WO2004035104A2

WO2004035104A2 - Electronic epidural indicator

Info

Publication number: WO2004035104A2
Application number: PCT/EG2003/000003
Authority: WO
Inventors: Mishail Ishak Ibrahim
Original assignee: Mishail Ishak Ibrahim
Priority date: 2002-10-15
Filing date: 2003-10-07
Publication date: 2004-04-29
Also published as: EG24364A; AU2003273796A8; WO2004035104A3; AU2003273796A1

Abstract

The epidural indicator relates to a device for locating the epidural space for introducing in such space e.g. anaesthetics. The device is formed of a major unit (A - E; fig.1) and an accessory unit 81, 2, 3; fig.2); the major units consists of an alarm(A), ON & OFF button (B), pressure switch valve (C) and 1.5 volt battery (D); the accessory unit is a plastic tube with a three-way connection having three ports (1, 2, 3; fig.2) namely ports (1, 2) for connection with port (E) of the major unit and the epidural needle respectively and port (3; fig.2) for connection with a syringe to injecting air in the pressure switch valve (C).

Description

ELECTRONIC EPIDURAL INDICATOR

Field of the invention

The present invention is related to medical devices and methods for approaching the epidural space in the human body by a very safe, easy and efficient manner .

Background to the invention

The epidural space in the human body is that compartment between the duramater and the bony and ligamentous walls of the spinal canal. It is a potential space, in life it is filled with extradural fat and the internal vertebral plexus of veins which are arranged in two paramedian channels extending the length of the epidural space from cranium to sacrum, the segmental nerves as they leave the duramater cross this epidural space before exiting from the spinal canal through the intervertebral foramina. Epidural anaesthesia is usually performed at similar lumbar level to spinal anaesthesia, but can be used in cervical, thoracic and sacral areas for specific indications, pressure inside this space is subatmospheric - Ronald D. Miller 1981 , 637 - 663.

The most commonly used technique for approaching the epidural space is determining the loss of resistance to injection as the needle passes from the dense ligamentum flavum into the epidural space, this technique depends mostly on the gained experience and the individual performance of the physician - Ronald D. Miller 1981 , 663.

Another technique which is in use today is introducing the epidural needle by the help of X. Ray screening (under vision) into the epidural space to avoid any possible damage from displacement of the needle in certain cases of epidural anaesthesia specially in cervical and thoracic epidural anaesthesia this technique has the hazard of the exposure of both the patient and the medical team to the harmful effect of the X. Ray which in turn needs special precautions in the form of special clothes ( to resist radiation ) for the medical team and special rooms prepared against radiation to minimize the harm of the X. Ray - however it cannot avoid the harm completely on the long run.

Summary of the invention

This invention is simply formed of an electric circuit consisted of the following parts ( Fig 1 ) : an electronic alarm (A) - On & Off button (B) - pressure switch valve (C) " Which has a frontal opening (E) " - and a battery 1.5 volts (D) as will as an accessory part ( Fig 2 ) which is a disposal sterile triple plastic connection tube ( it has 3 sides 1 ,2,3 ).

The pressure switch valve (C) is connected to the circuit of the device in order to open or close the circuit according to the pressure inside it. ⁾ Contents of the valve

It is formed of an air tight frontal room 2 ( Fig 3 ), a flexible plastic disc 3 ( Fig 3) , a ring form metal plate 4 ( Fig 3 ) " fixed " it forms the first electrode of the valve and the device, another ring plate is fixed backwards to the first plate 5 ( Fig 3 ) between both of them is a narrow space in which there is another freely ; mobile metal plate hat shaped 6 ( Fig 3 ) there is a zip 7 ( Fig 3 ) connecting between the frontal hat shaped plate and the second electrode of the valve 8 ( Fig 3 ) in the back of the valve which also is connected to the electric circuit of the device, this zip has a specific low resistance to allow the free mobility of the metal plate 6 ( Fig 3 ) under a very low possitive atmospheric pressure between the frontal metal ring plate 4 (Fig 3) and the other backward placed metal ring plate 5 (Fig 3)

The previous design of the valve as it is shown in the cross section of the valve ( Fig 3 ) represents the position of the different parts of the valve in the usual position before its use - in this position when the button (B) ( Fig 1 ) of the device is in the ON position the electric circuit of the device is open and the alarm must rings, after the injection of air into the device thorough the opening (E) ( Fig 1 ) during its testing for use or during its use in the procedure of epidural anaesthesia, certain changes occur in the different parts of the valve which are clearly appear in ( Fig 4 ) which is the cross section in the valve after injection of air and rising of pressure inside its room 2 ( Fig 4 ), at this moment the flexible plastic plate 3 ( Fig 4 ) bulges backwards pushing the metal plate 6 ( Fig 4 ) backwards separating it from the frontal metal ring plate 4 ( Fig 4 ) which represents the first electrode of the valve which is connected to the device also, this separation leads to closure of the electric circuit of the device which in turn leads to stoppage of the alarm. Before staring the procedure of epidural anaesthesia the device must be tested for function to avoid any manufactural defects in it as follows, the button (B) ( Fig 1 ) is turned to the ON position at this moment the alarm must rings indicating that the device is suitable for use - further testing of the device mast be done by • injecting about 0.5 - 1 cc of air into the opening (E) ( Fig 1 ) at this moment the alarm must stops ringing if the device is compatible - removal of the injected air leads to ringing of the alarm again, this must be rebated many times in order to be sure about the compatibility of the device.

In the procedure of epidural anaesthesia the physician after testing the device for compatibility as mentioned before with the position of the button (B) ( Fig 1 ) in the ON position the alarm must rings, the physician fixes the needle in the back of the patient to a certain limit, the physician fixes side 2 ( Fig 2 ) of the plastic connection ( Fig 2 ) to the needle fixed in the back of the patient, the other side of the tube side 1 ( Fig 2 ) is connected firmly by one of the assistants of the physician to the opening of the device (E) ( Fig 1 ), the physician by a sterile syringe injects abut 0.5 - 1 cc of air into the plastic connection ( connecting between the needle and the device) through side 3 ( Fig 2 ) of the plastic connection as this moment the pressure switch valve takes the position of (Fig 4) which was explained in detail before leading to closure of the electric circuit of the device by separating the first electrode 4 ( Fig 4 ) of the device from the second electrode of the device 8 ( Fig 4 ) ( which is electrically connected to the metal plate 6 ( Fig 4 ) though the zip forming together the second electrode of the valve and device ) this is happened through the pushing of the plastic flexible plate 3 (Fig 4) backwards due to increased pressure as a result of injection of air which in turn pushes the metal plate 6 ( Fig 4 ) backwards which is the electric continuation of the second electrode separating it from the first electrode 4 (Fig 4) leading to closure of the electric circuit of the device so the alarm stops ringing the physician proceeds very slowly with the needle forwards in the back of the its pressure - Clinical Anesthesiology Edward Morgan 233, 1996 the air inside the connection ( and the device ) escapes into the epidural space which leads to the return of the valye to its usual position in ( Fig 3 ) where the zip pushes forwards the metal plate 6 ( Fig 3 ) which represent the second electrode of the valve and device connecting it with the other metal ring plate 3 (Fig 3 ) which represent the first electrode of the valve and device leading to opening of the electric circuit of the device which in turn leads to ringing of the alarm again indicating that the tip of the needle at this moment is in the epidural space which is the target of the procedure, the physician removes away the plastic conation from the needle and he completes his anesthetic procedure as usual by injection of the local anesthetic or threading an epidural catheter into the epidural space through the epidural needle.

I want to stress 2 points the first is that in manufacturing of the device or the plastic connection tube, it is not allowed for any leakage to occure, both of them must be air tight - the second point is, during the procedure of epidural anesthesia the sides of the plastic connection connected to the needle and the device must be fitted well to both of them in order not to allow for any leakage which interferes with the function of the device .

During any epidural procedure there is the possibility that the needle may puncture a blood vessel in its course which'may cause bleeding through the needle which in turn flows into the plastic connection so this connection must be transparent in order to make any blood flowing through from the needle to be visible to the physician this will not interfere with the procedure or with using the device, in such case the physician can change the connection with another new one and changes the site of puncture of the back of the patient and then completes the procedure as usual.

In the case of sclerosed back patients like in old age patients or due to any sclerosing disease in the back it is better to inject more amount of air than the usual 0.5 - 1 cc of air, as example from 2 - 3 cc of air can be injected into the plastic connection, this helps to dislodge any sclerosed tissue which may blug the lumen of the needle during its course to the epidural space which if it has happened it may interfere with the function of the device so injecting more air into the connection increases the pressure inside the needle which helps in dislodging any plugs can block the needle and in gaining the benefit of the device in determination of the epidural space.

This device has many advantages than any other equipment and methods which are in use today it is simple and easy in its use, no training, personal skinless or experience are needed for its use as well as a very important advantage which is, its safety in use both for the patient and the medical team - another most important advantage is its efficiency in approaching the epidural space with a failure rate approaches the 0 %.

Brief description of drawings

Fig 1

Diagram of the electric circuit of the device.

A - Electronic alarm.

B - ON & OFF button. ,

C - Pressure switch valve.

D - Battery 1.5 volts.

E - Frontal opening of the valve.

Fig 2 The accessory triple plastic tube.

1 - Side 1 to the device.

2 - Side 2. to the needle.

2 - Side 3. for injection of air.

Fig 3 Cut section of the valve. The first position ( the usual position ). 1 - Opening of the valve.

2 - Air tight frontal chamber.

3 - Flexible plastic plate ( straight ).

4 - Frontal ring metal plate ( first electrode ).

5 - Back ring metal plate.

6 - Free mobile hat chap metal plate ( in contact with the first electrode No.4) .

7 - Zip wire.

8 - Second electrode.

Fig 4 Cut section of the valve. The second position ( after injection of air ). 1 - Opening of the valve. 2 - Air tight frontal chamber.

3 - Flexible plastic plate ( bulging backwards ).

4 - Frontal ring metal plate ( first electrode ).

5 - Back ring metal plate.

6 - Free mobile hat chap metal plate ( separated from the first electrode No.4) .

7 - Zip wire.

8 - Second electrode. Best mode for caring out of the invention

It can be made and marketed by a medical company specialized in medical equipment then it can be sold to hospitals and medical centers for clinical use.

Claims

1- An epidural indicator apparatus for epidural anesthesia, the apparatus can be used many times it is generated either by a changeable or rechargeable batteries, there is no need to sterilize the apparatus only the triple plastic connection tube must be sterile.

2- A disposal mini epidural indicator apparatus which is small in size ( size of a watch ) generated by a small electronic cell battery it is formed of a high resistance 5 cc syringe to which fixed the apparatus, the syringe here acts as a substitute of the triple plastic connection tube, the whole device can be sterilized either by gas or gamma rays and can be added to the contents of the epidural set.

3- An apparatus according to claim 2 in which a special lock can be added to the syringe of the device preventing the return of the plunger after injection of air.

4- An apparatus according to claim 1 to be used for labaroscopic operations in which a special triple sterile connection tube is prepared to fit with the purpose of connecting the device with the special needle used in puncturing the abdomen to reach the abdominal cavity safely to inflate Co₂ into abdominal cavity through ^• the needle as one of the important steps of labaroscopy, the apparatus here helps in reaching the abdominal cavity safely specially in difficult cases in which there are adhesions in the abdominal cavity. 5- An apparatus according to claim 3 a disposal mini epidural indicator apparatus can be made specially to fit with the labaroscopic operations.

6- An apparatus according to claim 1 or claim 2 or claim 3 can be made to fit with non medical uses as approaching cavities and spaces of an atmospheric or subatmospheric pressure. 7- An apparatus according to claims 1- 6 in which a pulsating light alarm can be added to the circuit of the device besides the auditory alarm already present.