Thomas M Fryer

US Patent:

41867491, Feb 5, 1980

Filed:

May 12, 1977

Appl. No.:

5/796256

Inventors:

Thomas B. Fryer - Saratoga CA

Assignee:

The United States of America as represented by the Administrator of the
National Aeronautics and Space Administration - Washington DC

International Classification:

A61B 500

US Classification:

128748

Abstract:

An induction powered implanted monitor for epidurally measuring intracranial pressure and telemetering the pressure information to a remote readout. The monitor utilizes an L-C oscillator in which the C comprises a variable capacitance transducer, one electrode of which is a small stiff pressure responsive diaphragm. The oscillator is isolated from a transmitting tank circuit by a buffer circuit and all electric components in the implanted unit except an input and an output coil are shielded by a metal housing.

US Patent:

39713628, Jul 27, 1976

Filed:

Oct 27, 1972

Appl. No.:

5/301418

Inventors:

Jack M. Pope - Saratoga CA
Thomas B. Fryer - Saratoga CA

Assignee:

The United States of America as represented by the Administrator of the
National Aeronautics and Space Administration - Washington DC

International Classification:

A61B 507

US Classification:

128 2P

Abstract:

A miniature, ingestible and encapsulated telemeter device for transmitting information relating to deep-body temperature of a subject comprising a battery source of power, and a free running multivibrator circuit having fixed biasing means connected to oscillator having a predetermind resonant frequency. A thermistor having a negative temperature coefficient of resistance is connected to the battery and the fixed biasing means and is operative to vary the output frequency of the multivibrator circuit in proportion to the temperature of the thermistor, the oscillator being pulsed into alernate states of conduction and non-conduction at the output frequency of the multivibrator to produce an output consisting of bursts of energy at the predetermined resonant frequency, preferably in the range 88 - 108 MHz. The time interval between successive bursts is proportionate to the deep-body temperature of the subject, and the thermistor having a very high resistance below a predetermind low temperature to cause inactivation of the multivibrator circuit and thereby only insignificant battery drain during refrigerated storage. A radiating inductor is connected to the output of the oscillator to transmit the bursts to a receiver.

Author:

Thomas B. Fryer

ISBN #:

0122692500