Neural event detection

• US 8,343,065 B2
• Filed: 08/16/2010
• Issued: 01/01/2013
• Est. Priority Date: 10/18/2007
• Status: Active Grant

• Current Assignee: Innovative Surgical Solutions, LLC (Johnson & Johnson)
• Original Assignee: Innovative Surgical Solutions, LLC (Johnson & Johnson)
• Inventors: Bartol, Stephen, Wybo, Christopher
• Primary Examiner(s): Dougherty, Sean P
• Assistant Examiner(s): Stout, Michael C
• Application Number:
  US12/857,151
• Publication Number:
  US 20110230783A1
• Time in Patent Office: 869 Days
• Field of Search: 600/300, 600/301, 600/554, 600/587, 600/595
• US Class Current: 600/554
• CPC Class Codes: A61B 2505/05 Surgical care
• CPC Class Codes: A61B 2560/0412 Low-profile patch shaped housings
• CPC Class Codes: A61B 5/1104 induced by stimuli or drugs; A61B5/1102 takes precedence; investigating medicinal preparations G01N33/15
• CPC Class Codes: A61B 5/1107 Measuring contraction of parts of the body, e.g. organ, muscle apparatus for measuring work or force in general G01L
• CPC Class Codes: A61B 5/389 Electromyography [EMG]
• CPC Class Codes: A61B 5/4029 for evaluating the peripheral nervous systems A61B5/24 takes precedence
• CPC Class Codes: A61B 5/4827 assessing touch sensitivity, e.g. for evaluation of pain threshold
• CPC Class Codes: A61B 5/4893 Nerves
• CPC Class Codes: A61B 5/6828 Leg
• CPC Class Codes: A61B 5/6843 Monitoring or controlling sensor contact pressure
• CPC Class Codes: A61B 5/7217 of noise originating from a therapeutic or surgical apparatus, e.g. from a pacemaker

Abstract

A method of detecting an induced muscle response includes monitoring a mechanical parameter of a muscle; computing an amount of muscle jerk from the monitored parameter; comparing the computed muscle jerk to a jerk threshold; and identifying the occurrence of an induced muscle response if the computed muscle jerk exceeds the threshold.

Claims

1. A method of detecting an induced muscle response comprising:

monitoring a mechanomyographic (MMG) response of a muscle using a mechanical sensor in mechanical communication with the muscle, the MMG response being attributable to a depolarization of a nerve innervating the muscle, the depolarization being in response to a provided electrical stimulus;

computing a time derivative of acceleration from the monitored MMG response;

comparing the computed time derivative of acceleration to a threshold; and

identifying the occurrence of an induced muscle response if the computed time derivative of acceleration exceeds the threshold.

2. The method of claim 1, wherein monitoring the MMG response of the muscle comprises receiving a signal from the mechanical sensor, the signal corresponding to a sensed acceleration.

3. The method of claim 2, further comprising:

comparing the sensed acceleration to an acceleration threshold; and

providing an alert if an induced muscle response is detected and the sensed acceleration exceeds the acceleration threshold.

4. The method of claim 3, wherein the acceleration threshold includes a recurring event threshold and a singular event threshold;

and wherein the recurring event threshold is lower than the singular event threshold.

5. The method of claim 1, further comprising receiving an indication of an amplitude of the provided electrical stimulus, wherein the electrical stimulus is provided by an invasive stimulator;

and

determining a distance between the invasive stimulator and the nerve using the amplitude of the provided electrical stimulus and a magnitude of acceleration of the MMG response.

6. The method of claim 3, wherein the alert includes a visual alert.

7. The method of claim 3, wherein the alert includes an audible alert.

8. The method of claim 2, wherein the threshold is an increasing function of the sensed peak acceleration.

9. The method of claim 1, further comprising correlating the occurrence of an induced muscle response with the application of a stimulus.

10. The method of claim 1, further comprising monitoring an electrical parameter of the muscle using a plurality of electrodes in electrical communication with the muscle.

11. A method of detecting an induced muscle response using a sensing device comprising:

providing an electrical stimulus;

monitoring an acceleration from a mechanical sensor associated with the sensing device;

computing a time derivative of acceleration from the monitored acceleration;

comparing the computed time derivative of acceleration to a threshold;

identifying the occurrence of an induced mechanomyographic (MMG) muscle response if the computed time derivative of acceleration exceeds the threshold, and

wherein the induced muscle response is in response to the provided electrical stimulus.

12. The method of claim 11, further comprising electrically determining if the sensing device is in contact with the subject.

13. The method of claim 12, wherein the step of electrically determining contact includes:

monitoring a capacitance between a plurality of electrodes disposed on the sensing device; and

comparing the monitored capacitance to a threshold.

14. The method of claim 12, wherein the step of electrically determining contact includes:

monitoring an electric field between a plurality of electrodes disposed on the sensing device; and

comparing the monitored electric field to a threshold.

15. The method of claim 12, wherein the step of electrically determining contact includes:

monitoring a respective voltage between a plurality of electrodes disposed on the sensing device; and

comparing the voltage to a threshold.

16. The method of claim 12, further comprising providing an alert if the sensing device is not in contact with the subject.

17. The method of claim 11, further comprising:

comparing the sensed acceleration to an acceleration threshold; and

providing an alert if an induced muscle response is detected and the sensed acceleration exceeds the acceleration threshold.

18. The method of claim 17, wherein the acceleration threshold includes a recurring event threshold and a singular event threshold;

and wherein the recurring event threshold is lower than the singular event threshold.

19. The method of claim 11, further comprising:

receiving an indication of the amplitude of the provided electrical stimulus, wherein the electrical stimulus is provided by an invasive stimulator; and

determining a distance between the invasive stimulator and a nerve innervating the muscle using the amplitude of the provided electrical stimulus and a magnitude of the monitored acceleration.

20. The method of claim 11, wherein the threshold is an increasing function of the sensed peak acceleration.

21. The method of claim 11, further comprising correlating the occurrence of the induced MMG muscle response with the application of a stimulus.