Medtronic, Inc.

Charles D Trautmann

John D Wahlstrand

Rick D McVenes

Bradley C Peck

Ross O Starkson

David J Jorgenson

A system for monitoring trends in lead impedance includes collecting data from various sources in an implantable medical device system. Lead impedance, non-physiologic sensed events percentage of time in mode switch, results of capture management operation, sensed events, adversion pace counts, refractory sense counts and similar data are used to determine the status of a lead. A set of weighted sum rules are implemented by a software system to process the data and provide displayable information to health care professionals via a programmer. The lead monitoring system includes a patient alert system for patients to seek help in the event a serious lead condition is identified.

Implantable lead functional status monitor and method

An implantable medical device (IMD) includes a lead status monitoring system. The lead status monitoring system employs a method including the steps of: collecting data sets from a lead impedance source, a stimulation threshold source, and at least one additional source included in the IMD; and processing the data sets to determine if a lead status event has occurred.

An implantable medical device (IMD) coupled with leads extending to body tissue providing storage of lead related data, monitoring of lead functional status, and indication of lead integrity to the clinician. A lead status monitor (LSM) processes lead related data in a system self test mode and provides a lead status report that identifies and declares conductor/connector issues, insulation issues, and electrode/tissue interface issues indicative of suspected lead related condition mechanisms for each lead employed in the IMD. The LSM operates employing a set of LSM rules that process measured lead impedance values and loss of capture (LOC) values. In a pacing system, particular LSM rules are defined that process periodically determined, pacing pulse characteristic at LOC and bipolar and unipolar lead impedance values that are measured periodically. The lead impedance values are compared to upper and lower limits or trip points of a normal impedance range. Simultaneously, significant changes in lead impedance are detected, and the unipolar impedance value is compared to the bipolar lead impedance value of each lead. Counts of deviations in lead impedances satisfying each LSM rule are maintained. Certain of the lead related condition mechanisms are declared if a count of lead impedance deviations meets a programmed threshold number of such lead impedance deviations within a further programmed number of sequential impedance measurements. Preferably, the pacing pulse strength or voltage at LOC (characterized as LOC_RHEOBASE herein) is periodically determined and compared to a reference LOC_RHEOBASE.

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Ham Lake, MN, United States of America

Charles D Trautmann