Method and system for heart failure status evaluation based on a disordered breathing index

• US 8,696,589 B2
• Filed: 07/30/2010
• Issued: 04/15/2014
• Est. Priority Date: 12/01/2005
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Kwok, Jonathan T., Brockway, Marina, Lee, Kent, Ni, Quan, Pu, Yachuan, Stahmann, Jeffrey E., Zhang, Yi, Hartley, Jesse W.
• Primary Examiner(s): Kahelin, Michael
• Assistant Examiner(s): TOTH, KAREN E
• Application Number:
  US12/847,698
• Publication Number:
  US 20100298733A1
• Time in Patent Office: 1,355 Days
• Field of Search: 600529-543
• US Class Current: 600/529
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/0809 by impedance pneumography
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/091 Measuring volume of inspired or expired gases, e.g. to determine lung capacity
• CPC Class Codes: A61B 5/113 occurring during breathing
• CPC Class Codes: A61B 5/4818 Sleep apnoea
• CPC Class Codes: A61N 1/3627 for treating a mechanical deficiency of the heart, e.g. congestive heart failure or cardiomyopathy
• CPC Class Codes: A61N 1/36521 the parameter being derived from measurement of an electrical impedance
• CPC Class Codes: A61N 1/36535 controlled by body position or posture

Abstract

An evaluation of heart failure status is provided based on a disordered breathing index. Patient respiration is sensed and a respiration signal is generated. Disordered breathing episodes are detected based on the respiration signal. A disordered breathing index is determined based on the disordered breathing episodes. The disordered breathing index is trended and used to evaluate heart failure status. The disordered breathing index may be combined with additional information and/or may take into account patient activity, posture, sleep stage, or other patient information.

Claims

1. A system for providing a patient assessment, the system comprising:

a respiration sensor configured to generate a signal responsive to patient respiration; and

a disordered breathing detector coupled to the respiration sensor and configured to detect disordered breathing episodes based on the respiration signal and discriminate between central disordered breathing episodes and obstructive disordered breathing episodes based on speed of transition to hyperventilation during the disordered breathing episodes; and

an index processor configured to determine a ratio of the central disordered breathing episodes and the obstructive disordered breathing episodes and to determine a disordered breathing index using the ratio.

2. The system of claim 1, further comprising:

a trend processor configured to trend the disordered breathing index; and

a diagnostics unit configured to evaluate heart failure status based on the trend.

3. The system of claim 1, further comprising a rapid eye movement (REM) detector, wherein the index processor is configured to correlate the disordered breathing episodes with REM and non-REM sleep stages.

4. The system of claim 1, further comprising a posture sensor configure to provide an output indicative of tilt angle during the disordered breathing episodes, wherein the index processor is configured to determine the disordered breathing index including weighing the disordered breathing episodes based on tilt angle.

5. The system of claim 1, further comprising an activity sensor configured to generate a patient activity signal, wherein the index processor is configured to determine the disordered breathing index using the activity signal including applying different weights to disordered breathing episodes that occur during periods of low activity and disordered breathing episodes that occur during periods of high activity.

6. The system of claim 1, wherein the disordered breathing detector is configured to discriminate between the central disordered breathing episodes and the obstructive disordered breathing episodes based on hyperventilation portions of the respiration signal during the disordered breathing episodes.

7. The system of claim 1, further comprising a pressure sensor configured to generate a pressure signal, wherein the disordered breathing detector is configured to further discriminate between the central disordered breathing episodes and the obstructive disordered breathing episodes based on the pressure signal.

8. The system of claim 7, wherein the pressure sensor is configured to sense intrathoracic pressure, intracardiac pressure or intravascular pressure.