Detection of disordered breathing

• US 7,252,640 B2
• Filed: 12/04/2002
• Issued: 08/07/2007
• Est. Priority Date: 12/04/2002
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Kim, Jaeho, Hartley, Jesse W., Hatlestad, John D., Lee, Kent, Ni, Quan, Stahmann, Jeff E.
• Primary Examiner(s): Nasser; Robert L.
• Application Number:
  US10/309,770
• Publication Number:
  US 20040111040A1
• Time in Patent Office: 1,707 Days
• Field of Search: None
• US Class Current: 600/538
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/4806 Sleep evaluation A61B5/4821 takes precedence; devices for inducing sleep A61M21/02
• CPC Class Codes: A61B 5/4809 Sleep detection, i.e. determining whether a subject is asleep or not
• CPC Class Codes: A61B 5/4818 Sleep apnoea
• CPC Class Codes: A61B 5/7264 Classification of physiological signals or data, e.g. using neural networks, statistical classifiers, expert systems or fuzzy systems neural networks per se G06N3/00; expert systems per se G06N5/00
• CPC Class Codes: G16H 50/20 for computer-aided diagnosis, e.g. based on medical expert systems

Abstract

Devices and methods for detecting disordered breathing involve determining that the patient is asleep and sensing one or more signals associated with disordered breathing indicative of sleep-disordered breathing while the patient is asleep. Sleep-disordered breathing is detected using the sensed signals associated with disordered breathing. The sensed signals associated with disordered breathing may also be used to acquire a respiration pattern of one or more respiration cycles. Characteristics of the respiration pattern are determined. The respiration pattern is classified as a disordered breathing episode based on the characteristics of the respiration pattern. One or more processes involved in the detection of disordered breathing are performed using an implantable device.

Claims

1. A method for detecting sleep-disordered breathing of a patient, comprising:

detecting a respiration pattern of one or more respiration cycles;

determining characteristics of the respiration pattern, comprising;

determining one or more breath intervals and one or more tidal volume measurements of the one or more respiration cycles;

identifying an ongoing disordered breathing event as one or both of an apnea event and a hypopnea event based on comparison of the breath intervals to a breath interval threshold or the tidal volume measurements to a tidal volume threshold; and

determining a duration of the ongoing disordered breathing event; and

if the ongoing disordered breathing duration exceeds an event duration threshold, discriminating between apnea, hypopnea and mixed apnea and hypopnea based on the one or more characteristics of the respiration pattern, wherein at least one of detecting, determining and discriminating is performed at least in part implantably.

2. The method of claim 1, further comprising determining that the patient is asleep.

3. The method of claim 1, wherein at least two of detecting, determining, and classifying is performed at least in part implantably.

4. The method of claim 1, wherein at each of detecting, determining, and classifying is performed at least in part implantably.

5. The method of claim 1, wherein detecting a respiration pattern comprises measuring transthoracic impedance.

6. The method of claim 1, further comprising

establishing one or both of the breath interval threshold or the tidal volume threshold for a particular patient.

7. The method of claim 6, wherein establishing the breath interval threshold or the tidal volume threshold comprises modifying the breath interval threshold or the tidal volume threshold based on a condition of the patient.

8. The method of claim 7, wherein the condition of the patient comprises a cardiopulmonary disease condition.

9. The method of claim 6, further comprising adapting a sensitivity of the breath interval threshold or the tidal volume threshold based on one or more previously detected episodes of sleep-disordered breathing.

10. The method of claim 9, wherein adapting the sensitivity of the breath interval threshold or the tidal volume threshold comprises adapting the sensitivity based on a frequency of the one or more previously detected episodes of sleep-disordered breathing.

11. The method of claim 9, wherein adapting the sensitivity of the breath interval threshold or the tidal volume threshold comprises adapting the sensitivity based on a severity of the one or more previously detected episodes of sleep-disordered breathing.

12. The method of claim 9, wherein adapting the sensitivity of the breath interval threshold or the tidal volume threshold comprises adapting the sensitivity based on an interval between two or more previously detected episodes of sleep-disordered breathing.

13. The method of claim 1, wherein:

determining the one or more characteristics of the respiration pattern comprises determining a tidal volume of each respiration cycle and a duration of the respiration pattern; and

classifying the respiration pattern as sleep-disordered breathing comprises classifying the respiration pattern as hypopnea by comparing the tidal volume of each respiration cycle to a tidal volume index and comparing the duration of the respiration pattern to a predetermined duration threshold.

14. The method of claim 1, wherein:

determining the one or more characteristics of the respiration pattern comprises determining a breathing interval; and

classifying the respiration pattern as sleep-disordered breathing comprises classifying the respiration pattern as apnea by comparing the breathing interval to a predetermined duration threshold.

15. The method of claim 1, further comprising storing information about the sleep-disordered breathing.

16. The method of claim 1, further comprising displaying information about the sleep-disordered breathing.

17. A method for detecting disordered breathing of a patient, comprising:

detecting a respiration pattern of one or more respiration cycles;

determining characteristics of the respiration pattern, comprising;

determining one or more breath intervals and one or more tidal volume measurements of the one or more respiration cycles;

identifying an ongoing disordered breathing event as one or both of an apnea event and a hypopnea event based on a comparison of the breath intervals to a breath interval threshold or the tidal volume measurement to a tidal volume threshold; and

determining a duration of the ongoing disordered breathing event; and

if the ongoing disordered breathing duration exceeds an event duration threshold, discriminating between apnea, hypopnea and mixed apnea and hypopnea based on the one or more characteristics of the respiration pattern, wherein at least one of detecting, determining and discriminating is performed at least in part implantably.

18. The method of claim 17, wherein detecting the respiration pattern comprises detecting the respiration pattern while the patient is awake.

19. The method of claim 17, wherein detecting the respiration pattern comprises measuring transthoracic impedance.

20. The method of claim 17, further comprising

establishing one or both of the breath interval threshold and the tidal volume threshold for a particular patient.

21. The method of claim 20, further comprising adapting a sensitivity of the breath interval threshold or the tidal volume threshold based on one or more previously detected episodes of disordered breathing.

22. The method of claim 17, wherein classifying the respiration pattern as disordered breathing comprises classifying the respiration pattern as periodic breathing.

23. The method of claim 17, wherein classifying the respiration pattern as disordered breathing comprises classifying the respiration pattern as Cheyne-Stokes breathing.

24. A device for detecting sleep-disordered breathing of a patient, comprising:

a sensor system configured to detect a respiration pattern of one or more respiration cycles; and

a detector system coupled to the sensor system and configured to;

determine one or more breath intervals and one or more tidal volume measurements of the one or more respiration cycles;

identify an ongoing disordered breathing event as one or both of an apnea event and a hypopnea event based on comparison of the breath intervals to a breath interval threshold or the tidal volume measurements to a tidal volume threshold;

determine a duration of the ongoing disordered breathing event; and

if the ongoing disordered breathing duration exceeds an event duration threshold, discriminating between apnea, hypopnea and mixed apnea and hypopnea using the one or more characteristics of the respiration pattern, wherein at least one of the sensor system and the detector system uses an implantable component.

25. The device of claim 24, wherein each of the sensor system and the detector system uses an implantable component.

26. The device of claim 24, wherein the sensor system is configured to detect the respiration patterns by measuring transthoracic impedance.

27. The device of claim 24, wherein the detector system is configured to establish one or both of the breath interval threshold or the tidal volume threshold for a particular patient.

28. The device of claim 27, wherein the detector system is configured to modify the breath interval threshold or the tidal volume threshold based on a condition of the patient.

29. The device of claim 24, wherein the detector system is configured to adapt a sensitivity of the breath interval threshold or the tidal volume threshold based on one or more previously detected episodes of sleep-disordered breathing.

30. The device of claim 24, wherein the detector system is configured to determine a non-breathing interval.

31. The device of claim 30, wherein the detector system is configured to compare the non-breathing interval to a predetermined sleep apnea interval and classify the respiration pattern as sleep apnea based on the comparison.

32. The device of claim 30, wherein the detector system is configured to compare the non-breathing interval to a predetermined severe sleep apnea interval and classify the respiration pattern as severe sleep apnea based on the comparison.

33. The device of claim 24, wherein the detector system is configured to compare the tidal volume of each respiration cycle to a tidal volume threshold, compare the duration of the respiration pattern to a predetermined duration threshold, and classify the respiration pattern as hypopnea based on the comparison.

34. The device of claim 24, wherein the detector system is configured to determine the breath interval threshold or the tidal volume threshold of the respiration pattern.

35. The device of claim 34, wherein the detector system is configured to compare the breath interval or the tidal volume measurement of the respiration pattern to the breath interval threshold or the tidal volume threshold and classify the respiration pattern as sleep-disordered breathing based on the comparison.

36. The device of claim 24, wherein the detector system is configured to compare the breathing interval of each respiration cycle to a predetermined duration threshold and classify the respiration pattern as apnea based on the comparison.

37. A device for detecting disordered breathing of a patient, comprising:

a sensor system configured to detect a respiration pattern of one or more respiration cycles; and

a detector system coupled to the sensor system and configured to;

determine one or more breath intervals and one or more tidal volume measurements of the one or more respiration cycles;

identify an ongoing disordered breathing event as one or both of an apnea event and a hypopnea event based on comparison of the breath intervals to a breath interval threshold or the tidal volume measurements to a tidal volume threshold;

determine a duration of the ongoing disordered breathing event; and

if the ongoing disordered breathing duration exceeds an event duration threshold, discriminating between apnea, hypopnea and mixed apnea and hypopnea using the one or more characteristics of the respiration pattern, wherein at least one of the sensor system and the detector system uses an implantable component.

38. The device of claim 37, wherein the sensor system is configured to detect the respiration patterns by measuring transthoracic impedance.

39. The device of claim 37, wherein the detector is configured to establish a disordered breathing index, compare the one or more characteristics to the sleep-disordered breathing index, and classify the respiration patterns as disordered breathing based on the comparison.

40. The device of claim 39, wherein the detector system is configured to modify the breath interval threshold or the tidal volume threshold based on a condition of the patient.

41. The device of claim 39, wherein the detector system is configured to adapt a sensitivity of the breath interval threshold or the tidal volume threshold based on one or more previously detected episodes of disordered breathing.

42. A disordered breathing detection system, comprising:

means for detecting a respiration pattern of one or more respiration cycles;

means for determining characteristics of the respiration pattern, comprising;

means for determining one or more breath intervals and one or more tidal volume measurements of the one or more respiration cycles;

means for identifying an ongoing disordered breathing event as one or both of an apnea event and a hypopnea event based on comparison of the breath intervals to a breath interval threshold or the tidal volume measurements to a tidal volume threshold; and

means for determining a duration of the ongoing disordered breathing event; and

means for discriminating between apnea, hypopnea or mixed apnea and hypopnea respiration patterns based on the one or more characteristics of the respiration pattern if the ongoing disordered breathing duration exceeds an event duration threshold, wherein at least one of the means for detecting, means for determining and means for discriminating uses an implantable component.

43. The system of claim 42, wherein the means for detecting the respiration pattern comprises means for detecting the respiration pattern while the patient is awake.

44. The system of claim 42, wherein the means for detecting the respiration pattern comprises means for detecting the respiration pattern while the patient is asleep.