Cardiac Pacemakers, Inc.

Daniel E Huntwork

Robert D Dreher

Jean-Cheui Hsung

Perry A Mills

Brian P Brockway

Lloyd A Van Hofwegen

Douglas C Morrison

Brock S Lindstedt

An automatic implantable defibrillator/cardioverter having a non-committed defibrillation/cardioversion algorithm. The defibrillator/cardioverter includes an ECG amplifier with automatic gain control (AGC) which detects the electrical activity of the heart for analysis by a cardiac condition detector. Logic is provided which receives input from the ECG amplifier and the cardiac condition detector for analyzing the heart activity. The non-committed defibrillation algorithm sensing begins upon the determination of an arrhythmia. The capacitor is charged while the heart activity is simultaneously monitored. After the capacitor is charged, a check is made on the duration of the last detected R-R interval while so charging the capacitor, and a comparison is made between this R-R interval and a preset value. If the last R-R interval is greater than the preset value, a non-committing period is entered which lasts approximately 2 seconds. The purpose of the non-committing period is to allow detection to monitor the arrhythmia further before making the decision to discharge the capacitor or dump the charge internally. If any R-R interval detected during this interval is less than PCLL, this indicates that the arrhythmia has not reverted and the capacitor charge is delivered to the patients, synchronously with the second R-wave of the fast R-R interval. If no rapid interval is detected during this time, a post intervention (PI) monitoring routine is entered at the end of the non-committing period to further monitor cardiac activity and shock if necessary.

Defibrillation/cardioversion system with multiple evaluation of heart

A programmable cardiac pacemaker that is selectively programmable via a radio frequency communications link into one of a plurality of a single and dual chamber pacing modes. Depending upon the mode selected, an associated plurality of pacing parameters may be programmed, each within a predetermined range of possible magnitudes. The pacemaker includes a rate smoothing function for preventing the rate interval from changing by more than a predetermined percentage on a cycle-to-cycle basis; and a graceful degradation function for causing the ventricular pacing rate to decay when the atrial rate exceeds a programmed upper rate limit for a predetermined length of time. A graceful degration onset time and rate of decay are also programmable. Additionally, the pacemaker contains a set of pre-programmed alternative pacing parameters for at least one mode and which can be independently reverted to. The pacemaker control circuitry is organized about a central bus into an I/O controller and a pacing controller. Pacing control is continuous and its I/O communications operate on a prioritized basis. I/O control permits the programming of any register and the interrogation of a variety of analog parameters associated therewith.

Programmable multi-mode cardiac pacemaker

Growing community of inventors

White Bear Lake, MN, United States of America

Daniel E Huntwork