Cardiac Pacemakers, Inc.

Bruce R Jones

Weimin Sun

Donald Lee Hopper

Douglas J Lang

Jeffrey E Stahmann

James P Nelson

Julio Cesar Spinelli

Gerrard Merrill Carlson

Veerichetty A Kadhiresan

Arthur L Olive

Wyatt Keith Stahl

A system and method for automatically adjusting the operating parameters of a rate-adaptive cardiac pacemaker. In accordance with the method, maximum exertion levels attained by the patient are measured at periodic intervals and stored. The stored maximum exertion levels may then be used to update a long-term maximal exertion level, and the slope of the rate-response curve is adjusted to map the updated long-term maximal exertion level to a maximum allowable pacing rate. The stored maximum exertion levels may also be used to update a sensor target rate which is used to adjust the slope of the rate response curve.

Self-calibrating rate-adaptive pacemaker

A method and system for automatically adjusting the operating parameters of a rate-adaptive cardiac pacemaker in which maximum exertion levels attained by the patient are measured at periodic intervals and stored in order to compute or update a maximum exercise capacity. The slope of the rate-response curve is then adjusted to map an exertion level corresponding to the updated maximum exercise capacity to a maximum allowable pacing rate. In accordance with the invention, a maximum exercise capacity is determined by cross-checking periodic maximum exertion level sensor values with a motion-level sensor value.

Rate-adaptive therapy with sensor cross-checking

A system and method for automatically adjusting the operating parameters of a rate-adaptive cardiac pacemaker in which maximum exertion levels attained by the patient are measured at periodic intervals and stored. The stored maximum exertion levels may then be used to update a long-term maximal exertion level, and the slope of the rate-response curve is adjusted to map the updated long-term maximal exertion level to a maximum allowable pacing rate. In accordance with the invention, the rate response curve is defined such that an exertion level corresponding to the patient's maximum exercise capacity would be mapped to a physiologically favorable maximum rate that is independent from a specified maximum sensor indicated rate.

Rate-adaptive therapy with automatic limiting of maximum pacing rate

A method and apparatus for providing congestive heart failure therapy status. An electronic device, preferably a cardiac rhythm management device, capable of measuring transthoracic impedance and for sensing a level of physical activity is implanted in a patient. The transthoracic impedance signal is processed to obtain an estimate of the subject's minute ventilation, respiratory rate, tidal volume, inspiratory rate and expiratory rate. From accelerometer measured activity, an estimate is obtained of oxygen uptake, carbon dioxide production and work rate. Ratios of tidal volume to respiratory rate, tidal volume to inspiratory time, tidal volume to expiratory time, heart rate to minute ventilation, respiratory rate to minute ventilation, tidal volume to minute ventilation, minute ventilation to oxygen uptake, minute ventilation to carbon dioxide production, minute ventilation to work rate, heart rate to work rate, oxygen uptake to heart rate and other ratios are meaningful status indicators for assessing the efficacy of particular therapy regimens to CHF patients.

Implantable cardiac rhythm management device for assessing status of CHF patients

Exertion levels of a patient are measured by monitoring signals from adaptive-rate sensors such as an accelerometer and or a minute ventilation sensor; sensor data is collected for conversion into metabolic equivalent measurements. The data obtained can be used to evaluate patient physical activity levels and can be used to assess the patient's condition and change pacing therapy or other treatments accordingly. An automatic adjustment of the adaptive-rate pacing therapy may be based on the activity levels detected by the metabolic equivalent measurements made by the pacemaker.

Apparatus and methods for METS measurement by accelerometer and minute ventilation sensors

A method and apparatus for providing congestive heart failure therapy status. An electronic device, preferably a cardiac rhythm management device, capable of measuring transthoracic impedance and for sensing a level of physical activity is implanted in a patient. The transthoracic impedance signal is processed to obtain an estimate of the subject's minute ventilation, respiratory rate and tidal volume. From accelerometer measured activity, an estimate is obtained of oxygen uptake and carbon dioxide production. Ratios of tidal volume to respiratory rate, tidal volume to inspiratory time, minute ventilation to carbon dioxide production and oxygen uptake to heart rate are meaningftil status indicators for assessing the efficacy of particular therapy regimens to CHF patients.

An implantable electronic circuit for monitoring a patient's aerobic capacity includes an accelerometer for detecting the onset and termination of a period of exercise and a means for measuring the patient's minute volume. By computing the time interval from the cessation of exercise to the point where the patient's minute volume reaches a predetermined value at or near an at-rest value thereof, a measure of aerobic capacity relating to a patient's physical fitness can be determined.

Implantable device for monitoring aerobic capacity of patients

An implantable cardiac rhythm management device includes an accelerometer along with apparatus for processing the analog signal output from the accelerometer for deriving therefrom the time of occurrence of a selected heart sound in relation to a previously occurring ventricular depolarization event. The thus-derived heart sound information can be used to establish a hemodynamic upper rate limit for a rate adaptive pacemaker.

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Hopkins, MN, United States of America

Bruce R Jones