Method and apparatus for detection and treatment of tachycardia and fibrillation

• US 20010034539A1
• Filed: 03/21/2001
• Published: 10/25/2001
• Est. Priority Date: 03/21/2000
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Gillberg, Jeffrey M., Stadler, Robert W., Gunderson, Bruce D., Olson, Walter H.
• Granted Patent: US 6,879,856 B2
• Time in Patent Office: Days
• US Class Current: 607/14
• CPC Class Codes: A61N 1/3622 comprising two or more electrodes co-operating with different heart regions
• CPC Class Codes: A61N 1/39622 Pacing therapy

Abstract

The invention relates to devices that detect and/or treat tachyarrhythmias. The invention includes software systems that distinguish among various tachyarrhythmias in order to provide treatment for specific tachyarrhythmias. One aspect of the invention employs a methodology to provisionally detect ventricular tachycardia and/or fibrillation and thereafter apply a discrimination function to a series of measured intervals preceding the provisional detection. Discrimination is accomplished by sorting the intervals preceding provisional detection into bins corresponding to interval ranges and examining the relative distribution of the intervals within the bins.

Claims

1. Apparatus for treating tachyarrhythmias, comprising:

treatment means for delivering a first therapy to a patient'"'"'s heart to treat tachycardia and a second therapy to said patient'"'"'s heart to treat fibrillation;

first means for sensing electrical signals from said patient'"'"'s heart indicative of the depolarization of a chamber or chambers of said patient'"'"'s heart;

means for measuring and storing the intervals separating said electrical signals;

means for detecting the occurrence of a tachyarrhythmia; and

tachycardia/fibrillation discriminator means responsive to said detecting means for selecting between said first and second therapies.

2. The apparatus of

claim 1

wherein:

said discriminator means in turn comprising;

means for sorting said measured intervals into interval ranges;

means for determining the numbers of intervals within each said interval range;

means for identifying ones of said interval ranges which have the highest numbers of said stored intervals;

means for determining the total number of said stored intervals falling within said identified interval ranges;

means for deriving a variable threshold criterion varying as a function of the length of the intervals separating preceding depolarizations; and

means for triggering said first therapy if said total number meets said variable threshold criterion.

3. The apparatus of

claim 1

wherein the deriving means comprises means for deriving said threshold criterion as a value which increases as an inverse function of the length of the intervals separating preceding depolarizations.

4. A device according to

claim 1

wherein the deriving means comprises means for deriving said threshold criterion as a value which increases as an inverse function of the length a defined percentile interval over a sequence of a predetermined number of intervals separating preceding depolarizations.

5. A device according to

claim 1

wherein the deriving means comprises means for deriving said threshold criterion as a value which increases as an inverse function of the length of the 75th percentile interval over a sequence of a predetermined number of intervals separating preceding depolarizations.