Detection of disordered breathing

• US 8,475,388 B2
• Filed: 07/30/2010
• Issued: 07/02/2013
• Est. Priority Date: 12/04/2002
• Status: Expired due to Fees

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Ni, Quan, Hatlestad, John D., Hartley, Jesse W., Stahmann, Jeffrey E., Kim, Jaeho, Lee, Kent
• Primary Examiner(s): Kahelin, Michael
• Assistant Examiner(s): ALTER, MITCHELL E
• Application Number:
  US12/847,711
• Publication Number:
  US 20100324438A1
• Time in Patent Office: 1,068 Days
• Field of Search: None
• US Class Current: 600/529
• 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 of operating a medical device, comprising:

sensing respiration of a patient and generating a respiration signal;

determining respiration signal characteristics from the respiration signal;

comparing the respiration characteristics to respiration threshold values;

sensing non-respiration related artifacts and generating an artifact signal;

sensing two or more sleep related signals;

comparing at least one of the sensed sleep related signals to a first sleep threshold, the first sleep threshold adjusted by another of the one or more sensed sleep related signals;

determining a sleep status of the patient based at least in part on the sleep threshold comparison;

detecting disordered breathing including discriminating between apnea, hypopnea, and episodes of mixed apnea and hypopnea, using a processor, based on the sleep status and comparing the respiration signal characteristics to the respiration threshold values;

reducing erroneous detection of the disordered breathing based on the artifact signal; and

storing historical data related to the disordered breathing in memory of the medical device.

2. The method of claim 1, wherein the sleep related signals comprise an accelerometer signal and the respiration signal.

3. The method of claim 1, wherein detecting the disordered breathing comprises detecting Chine-Stokes respiration.

4. The method of claim 1, wherein the non-respiration related artifacts comprise one or both of motion and posture related artifacts.

5. The method of claim 1, wherein the first sleep threshold is a patient activity threshold and the first sleep threshold is adjusted using a minute ventilation signal.

6. The method of claim 1, wherein storing the historical data related to the disordered breathing comprises storing one or more of a duration, severity, and frequency of the disordered breathing episodes.

7. The method of claim 1, wherein storing the historical data related to the disordered breathing comprises storing respiratory signals of the disordered breathing episode.

8. A method of operating a medical device, comprising:

sensing respiration of a patient and generating a respiration signal;

determining tidal volumes and breath intervals from the respiration signal;

comparing the tidal volumes and the breath intervals to respiration indices, including comparing the tidal volumes to a hypopnea index and comparing the breath intervals to an apnea index;

sensing non-respiration related artifacts and generating an artifact signal;

sensing one or more sleep related signals;

comparing at least one sleep related signal to a first sleep threshold;

determining a sleep status of the patient based at least in part on comparison of the sleep related signal to the first sleep threshold;

detecting disordered breathing based on the sleep status and on comparing the tidal volumes and the breath intervals to the hypopnea and apnea indices; and

reducing erroneous detection of the disordered breathing based on the artifact signal, wherein detecting the disordered breathing is performed implantable within the medical device.

9. The method of claim 8, wherein determining the sleep status of the patient comprises:

comparing a first sleep related signal to the first threshold; and

modifying the first sleep threshold using another of the sleep related signals.

10. The method of claim 8, further comprising storing one or more of a duration, severity, and frequency of the disordered breathing episodes in a memory of the medical device.

11. The method of claim 8, wherein the respiration signal comprises a transthoracic impedance signal.

12. The method of claim 8, further comprising generating an output signal, the output signal including one or both of an indication that the disordered breathing has been detected and data providing one or both of severity and duration of the disordered breathing.

13. The method of claim 8, wherein detecting the disordered breathing comprises detecting periods of shallow breathing.

14. The method of claim 8, wherein detecting the disordered breathing comprises detecting Cheyne-Stokes respiration.

15. A method of operating a medical device, comprising:

sensing respiration of a patient and generating a respiration signal;

determining characteristics of the respiration signal;

comparing the respiration signal characteristics to hypopnea and apnea indices;

sensing non-respiration related artifacts and generating an artifact signal;

discriminating between apnea, hypopnea, and mixed apnea and hypopnea disordered breathing episodes based on comparing the respiration signal characteristics to the hypopnea and apnea indices; and

reducing erroneous detection of the disordered breathing based on the artifact signal, wherein discriminating between the apnea, hypopnea, and mixed apnea and hypopnea is performed implantably in the medical device.

16. The method of claim 15, further comprising storing historical data related to the disordered breathing episodes including storing one or both of a severity and a duration of the disordered breathing episodes.

17. The method of claim 15, wherein detecting the disordered breathing comprises detecting rhythmic increases and decreases in tidal volume.

18. The method of claim 15, further comprising expressing one or more of the respiration signal characteristics as a median value.