Method and apparatus for assessing patient well-being

• US 6,021,351 A
• Filed: 06/25/1999
• Issued: 02/01/2000
• Est. Priority Date: 05/11/1998
• Status: Expired due to Term

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Spinelli, Julio C., Kadhiresan, V. A.
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US09/344,668
• Time in Patent Office: 221 Days
• Field of Search: 600/910, 607/19, 607/27, 607/30
• US Class Current: 607/19
• 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 1/3702 Physiological parameters A61N1/365 takes precedence; evoked response A61N1/371

Abstract

An apparatus and method for assessing the status of well-being of patients being treated for CHF using cardiac pacing as a therapy. By sampling the output from an activity sensor or the like, and by noting the frequency with which the averaged rectified sensor output exceeds a preset threshold following changes in the pacing mode, the efficacy of the new mode compared to the previous one can be evaluated.

Claims

1. Apparatus for assessing the well-being of a patient in whom a cardiac pacemaker is implanted to assess the efficacy of a given pacing therapy, comprising:

(a) sensor means for detecting a physiologic parameter of a patient on or in whom the sensor means is affixed and for producing electrical signals that vary with the patient'"'"'s level of exertion;

(b) signal processing means coupled to receive said electrical signals for providing an output signal that is a rectified average of selected signal components within said electrical signals;

(c) comparator means coupled to receive the output signals from the signal processing means for producing output pulses only when the output signals of the signal processing means exceed a predetermined threshold;

(d) a programmed microprocessor coupled to receive the output pulses from the comparator means for tallying the frequency of occurrence of the output pulses during a predetermined time intervals within a larger time period in which the pacemaker is operating in a predetermined pacing mode, said programmed microprocessor also computing the average of the tallies of all of the plurality of the plurality of predetermined time intervals.

2. The apparatus of claim 1 and further including means for periodically changing the pacing mode of the implanted pacemaker.

3. The apparatus of claim 2 wherein the microprocessor includes a memory means for storing said tallies developed in successive ones of the larger time periods for subsequent readout.

4. The apparatus of claim 2 wherein the means for periodically changing the pacing mode comprises means for changing a pacing parameter selected from the group consisting of pacing rate, A-V delay interval, interventricular delay interval and pacing electrode location.