Neuromuscular monitoring using phonomyography

• US 7,236,832 B2
• Filed: 12/08/2003
• Issued: 06/26/2007
• Est. Priority Date: 12/09/2002
• Status: Expired due to Fees

• Current Assignee: Corporation De L'Ecole Polytechnique De Montreal, Universite De Montreal, L', Val-Chum Societe EN Commandite
• Original Assignee: Corporation De L'Ecole Polytechnique De Montreal, The University of Montreal, Val-Chum Societe EN Commandite
• Inventors: Babin, Denis, Trager, Guillaume, Mathieu, Pierre A., Hemmerling, Thomas, Guardo, Robert, Bou-Phon, Chang, Donati, Francois
• Primary Examiner(s): MANUEL, GEORGE C
• Application Number:
  US10/730,811
• Publication Number:
  US 20040254617A1
• Time in Patent Office: 1,296 Days
• Field of Search: 607/48, 607/49, 600485-499
• US Class Current: 607/48
• CPC Class Codes: A61B 2560/0443 Modular apparatus
• CPC Class Codes: A61B 5/4821 Determining level or depth of anaesthesia A61B5/1106 takes precedence
• CPC Class Codes: A61B 5/7217 of noise originating from a therapeutic or surgical apparatus, e.g. from a pacemaker
• CPC Class Codes: A61B 7/006 Detecting skeletal, cartilage or muscle noise A61B7/003 and A61B7/008 take precedence

Abstract

A neuromuscular monitoring system comprises at least one neurostimulator to apply muscle-activating stimulation signals to a patient'"'"'s body via at least one electrode, and at least one pressure waveform sensor to detect pressure waveform signals produced by a patient'"'"'s muscle in response to the applied stimulation signals. The detected pressure waveform signals are processed and data related to these detected pressure waveform signals are displayed. A method for neuromuscular monitoring using pressure waveform sensors is also described.

Claims

1. A system using phonomyography for monitoring relaxation of a given muscle of a living subject, comprising:

means for applying muscle-activating stimulation signals to the living subject'"'"'s body via at least one electrode to stimulate the given muscle of the living subject;

means for sensing pressure waveform signals produced by the given muscle of the living subject in response to the applied stimulation signals;

means for processing the sensed pressure waveform signals to produce data indicative of a level of relaxation of the given muscle of the living subject; and

means for displaying the data indicative of the level of relaxation of the given muscle of the living subject from the processing means.

2. A system using phonomyography for monitoring relaxation of a given muscle of a living subject, comprising:

at least one neurostimulator to apply muscle-activating stimulation signals to the living subject'"'"'s body via at least one electrode to stimulate the given muscle of the living subject;

at least one pressure waveform sensor to detect pressure waveform signals produced by the given muscle of the living subject in response to the applied stimulation signals;

a processor of the detected pressure waveform signals to produce data indicative of a level of relaxation of the given muscle of the living subject; and

a display of the data indicative of the level of relaxation of the given muscle of the living subject from the processor.

3. The system of claim 2, wherein the data displayed through the display is selected from the group consisting of:

raw pressure waveform signals detected through said at least one pressure waveform sensor, amplitudes of the pressure waveform signals, and ratios of said amplitudes.

4. The system of claim 2, further comprising an amplifier for amplifying the pressure waveform signals detected by said at least one pressure waveform sensor.

5. The system of claim 2, comprising a controller connected to said at least one neurostimulator and to said at least one pressure waveform sensor, said controller incorporating the processor and display.

6. The system of claim 5, wherein the controller includes a laptop computer.

7. The system of claim 5, wherein said controller includes a pocket computer.

8. The system of claim 2, wherein said at least one neurostimulator includes a plurality of neurostimulators respectively associated to different muscles of the living subject.

9. The system of claim 2, wherein said at least one pressure waveform sensor includes a plurality of pressure waveform sensors respectively associated to different muscles of the living subject.

10. The system of claim 2, wherein said at least one pressure waveform sensor has a detection frequency bandwidth ranging from about 2 Hz to about 10 Hz.

11. The system of claim 10, wherein said at least one pressure waveform sensor comprises at least one microphone.

12. The system of claim 2, wherein the muscle-activating stimulation signals comprises single stimulation signals.

13. A neuromuscular monitoring system using phonomyography, comprising:

at least one neurostimulator to apply muscle-activating stimulation signals to a patients body via at least one electrode;

at least one pressure waveform sensor to detect pressure waveform signals produced by a patient'"'"'s muscle in response to the applied stimulation signals; and

a controller connected to said at least one neurostimulator and to said at least one pressure waveform sensor, said controller including a processor of the detected pressure waveform signals and a display of data, from the processor, related to the detected pressure waveform signals;

wherein the controller is so configured as to;

before the administration of a relaxant to the patient;

apply a predetermined muscle-activating stimulation signal to the patient'"'"'s body through said at least one neurostimulator and via said at least one electrode;

sample the pressure waveform signal detected by said at least one pressure waveform sensor in response to the applied predetermined stimulation signal; and

measure a reference amplitude (A_ref) of the sampled signal; and

after a relaxant has been administered to the patient;

apply the predetermined muscle-activating stimulation signal through said at least one neurostimulator and via said at least one electrode;

sample the pressure waveform signal detected by said at least one pressure waveform sensor in response to the applied predetermined stimulation signal;

measure an amplitude (A) of the response signal;

calculate a ratio A/A_ref; and

display the calculated ratio.

14. A neuromuscular monitoring system using phonomyography, comprising:

at least one neurostimulator to apply muscle-activating stimulation signals to a patient'"'"'s body via at least one electrode;

at least one pressure waveform sensor to detect pressure waveform signals produced by a patient'"'"'s muscle in response to the applied stimulation signals; and

a processor of the detected pressure waveform signals and a display of data, from the processor, related to the detected pressure waveform signals;

wherein the muscle-activating stimulation signals comprise train-of-four twitches.

15. A neuromuscular monitoring system using phonomyography, comprising:

at least one neurostimulator to apply muscle-activating stimulation signals to a patient'"'"'s body via at least one electrode;

at least one pressure waveform sensor to detect pressure waveform signals produced by a patient'"'"'s muscle in response to the applied stimulation signals; and

a controller connected to said at least one neurostimulator and to said at least one pressure waveform sensor, said controller including a processor of the detected pressure waveform signals and a display of data, from the processor, related to the detected pressure waveform signals;

wherein the muscle-activating stimulation signals comprise train-of-four twitches, and wherein the controller is so configured as to;

measure a peak-to-peak amplitude of a pressure waveform signal detected by said at least one pressure waveform sensor in response to a first pulse of the train-of-four (T1);

measure a peak-to-peak amplitude of a pressure waveform signal detected by said at least one pressure waveform sensor in response a fourth pulse of the train-of-four (T4);

calculate a ratio T4/T1; and

display the calculated ratio.

16. A neuromuscular monitoring method using phonomyography, comprising:

providing at least one pressure waveform sensor;

positioning said at least one pressure waveform sensor at a predetermined position of a patient'"'"'s body;

providing at least one electrode;

positioning said at least one electrode at a predetermined position of the patient'"'"'s body;

applying a muscle-activating stimulation signal to the patient'"'"'s body via said at least one electrode;

sampling a pressure waveform signal detected by said at least one pressure waveform sensor in response to the applied muscle-activating stimulation signal;

measuring a reference amplitude (A_ref) of the sampled signal;

after a relaxant has been administered;

applying a subsequent muscle-activating stimulation signal to the patient'"'"'s body via said at least one electrode;

sampling a subsequent pressure waveform signal detected by said at least one pressure waveform sensor in response to the subsequent muscle-activating stimulation signal;

measuring an amplitude (A) of the subsequent pressure waveform signal;

calculating a ratio A/A_ref; and

displaying the calculated ratio.

17. The neuromuscular monitoring method of claim 16, wherein applying a muscle-activating stimulation signal comprises applying a single pulse stimulation signal.

18. The neuromuscular monitoring method of claim 16, wherein measuring an amplitude comprises measuring a peak-to-peak amplitude.

19. A method using phonomyography for monitoring relaxation of a muscle of a living subject, comprising:

providing at least one pressure waveform sensor;

positioning said at least one pressure waveform sensor at a first predetermined position of the living subject'"'"'s body;

providing at least one electrode;

positioning the at least one electrode at a predetermined second position of the living subject'"'"'s body;

applying muscle-activating stimulation signals to the living subject'"'"'s body via said at least one electrode to stimulate the given muscle of the living subject;

sampling pressure waveform signals detected by said at least one pressure waveform sensor and produced by the given muscle of the living subject in response to the applied muscle-activating stimulation signals;

processing the sampled detected pressure waveform signals to produce data indicative of a level of relaxation of the given muscle of the living subject; and

displaying the data indicative of the level of relaxation of the given muscle of the living subject from the act of processing.

20. The method of claim 19, wherein:

processing the sampled detected pressure waveform signals comprises measuring amplitudes of the detected pressure waveform signals; and

displaying data comprises displaying the detected pressure waveform signals and the measured amplitudes.

21. A neuromuscular monitoring method using phonomyography, comprising:

providing at least one pressure waveform sensor;

positioning said at least one pressure waveform sensor at a predetermined position of a patient'"'"'s body;

providing at least one electrode;

positioning the at least one electrode at a predetermined position of the patient'"'"'s body;

applying muscle-activating stimulation signals to the patient'"'"'s body via said at least one electrode;

sampling pressure waveform signals detected by said at least one pressure waveform sensor in response to the applied muscle-activating stimulation signals;

processing the detected pressure waveform signals; and

displaying data, from the act of processing, related to the detected pressure waveform signals;

wherein applying muscle-activating stimulation signals comprises applying train-of-four twitches.

22. A neuromuscular monitoring method using phonomyography, comprising:

providing at least one pressure waveform sensor;

positioning said at least one pressure waveform sensor at a predetermined position of a patient'"'"'s body;

providing, at least one electrode;

positioning the at least one electrode at a predetermined position of the patient'"'"'s body;

applying muscle-activating stimulation signals to the patient'"'"'s body via said at least one electrode;

sampling pressure waveform signals detected by said at least one pressure waveform sensor in response to the applied muscle-activating stimulation signals;

processing the sampled detected pressure waveform signals; and

displaying data, from the act of processing, related to the detected pressure waveform signals;

wherein;

processing the sampled detected pressure waveform signals comprises measuring amplitudes of the detected pressure waveform signals; and

displaying data comprises displaying the detected pressure waveform signals and the measured amplitudes; and

wherein applying muscle-activating stimulation signals comprises applying train-of-four twitches, and wherein measuring amplitudes of the detected pressure waveform signals comprises;

measuring a peak-to-peak amplitude of the pressure waveform signal detected by said at least one pressure waveform sensor in response to a first pulse of each train-of-four (T1);

measuring a peak-to-peak amplitude of the pressure waveform signal detected by said at least one pressure waveform sensor in response to a fourth pulse of the same train-of-four (T4); and

calculating a ratio T4/T1.

23. The neuromuscular monitoring method of claim 22, wherein displaying the measured amplitudes comprises displaying the T4/T1 calculated ratio.