Wade E Radford

US Patent:

45614431, Dec 31, 1985

Filed:

Mar 8, 1983

Appl. No.:

6/473248

Inventors:

Arthur F. Hogrefe - Laurel MD
Wade E. Radford - Columbia MD

Assignee:

The Johns Hopkins University - Baltimore MD

International Classification:

A61N 136

US Classification:

128419PG

Abstract:

A two-way coherent inductive communications link between an external transceiver and an internal transceiver located in a biologically implanted programmable medical device. Digitally formatted command data and programming data is transmitted to the implanted medical device by frequency shift keying the inductive communications link. Internal transceiver is powered by the inductive field between internal and external transceivers. Digitally formatted data is transmitted to external transceiver by internal transceiver amplitude modulating inductive field. Immediate verification of the establishment of a reliable communications link is provided by determining existence of frequency lock and bit phase lock between internal and external transceivers.