Abstract: An apparatus and method for the control and prevention of bruxing (nocturnal teeth grinding) which comprises a sound generating means affixed to the jaw of the user, an electronic control means to "read" electrical impedance variations within said sound generating means caused by bruxing and to activate an alarm when bruxing occurs. Said apparatus utilizes the principle of bone conduction wherein sonic loading of said sound generating means differs between the open-jaw and the closed-jaw states. The alarm develops a conditioned reflex in the user such that after the first few alarms incident to bruxing the user does not awaken but merely reacts by relaxing the jaw when the alarm occurs.

Abstract: An apparatus and method for the control and prevention of bruxing (nocturnal teeth grinding) which comprises a sound generating means affixed to one area of the face of the user, a sound receiving means affixed to another area of the face, and an electronic control means to "read" signals from said sound receiver and to activate an alarm when bruxing occurs. Said apparatus utilizes the principle of bone conduction whereby the sonic vibrations from said second generator are transmitted to said sound receiver bottom when the jaw of the user is closed than when it is open. The alarm develops a conditioned reflex in the user such that after the first few alarms incident to bruxing the user does not awaken but merely reacts by relaxing the jaw when the alarm occurs.

Abstract: A radio frequency switch which has input and output diodes and a quarter length impedance inverter interconnecting the diodes. A switch drive signal is clamped to a predetermined voltage between drive signals so that the impedance with respect to the input source remains substantially constant during the entire switch operation.

Abstract: Movement of an object (intruder) in a specified area is sensed by transmitting microwave energy from an antenna (10) that also receives energy reflected from the intruder, where the received energy is quadrature processed using Doppler techniques. Connected to the antenna (10) is a transceiver (12) that includes a quadrature mixer (48) coupled to an RF oscillator (50) through an RF switch (52). The RF switch (52) is controlled by a switch driver (54) to provide pulse energy from the antenna (10). Doppler outputs E.sub.1 and E.sub.2 from transceiver (12) are processed in the same manner except for a 90-degree phase lead applied to the Doppler output E.sub.2 by a phase lead network (18). Doppler outputs E.sub.1 and E.sub.2 (E.sub.2 90-degree phase shifted) are applied simultaneously to a sum and signature processor (24) and to a difference and signature processor (22). The sum and signature processor provides the "approach" receiving signal and processes the signature to further reduce the nuisance alarm rates.