System and method for detection of respiration patterns via integration of intracardiac electrogram signals

• US 7,404,799 B1
• Filed: 04/05/2005
• Issued: 07/29/2008
• Est. Priority Date: 04/05/2005
• Status: Active Grant

• Current Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Inventors: Koh, Steve
• Primary Examiner(s): Natnithithadha; Navin
• Application Number:
  US11/100,189
• Time in Patent Office: 1,211 Days
• Field of Search: 600/481, 600/483, 600/484, 600500-504, 600508-526, 600/529, 600/536, 600/547, 607 1- 38
• US Class Current: 600/484
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/318 Heart-related electrical modalities, e.g. electrocardiography [ECG]
• CPC Class Codes: A61B 5/411 Detecting or monitoring allergy or intolerance reactions to an allergenic agent or substance
• CPC Class Codes: A61B 5/4818 Sleep apnoea
• CPC Class Codes: A61B 5/7242 using integration
• CPC Class Codes: A61N 1/3601 of respiratory organs
• CPC Class Codes: A61N 1/365 controlled by a physiological parameter, e.g. heart potential evoked response A61N1/371
• CPC Class Codes: A61N 1/37258 Alerting the patient

Abstract

Techniques are provided for tracking patient respiration based upon intracardiac electrogram signals or other electrical cardiac signals. Briefly, respiration patterns are detected by integrating cardiac electrical signals corresponding to individual paced cardiac cycles. The integrals may be obtained between consecutive pairs of ventricular pacing pulses or between consecutive pairs of atrial pacing pulses. In either case, cyclical changes in the integrals of the individual cardiac cycles are tracked. The cyclical changes are representative of respiration. Once respiration patterns have been identified, episodes of abnormal respiration, such as apnea, hyperpnea, nocturnal asthma, or the like, may be detected and therapy automatically delivered.

Claims

1. A method for detecting respiration within a patient using an implantable medical device, the method comprising:

delivering pacing pulses to the heart;

sensing cardiac electrogram signals resulting from the pacing pulses using electrodes coupled to the heart;

identifying individual complete cardiac cycles within the cardiac electrogram signals;

determining values representative of integrals of cardiac electrogram signals corresponding to individual complete cardiac cycles; and

detecting patient respiration based on the values representative of the integrals of the cardiac electrogram signals.

2. The method of claim 1 wherein delivering pacing pulses is performed to deliver atrial pacing pulses and wherein determining the values is performed to determine values representative of integrals of cardiac electrogram signals between consecutive atrial pacing pulses.

3. The method of claim 1 wherein delivering pacing pulses is performed to deliver ventricular pacing pulses and wherein determining values representative of integrals is performed to determine values representative of integrals of cardiac electrogram signals between consecutive ventricular pacing pulses.

4. The method of claim 1 wherein determining the values representative of integrals is performed by calculating a numerical sum of the absolute values of a plurality of individual voltage samples of the cardiac electrogram signal corresponding to a complete cardiac cycle.

5. The method of claim 1 further comprising detecting an episode of abnormal respiration based on patient respiration.

6. The method of claim 5 wherein the episode of abnormal breathing is one or more of apnea, hypopnea, hyperpnea, asthma, Cheyne-Stokes Respiration (CSR).

7. The method of claim 6 further comprising delivering therapy upon detection of an episode of abnormal respiration.

8. The method of claim 7 wherein the implantable device is equipped to deliver overdrive pacing therapy to the heart of the patient and wherein delivering therapy comprises delivering overdrive pacing therapy to the heart of the patient in response to an episode of apnea.

9. The method of claim 8 wherein the overdrive pacing therapy is dynamic atrial overdrive (DAO) pacing therapy.

10. The method of claim 7 wherein an implantable drug pump is provided and wherein delivering therapy comprises selectively delivering drug therapy to the patient using the drug pump.

11. The method of claim 10 wherein delivering therapy upon detection of an episode of abnormal respiration includes changing cardiac stimulation parameters.

12. The method of claim 11 wherein changing cardiac stimulation parameters is performed to increase a pacing rate.

13. The method of claim 5 further comprising generating a warning signal in response to an episode of abnormal respiration.

14. The method of claim 13 wherein generating a warning signal comprises one or more of:

transmitting a signal to an external alarm device;

electrically stimulating selected muscles of the patient to cause the muscles to twitch using an implantable electrical stimulator;

or controlling an implantable device to vibrate.

15. The method of claim 1 further comprising recording diagnostic information representative of respiration.

16. A system for detecting respiration within a patient for use within an implantable medical device, the system comprising:

pacing circuitry operative to deliver pacing pulses to the heart of the patient;

sensing circuitry including electrodes coupled to the heart, operative to sense cardiac electrogram signals resulting from pacing pulses delivered by the pacing circuitry;

a cardiac cycle integration unit operative to determine values representative of integrals of cardiac electrogram signals corresponding to individual complete cardiac cycles defined by consecutive pacing pulses; and

a complete cardiac cycle integral-based respiration detector operative to detect patient respiration based on the values.

17. A system for detecting respiration within a patient for use within an implantable medical device, the system comprising:

means coupled to the heart for delivering pacing pulses to the heart;

means for sensing cardiac electrogram signals resulting from pacing pulses delivered to a heart;

means for determining values representative of the area of the cardiac electrogram signals corresponding to individual complete cardiac cycles defined by consecutive pacing pulses; and

means for detecting patient respiration based on the values.

18. The system of claim 17 and further comprising means for detecting an episode of abnormal respiration based on patient respiration.

19. The system of claim 18 wherein the episode of abnormal breathing is one or more of apnea, hypopnea, hyperpnea, asthma, Cheyne-Stokes Respiration (CSR).

20. The system of claim 18 further comprising means for delivering therapy upon detection of an episode of abnormal respiration.