The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 14, 1993
Filed:
Nov. 15, 1991
Paul M Stein, Maple Grove, MN (US);
David L Thompson, Fridley, MN (US);
Medtronic, Inc., Minneapolis, MN (US);
Abstract
A cardiac pacemaker of the type including a sensor responsive to the patient's metabolic demand for oxygenated blood and which varies the pacing rate in response to the output of the sensor. In the disclosed embodiment, a piezoelectric sensor bonded to the inside surface of the pacemaker's outer shield delivers a pulsatile sensor signal to activity circuitry, where the different peak values of the pulsatile signal correspond to different levels of patient activity. The activity circuit defines a plurality of sensor signal threshold levels. Rate control circuitry increases the pacing rate of the pacemaker by amounts corresponding to the threshold level exceeded by recent peak values of said pulsatile signal; peaks of said pulsatile signal which exceed only the lowest of the thresholds cause the smallest increase in the pacing rate, while sensor signals which exceed higher thresholds cause larger increases in the pacing rate. Several parameters, including upper and lower pacing rate limits and rate-response settings are selectable by means of an external programming device communicating with the pacemaker via radio-frequency telemetry.