Medtronic, Inc.

Timothy Patrick

Keith A Ufford

Keith Alan Miesel

Anthony J Varrichio

Richard D Sandstrom

Louis E Halperin

James R Svensk

Beth A Hassler

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.

Implantable capacitive absolute pressure and temperature sensor

A cross-over adaptor for reversing the electrical connection of outer and inner coaxial coiled wire conductors is provided in the body of a pacing lead having a physiologic sensor incorporated therein so that the lead may be employed advantageously for conventional pacing functions with or without physiologic sensor function. In a specific embodiment, the adaptor is placed adjacent to a physiologic pressure sensor positioned in line in the lead body between the connector end thereof and the distal pace/sense electrode end thereof. The physiologic pressure sensor possesses an elongated cylindrical outer housing and an axially oriented electrical feed-through to the active components thereof. The cross-over adaptor is coupled at one end thereof to the sensor housing and electrical feed-through and at the other end thereof to the inner and outer coaxial coiled wire lead conductors which extend back to the proximal end of the lead body and are electrically connected to proximal pin and ring connector elements. At the distal end of the lead, the distal tip electrode is electrically coupled to the outer housing of the physiologic sensor. The electrical cross-over adaptor electrically connects the inner coiled wire conductor to the cylindrical housing of the physiologic sensor and the outer coiled wire conductor to the electrical feed-through of the physiologic sensor so that the proximal pin connector element is electrically connected to the distal tip electrode and the proximal ring connector element is electrically connected to the electrical feed-through of the physiological sensor. Thus, the electrical interconnection allows the lead to be employed as a conventional unipolar pacing lead in those situations where the physiological sensor is not employed in the pacing system.

Implantable medical lead with electrical cross-over adaptor

Growing community of inventors

Saint Paul, MN, United States of America

Timothy Patrick