acceleration profile for the patient and detects at least one of a patient fall or a patient orientation in response to the acceleration profile.

57. The method of claim 56, wherein a notification is sent in response to the detection of the at least one of the patient fall or the patient orientation.

58. The method of claim 56 wherein the accelerometer comprises at least three measurement axes, each axis of the accelerometer being sensitive to an acceleration of the patient along the axis and sensitive to gravity along the axis and wherein violation of at least one of an orientation restriction or a movement restriction is detected in response to acceleration profiles generated for the three axes.

59. The method of claim 58 wherein a notification is provided of at least one of the orientation-restriction violation or the movement-restriction violation in response to detection of the patient violation of the at least one of the orientation restriction or the movement restriction.

60. The method of claim 58, wherein the monitoring device is adhered to the patient's torso, wherein the orientation restriction comprises at least one of a torso- inclination restriction or a torso-rotation restriction, and wherein the method further comprises: selecting the at least one of the orientation restriction or the movement restriction; and transferring the at least one of the orientation restriction or the movement restriction to the monitoring device.

61. The method of claim 60, wherein transferring the at least one of the orientation restriction or the movement restriction comprises wirelessly transmitting the at least one of the orientation restriction or the movement restriction to the monitoring device.

62. The method of claim 58, wherein the movement restriction comprises restricting the patient from leaving a bed.

63. The method of claim 58, wherein: the processor is configured to process at least one axis acceleration profile to generate an activity- level profile for the patient, and provide a notification of an activity-level violation in response to detecting an activity level of the patient that exceeds an activity-level restriction; and the method further comprises receiving notification of the activity-level violation.

64. The method of claim 63, further comprising: selecting the activity-level restriction; and transferring the activity-level restriction to the monitoring device.

65. The method of claim 64, wherein transferring the activity-level restriction comprises wirelessly transmitting the activity-level restriction to the monitoring device.

66. A device for use in monitoring a patient, the device comprising: an adherent support configured to adhere to a skin of the patient; an accelerometer coupled with the support to support the accelerometer when the support is adhered the skin of the patient; and a processor coupled with the support and the accelerometer, the processor comprising a tangible medium and configured to process signals from the accelerometer to detect when the patient violates at least one of an orientation restriction or a movement restriction.

67. The device of claim 66, further comprising sensors to measure at least one of an electrocardiogram of the patient or a respiratory rate of the patient.

68 The device of claim 67, wherein the processor is configured to at least one of impose or adjust the at least one of the orientation restriction or the movement restriction in response to the at least one of the electrocardiogram or the respiratory rate.

69. The device of claim 67, wherein the processor is configured to detect a syncope of the patient in response to the electrocardiogram and the signal from the accelerometer.

70. The device of claim 67, wherein the electrocardiogram comprises an arrhythmia and the processor is configured to: detect the arrhythmia in response to the electrocardiogram; and at least one of impose or adjust the at least one of the orientation restriction or the movement restriction in response to detection of the arrhythmia.

71. The device of claim 70, wherein the arrhythmia comprises at least one of a heart-rate variability, a heart-rate turbulence, a tachycardia, a bradycardia, or a non- sustained ventricular tachycardia and wherein the processor is configured to the at least one of impose or adjust the at least one of the orientation restriction or the movement restriction in response to the at least one of the heart-rate variability, the heart-rate turbulence, the tachycardia, the bradycardia, or the non-sustained ventricular tachycardia.

72. The device of claim 66, further comprising at least two electrodes coupled with electrocardiogram circuitry to measure electrocardiogram data of the patient, the at least two electrodes and electrocardiogram circuitry being coupled with the support to support the at least two electrodes and the electrocardiogram circuitry when the support is adhered to the skin of the patient and wherein the processor is configured to at least one of store, transmit or analyze the electrocardiogram data in response to detection of the restriction violation.

73. The device of claim 72, wherein the processor is coupled with the electrocardiogram circuitry to store the electrocardiogram data in a buffer of the processor and wherein the electrocardiogram data stored in the buffer correspond to a period of time preceding detection of the restriction violation.

74. The device of claim 73, wherein the period of time preceding the restriction violation corresponds to at least about 15 seconds of electrocardiogram data and wherein the processor is configured to store the at least about 15 seconds of electrocardiogram data preceding the restriction violation in response to detection of the restriction violation.

75. The device of claim 74, wherein the electrocardiogram data comprise a digitized electrocardiogram signal and wherein the processor is configured to transmit at least about 15 seconds of the digitized electrocardiogram signal measured before detection of the restriction violation.

76. The device of claim 75, wherein the processor is configured to sample the electrocardiogram data at a rate of at least about 50 Hz and store the digitized electrocardiogram signal continuously in a circular buffer such that the digitized electrocardiogram data corresponding to the period of time is stored in the circular buffer when the restriction violation is detected.

77. The device of claim 72, wherein the processor is configured to transmit the electrocardiogram data in response to detection of the restriction violation.

78. The device of claim 72, wherein the processor is configured to determine a heart rate from the electrocardiogram data and transmit the heart rate in response to detection of the restriction violation.

79. The device of claim 72, further comprising impedance circuitry supported with the support to measure a respiration data of the patient in response to an impedance of the patient and wherein the processor is coupled with the impedance circuitry and configured to at least one of store, transmit or analyze the respiration data in response to detection of the restriction violation.

80. The device of claim 79, wherein the processor is configured to store respiration data corresponding to a period of time preceding detection of the restriction violation.

81. The device of claim 80, wherein the period of time preceding the restriction violation corresponds to at least about 15 seconds of respiration data and wherein the processor is configured to store the at least about 15 seconds of respiration data preceding the restriction violation in response to detection of the restriction violation.

82. The device of claim 79, wherein the respiration data comprise at least one of an impedance, an impedance magnitude, a resistance or a respiration rate of the patient.

83. The device of claim 79, wherein the processor is configured to transmit the respiration data in response to detection of the restriction violation.

84. The device of claim 79, wherein the at least two electrodes comprise at least four electrodes and wherein the impedance circuitry comprises drive circuitry to drive a current through a first two of the at least four electrodes and measurement circuitry to measure a voltage across a second two of the at least four electrodes in response to the current.

85. A system for monitoring a patient, the system comprising: an adherent monitoring device configured to adhere to a skin of the patient, the monitoring device comprising, an adherent support configured to adhere to a skin of the patient, a plurality of sensors coupled with the support and configured to measure patient data, the plurality of sensors comprising an accelerometer, and a processor coupled with the support and the accelerometer, the processor comprising a tangible medium and configured to process signals from the accelerometer to detect when the patient violates at least one of an orientation restriction or a movement restriction, and wireless communication circuitry coupled with the support and the processor, the wireless communication circuitry configured to transmit the patient data; a gateway configured to communicate with the wireless communication circuitry; and a server communicatively coupled with the gateway, the server configured to receive the patient data transmitted in response to the detection of the violation of the at least one of the orientation restriction or the movement restriction.

86. The system of claim 85, wherein the monitoring device is configured for placement on a patient's torso, and wherein the orientation restriction comprises at least one of a torso-inclination restriction or a torso-rotation restriction.

87. The system of claim 85, wherein the accelerometer comprises three measurement axes, and wherein each axis is sensitive to gravity to detect an orientation of the patient.

88. The system of claim 87, further comprising a processor system, the processor system comprising at least one of the processor of the monitoring device, a processor of the gateway, or a processor of the server, wherein the processor system is configured to detect when the patient violates the at least one of the orientation restriction or the movement restriction.

89. The system of claim 88, wherein the gateway and the server each comprise a processor having a tangible medium and wherein the tangible medium of at least one processor of the processor system is configured to measure and store an acceleration profile along each axis.

90. The system of claim 89, wherein the processor system is configured to: generate a low-pass filtered acceleration profile along each axis by applying a low-pass filter to each of the acceleration profiles; and determine an orientation of the patient by processing a low-pass filtered acceleration value for each axis.

91. The system of claim 86, wherein: the server is configured to receive at least one of a user-selected orientation restriction or a user-selected movement restriction; and the system is configured to transfer the at least one of the user-selected orientation restriction or the user-selected movement restriction from the server to the monitoring device.

92. The system of claim 85, further comprising a processor system, the processor system comprising at least one of the processor of the adherent device, a processor of the gateway, or a processor of the server, wherein the processor system is configured to detect when the patient violates the at least one of the orientation restriction or the movement restriction.

93. The system of claim 92, wherein the movement restriction comprises an activity-level restriction.

94. The system of claim 93, wherein the processor system is configured to: generate an acceleration profile for the patient; and generate an activity-level profile for the patient by processing the acceleration profile.

95. The system of claim 94, wherein the processor system is configured to: generate a high-pass filtered acceleration profile by applying a high-pass filter to the acceleration profile to filter out gravity induced accelerations; and generate the activity-level profile by processing the high-pass filtered acceleration profile.

96. The system of claim 95, wherein the processor system is configured to generate the activity-level profile by smoothing the high-pass filtered acceleration profile.

97. The system of claim 96, wherein the smoothing comprises applying at least one of a moving-median filter or a moving-average filter.

98. The system of claim 94, wherein: the accelerometer comprises two or more measurement axes; and the processor system is configured to generate an acceleration profile along each axis, generate high-pass filtered acceleration profile along each axis by applying a high-pass filter to each axis acceleration profile, generate a power-sum acceleration profile by taking the power-sum of the high-pass filtered acceleration profiles, and generate an activity-level profile by processing the power-sum acceleration-profile values that exceed an activity-level threshold.

99. The system of claim 98, wherein the activity-level threshold is selected to substantially remove device-noise contributions to the activity-level profile.

100. The system of claim 94, wherein the processing system is configured to process the activity-level profile to detect when the patient violates an activity-level restriction, and wherein the server is configured to receive the patient data transmitted in response to the detection of the activity-level violation.

101. The system of claim 100, wherein the server is configured to accept a user-input activity-level restriction and the system is configured to transfer the user-input activity-level restriction to the monitoring device.

102. The system of claim 88, wherein the plurality of sensors comprises sensors to measure at least one of an electrocardiogram or a respiratory rate, and wherein the processor system is configured to at least one of impose or adjust the at least one of the orientation restriction or the movement restriction in response to the at least one of the electrocardiogram or the respiratory rate.