Cardiac Pacemakers, Inc.

William L Zimmer

William J Linder

James O Gilkerson

David B Krig

Robert D Dreher

Jan D Wald

Ron A Balczewski

Jeremy J Maniak

Rodney W Salo

Arthur L Olive

Brian D Pederson

Renold J Russie

Michael W Dooley

Brian P Citak

A method comprising providing a programmable non-volatile memory (PNVM) circuit fabricated together with a processor on an integrated circuit chip (IC) in an implantable medical device (IMD), partitioning the PNVM circuit into a plurality of portions based on how often that the processor accesses a portion, and selectively providing power or selectively restricting power to one or more of the portions according to how often that the processor accesses a portion.

Implantable medical device with embedded programmable non-volatile memory

A system and method for selectively treating a ventricular tachycardia based on sensed atrial and ventricular intervals from the patient's heart. A detection window of the ten most recent atrial and ventricular intervals are analyzed for the occurrence of either tachycardia or fibrillation. When a majority of the sensed intervals are satisfied, the apparatus starts a duration time interval. Ventricular intervals and atrial intervals are compare, ventricular interval greater than the atrial interval by a bias factor the system delivers tachycardia therapy to the heart. Alternatively, the method withholds tachycardia therapy to the heart when the atrial rate is classified as atrial fibrillation and the ventricular response is unstable.

Apparatus and method for treating ventricular tachyarrhythmias

A system comprising an implantable medical device (IMD). The IMD includes a processor fabricated on an integrated circuit chip (IC), a random access memory (RAM) circuit fabricated on the same IC, and a programmable non-volatile memory (PNVM) circuit also fabricated on the same IC.

A multi-pole pacing/sensing lead is used to measure the instantaneous impedance in the right ventricle of a patient's heart. The resulting impedance waveform is signal processed to obtain a measure of the time interval beginning with the occurrence of a paced beat or a spontaneous QRS complex (systole marker) and ending with the point where the impedance versus time signal crosses the zero axis in the positive direction following the paced or spontaneous QRS complex initiating the interval or some other predetermined point along the positive-going waveform. The resulting time interval is inversely proportional to the contractility of the heart and is found to decrease with exercise and the introduction of catecholamines. Thus, it can be used as a control parameter for a demand-type cardiac pacemaker. A means for obviating changes in pacing rate due to long-term drift in the impedance sensing circuitry is also disclosed.

Physiologic control of pacemaker rate using pre-ejection interval as the

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Roseville, MN, United States of America

William L Zimmer