Method and System for the Monitoring of Respiratory Acitivity and for the Treatment of Breathing Disorders Such as Sleep Apnea

• US 20100016749A1
• Filed: 09/19/2007
• Published: 01/21/2010
• Est. Priority Date: 09/19/2006
• Status: Abandoned Application

• Current Assignee: 4491343 Canada Inc.
• Original Assignee: Victhom Human Bionics Inc. (Ergoresearch Ltd.)
• Inventors: Atsma, Willem, Kameli, Nader
• Application Number:
  US11/920,795
• Publication Number:
  US 20100016749A1
• Time in Patent Office: Days
• US Class Current: 600/529
• CPC Class Codes: A61B 5/0803 Recording apparatus specially adapted therefor
• CPC Class Codes: A61B 5/24 Detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof
• CPC Class Codes: A61B 5/316 Modalities, i.e. specific diagnostic methods
• CPC Class Codes: A61B 5/4035 Evaluating the autonomic nervous system
• CPC Class Codes: A61B 5/4519 Muscles A61B5/389, A61B5/224 take precedence
• CPC Class Codes: A61B 5/4818 Sleep apnoea
• CPC Class Codes: A61N 1/3601 of respiratory organs

Abstract

A method and system for sensing the vagus nerve in order to monitor respiratory activity, treating breathing disorders, such as, for example, sleep apnea and a generic bio-interfacing platform that may be adapted for either open-loop or closed-loop applications.

Claims

1. A method for monitoring the respiratory activity of a subject, comprising the steps of:

recording an electroneurogram signal from the vagus nerve of the subject;

amplifying the electroneurogram signal;

computing an amplitude envelope of the amplified electroneurogram signal;

applying a matched filter to the amplitude envelope; and

computing a time between successive peaks of the filtered amplitude envelope;

wherein the time between successive peaks is indicative of the respiratory activity of the subject.

3. A method according to claim 1, further comprising the step of displaying the time between successive peaks.

4. A method according to claim 1, wherein the electroneurogram signal is recorded from a portion of the vagus nerve located between the head and the pulmonary branches of the subject.

5. A method according to claim 1, wherein the electroneurogram signal is recorded from a portion of the vagus nerve located in the neck of the subject.

6. A method according to claim 1, wherein the amplitude envelope computing step includes includes the application of a low-pass filter.

7. A method according to claim 1, wherein the amplitude envelope computing step includes applying a filter selected from a group consisting of a matched filter, a simple averaging filter and a finite-impulse-response filter.

8. A method according to claim 1, wherein the amplitude envelope computing step includes includes applying a rectification and bin integration algorithm to the amplified electroneurogram signal.

9. A method according to claim 8, wherein the amplitude envelope computing step includes further includes applying a moving average filter to the amplified electroneurogram signal after the application of the rectification and bin integration algorithm.

10. A method according to claim 9, wherein the amplitude envelope computing step includes further includes optimizing the result of the moving average filter using the solution to the Wiener-Hopf equation.

11. A method according to claim 1, further comprising the steps of:

comparing the time between successive peaks with a sleep apnea event threshold;

reporting a sleep apnea event should the compared time between successive peaks be greater than the sleep apnea event threshold.

12. A method according to claim 11, wherein the apnea event threshold is set individually for each subject according to the normal respiration rate of the subject during sleep.

13. A method according to claim 11, wherein the apnea event threshold is set to about 10 seconds.

14. A method according to claim 11, wherein the reporting step includes triggering an airway opening stimulation.

15. A method according to claim 14, wherein the airway opening stimulation includes stimulation of the genioglossus muscle.

16. A method according to claim 14, wherein the airway opening stimulation includes stimulation of the hypoglossal nerve.

17. A method according to claim 14, wherein stimulation is applied to the phrenic nerve in order to maintain respiration.

2. A method for monitoring the respiratory activity of a subject, comprising the steps of:

recording an electroneurogram signal from the vagus nerve of the subject;

amplifying the electroneurogram signal;

computing an amplitude envelope of the amplified electroneurogram signal;

applying a matched filter to the amplitude envelope; and

computing a time between successive peaks of the filtered amplitude envelope;

wherein the time between successive peaks is indicative of the respiratory activity of the subject.

18. A method for maintaining airway patency of a subject through stimulation, comprising the steps of:

recording an electroneurogram signal from the vagus nerve of the subject;

amplifying the electroneurogram signal;

computing an amplitude envelope of the amplified electroneurogram signal;

applying a matched filter to the amplitude envelope;

detecting a positive peak in the filtered amplitude envelope;

waiting for a duration equal to a first offset value;

triggering an airway opening stimulation;

detecting a negative peak in the filtered amplitude envelope;

waiting for a duration equal to a second offset value; and

stopping the airway opening stimulation.

19. A method according to claim 18, wherein the first and second offset values are computed from a previously obtained respiratory rhythm.

20. A method according to claim 18, wherein the electroneurogram signal is recorded from a portion of the vagus nerve located between the head and the pulmonary branches of the subject.

21. A method according to claim 18, wherein the electroneurogram signal is recorded from a portion of the vagus nerve located in the neck of the subject.

22. A method according to claim 18, wherein the airway opening stimulation includes stimulation of the genioglossus muscle.

23. A method according to claim 18, wherein the airway opening stimulation includes stimulation of the hypoglossal nerve.

24. A method according to claim 18, wherein the amplitude envelope computing step includes the application of a low-pass filter.

25. A method according to claim 18, wherein the amplitude envelope computing step includes applying a filter selected from a group consisting of a matched filter, a simple averaging filter and a finite-impulse-response filter.

26. A method according to claim 18, wherein the amplitude envelope computing step includes applying a rectification and bin integration algorithm to the amplified electroneurogram signal.

27. A method according to claim 26, wherein the amplitude envelope computing step further includes applying a moving average filter to the amplified electroneurogram signal after the application of the rectification and bin integration algorithm.

28. A method according to claim 27, wherein the amplitude envelope computing step further includes optimizing the result of the moving average filter using the solution to the Wiener-Hopf equation.

29. A method for detecting hypopnea during the respiratory activity of a subject, comprising the steps of:

recording an electroneurogram signal from the vagus nerve of the subject;

amplifying the electroneurogram signal;

computing an amplitude envelope of the amplified electroneurogram signal;

applying a matched filter to the amplitude envelope;

computing a deviation of the signal resulting from the application of the matched filter to the amplitude envelope from a predictor, the predictor being based on previously obtained respiration activity;

reporting a hypopnea event should the deviation be greater than a hypopnea event threshold.

30. A method according to claim 29, wherein the deviation is an increase in amplitude.

31. A method according to claim 29, wherein the deviation is an increase in respiratory rhythm.

32. A method according to claim 29, wherein the electroneurogram signal is recorded from a portion of the vagus nerve located between the head and the pulmonary branches of the subject.

33. A method according to claim 29, wherein the electroneurogram signal is recorded from a portion of the vagus nerve located in the neck of the subject.

34. A system for monitoring the respiratory activity of a subject, comprising:

an electrode for detecting an electroneurogram signal from the vagus nerve of the subject;

a transceiver;

an implantable control unit operatively connected to to the electrode and the transceiver, the implantable control unit including;

a signal amplifier for amplifying the electroneurogram signal;

a rectifier for rectifying the amplified electroneurogram signal;

a monitoring and detection module for;

computing an amplitude envelope of the amplified electroneurogram signal;

applying a matched filter to the amplitude envelope; and

computing a time between successive peaks from filtered amplitude envelope; and

transmitting the computed time between successive peaks using the transceiver;

wherein the time between successive peaks is indicative of the respiratory activity of the subject.

35. A system according to claim 34, wherein the electrode includes a cuff electrode assembly adapted to surround part of the vagus nerve of the subject.

36. A system according to claim 35, wherein the cuff electrode assembly is provided with multiple chambers having electrodes therein.

37. A system according to claim 34, further comprising an external control unit including a transceiver for communication with the transceiver of the implantable control unit, the external control unit allowing interaction with the implantable control unit.

38. A system according to claim 37, wherein the external and implantable control units further include respective power interfaces for transferring power from the external control unit to the implantable control unit.

39. A system according to claim 34, wherein the implantable control unit further includes a power source.

40. A system according to claim 34, wherein the algorithm further includes:

comparing the time between successive peaks with a sleep apnea event threshold;

transmitting the occurrence of a sleep apnea event using the transceiver should the compared time between successive peaks be greater than the sleep apnea event threshold.

41. A system according to claim 40, wherein the apnea event threshold is set individually for each subject according to the normal respiration rate of the subject during sleep.

42. A system according to claim 40, further comprising a second electrode and wherein the algorithm further includes triggering an airway opening stimulation using the second electrode.

43. A system according to claim 42, wherein the second electrode is configured to be positioned in contact with the genioglossus muscle.

44. A system according to claim 42, wherein the second electrode is configured to be positioned in contact with the genioglossal nerve.

45. A system according to claim 42, wherein the second electrode is configured to be positioned in contact with the phrenic nerve.

46. A system for maintaining airway patency of a subject through stimulation, comprising:

a first electrode for recording an electroneurogram signal from the vagus nerve of the subject;

a second electrode;

a transceiver;

an implantable control unit operatively connected to the first and second electrodes and to the transceiver, the implantable control unit including;

a signal amplifier for amplifying the electroneurogram signal;

a rectifier for rectifying the amplified electroneurogram signal;

a monitoring and detection module for;

computing an amplitude envelope of the amplified electroneurogram signal;

applying a matched filter to the amplitude envelope;

detecting a positive peak in the filtered amplitude envelope;

waiting for a duration equal to a first offset value;

triggering an airway opening stimulation using the second electrode;

detecting a negative peak in the filtered amplitude envelope;

waiting for a duration equal to a second offset value; and

stopping the airway opening stimulation.

47. A system according to claim 46, wherein the first and second offset values are determined from an observed respiratory rhythm.

48. A system according to claim 46, wherein the airway opening stimulation includes stimulation of the genioglossus muscle.

49. A system according to claim 46, wherein the airway opening stimulation includes stimulation of the hypoglossal nerve.

50. A system according to claim 46, wherein the first electrode includes a cuff electrode assembly adapted to surround part of the vagus nerve of the subject.

51. A system according to claim 50, wherein the cuff electrode assembly is provided with multiple chambers having electrodes therein.

52. A system according to claim 46, further comprising an external control unit including a transceiver for communicating with the transceiver of the implantable control unit, the external control unit allowing interaction with the implantable control unit.

53. A system according to claim 52, wherein the external and implantable control units further include respective power interfaces for transferring power from the external control unit to the implantable control unit.

54. A system according to claim 46, wherein the implantable control unit further includes a power source.

55. A system for detecting hypopnea during the respiratory activity of a subject, comprising:

an electrode for recording an electroneurogram signal from the vagus nerve of the subject;

a transceiver;

an implantable control unit operatively connected to the electrode and the transceiver, the implantable control unit including;

a signal amplifier for amplifying the electroneurogram signal;

a rectifier for rectifying the amplified electroneurogram signal;

a monitoring and detection module for;

computing an amplitude envelope of the amplified electroneurogram signal;

applying a matched filter to the amplitude envelope;

computing a deviation of the signal resulting from the application of the matched filter to the amplitude envelope from a predictor, the predictor being based on previously obtained respiration activity;

transmitting the occurrence of a hypopnea event using the transceiver should the deviation be greater than a hypopnea event threshold.

56. A system according to claim 55, wherein the deviation is an increase in amplitude.

57. A system according to claim 55, wherein the deviation is an increase in respiratory rhythm.

58. A system according to claim 55, wherein the electrode includes a cuff electrode assembly adapted to surround part of the vagus nerve of the subject.

59. A system according to claim 58, wherein the cuff electrode assembly is provided with multiple chambers having electrodes therein.

60. A system according to claim 55, further comprising an external control unit including a transceiver for communicating with the transceiver of the implantable control unit, the external control unit allowing interaction with the implantable control unit.

61. A system according to claim 60, wherein the external and implantable control units further include respective power interfaces for transferring power from the external control unit to the implantable control unit.

62. A system according to claim 55, wherein the implantable control unit further includes a power source.

63. A method for monitoring the respiratory activity of a subject, comprising the steps of:

recording an electroneurogram signal from the vagus nerve of the subject;

amplifying the electroneurogram signal;

extracting respiratory activity information from the amplified signal; and

providing the extracted respiratory activity information.

64. A system for monitoring the respiratory activity of a subject, comprising:

an electrode for detecting an electroneurogram signal from the vagus nerve of the subject;

a transceiver;

an implantable control unit operatively connected to to the electrode and the transceiver, the implantable control unit including;

a signal amplifier for amplifying the electroneurogram signal;

a rectifier for rectifying the amplified electroneurogram signal;

a monitoring and detection module for;

extracting respiratory activity information from the amplified signal; and

transmitting the extracted respiratory activity information using the transceiver.