Detection of disordered breathing

• US 7,766,842 B2
• Filed: 08/06/2007
• Issued: 08/03/2010
• 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: Ni, Quan, Kim, Jaeho, Hartley, Jesse W., Hatlestad, John D., Lee, Kent, Stahmann, Jeff E.
• Primary Examiner(s): Nasser; Robert L
• Application Number:
  US11/890,404
• Publication Number:
  US 20070282215A1
• Time in Patent Office: 1,093 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. An implantable medical device, comprising:

a respiration sensor configured to sense respiration of a patient and to generate a respiration signal;

an artifact sensor configured to sense a signal indicative of non-respiration related artifacts and to generate an artifact signal;

a disordered breathing detector configured to avoid erroneous detections of disordered breathing based on the artifact signal, the disordered breathing detector further configured to determine characteristics of the respiration signal, including at least determining one or both of tidal volumes and breath intervals from the respiration signal, to compare the characteristics of the respiration signal to one or more respiration metrics, and to detect the disordered breathing based on the comparison, the disordered breathing detector further configured to determine characteristics of the disordered breathing, including at least an apnea/hypopnea index;

a memory coupled to the disordered breathing detector and configured to store the characteristics of disordered breathing; and

a sleep detector configured to determine if the patient is awake or asleep based on a sleep threshold that is adjustable using another sleep-related signal.

2. The device of claim 1, wherein the sleep threshold is a patient activity threshold and the other sleep-related signal is a minute ventilation signal.

3. An implantable medical device, comprising:

a respiration sensor configured to sense respiration of a patient and to generate a respiration signal;

an artifact sensor configured to sense a signal indicative of non-respiration related artifacts and to generate an artifact signal;

a disordered breathing detector configured to avoid erroneous detections of disordered breathing based on the artifact signal, the disordered breathing detector further configured to determine characteristics of the respiration signal, including at least determining one or both of tidal volumes and breath intervals from the respiration signal, to compare the characteristics of the respiration signal to one or more respiration metrics, and to detect the disordered breathing based on the comparison, the disordered breathing detector further configured to determine characteristics of the disordered breathing, including at least an apnea/hypopnea index; and

a memory coupled to the disordered breathing detector and configured to store the characteristics of disordered breathing;

wherein the disordered breathing detector is configured to analyze the respiration pattern using the respiration metrics and detect mixed apnea and hypopnea or Cheyne Stokes respiration based on the analysis.

4. An implantable medical device, comprising:

a respiration sensor configured to sense respiration of a patient and to generate a respiration signal;

an artifact sensor configured to sense a signal indicative of non-respiration related artifacts and to generate an artifact signal;

a disordered breathing detector configured to avoid erroneous detections of disordered breathing based on the artifact signal, the disordered breathing detector further configured to determine characteristics of the respiration signal, including at least determining one or both of tidal volumes and breath intervals from the respiration signal, to compare the characteristics of the respiration signal to one or more respiration metrics, and to detect the disordered breathing based on the comparison, the disordered breathing detector further configured to determine characteristics of the disordered breathing, including at least an apnea/hypopnea index; and

a memory coupled to the disordered breathing detector and configured to store the characteristics of disordered breathing;

wherein the disordered breathing detector is configured to discriminate between apnea, hypopnea, and mixed apnea and hypopnea disordered breathing episodes.

5. An implantable medical device, comprising:

a respiration sensor configured to sense respiration of a patient and to generate a respiration signal;

an artifact sensor configured to sense a signal indicative of non-respiration related artifacts and to generate an artifact signal;

a disordered breathing detector configured to avoid erroneous detections of disordered breathing based on the artifact signal, the disordered breathing detector further configured to determine characteristics of the respiration signal, including at least determining one or both of tidal volumes and breath intervals from the respiration signal, to compare the characteristics of the respiration signal to one or more respiration metrics, and to detect the disordered breathing based on the comparison, the disordered breathing detector further configured to determine characteristics of the disordered breathing, including at least an apnea/hypopnea index; and

a memory coupled to the disordered breathing detector and configured to store the characteristics of disordered breathing;

wherein the disordered breathing detector is configured to determine a duration of an ongoing disordered breathing episode and to discriminate between apnea, hypopnea, and mixed apnea and hypopnea if the disordered breathing duration exceeds an event duration threshold.

6. An implantable medical system, comprising:

a respiration sensor configured to sense respiration of the patient and generate a respiration signal;

a sensor configured to generate a signal indicative of non-respiration related artifacts;

means for avoiding erroneous detections of disordered breathing based on the sensed artifact signal;

means for determining characteristics of the respiration signal, including at least determining one or both of tidal volumes and breath intervals of the respiration signal, comparing the characteristics of the respiration signal to one or more respiration metrics, detecting the disordered breathing based on the comparison, and determining characteristics of the disordered breathing, including at least an apnea/hypopnea index;

a memory configured to store the characteristics of the sleep disordered breathing in the implantable device; and

means for determining if the patient is asleep based on a sleep threshold that is adjustable using another sleep-related signal.

7. An implantable medical system, comprising:

a respiration sensor configured to sense respiration of the patient and generate a respiration signal;

a sensor configured to generate a signal indicative of non-respiration related artifacts;

means for avoiding erroneous detections of disordered breathing based on the sensed artifact signal;

means for determining characteristics of the respiration signal, including at least determining one or both of tidal volumes and breath intervals of the respiration signal, comparing the characteristics of the respiration signal to one or more respiration metrics, detecting the disordered breathing based on the comparison, and determining characteristics of the disordered breathing, including at least an apnea/hypopnea index;

a memory configured to store the characteristics of the sleep disordered breathing in the implantable device; and

means for discriminating between apnea, hypopnea, and mixed apnea and hypopnea disordered breathing episodes.

8. An implantable medical system, comprising:

a respiration sensor configured to sense respiration of the patient and generate a respiration signal;

a sensor configured to generate a signal indicative of non-respiration related artifacts;

means for avoiding erroneous detections of disordered breathing based on the sensed artifact signal;

means for determining characteristics of the respiration signal, including at least determining one or both of tidal volumes and breath intervals of the respiration signal, comparing the characteristics of the respiration signal to one or more respiration metrics, detecting the disordered breathing based on the comparison, and determining characteristics of the disordered breathing, including at least an apnea/hypopnea index;

a memory configured to store the characteristics of the sleep disordered breathing in the implantable device;

means for determining a duration of the disordered breathing; and

means for discriminating between apnea, hypopnea, and mixed apnea and hypopnea if the disordered breathing duration exceeds an event duration threshold.

9. An implantable medical system, comprising:

a respiration sensor configured to sense respiration of the patient and generate a respiration signal;

a sensor configured to generate a signal indicative of non-respiration related artifacts;

means for avoiding erroneous detections of disordered breathing based on the sensed artifact signal;

means for determining characteristics of the respiration signal, including at least determining one or both of tidal volumes and breath intervals of the respiration signal, comparing the characteristics of the respiration signal to one or more respiration metrics, detecting the disordered breathing based on the comparison, and determining characteristics of the disordered breathing, including at least an apnea/hypopnea index;

a memory configured to store the characteristics of the sleep disordered breathing in the implantable device; and

sleep detection means for detecting sleep based on a plurality of sleep-related signals and at least a first sleep threshold, the sleep detection means providing a sleep indication to the means for determining characteristics of the respiration signal.

10. The system of claim 9, wherein the sleep detection means compares a first signal value for one of the sleep-related signals to the first sleep threshold, and adjusts the first sleep threshold based on another of the sleep-related signals.

11. An implantable medical device, comprising:

a respiration sensor configured to sense respiration of a patient and to generate a respiration signal;

an artifact sensor configured to sense a signal indicative of non-respiration related artifacts and to generate an artifact signal;

a disordered breathing detector configured to avoid erroneous detections of disordered breathing based on the artifact signal, the disordered breathing detector further configured to determine characteristics of the respiration signal, including at least determining one or both of tidal volumes and breath intervals from the respiration signal, to compare the characteristics of the respiration signal to one or more respiration metrics, and to detect the disordered breathing based on the comparison, the disordered breathing detector further configured to determine characteristics of the disordered breathing, including at least an apnea/hypopnea index;

a memory coupled to the disordered breathing detector and configured to store the characteristics of disordered breathing; and

a sleep detector configured to determine the patient'"'"'s sleep status based on a plurality of sleep-related signals and at least a first sleep threshold, the sleep detector providing the determined sleep status to the disordered breathing detector.

12. The device of claim 11, wherein the sleep detector is configured to compare a first signal value for one of the sleep-related signals to the first sleep threshold, and wherein the sleep detector is further configured to adjust the first sleep threshold based on another of the sleep-related signals.

13. The device of claim 12, wherein the plurality of sleep-related signals comprise an accelerometer signal and the respiration signal.