Intermedics Inc.

Lutron Electronics Company, Inc.

Cardiac Pacemakers, Inc.

Lutron Electronics, Inc.

Gregory R Martin

David Prutchi

Patrick J Paul

Noel Mayo

Robert Charles Newman

Robin C Moseley

Donald F Hausman

Mark A Cieri

Gary E Will

Charles J Digney, Jr

Tony W Azar

Stephen W Lynn

David L Kates

Timothy R Reinhard

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.

Implantable cardiac stimulator with electrode-tissue interface characterization

A cardiac stimulator capable of measuring pacing impedance includes a tank capacitor for delivering charge to the heart via device leads, a shunt resistor, and high-impedance buffers for measuring pacing current through the shunt resistor. Soon after the leading edge of the stimulation pulse, the voltage across the shunt resistor, as sampled by a high-impedance buffer, indicates lead and cardiac tissue resistance. Just prior to opening the pacing switch to terminate the stimulation pulse, the voltage across the shunt resistor is sampled by a high-impedance buffer and held once again to allow the capacitance of the lead/heart tissue to be calculated. In alternative embodiments, 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. In one alternative embodiment, a look-up table is created in main memory and searched to find the closest lead/heart tissue capacitance estimate to any arbitrary degree of accuracy. In another alternative embodiment, the lead/heart tissue capacitance is estimated by successive approximation to any arbitrary degree of accuracy. When the lead/heart tissue capacitance and lead resistance have been determined, a plurality of parameters of importance 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.

An elongated reelable shade, first and second spaced support brackets removably connected to first and second and opposite ends of said elongated reelable shade for supporting said reelable shade from a fixed support, an electrical drive motor having an output shaft for rotating said elongated reelable shade around its axis to selectively reel and unreel said shade, an electrical circuit for energizing and operating said motor, the electrical circuit including a controller coupled to and controlling the operation of said drive motor, and a coupler for removably coupling said output shaft of said motor to said first end of said elongated reelable shade, a single housing having said first bracket fixed thereto, said single housing containing and supporting said motor, said electrical circuit and said coupler, said coupler comprising an output driver which removably receives said first end of said shade with rotatable driving relationship.

Motorized window shade system

Implantable cardiac stimulator with electrode-tissue interface

An elongated reelable shade, first and second spaced support brackets removably connected to first and second and opposite ends of the elongated reelable shade for supporting the reelable shade from a fixed support, an electrical drive motor having an output shaft for rotating the elongated reelable shade around its axis to selectively reel and unreel the shade, an electrical circuit for energizing and operating the motor, the electrical circuit including a controller coupled to and controlling the operation of the drive motor, a single shade limit switch for stopping the motor when the shade reaches a fully reeled or fully extended position, and a coupler for removably coupling the output shaft of the motor to the first end of the elongated reelable shade, a single housing having the first bracket fixed thereto, the single housing containing and supporting the motor, the electrical circuit and the coupler, the coupler comprising an output driver which removably receives the first end of the shade with rotatable driving relationship.

Growing community of inventors

Pearland, TX, United States of America

Gregory R Martin