FORM 2

THE PATENT ACT 1970

(39 OF 1970)

&

THE PATENTS RULES  2003

COMPLETE SPECIFICATION

(See SECTION 10  RULE 13)

1.TITLE OF THE INVENTION :

NEUROMUSCULAR STIMULATOR WITH ELECTROMYOGRAPHY

2.APPLICANT

NAME : KRISHNA INSTITUTE OF MEDICAL SCIENCES

NATIONALITY: DEEMED TO BE UNIVERSITY DECLARED
U/S 3 OF UGC ACT  1956 VIDE
NOTIFICATION NO. F.9-15 / 2001 – U-3 OF
THE MINISTRY OF HUMAN RESOURCES
DEVELOPMENT  GOVT.OF INDIA

ADDRESS : KRISHNA INSTITUTE OF MEDICAL SCIENCES 
NEAR DHEBEWADI ROAD  MALKAPUR  KARAD
MAHARASHTRA  INDIA

3.PREAMBLE TO THE DESCRIPTION
PROVISIONAL

N / A COMPLETE

The following Specification particularly describes the nature of this invention and the manner in which it is to be performed :

4. TEACHING FIELD

The present invention has applications in various areas of medical sciences & paramedical faculties for basic studies  monitoring of patients under anaesthesia and various Intensive Care Units (ICU’s); as well as diagnostic tool in many disease states etc.

5. BACKGROUND

Use of simple peripheral nerve stimulator is common practice in Anaesthesia where the drugs (muscle relaxants) are used to paralyse patients under anaesthesia so that he / she will not move during a surgery and operation could become successful.

However  the dose selection of these drugs  which are dangerous and have a very narrow safety margin  depends on large number of factors like individual response of a patient  severity of illness  which can be really unpredictable.

The present practice of monitoring patients simply by visual impression of finger movement on nerve stimulation needs to be upgraded by designing an instrument which can give objective results with precision and ready display of results in graphical as well as numerical values leading to a high standard of patient monitoring  patient service and care.

6.SUMMARY

NEUROMUSCULAR STIMULATOR WITH ELECTROMYOGRAPHY EQUIPMENT is designed using latest and modern electronics technology to ensure objective assessment of Neuromuscular (NM) function instantly with a high precision and calibration in graphical form and numerical values as final results and being displayed on LCD screen.

It will prove useful in many other areas of medical & paramedical services. The function of the equipment is superior to ones in present day use since it gives objective results of the tests qualitatively as well as quantitatively and on analysis displays all test results instantly on the LCD screen.

7. BRIEF DESCRIPTION OF DRAWINGS:

Fig. No. 01 Block Diagram of the NEUROMUSCULAR STIMULATOR WITH ELECTROMYOGRAPHY.
Fig. No. 02 Schematic diagram of the NEUROMUSCULAR STIMULATOR WITH ELECTROMYOGRAPHY.
8.DETAILS DESCRIPTION OF DRAWINGS:

Fig. No. 01:-
This neuromuscular stimulator is used to stimulate a superficial motor nerve (1) with two leads coming from the above device (2) as a result of which the skeletal muscle belly (5) which is stimulated by that nerve will transiently show contraction because of action potential generated within the muscle.
Capturing this action potential (EMG signal) poses a great challenge because of variety of reasons e.g. amplitude is miniature to the tune of 0 – 10 mV  the usable energy of signal being limited to 50 – 150 HZ range  there are great distortions in the signal quality  noise being the greatest obstacle in electrical signal which is seen in all such electronic devices and need filtering effectively. To process and overcome this distortion  the signal current from the muscles is passed through a preamplifier (6) and a sensor (7) which is designed in such a way to give the pure and final fidelity of the signal. The pre-amplification of signal (6) formed one of the greatest technological challenges while developing this device.
This EMG signal is then supplied to microcontroller (8) which  with its multiple tasks handles it  correlates it  analyses it  through various electronic methods  e.g. Software designing for operational performance through Pulse Width Modulation (PMW) based modes  EMG signal can be displayed in graphical format  and analytical results can be displayed in numerical values on LCD screen (9).
This invention consists of developing a microcontroller based design of neuromuscular (NM) stimulator which will stimulate superficial motor nerve (1) and lead to contraction of a small muscle of hand or leg and the resultant magnitude of the muscle contraction being displayed on LCD screen as action potential with all the test results of different modes of nerve stimulation used to assess the function of muscle  objectively.
1. A superficial motor nerve of hand is selected for stimulation.
2. The instrument is operated by dry BATTERY (09 Volts).
3. It is connected to patient’s hand along the course and over a superficial motor nerve - through the positive and negative electrode output sockets with colour coded (Black –ve  Red +ve) wires and the self-adhesive disposable ECG electrodes (readily available in market) with the help of conductive jelly.
4. For selection of the leads to pick up EMG potentials from muscles round silver chloride electrodes of 1 c.m. diameter surface area and 1mm thickness are employed and fixed securely to skin with interposition of conductive jelly  throughout the monitoring time. The hand which is used for monitoring is secured against any gross movement. The EMG leads connected to the patient are Active electrode – AR connected to muscle belly  Reference electrode – Ref. fixed at a distance of 1 cm. but parallel to muscle fibre length and third Grounding lead – G  put between the motor nerve stimulation electrodes and the sensor electrodes.
5. The single muscle of the thumb of hand is used to detect the magnitude of its contraction precisely by measuring the electrical activity (EMG) i.e. action potential that develops within it during contraction.
6. Preamplifying EMG signal forms one of the greatest technological challenges while developing this device.
7. To process and overcome the difficulty in capturing the action potential of muscle as an electromyography signal  current from the muscles is passed through sensor which is designed in such a way to give the pure and final fidelity of the signal.
8. This EMG signal is then supplied to the microcontroller which  with its multiple tasks handles it  correlates it  analyses it  through various electronic methods. e.g. Software designing for operational performance through Pulse Width Modulation (PWM) based modes.
9. EMG signal to be displayed on LCD screen in graphical format  analytical results to be displayed in numerical values etc.
Fig. No. 02:-
The proposed instrument is a small  compact  lightweight and portable device  which is operated by a dry battery. It delivers direct and constant current output in operation  varying from a minimum of 5 mV to 100 mV ranges in step-up of 5 mV strength. It is connected to the patient’s hand or leg through the positive and negative electrode output sockets present on the instrument (3)  (Black – ve  Red + ve) with same colour wires and self-adhesive disposable ECG electrodes with the help of conductivegelly. The two electrodes are placed on the surface of skin along the course of the nerve at a distance from each other by minimum 1 cm. which is covering the most superficial motor nerve supplying distal muscle group.
On switching ON (1) the machine starts  with indication of Batteries status being displayed on LCD screen (4) to ensure smooth running of monitoring as well as testing the NM function. Baseline setting is first done for standardisation of the graphic output by selecting the lowest current strength of 5mV and delivering a Twitch stimulus on Demand (5) from the key board (14). If it fails  then the current strength is stepped up by 5 mV to 10mV etc.  till first visible acceptable muscle contraction is seen to result. The service current output at this step will be displayed on LCD in mA (6).
For continuous monitoring of NM function during the course of anaesthesia and surgery  which can run for few couple of hours  an automatic discharge of either a Twitch (TW) at every 10 seconds or Train of Four (TOF) at every 20 seconds can be given by the REPEAT mode (7) selection provided on the key board. Otherwise if one wants to monitor it only infrequently  DEMAND setup (5) provides keys for Twitch (TW)  Tetanus (TET)  Train of Four (TOF) and Double Burst Stimulation (DBS).
The LCD screen (9) is provided for display of various operative functions of the motor nerve stimulation of present instrument  like Battery status  current finally being selecting for monitoring  the Mode of stimulation of motor nerve (10) selected. Finally the success of current being delivered lies in completing the circuit through body of the patient (11).
The major area of screen will display the final graphical presentation of single muscle contraction (12)  qualitatively as well as quantitatively  giving the magnitude and duration of electrical activity originating in the muscle belly.
The display will also show the final analytical results of either routine monitoring over a time period at the movement as well as on special test being done  digitally in numbers and in percentile calculation instantly (13).
The instrument is small  compact  lightweight and a portable device.
1. When switched ON  the machine starts.
2. Base line setting is first done for standardization of graphic output by selecting the lowest current strength of 5 mV and delivering a Twitch stimulus. If it fails to give muscle contraction  the current strength is stepped up by 5 mV to 10 mV etc.; till visibly acceptable muscle contraction is seen.
3. It delivers a direct and constant current output in operation from positive and negative terminals.
4. The indication of battery status is displayed on LCD screen to ensure smooth function of monitoring as well as special testing of NM function.
5. If one wants to monitor it only infrequently  DEMAND setup provides keys for Twitch (TW)  Tetanus (TET)  Train of four (TOF) and Double Burst Stimulation (DOB)  the last test being a stress test for NM function to assess ambiguous situation produced by long lasting NM blocks which pose difficulty in managing patient.
6. The service current output will be displayed on LCD screen in mA.
7. For continuous monitoring of NM function during the course of anaesthesia and surgery  which can run for few couple of hours  an automatic discharge of either a Twitch (TW) at every 10 seconds or Train of four (TOF) at every 20 secs can be given by the REPEAT mode selection provided on the key Board.
8. All the three EMG leads from hand muscle selected and coming from patient are connected to the instrument through a socket provided in the instrument.
9. The LCD screen is provided for display of various operative functions of the motor nerve stimulation component of the present instrument  like Battery status  Current finally being selected for monitoring  the Mode of stimulation of motor nerve selected and finally the success of the current being delivered completing the circuit through body of patient or not.

9.I claim

1. The NEUROMUSCULAR STIMULATOR WITH ELECTROMYOGRAPHY instrument will upgrade the standards of NM function monitoring in patients under anaesthesia  in ICU’s  in diagnosis of disease states.

2. The NEUROMUSCULAR STIMULATOR WITH ELECTROMYOGRAPHY instrument is designed with help of latest electronic technology enabling the objective and quantitative assessment and with facility by LCD screen to display test results instantly thereby improving patient care & safety.

3. The cost involved for developing the instrument is reasonably small.

Dated this 8th Day of June  2012

DR.M.V.GHORPADE
(REGISTRAR)
FOR KRISHNA INSTITUTE OF MEDICAL SCIENCES

To
The Controller of Patents 
The patent office 
At Mumbai – 400 037

10.ABSTRACT OF THE INVENTION

The NEUROMUSCULAR STIMULATOR WITH ELECTROMYOGRAPHY is designed to monitor NM function more accurately  objectively and with ready digital readings on LCD display as Test Results  improving greatly the convenience of treating doctor as well as markedly improve patient services  adding safety and care. It will find usefulness in many other areas of medical  paramedical fields for teaching  monitoring  diagnostic and therapeutic purposes.

DR.M.V.GHORPADE
(REGISTRAR)
FOR KRISHNA INSTITUTE OF MEDICAL SCIENCES