WO2012089223A1

WO2012089223A1 - Device for detecting epidural space and accurate catheter placement

Info

Publication number: WO2012089223A1
Application number: PCT/EG2010/000046
Authority: WO
Inventors: Mishail Ishak Ibrahim
Original assignee: Mishail Ishak Ibrahim
Priority date: 2010-12-28
Filing date: 2010-12-28
Publication date: 2012-07-05

Abstract

A Device for locating the epidural space. The device comprises a tube, a pressure sensor (1) and a pressure switch valve (2) for manually or electronically controlling an air pump connected to the tube.

Description

DEVICE FOR DETECTING EPIDURAL SPACE AND ACCURATE

CATHETER PLACEMENT

Technical Field :

The present invention is related to medical devices and methods for detecting the epidural space in the human body by very safe, easy and a high efficient manner as well as in accurate catheter placement.

Background Art :

The epidural space in the human body is that compartment between the diameter and the bony and ligament us walls of the spinal canal.

It is a potential space, in life it is filled with extramural fat and the internal vertebral plexus of veins which are arranged in two paramecia channels extending the length of the epidural space from cranium to sacrum, the segmental nerves as they leave the diameter cross this epidural space before exiting from the spinal canal through the intervertebral foramina.

Epidural anesthesia is usually performed at similar lumbar level to spinal anesthesia, but can be used in cervical, thoracic and sacral areas for specific indications, pressure inside this space is sub atmospheric - Ronald D. Miller 1 981 ,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 ligament flavor into the epidural space, this technique depends mostly on the gained experience and the individual performance of the physician - Ronald D. Miller 1 981 , 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 anesthesia specially in cervical and thoracic epidural anesthesia 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 :

The invention is simply formal of the following parts fig 1 a pressure gauge 1 Fig 1 - pressure Switch Valve 2 Fig 1 - auditory alarm 5 Fig 1 - Visual alarm 8 Fig 1 one way Valve 3 Fig 1 - Port of the Valve 9 Fig 1 - Frontal Port of the one way valve 9 Fig 1 frontal port of the device 4 Fig ] - 2 batteries each 1 .5 V 7 Fig 1 - ON and OFF button 8 Fig 1

As well as an accessory part Fig 11 a sterile disposal polyvinyl transparent tube about 4mm diameter and 75 cm length . it has 2 ends end no.

1 fig 11 to connect with the device and num 2 fig 11 to connect with the needle.

Before using the devise in the anaesthetis procedure the device must be tested for function as follows ..

The button 8 Fig 1 is Turned to the ON position . both alarms must start actinide block the frontal port of the device 4 Fig 1 with finger - inject about 1 cc into the one way valve 3 Fig 1 through its frontal Port 9 Fig 1 - both alarms must stop if the device is compatible - repeat this test many times in order to be sure about the compatibility of the device

The physician fixes the needle in the back of the patient for about 3 to 4 cm into the back of the patient up to the ligaments level . the physician tests that the introduced needle is air tight by using a syringe filled with air and trying to inject the air inside in the syringe through the needle if there is any sort of leakage . the physician must correct the position of the needle until it becomes air tight . the physician fixes and 2 Fig 11 of the sterile connection tube in the back opening of the needle fixed in the back of the patient the other end of the sterile plastic tube and 1 Fig 11 is fixed will by 1 of the assistances of the physician into the frontal port of the device 4 Fig 1 the assistant turns the button 8 Fig 1 of the device to the ON position - both alarms must start acting the assistant with a sterile siring injects 1 cc of air through the one way valve three fig 1 through its port 9 Fig 1 - both alarms must stop this is due to disconnection of the electric circuit of the device by the pressure switch valve

2 Fig 1 - the physician notices the pressure gauge of the device to be sure that there is no leakage in the circuit of the device . the tube and the needle which is very important for the function of the device . if there is any leakage . the cause must be searched about it and must be corrected . when the physician becomes sure that there is no leakage he proceeds with needle steadily and slowly forwards towards the space . when the tip of the needle reaches the epidural space which is sub subatmospheric in its pressure ( clinical aneasthesiology Edward Morgan 233 , 1996 ) the air inside the connection tube ( and the device ) escapes into the space the thing which leads the pressure switch valve of the device 2 Fig 1 to reconnects the electric circuit in the device again ( which was disconnected by the injections of air through the one way valve 3 Fig 1 )

This will lead to the working of both alarms of the device denoting that the needle has reached the right place the (epidural space) Which is the Target of the procedure , the physician disconnects the connection tube from the needle and starts threading of catheter into the space through the needle the assistant turns the button 8 Fig 1 of the device to OFF position , escape of air into the space through the needle shall lead to a very important thing which is sudden sharp drop of pressure which is recorded by the gauge of the device 2 Fig 1 this is important to differentiate between true alarming when the needle reaches the space and false alarming which can be happened in rare cases when the needle enters a minute degenerative cavity in the back of some elderly patients in such case the gauge will record a small drop of pressure other than the sudden sharp drop which happens when the needle enters the epidural space . this phenomena helped me so much in designing of this new device it has and to program the device to avoid the occurrence of such false alarming which can happen when the needle enters such cavities the medical knowledge about such cavities that it does not exceed a cubic each of its diminutions about 5 mm so this cavity can accept a volume of air equals to 5*5*5 cmms = 1 25 cmms which equals 0 , 125 cm of air so during designing the device I took care that the pressure switch valve and the alarms must be adapted together to avoid false alarming when this slight drop of pressure happens in case that the needle has entered such cavity . I could adjust the power of the pressure switch valve with the amount of the injected air to produce a pressure inside the circuit of the device - the tube and the needle exceeding the level of pressure inside the circuit needed by the pressure switch valve to connect the electric circuit of the alarms even after the escape of this amount of air ( 0, 125cm ) when the needle enters such cavity this is very important inventive step in the device making it novel among other devices which are news in the field of detection of the epidural space I can summarize the benefits of adding this pressure gauge to the devise as follows :

1 - It helps in the discovery of any leakage in the circuit of the device , tube and the needle from the beginning of the procedure or during it and avoiding it because , any sort of leakage leads to failure of the device to detect the space

I- The rang of drop in the pressure inside the device circuit with the needle gives an idea about the sequences of the procedure and helps an the successful approach of the space , continuous even slight drop pressure recorded by the gauge means that there is leakage which must be corrected - sudden slight drop in pressure means that needle has entered a cavity - sudden sharp drop in pressure means that needle has entered the epidural space It helps in avoiding false alarming either from leakage or due to entering of the needle into cavity the thing which is troublesome during the procedure and causes some sort of delay in doing the procedure

Beside this very important development in the design of the device through introducing of such pressure gauge I could add some developing parts in the design of the device which improves the performance and the accuracy of the device .

Example of such introduced parts :

Exchange of the one way valve 3 Fig 1 with a manual pump connected to special button ( set up button ) through this button air is pumped into the device circuit to set up the device

Exchange of the mechanical gauge with an electronic pressure gauge

Exchange of the mechanical pressure switch valve with an electronic switch valve

Introducing an electronic air pumps 10 Fig lVcontroled with special pressure switch valve 9 Fig lVto control the injected air into the circuit of the device , extension tube and the needle.

Beside the use of the device in approaching the epidural space the device can be used in another important act concerning the procedure of the epidural anaethesia which is conformation of the place of the Catheter threaded into the space , sometimes the threaded catheter may be kinked or miss leaded into a wrong place as a foramen of a bony segment of the vertebral column which blocks its patent end an interferes with the injections of the anaethetic material through the catheter into the space this cases the devices helps in confirming the place of the catheter and in correcting its positions to be in the proper situation this is as follows the catheter is connected to the sterile connection tube the other end of the tube is connected to the frontal port of the device 4 Fig 1 - the button 8 Fig 1 is turned to the ON position both alarms must start - the assistant injects 1 cc of air with a sterile syringe into the one way valve 3 Fig 1 through its port 9 Fig 1 if the alarms does not stop this means that the catheter is in right place ( transient cessation of the alarms may occur do you to the high resistance of the tube to the passage of air because of its minute caliber which allows the air to escape slowly to the space this can be noticed through the pressure gauge when its lever moves from the ziro point up during the injection the of air but it declines gradually returning back again in the same time transient cessation of the alarms may occur due to the transient increase in pressure

If the alarms stopped after the injection of air this means that the catheter is not in the proper position and must be readjusted this can be happen by withdrawal of the catheter slowly and slightly backwards until the alarms restart again this means that the catheter regained its patency inside the space , withdrawal of the catheter removes any kink preventing its patency and in the same time withdrawal of the catheter with withdraws the patent end of the catheter from any foramen clothing it

Without this confirmation and the readjustment of the catheter inside the space the whole of the anaethetic procedure may fail completely so this advantage can be added to the other many advantages of the devices which are ..

Its simple and easy to use

Extreme safety for the patient - it keeps the patient out of the complications that can be happen with other methods which is in use in this field

No personal skylines or experience are needed for its use as in other traditional methods as LOR .

Brief Description of Drawings :

Fig I

1 - pressure gauge

2 - pressure switch valve

3 - one way valve

4 - Frontal port of the device

5 - Auditory alarm

6- Visual alarm

7- Tow batteries 1 . 5 v

8 - On and Off button

9 - Port of the one way valve

Fig II

1 - End to the device

2 - End to the Needle

3 - polyvinyle disposal tub Fig III

- pressure gauge

- Frontal port of the device

- Manual air Pump

- Alarm Set Up button

- pressure switch valve

- Auditory alarm

- Visual alarm

- Tow batteries 1. 5 v

- On and Off button

Fig. IV - Frontal port of the device

- pressure gauge

- pressure switch valve

- Auditory alarm

- Visual alarm

- Tow batteries 1. 5 v

- On and Off button

- On and Off button Of the electronic air pump - pressure switch valve Of the electronic air pump 0 - electronic air pump

Fig . IV

- Frontal port of the device - Port for injection Of air - pressure switch valve 4 - Auditory alarm

5 - Visual alarm

6- Tow batteries 1 . 5 v

7 - On and Off button

Best mode for caring out of the invention

It can be made and marketed pay a specialized medical companies and distributed to hospitals and medical canters for practical use

Claims

- A device for detecting the epidural space and for accurate placement of the catheter supplied with a mechanical pressure switch valve and a mechanical pressure gauge generated by Changeable or rechargeable batteries

- A device according to claim 1 supplied with a manual air pump connected to a special button to set up the device to prepare it for function

- A device according to claims 1 , 2 supplied with electronic pressure gauge with electronic screen to display the pressure changes in the circuit of the device

- A device according to claims 1 ,2 supplied with electronic air pump

- A device according to claim 3 supplied with electronic air pump

In both claims 4.5 the electronic air pump is connected electrically with a standard pressure switch valve to control the amount of air injected to the device circuit as well as a special setup button through which the pump is generated to set up the device to prepare it for function - the power to the pump is supplied through a special electrical connection from the main power supply of the device

- A device according to claims 1 ,2 ,4 supplied with a5 cc syringe

Connected to the circuit of the device its plunger is connected with a special Motor to move it forwards and backwards to inject

- A device according to claims 4,5 in which the electronic air pump is generated through a special cable built in the sterile connection tub the end of the cable in the side of the device is connected with the power source of the device through a special plug and in the other end of the tub there is a special button through which the doctor can us it to generate the pump 8 - A device according to claims From 1 :7 supplied with electronic pressure switch valve

9 - A device according to claims from 1 :8 can be used for laparoascopic operations through a special connection tube is prepared to fit with the purpose