METHOD AND APPARATUS FOR DETECTING RESPIRATORY DISTURBANCES

• US 20070167843A1
• Filed: 11/30/2006
• Published: 07/19/2007
• Est. Priority Date: 04/21/2003
• Status: Active Grant

• Current Assignee: H Markowitz, Luc Mongeon, Mark Erickson, Scott Davie, Steven Lu, Todd Sheldon, Yong Cho
• Original Assignee: H Markowitz, Luc Mongeon, Mark Erickson, Scott Davie, Steven Lu, Todd Sheldon, Yong Cho
• Inventors: Erickson, Mark, Cho, Yong, Sheldon, Todd, Markowitz, H., Lu, Steven, Davie, Scott, Mongeon, Luc
• Granted Patent: US 7,524,292 B2
• Time in Patent Office: Days
• US Class Current: 600/484
• 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 5/0215 by means inserted into the body catheters A61M25/00
• CPC Class Codes: A61B 5/0809 by impedance pneumography
• CPC Class Codes: A61B 5/1459 invasive, e.g. introduced into the body by a catheter A61B5/1464 takes precedence
• CPC Class Codes: A61B 5/318 Heart-related electrical modalities, e.g. electrocardiography [ECG]
• CPC Class Codes: A61B 5/4818 Sleep apnoea

Abstract

A system and method for monitoring respiration including sensing a signal that varies with respiration, deriving a respiration parameter, applying criteria for detecting a respiration disturbance and determining one or more respiratory disturbance metrics. The system preferably includes an implantable sensor with an associated implantable medical device such that chronic respiration monitoring is possible. The implantable medical device may execute methods for detecting and measuring respiratory disturbances or may store data to be transferred to an external device for detecting and measuring respiratory disturbances. Respiratory disturbance detection may trigger a responsive action such as physiological data storage, a change in therapy delivery, or a clinician warning. Assessment of cardiac function may be made based on metrics of respiratory disturbances or a measure of circulatory delay time following detection of a respiratory disturbance.

Claims

1. A device for detecting a respiratory disturbance, comprising:

means for sensing a physiological signal containing a frequency component or an amplitude component related to a common characteristic of at least two respiratory cycles;

means for deriving at least one respiratory parameter from the physiologic signal; and

means for detecting a respiratory disturbance event when the at least one respiratory parameter meets or exceeds a predetermined criteria threshold for detecting the respiratory disturbance.

2. A computer readable medium for storing a set of computer instructions for performing the following method:

instructions for sensing a physiological signal containing a frequency component or an amplitude component related to a common characteristic of at least two respiratory cycles;

instructions for deriving at least one respiratory parameter from the physiologic signal; and

instructions for detecting a respiratory disturbance event when the at least one respiratory parameter meets or exceeds a predetermined criteria threshold for detecting the respiratory disturbance.

3. A method according to claim 2, further including:

instructions for measuring the magnitude of a characteristic of the respiratory disturbance.

4. A method of claim 3, wherein a measure of the respiratory disturbance is at least a one of:

an apnea duration;

a hypopnea duration;

a hyperpnea duration; and

a periodic breathing cycle length.

5. A method according to claim 2, wherein the physiological signal is at least a one of:

a thoracic impedance;

an ECG signal;

an EGM signal;

a blood pressure signal;

an activity level measurement; and

an oxygen saturation measurement.

6. A method according to claim 2, wherein the respiratory disturbance comprises Kussmaul breathing.

7. A method according to claim 2, wherein the respiratory disturbance comprises a Cheyne-Stokes respiration event.

8. A method according to claim 2, wherein the respiratory disturbance comprises a sleep apnea event.

9. A method according to claim 2, further including a step of determining a circulatory delay time, comprising:

instructions for measuring an oxygen saturation; and

instructions for determining the time between the end of the respiratory disturbance and a subsequent minimum or a subsequent maximum oxygen saturation.

10. A method according to claim 9, further comprising:

instructions for determining an estimate of cardiac output based on the circulatory delay time.

11. A method according to claim 4, further including a step of instructions determining an estimate of cardiac function based on a metric of the respiratory disturbance.

12. A method according to claim 2, further comprising instructions for triggering the storage of a physiological data item upon the detection of the respiratory disturbance.

13. A method according to claim 2, further comprising instructions for triggering a therapy based at least in part upon detection of the respiratory disturbance.

14. A method according to claim 2, further comprising instructions for generating a warning to alert a clinician or a patient of the detection of the respiratory disturbance.

15. A method according to claim 10, further comprising instructions for determining a heart failure status of a patient in the event that the estimate of cardiac function is lower than a predetermined lower threshold.