Robert L Seeley

41322266, Jan 2, 1979

Jul 13, 1977

5/815327

Robert L. Seeley - San Diego CA
William F. Flanigan - San Diego CA

The United States of America as represented by the Secretary of the Navy - Washington DC

A61B 504

128 21R

The broadband auditory thresholds of marine mammals are determined by an apparatus which compensates for the animals' movement artifact. A number of evoked responses to audio stimuli are average during discrete time intervals. This approach reduces the effects of potentials attributed to movements of the animal, for example, the opening and closing of the blow hole. A threshold detector circuit, a tape delay and related circuitry electronically cooperate to block potentials attributed to the movement artifact when the potentials exceed the likely magnitude of the evoked response. Optionally, an oscilloscope is used to provide a visual representation of the evoked response and the potentials are manually inhibited when the movement artifact masks or otherwise overrides the evoked response.

39672247, Jun 29, 1976

Apr 25, 1975

5/571658

Robert L. Seeley - San Diego CA

The United States of America as represented by the Secretary of the Navy - Washington DC

H01H 166

335151

A small reed switch having a glass tubularly shaped envelope containing a ir of reed contacts is modified to ensure its being biased to either an open or a closed position. A donut-shaped piece of a rubber-bonded, barium-ferrite, magnetic material is circumferentially mounted on the reed switch at a position where its magnetic field influences the contacts to an open position or a closed position. Thusly arranged, an actuating magnet, having a sufficient field at a single pre-established distance from the contacts, actuates the switch from all radial directions from the switch. Potting the modified switch in an epoxy resin further ensures a greater reliability and makes it ideal for implantations in laboratory animals.

39769623, Aug 24, 1976

Apr 25, 1975

5/572473

Robert L. Seeley - San Diego CA

The United States of America as represented by the Secretary of the Navy - Washington DC

H01H 5122

335153

An improved dual threshold switch is actuated by magnetic fields in the sch's proximity. An elongate glass envelope contains a pair of reed contacts. The contacts are biased by a piece of donut-shaped magnetic material circumscribing the envelope to be switched to a closed position at one magnetic threshold or an open position at another magnetic threshold. Both magnetic thresholds are induced in the contacts by external actuating magnets and the thresholds can be changed by physically moving the donut along the elongate glass envelope. A coil is provided and encompasses the envelope and magnetic donut to provide an electro-magnetic field which shifts the biasing field induced by the donut. When the electro-magnetic shifting field is turned on the thresholds established by the biasing field are shifted so that the contacts would be actuated from external actuation fields at different magnetic thresholds. This feature gives flexibility since various combinations of weak or strong external magnetic fields can be employed as the situation demands without sacrificing reliability or calling for extensive modifications of the switch.