WO1996011036A1

WO1996011036A1 - Process and device for providing implanted measuring, control and regulating systems with power and bidirectional data transfer

Info

Publication number: WO1996011036A1
Application number: PCT/DE1995/001382
Authority: WO
Inventors: Gunter Preiss
Original assignee: Vtv Verfahrenstechnik Verwaltung Gmbh
Priority date: 1994-10-05
Filing date: 1995-10-03
Publication date: 1996-04-18
Also published as: DE4435602C2; AU3561495A; DE4435602A1

Abstract

The adverse effects on the patient on implantation and in use are to be minimised and the extent and operative effort, the sensitivity to electromagnetic fields and the transmission losses reduced. Implanted solar cells (5) are irradiated with light in the visible and/or i/r range which impinges in the region of a light immission skin region (18) on the skin surface and penetrates the latter and the bodily tissues (16) on the way to the solar cells (5) with absorption losses. The bi-directional data transfer takes place on the same route via control-modulated light in the wavelength ranges 800 to 900 nm or 1250 to 1350 nm or 1450 to 1550 nm by means of light-guide technology between an exogenous opto-electronic light transmission component (4) flexibly fitted above the light immission skin region (18) and an implanted opto-electronic light receiving component (3) with a possible reversal of operations between the two. Implanted electromedical devices for maintaining and supporting and measuring and diagnosing organ and bodily functions, like tissue stimulators, insulin control systems and especially cardiac pacemakers (2).

Description

Method and device for supplying implanted measuring, control and regulating systems with energy and bidirectional patient transfer

The invention relates to a method and an apparatus for carrying out the method for supplying measurement, control and regulation systems, in particular cardiac pacemakers, implanted in human body tissue with photovoltaic energy and the bidirectional data transfer between them and an exogenous evaluation and control module with an encoder-receiver display , for the maintenance and support as well as measurement and diagnosis of organ and body functions.

Systems of the type described are used in various implanted electromedical devices, such as tissue stimulators, insulin control systems and others. Such devices are assigned an ever increasing number of complex functions in order to make them more effective in their therapeutic and diagnostic efficacy as well as simple and tolerable use.

The quality of life of their wearers is influenced by these devices to a not inconsiderable extent, or their life is extended.

The duration of the functionality of the systems implanted by surgery alone is of considerable importance to the patient and, as a result, essentially depends on the possible energy supply of the systems. With a lithium battery, for example, it is possible to secure the energy supply for a simple pacemaker without an extended functional range for about 15 years. Such a pacemaker correlatively adjusts the heartbeat rate according to a fixed, predetermined pattern via the blood oxygen value determined and thus no longer meets the latest requirements, which, for example, enable input of control commands in the case of changes in the stress caused by the circulatory system or diagnosis of physical functions via data ^feedback . The constant expansion of the measuring, control and regulation functions, but with increasing energy demand verbun ^¬. As a result, the operating time of the implanted expensive electronic see devices that would otherwise function lifelong, limited to the time the functionality of their energy suppliers, batteries or accumulators. They can only be replaced in the course of an expensive surgical procedure that is associated with various difficulties for the patient.

For this reason, attempts have been made to circumvent the use of implanted energy suppliers, which have to be replaced by surgery after their energy reserves have been used up.

DE-OS 36 05915 describes a control and power supply unit for implanted electromedical measuring, control and regulating systems with an electronic unit, the energy requirement of which is generated photovoltaically by solar cells. These are not implanted, but rather are arranged on preferred parts of the body so that there is no galvanic connection between them and the implanted electronic unit. Rather, the solar cell energy is transmitted inductively via a transmission system with a primary winding that can be attached to parts of the body and an implanted secondary winding, and is supplied to the implanted electronic unit via lines inserted into blood vessels. The transmission system also provides a bidirectional data transfer between a control panel fed directly by the solar cells for issuing control commands and the implanted measuring, control and regulating system with the electronic unit.

This solution is disadvantageous in several ways.

In addition to the indispensable one-time implantation of the measuring, control and regulating system with the rechargeable battery cells themselves, complex surgical interventions, which are additionally burdensome for the patient, are necessary for introducing the transmission system, in particular the secondary winding and the leads.

In a large number of applications, compatibility problems are to be expected with regard to the supply lines running in the blood vessels and the secondary winding, especially since, in contrast to the measuring, control and regulating system, these are in the arm, i.e. in a human limb that is in constant motion / and under stress are positioned. Pain-related restrictions on use are to be expected. Another disadvantage is that the system is susceptible to faults against alternating electromagnetic fields. The occurrence of energy-proportional electromagnetic alternating fields, particularly with pacemakers, places certain limits on the transmission or additional shielding of the control electronics is necessary.

An increased risk to the patient arises above all from external, unpredictable electromagnetic fields, because the system has an input cross-section several times higher for them, such as pacemakers with conventional accumulator cells or batteries.

In addition to the limited transmission intensity, there are efficiency losses in the system. These are on the one hand the conversion and rectification losses of the primary solar power, on the other hand due to the inductive transmission over a very open stray field. Further losses occur in the feed line in the feed lines.

The problem which is to be solved by the invention is to demonstrate a method and a device for supplying implanted MeR, control and regulating systems with photovoltaic energy and the bidirectional transfer of oats between these and exogenous evaluation and control modules which show the impairments of the Minimize patients with regard to implantation and during use, reduce the expenditure on equipment and surgery, reduce the susceptibility to electromagnetic fields and the transmission losses.

The stated problem is solved by the invention described in claims 1 and 5.

According to the inventive method, like the electromedical measuring, control and regulating systems, the solar cells implanted in the body tissue are irradiated with light in the visible and / or infrared spectral range, which strikes the skin surface in the area of a light immission skin zone and this and the further translucent body tissue penetrates on the way to the solar cells with absorption losses and the bidirectional oate transfer takes place in the same way by means of control-modulated light in the wavelength ranges 800 to 900 nm or 1250 to 1350 nm or 1450

The invention is explained in more detail below in an exemplary embodiment.

In the accompanying drawing:

1: energy supply and data transfer for a pacemaker, in a schematic representation,

2: pacemaker, in side view,

Fig. 3: Evaluation and control module with encoder-receiver display, in

perspective view,

Fig. 4: Block diagram.

The principle shown in Fig. 1 in a schematic representation of the energy supply and data transfer of a pacemaker 2 according to Fig. 2 is based on the knowledge that the all-available energy carrier light in the visible and / or infrared spectral range, with certain absorption losses, basically without problems the body tissue 16, ie skin, husk, connective tissue, etc., must be penetrated and then photovoltaic energy must be generated, as the results shown below prove both with sunlight and with artificial light tests. The tests were carried out using a commercially available thin-film solar cell with an effective area of 48.5 × 52.5 mm and a thickness of 1.4 mm, 95% of which being glass cover as transparent protection and mechanical support of the light-sensitive energy-generating layer, carried out. Instead of human body tissue, 16 coarse-fiber, lean pork cut across the muscle fiber in various layers was used as the "replacement medium".

Experiment No. 1.: Sunlight.

Daily angle of incidence to the earth's surface: 40º cloudless sky.

Experiment No. 2 .: Sunlight.

Daily angle of incidence to the earth's surface: 55 °, cloudless sky.

Experiment No. 3 .: Sunlight.

Daily angle of incidence to the earth's surface: 50%, closed cirrus stratus cloud cover

Experiment No. 4 .: Sunlight.

Daily angle of incidence to the earth's surface: 50º, closed clouds with small Cumulus congestus

Experiment No. 5 .: Sunlight.

Daily angle of incidence to the earth's surface: 45º,

Cloud cover: Large Cumulus congestus, a large Comulus nimbus (60%) from the sun.

Experiment No. 6 .: artificial light.

Halogen spotlight 80 watts, parabolic mirror with a diameter of 167 mm,

Total light intensity: 750 cd,

vertical distance to the tissue layer at the focal point: 1200 mm

The tests carried out have shown that the yellow, orange and bright red spectral components of the visible light were able to generate a high proportion of the solar energy after passing through relatively small tissue thicknesses. With increasing tissue thickness, an increasing proportion of the light of shorter wavelength is absorbed and does thermal work in the tissue. However, this was low and compatible with tissue.

With a further increase in the tissue thickness, the drop in the generated solar energy was non-linear, since the longer-wave red and infrared spectral components were able to penetrate the tissue with almost no absorption. In the same way, tests No. 3 to 5 are to be evaluated with sunlight damped by clouds, in the result of which acceptable performances of the solar cell were still achieved even with the greatest tissue thickness.

In experiment no. 6, artificial light was used with brightness values comparable to light box therapy. The results were also completely satisfactory.

The evidently possible high charging capacity for the accumulator 15 of the pacemaker 2 was associated with a comparatively low thermal load on the body tissue 16 upstream of the solar cell 5 in this experiment No. 6. It was not disturbing, but tolerable. Even heavily pigmented skin does not represent a barrier to red and infrared light rays with permanent or intermittent charging of the rechargeable battery 15 of implanted, electro-medical measuring, control and regulating systems.

In the simplest case, namely when the light immission skin zone 18 is exposed to direct radiation from sunlight, the results that can be achieved by available minisolar cells with a wide power spectrum down to the infrared spectral range of the light are entirely sufficient for the intended purpose.

However, the method according to the invention also provides for the light incident in the area of the light immission skin zone 18 to be amplified. To improve tissue compatibility, this light is partially decoupled with regard to the infrared wavelengths and entirely with respect to the ultraviolet. The choice of appropriate material for the optical fiber ends 10, 11 and the control light guide 12 already allows a determined decoupling of certain wavelength ranges. This material opposes the wavelengths with a high attenuation value. This eliminates the need for technically complex filter attachments.

The bidirectional data transfer is basically based on the same principle as the energy transfer. For the response, it is also possible to use the modulated radio frequency emitted via the radio-frequency transmission antenna 1 and received via the radio-frequency reception antenna 27, in the event that the energy level of an optical feedback is too low. This requires the use of interference and litter-free frequency bands.

However, the use of light-emitting diodes and highly sensitive semiconductor radiation receivers in the visible and near infrared spectral range with a reliably long lifespan of several thousand hours enables purely optoelectronic logic circuitry via the control light guide 12 and the evaluation and control module with transmitter-receiver display 13, in this case the laser - Transmitter module 20, for the bidirectional control of the implanted pacemaker 2. This has very good insulation values and feedback is almost impossible, which guarantees freedom from errors.

The principle of energy and data transfer is clearly shown in the block diagram according to FIG. 4. Light emerging from the luminous surface 7 is optionally via optical fiber ends 10; 11, it penetrates the body tissue 16 with absorption losses and strikes the solar cells 5, which provide the charging energy for the battery 15 continuously or temporarily via the control and regulating unit 17. Via the control light guide 12, the same principle of bidirectional is used Data transfer between the control and regulating unit 17 of the pacemaker 2 and the evaluation and control module with transmitter-receiver display 13 with the possibility of entering control commands and outputting diagnostic data.

The device shown in Fig. 1 for supplying the implanted pacemaker 2 with energy and data transfer describe themselves as follows with regard to their structure and mode of operation.

The light enters the body in the area of the light immission skin zone 18, penetrates the body tissue 16 with certain absorption losses and strikes the solar cells 5. These are combined in a segment 19, which is aligned with the light immission skin zone 18, and fastened in the body tissue 16 . In the exemplary embodiment shown, the segment 19 is arranged directly on the capsule 6, preferably made of ceramic, of the pacemaker 2 under the highly transparent casing 14, which is permeable to light waves in the visible and infrared range. Even with an extreme thickness of the body tissue 16 of approximately 5 cm, the solar cells 2 arranged directly on the capsule 6 provide sufficient energy for the supply of supply voltage for the permanent charging of the battery 15, on the one hand, with control dominance, for optoelectronic control of the pacemaker 2 via the light receiving element 3, a photodetector, which is positioned centrally in the segment 19, instead. The galvanic connections from the solar cells 5 and the light receiving element 3 to the control and regulating unit 17, which is also located inside the capsule 6, and from this to the accumulator 15 are only a few millimeters long. In this way, the direct current generated reaches the control and regulating unit 17 without conversion and with very little loss. The accumulator 15 has a number of charging cycles of over 2000. With an energy density of 700 mWh / g and special charging processes, 15 lithium secondary elements are special as accumulators suitable. There are cell voltages of 3 volts for solid electrolytes 1.5 to 1.9 volts per cell and energy densities of 0.6 to 1.7 Wh per cm / 3. The almost complete elimination of self-discharge in the wide temperature range makes a lifespan of decades possible. Asynchronous AC charging enables charging cycles to be further increased. This results in a capacity expansion of approx. 300 per 1000 charging cycles. Outside of the body, the luminous surface 7, flexibly fastened in holders, bandages or items of clothing, can be aligned with the light immission skin zone 18. The luminous surface 7 serves to amplify the incoming light. That can be done by consisting of light-emitting diodes shining in the appropriate wave range, which receive their energy from external accumulators, batteries or solar cells.

However, Fig. 1 shows another solution. Glass heads 9 of light fiber ends 10, 11 are arranged in the illuminated area 7. The bundled light fiber ends 10 are connected to a daylight plane, not shown, and the light fiber ends 11 are connected to an artificial light plane by optical fibers, which are arranged two-dimensionally in textile or other suitable partial areas of clothing in light entry areas.

For the bidirectional data transfer, the light emitting element 4, which is adjusted to the light receiving element 3, is preferably arranged centrally in the luminous area 7. It is connected via the control light guide 12 to the laser transmission module 20, the structure of which is shown in FIG. 3. It comprises the light guide plug connection 26, the laser module 25, the database scanning display 24 with the control panel 23 and the energy connection socket 21 and the connection contact 22, which is designed as a serial or parallel interface, via which the data of the implanted pacemaker 2 can be diagnosed . The control panel 23 allows the active input of control commands to the pacemaker 2 in adaptation to the human circulation and the current external conditions. To control the pacemaker 2, the control light guide 12 is flooded with control-modulated light in the wavelength ranges 1250 to 1350 nm or 1450 to 1550 nm and emerges in the light transmission element 4.

Instead of the laser transmitter module 20, a transmitter module of an LED transmitter with a luminous diode can be used. Depending on the choice of material and its mixing ratio, for example indium / gallium and arsenic / phosphorus, the wavelength can be selected to which the data can be modulated.

The light pulses emerging from the light-emitting element 4 and penetrating the body tissue 16 on the way to the light-receiving element 3 have control dominance over the uniform light emission serving to supply energy to the solar cells 5. The light receiving element 3 designed as a photodetector receives the light pulses, converts these into electrical and forwards them to the control and regulating unit 17 of the pacemaker 2 via short conduction paths. For the response from the control unit 17 to the evaluation and control module with transmitter-receiver display 13, in the present case to the laser transmitter module 20, the function of the light receiving element 3 and the light emitting element 4 is reversed. As an additional safety precaution, a galvanic return line can be parallelized to the control light guide 12, in the event that the energy level of an optical feedback should appear too low considering the length of the control light guide 12. Another possibility of feedback is the use of modulated radio frequency via the radio frequency transmission term 1 and the radio frequency receiving antenna 27.

List of reference numbers

1 ... high frequency transmission antenna

2 ... pacemakers

3 ... light receiving element

4 ... light emitting element

5 ... solar cell

6. . . capsule

7 ... illuminated area

8 ... optical fiber

9 ... glass head

10 ... optical fiber end

11 ... optical fiber end

12 ... control light guide

13 ... evaluation and control module with encoder-receiver display

14 ... transparent cover

15 ... accumulator

16 ... body tissues

17 ... control unit

18 ... light immission skin zone

19 ... segment

20 ... laser transmitter module

21 ... power connection socket

22 ... connector

23 ... control panel

24 ... database scanning display

25 .... laser module

26 ... fiber optic connector

27 ... radio frequency receiving antenna

Claims

1.Procedure for supplying electromedical measuring, control and regulating systems, in particular cardiac pacemakers, with photovoltaic energy and the bidirectional data transfer between them and an exogenous evaluation and control module with donor-receiver display, for maintenance and support as well as for the implantation in human body tissue Measurement and diagnosis of

Organ and body functions,

d a d u r c h g e k e n n z e i c h n e t, d a ß

Also known in the human body tissue (16), known solar cells (5) are irradiated with light in the visible and / or infrared spectral range, which strikes the skin surface in the area of a light immission skin zone (18) and this and the translucent body tissue (16) penetrates on the way to the solar cells (5) with absorption losses and that the bidirectional data transfer in the same way by means of control-modulated light of the wavelength ranges 800 to 900 nm or 1250 to 1350 nm or 1450 to 1550 nm by light guide technology between an exogenous over the light immission skin zone (18 ) flexibly attached optoelectronic light emitting element (4) and an implanted optoelectronic light receiving element (3), with possible reversal of function between the two.

2. The method according to claim 1,

d a d u r c h g e k e n n z e i c h n e t, d a ß

that in the area of the light immission skin zone (18)

Light is amplified.

3. The method according to claim 2,

d a d u r c h g e k e n n z e i c h n e t, d a ß

the light is partially filtered with regard to its infrared spectral component and completely decoupled from its ultraviolet spectral component.

4. The method according to claim 1,

d a d u r c h g e k e n n z e i c h n e t, d a ß

the response of the data transfer through the body tissue (16) is alternatively carried out by sending and receiving modulated radio frequency.

5. Device for performing the method according to claim 1,

d a d u r c h g e k e n n z e i c h n e t, d a ß

- The solar cells (5) positioned in a defined, aligned with the light immission skin zone (18)

Segment (19) summarized and

- Are electrically connected to an accumulator (15) via an electronic control and regulating unit (17),

- The light-receiving element (3), preferably a photodetector, is arranged flat within the segment (19) and is in galvanic connection with the electronic control and regulating unit (17),

- Exogenous over the light immission skin zone (18), flexible

attached, which is arranged on the light receiving element (3) aligned light emitting element (4), with possible function reversal of both, which

- Is preferably connected via a control light guide (12) to the evaluation and control module with encoder-receiver display (13).

6. The device according to claim 5,

d a d u r c h g e k e n n z e i c h n e t, d a ß

the segment (19) with the solar cells (5) and the light receiving element (3) is arranged on a capsule (6) of the measuring, control and regulating system designed as a pacemaker (2), enclosed by a common transparent sheath (14) .

7. Device according to claims 5 and 6,

d a d u r c h g e k e n n z e i c h n e t, d a ß

the light-emitting element (4) is arranged centrally within a light-emitting surface (7) that is flexibly attachable to the light-imitation skin zone (18).

8. The device according to claim 7,

d a d u r c h g e k e n n z e i c h n e t, d a ß

the luminous surface (7) is attached to stanchions, bandages or items of clothing adapted in a special way to the respective body part.

9. The device according to claim 7,

d a d u r c h g e k e n n z e i c h n e t, d a ß

the luminous surface (7) consists of light-emitting diodes radiating in the visible and / or infrared spectral range, with energy supply in a manner known per se by means of accumulators, batteries or on a photovoltaic basis.

10. The device according to claim 7,

d a d u r c h g e k e n n z e i c h n e t, d a ß

the luminous surface (7) consists of glass heads (9) which are connected via optical fibers (8) combined in a group to optical fiber ends (10; 11) which end in at least one textile or other suitable partial area of clothing in a light entry area.

11. The device according to claim 10,

d a d u r c h g e k e n n z e i c h n e t, d a ß

the optical fibers end (10) end in a light entry surface designed as a daylight illumination plane.

12. The device according to claim 10,

d a d u r c h g e k e n n z e i c h n e t, d a ß

the optical fiber ends (11) end in a light entry area designed as an artificial light plane.

13. The apparatus of claim 5,

d a d u r c h g e k e n n z e i c h n e t, d a ß

the evaluation and control module with transmitter-receiver display (13) is designed as a laser transmitter module (20) with the working widths in the wavelength ranges from 1250 to 1350 nm or 1450 to 1550 nm.

14. The apparatus according to claim 13,

d a d u c h g e k e n n z e i c h n e t, d a ß

the laser transmitter module (20) has an energy connection charging socket (21), one designed as a serial or parallel interface

Connection contact (22), a control panel (23), a database scanning display (24), a laser module (25) and an optical fiber connector (26).

15. The apparatus according to claim 5,

d a d u r c h g e k e n n z e i c h n e t, d a ß

the evaluation and control module with transmitter-receiver display (13) is designed as a transmitter module of an LED transmitter with a luminescent diode with a working width in the wavelength range from 800 to 1550 nm.

16. The apparatus according to claim 5,

d a d u r c h ge k e n n z e i c h n e t, d a ß

the light emitting element (4) is in galvanic connection with the evaluation and control module with transmitter-receiver display (13).

17. The device according to claims 5 and 16,

d a d u r c h g e k e n n z e i c h n e t, d a ß

alternatively, the control light guide (12) and a galvanic connection between the light-emitting element) and the evaluation and control module with encoder-receiver display (13) can be used for the response.

8. Device according to claims 5, 16 and 17,

d a d u r c h g e k e n n z e i c h n e t, d a ß

a high-frequency transmission antenna (1), which is galvanically connected to the electronic control and regulating unit (17), and a high-frequency reception antenna (27) are arranged on the light transmission element (4) on the pacemaker (2).