1
Jeffery C Lesho, Arthur F Hogrefe: Ingestible size continuously transmitting temperature monitoring pill. The Johns Hopkins University, Robert E Archibald, Howard W Califano, July 4, 1989: US04844076 (437 worldwide citation)

A temperature responsive transmitter is disclosed. The transmitter utilizes a unique circuit design that allows encapsulation in an ingestible size capsule. The inventive circuit design uses a one transistor inverting amplifier with a tank circuit forming the link between the transistor's collector ...


2
Arthur F Hogrefe, Wade E Radford: Coherent inductive communications link for biomedical applications. The Johns Hopkins University, Robert E Archibald, Howard W Califano, December 31, 1985: US04561443 (269 worldwide citation)

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 ...


3
Arthur F Hogrefe, Jeffery C Lesho, Harry A C Eaton: AM/FM multi-channel implantable/ingestible biomedical monitoring telemetry system. The Johns Hopkins University, Eugene J Pawlikowski, May 16, 1995: US05415181 (126 worldwide citation)

A multi-channel circuit for telemetering signals representing physiological values from a point in a human body to a receiver (24) outside of the body. The two signals (S.sub.1, S.sub.2) other than the temperature signal (27') are used to provide two frequency modulated signals (14, 16) summed by an ...


4
Arthur F Hogrefe: Minimum interface biomedical monitoring system. The Johns Hopkins University, Robert E Archibald, Howard W Califano, May 21, 1991: US05016631 (96 worldwide citation)

The present invention is a universal interface allowing a main implant to supply power and receive data from remotely implanted sensor modules through a minimum number of interconnecting lines. The main module can supply a single DC voltage, two sequentially applied DC voltages or an AC voltage to t ...


5
Arthur F Hogrefe: Pulse to zero digital (PZ) modulation. The Johns Hopkins University, Robert E Archibald, Howard W Califano, Francis A Cooch, June 18, 1991: US05025454

A "pulse to zero" modulation scheme is taught to transmit binary information by modulating a bit mark onto a carrier at the start of each "0" in the bit stream. The "pulse to zero" decoder produces an output that switches to "0" at the occurrence of the detected bit mark and resets to "1" if a secon ...