Biomedical subjects

P R Troyk

Publications and source records attributed to P R Troyk.

3 recordsLinked to original sources

PubMed1992

Class E driver for transcutaneous power and data link for implanted electronic devices.

Magnetic transcutaneous coupling is frequently used for power and data transfer to implanted electronic devices. The paper describes a transmitter/coil driver based on the class E topology. The development of a 'high-Q approximation' simplifies the design procedure. A method of data modulation using synchronous frequency shifting is described. The class E circuit shows great promise, especially for circuits with unusually low coefficients of coupling. Transmitter coil currents of several amperes, at radio frequencies, with relatively low active device power dissipation, can easily be obtained.

Electric Power Supplies↗

PubMed1992

Closed-loop class E transcutaneous power and data link for microimplants.

Magnetic transcutaneous coupling is frequently used for power and data transfer to implanted electronic devices. The proposed development of MicroImplants, small enough to be injected through a hypodermic needle suggest the need for a high-efficiency magnetic transcutaneous link. This paper describes the use of a multifrequency transmitter coil driver based upon the Class E topology. The development of a "high-Q approximation" which simplifies the design procedure is presented. A closed-loop controller to compensate for transmitter and receiver variations, and a method of data modulation, using synchronous frequency shifting are described. The closed-loop Class E circuit shows great promise, especially for circuits with unusually low coefficients of coupling. Currents of several amperes, at radio frequencies, can easily and efficiently be obtained.

Equipment Design↗

PubMed1991

Injectable microstimulator for functional electrical stimulation.

A family of digitally controlled devices is constructed for functional electrical stimulation in which each module is an hermetically sealed glass capsule that is small enough to be injected through the lumen of a hypodermic needle. The overall design and component characteristics of microstimulators that receive power and command signals by inductive coupling from a single, externally worn coil are described. Each device stores power between stimulus pulses by charging an electrolytic capacitor formed by its two electrodes, made of sintered, anodised tantalum and electrochemically activated iridium, respectively. Externally, a highly efficient class E amplifier provides power and digitally encoded command signals to control the amplitude, duration and timing of pulses from up to 256 such microstimulators.

Electric Stimulation↗