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:
Apr. 03, 2007
Filed:
Jun. 21, 2004
David Prutchi, Lake Jackson, TX (US);
Patrick J. Paul, Lake Jackson, TX (US);
Gregory R. Martin, Pearland, TX (US);
David Prutchi, Lake Jackson, TX (US);
Patrick J. Paul, Lake Jackson, TX (US);
Gregory R. Martin, Pearland, TX (US);
Cardiac Pacemakers, Inc., St. Paul, MN (US);
Abstract
A cardiac stimulator for measuring pacing impedance includes a tank capacitor for delivering charge to the heart via leads, a shunt resistor, and high-impedance buffers for measuring pacing current through the shunt resistor. During the stimulation pulse, the voltage across the shunt resistor, as sampled by a high-impedance buffer, variously indicates lead and cardiac tissue resistance or capacitance. A high-impedance buffer measures the voltage between the tank capacitor and ground immediately following the stimulation pulse to allow estimation of the lead/heart tissue capacitance. A lead/heart tissue capacitance estimate is determined by look-up table is in memory or successive approximation. When the lead/heart tissue capacitance and lead resistance have been determined, a plurality of parameters for analyzing and optimizing a cardiac stimulation system may be calculated, such as the instantaneous current, the average current, the charge, and the energy delivered to the cardiac tissue.