05562711 is referenced by 159 patents and cites 27 patents.

A body-implantable rate-responsive cardiac pacemaker is provided with circuitry for sensing a plurality of physiologic parameters known to be indicative of a patient's metabolic demand for increased cardiac output. In one embodiment, a rate-responsive pacemaker is provided with an activity sensor for detecting the patient's level of physical activity, and is further provided with an impedance sensing circuit for detecting the patient's level of minute ventilation by monitoring cardiac impedance. A rate-response transfer function, implemented by the pacemaker's control circuitry, periodically computes a rate-responsive pacing rate as a function of the outputs from both physiologic sensing circuits. The pacemaker's pacing rate is variable within a rate range defined by predetermined (programmable) upper and lower limits. In the preferred embodiment, the influence of activity sensing and minute ventilation parameters varies in accordance with the current pacing rate. In particular, the influence of activity sensing in rate determination in accordance with the rate-response function is greater than that of minute ventilation, for slower pacing rates, while the influence of minute ventilation sensing dominates over that of activity sensing for higher pacing rates. Rate response operation of the disclosed system is recorded in the form of histogram data stored over a predetermined history time. The relative influence of the activity sensing and minute ventilation sensing on rate determination is periodically scaled or balanced based upon comparison of the histogram data with predetermined desired response data.

Title
Method and apparatus for rate-responsive cardiac pacing
Application Number
8/346813
Publication Number
5562711
Application Date
November 30, 1994
Publication Date
October 8, 1996
Inventor
John D Wahlstrand
Shoreview
MN, US
Richard S Schallhorn
St. Paul
MN, US
Eric J Panken
Minneapolis
MN, US
Karen J Kleckner
New Brighton
MN, US
William J Combs
Eden Prairie
MN, US
Charles G Yerich
Fridley
MN, US
Agent
Harold R Patton
Michael B Atlass
Assignee
Medtronic
MN, US
IPC
A61N 1/365
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