05564434 is referenced by 334 patents and cites 14 patents.

An endocardial lead for implantation in a right heart chamber for responding to blood pressure and temperature and providing modulated pressure and temperature related signals to an implanted or external hemodynamic monitor and/or cardiac pacemaker or pacemaker/cardioverter/defibrillator. The lead has a sensor module formed in its distal end and is coupled to a monitor that powers a sensor circuit in the sensor module. The sensor module is formed with a pickoff capacitor that changes capacitance with pressure changes and a reference capacitor that is relatively insensitive to pressure changes. The sensor circuit provides charge current that changes with temperature variation at the implant site, alternately charges and discharges the two capacitors, and provides timing pulses having distinguishable parameters at the end of each charge cycle that are transmitted to the demodulator. The demodulator detects and synchronizes the timing pulses and derives pressure and temperature analog voltage values representative of the intervals between the timing pulses which are digitized and stored in the monitor. The monitor may also be coupled with other sensors for measuring and storing related patient body parameters, e.g. blood gas, EGM, and patient activity.

Title
Implantable capacitive absolute pressure and temperature sensor
Application Number
8/394870
Publication Number
5564434
Application Date
February 27, 1995
Publication Date
October 15, 1996
Inventor
Anthony J Varrichio
Flanders
NJ, US
Beth A Hassler
White Bear Lake
MN, US
Timothy Patrick
South St. Paul
MN, US
James R Svensk
Coon Rapids
MN, US
Keith A Ufford
Chisago City
MN, US
Keith A Miesel
St. Paul
MN, US
Louis E Halperin
St. Paul
MN, US
Assignee
Medtronic
MN, US
IPC
A61B 5/00
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