System and method for providing demand-based Cheyne-Stokes Respiration therapy using an implantable medical device

• US 7,357,775 B1
• Filed: 05/11/2004
• Issued: 04/15/2008
• Est. Priority Date: 05/11/2004
• Status: Active Grant

• Current Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Inventors: Koh, Steve
• Primary Examiner(s): Marmor, II; Charles A.
• Assistant Examiner(s): SAIDI, AZADEH
• Application Number:
  US10/844,023
• Time in Patent Office: 1,435 Days
• Field of Search: 600/536, 600/538, 600/529, 600/324, 600/323, 600/518, 600/509, 600/534, 600483-484, 600/531, 600/540, 600/543, 607/4, 607/11, 607/17, 607/42, 607/9, 607 5- 6, 607/14, 607 18- 20, 607/27, 607/123, 12820117-20118, 12820123-20124, 128/201.28, 128/203.14, 12820323-20324, 128/204.26, 128/204.18, 128/200.24
• US Class Current: 600/536
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/4818 Sleep apnoea
• CPC Class Codes: A61B 5/7239 using differentiation including higher order derivatives
• CPC Class Codes: A61N 1/3601 of respiratory organs
• CPC Class Codes: A61N 1/36514 controlled by a physiological quantity other than heart potential, e.g. blood pressure controlled by two or more physical parameters A61N1/36585
• CPC Class Codes: A61N 1/3702 Physiological parameters A61N1/365 takes precedence; evoked response A61N1/371
• CPC Class Codes: A61N 1/3956 Implantable devices for applying electric shocks to the heart, e.g. for cardioversion
• CPC Class Codes: G16H 20/30 relating to physical therapies or activities, e.g. physiotherapy, acupressure or exercising
• CPC Class Codes: G16H 50/20 for computer-aided diagnosis, e.g. based on medical expert systems

Abstract

Techniques are provided for controlling therapy delivered in response to Cheyne-Stokes Respiration (CSR) or other forms of periodic breathing in an effort to reduce the likelihood of unnecessary therapy directed toward preventing sleep interruption. Following each burst of respiration during CSR, a prediction is made as to whether the amount of respiration achieved during the burst will be sufficient to sustain the patient through a period of apnea until the next respiration burst. If not, aggressive therapy, such as aggressive diaphragmatic pacing, is delivered to improve respiration and prevent the imminent sleep interruption. If, however, the amount of respiration achieved during the burst appears to be sufficient to sustain the patient until the next respiration burst, then relatively mild therapy is instead delivered. Preferably, the prediction is made by comparing respiration achieved during a CSR respiration burst against the minimal respiration demands of the patient, evaluated based on respiration occurring shortly after the onset of sleep.

Claims

1. A method for controlling therapy delivered in response to periodic breathing within a patient using an implantable medical device, the method performed while the patient is asleep and comprising:

predicting whether the patient is likely to awaken due to an upcoming episode of reduced respiration occurring during periodic breathing; and

controlling delivery of therapy based on whether the patient is likely to awaken due to the upcoming episode of apnea.

2. The method of claim 1 wherein predicting whether the patient is likely to awaken due to an upcoming episode of reduced respiration occurring during periodic breathing comprises determining whether respiration demands of the patient are likely to be met during the upcoming episode of reduced respiration.

3. The method of claim 2 wherein the periodic breathing is Cheyne-Stokes Respiration involving frank apnea and wherein determining whether respiration demands of the patient are likely to be met comprises:

determining a threshold value representative of minimal respiration demands of the patient;

determining a value representative of actual respiration achieved within the patient during a respiration burst during periodic breathing; and

comparing the value representative of actual respiration against the threshold value to determine whether respiration demands of the patient are likely to be met.

4. The method of claim 3 wherein determining a threshold value representative of minimal respiration demands of the patient comprises:

determining a value representative of normal respiration demands of the patient during sleep; and

deriving the threshold value representative of minimal respiration demands from the value representative of normal respiration demands of the patient during sleep.

5. The method of claim 4 wherein determining a value representative of normal respiration demands of the patient during sleep comprises:

detecting the onset of sleep;

detecting actual respiration demands of the patient during an initial period of sleep; and

setting the value representative of normal respiration demands equal to the respiration demands of the patient detected during the initial period of sleep.

6. The method of claim 5 wherein detecting the onset of sleep is performed based on one or more of activity, activity variance, minute ventilation or blood chemistry levels.

7. The method of claim 5 wherein detecting actual respiration demands of the patient during an initial period of sleep is performed based on no more than the first fifteen minutes of sleep.

8. The method of claim 5 wherein detecting actual respiration demands of the patient during an initial period of sleep comprises:

detecting peak-to-peak respiration amplitudes for a plurality of respiration cycles during the initial period of sleep;

determining an average based on a summation of detected peak-to-peak respiration amplitudes; and

setting the actual respiration demands equal to the average obtained during the initial period of sleep.

9. The method of claim 8 wherein detecting peak-to-peak respiration amplitudes and determining an average based on the detected peak-to-peak respiration amplitudes is performed by:

accumulating peak-to-peak respiration amplitudes for five one-minute interval during the initial period of sleep; and

averaging the accumulated respiration amplitudes.

10. The method of claim 8 wherein detecting peak-to-peak respiration amplitudes is performed based on one or more of thoracic impedance values and minute ventilation values.

11. The method of claim 4 wherein deriving the threshold value representative of minimal respiration demands is performed by setting the threshold equal to the value representative of the normal respiration demands of the patient.

12. The method of claim 4 wherein deriving the threshold value representative of minimal respiration demands is performed by setting the threshold equal to a predetermined fraction of the value representative of the normal respiration demands of the patient.

13. The method of claim 3 wherein determining a value representative of actual respiration achieved within the patient during a respiration burst during CSR comprises accumulating peak-to-peak respiration amplitudes during the respiration burst.

14. The method of claim 13 wherein accumulating peak-to-peak respiration amplitudes during the respiration burst comprises:

detecting the onset of a crescendo phase of the respiration burst;

detecting the end of a decrescendo phase of the respiration burst; and

accumulating peak-to-peak respiration amplitudes from the onset of the crescendo phase to the end of the decrescendo phase.

15. The method of claim 13 wherein accumulating peak-to-peak respiration amplitudes during the respiration burst is performed based on one or more of thoracic impedance values and minute ventilation values.

16. The method of claim 3 wherein comparing the value representative of actual respiration against the threshold value to determine whether respiration demands of the patient are likely to be met comprises:

determining whether the value representative of actual respiration exceeds the threshold value;

if the value representative of actual respiration exceeds the threshold value, concluding that the respiration demands of the patient are likely to be met; and

if the value representative of actual respiration does not exceed the threshold value, concluding that the respiration demands of the patient are not likely to be met.

17. The method of claim 3 wherein the value representative of actual respiration is based on accumulated peak-to-peak respiration amplitudes over a single respiration burst during CSR and wherein the threshold value is based on accumulated peak-to-peak respiration amplitudes detected over a predetermined interval of time during an initial period of sleep.

18. The method of claim 3 wherein controlling delivery of therapy based on whether the patient is likely to awaken due to the upcoming episode of apnea is performed in an effort to prevent the patient from awakening during the upcoming episode of apnea.

19. The method of claim 18 wherein therapy is delivered only if the patient is likely to awaken during the upcoming episode of apnea.

20. The method of claim 18 wherein controlling delivery of therapy comprises:

delivering aggressive therapy if the patient is likely to awaken during the upcoming episode of apnea; and

delivering less aggressive therapy if the patient is not likely to awaken during the upcoming episode of apnea.

21. The method of claim 18 wherein therapy comprises delivering diaphragmatic pacing.

22. The method of claim 21 wherein a phrenic nerve stimulator is provided and wherein the diaphragmatic pacing is performed via electrical nerve stimulation of the phrenic nerves of the patient.

23. The method of claim 18 wherein therapy comprises overdrive pacing therapy applied to the heart of the patient.

24. The method of claim 23 wherein the overdrive pacing therapy is dynamic atrial overdrive (DAO) pacing therapy.

25. A system for controlling therapy delivered in response to periodic breathing within a patient using an implantable medical device, the system comprising:

a respiration-based sleep interruption prediction unit operative to predict whether the patient is likely to awaken due to an upcoming episode of reduced respiration occurring during periodic breathing; and

a demand-based therapy controller operative to selectively delivering therapy in an effort to prevent the patient from awakening during the upcoming episode of reduced respiration.

26. A system for controlling therapy delivered in response to periodic breathing within a patient using an implantable medical device, the system comprising:

means for predicting whether the patient is likely to awaken due to an upcoming episode of reduced respiration occurring during periodic breathing based on respiration demands of the patient; and

means for selectively delivering therapy in an effort to prevent the patient from awakening during the upcoming episode of reduced respiration.