Abstract: A dental patient's chair which is fully and completely adjustable which includes a foot control system that eliminates the need to manipulate any hand-operated control knobs or levers. The dental patient's chair includes a linkage assembly which allows the seat to pivot and move in the same manner as the human body when the human body articulates about the complex pivot created at the pelvic bone, the upper legs, and the lower part of the backbone. The dental patient's chair allows the patient's body to remain in the same position relative to the backrest and the seat of the patient's chair as the chair is articulated in a variety of positions.

Abstract: A dental patient's chair which is fully and completely adjustable which includes a foot control system that eliminates the need to manipulate any hand-operated control knobs or levers. The dental patient's chair includes a linkage assembly which allows the seat to pivot and move in the same manner as the human body when the human body articulates about the complex pivot created at the pelvic bone, the upper legs, and the lower part of the backbone. The dental patient's chair allows the patient's body to remain in the same position relative to the backrest and the seat of the patient's chair as the chair is articulated in a variety of positions.

Abstract: A system (10) is disclosed for facilitating the healing of traumatized tissue and broken or fractured bone. The system (10) establishes an electric field between a pair of electrodes (14) positioned on opposite sides of the patient site (12), resulting in the production of an alternating current having the desired frequency and amplitude characteristics in the tissue or bone. Specifically, the system (10) includes a resonator (32) formed by an inductor (36) coupled in series with the resistor (R1) and capacitor (C1) of an equivalent circuit (34) representing the patient site (12), the electrodes (14), and any gaps (30) therebetween. This resonator (32) also includes a capacitor (C2) designed to prevent spurious, high-frequency oscillations. The resonator (32) is operated by a free-running oscillator (16), which maintains the operation of the resonator (32) at its resonant frequency.

Abstract: A system (10) is disclosed for facilitating the healing of traumatized tissue and broken or fractured bone. The system (10) establishes an electric field between a pair of electrodes (14) positioned on opposite sides of the patient site (12), resulting in the production of an alternating current having the desired frequency and amplitude characteristic in the tissue or bone. Specifically, the system (10) includes a resonator (32) formed by an inductor (36) coupled in series with the resistor (R1) and capacitor (C1) of an equivalent circuit (34) representing the patient site (12), the electrodes (14), and any gaps (30) therebetween. This resonator (32) also includes a capacitor (C2) designed to prevent spurious, high-frequency oscillations. The resonator (32) is operated by a free-running oscillator (16), which maintains the operation of the resonator (32) at its resonant frequency.

Abstract: A railway vehicle motion detector that monitors vibrations within the vehicle and the acceleration thereof to provide an indication of the condition of motion of the vehicle. The motion detector is adapted to be mounted on any railway vehicle, and in particular on the last vehicle of a railway train, and to be incorporated into a system that monitors and remotely displays a plurality of train status conditions. The motion detector includes a transducer (10) that converts the vehicle vibrations and acceleration into an electrical output signal. A velocity circuit (12) selectively passes and integrates a range of frequencies of the transducer output signal that are reliable indicators of vehicle motion to obtain a velocity signal having a magnitude that is proportional to a change in the velocity of the vehicle and a polarity that is indicative of the direction of a change in velocity.

Abstract: An information system for communicating information from each of a plurality of separate locations to each of a plurality of mobile objects includes a beacon at each location and a beacon triggering and detecting apparatus mounted on each object. Each beacon triggering and detecting apparatus is assigned a predetermined and unique time window within a common system cycle. During the initial portion of its window, the beacon triggering and detecting apparatus transmits a trigger signal at a frequency f.sub.1, with the trigger signal as transmitted having a substantially constant amplitude and with frequency f.sub.1 being chosen so that the intensity of the trigger signal decays as the cube of radial distance from the object. If the object is within a predetermined beacon trigger range of a location, the beacon at that location detects the trigger signal and transmits a beacon signal at a frequency f.sub.2 (substantially greater than frequency f.sub.