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. 17, 1985
Filed:
Sep. 20, 1984
Ibrahim H Ibrahim, North Ryde, AU;
Christopher N Daly, Bilgola Plateau, AU;
Telectronics Pty. Ltd., Lane Cove, AU;
Abstract
A combined telemetry system and magnetic field sensor for use in an implantable medical device. The telemetry system includes a conventional resonant circuit for transmitting and receiving data. The resonant circuit has a coil which is also used to sense the presence of a magnetic field exceeding a threshold value. The resonant frequency varies with the strength of the magnetic field which passes through the coil. Periodically, the resonant circuit is energized, and during a sensing window of predetermined duration which then immediately follows the voltage across the coil is examined for a predetermined number of zero crossings. That number of zero crossings will occur only in the presence of a magnetic field whose amplitude exceeds the threshold value. It is possible to achieve a sensitivity in such a system which is comparable to that of conventional miniature reed switches.