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:
Sep. 23, 1980
Filed:
Feb. 28, 1979
Joseph H Schulman, Los Angeles, CA (US);
Brian M Mann, Northridge, CA (US);
Russell R Beane, Sepulveda, CA (US);
Pacesetter Systems, Inc., Sylmar, CA (US);
Abstract
A telemetry system for use in a living tissue stimulator system in which an externally located oscillator is controlled by impedance changes in an impedance reflecting circuit located in an implantable tissue stimulator. In a first embodiment the impedance reflecting circuit is an LC circuit thereby frequency modulating the externally located oscillator and in a second embodiment it is an LR circuit thereby amplitude modulating the externally located oscillator. More specifically, the externally located oscillator drives an LC circuit in which the inductor is positioned in magnetically coupled relationship to an inductor in the impedance reflecting circuit. The externally located oscillator is chosen so that its frequency and amplitude is partially determined by the impedance of the LC circuit and the magnetically coupled impedance reflecting circuit. A parameter or signal to be telemetered, which could be in the form of a digital or an analog signal, is used to modulate an output frequency of a voltage controlled oscillator located in the implantable tissue stimulator. This frequency modulated output of the voltage controlled oscillator drives an FET switch which alters the impedance of the impedance reflecting circuit, thereby modulating the output of the externally located oscillator. Thus, a telemetry system is provided in which minimum power is required from the implantable tissue stimulator.