Abstract: An apparatus adjusts the pressures of a therapeutic mattress surface in accordance with the angular position of that surface. The apparatus comprises an angular position sensor and a rotation sensor which are housed together in an enclosure having a top surface in the form of a circular plate. The circular plate mounts either on the surface of the mattress or on the bottom of a bed frame supporting the mattress. The angular position and rotation sensors measure the horizontal plane referenced perpendicular to the direction of the force of gravity. The apparatus further comprises a controller blower valve assembly which processes data received from the angular position and rotation sensors to maintain, increase, or decrease the pressures within the mattress.

Abstract: An apparatus adjusts the pressures of a therapeutic mattress surface in accordance with the angular position of that surface. The apparatus comprises an angular position sensor and a rotation sensor which are housed together in an enclosure having a top surface in the form of a circular plate. The circular plate mounts either on the surface of the mattress or on the bottom of a bed frame supporting the mattress. The angular position and rotation sensors measure the horizontal plane referenced perpendicular to the direction of the force of gravity. The apparatus further comprises a controller blower valve assembly which processes data received from the angular position and rotation sensors to maintain, increase, or decrease the pressures within the mattress.

Abstract: A touch input device, suitable for use in detecting the presence of an opaque element within a display area bounded by light emitting elements and light detecting elements includes light emitter activating circuitry in which the light emitting elements are individually selectable. Each light emitting element is contained within a matrix and source drivers and sink drivers are effective to select a specific row and column address for each individual light emitter. Current for the light emitters is provided by a voltage source which is chosen for compatibility with the logic used in the touch input system. A charge pump operating sequentially with the selection light emitting elements is used to establish a voltage greater than the normal supply voltage to overcome the voltage drops of the source and sink driver and the activated light emitter to insure light emission greater than a minimum threshold.

Abstract: An apparatus and method to generate high intensity sound having a strong directional characteristic. The apparatus preferably uses a sound element (e.g. piezo sounder) which is capable of generating a high intensity, power efficient sound, but which has poor directional characteristics because of its high frequency (e.g. 3000 Hz). The apparatus drives the sound element with a variable frequency signal which sweeps across the resonant bandwidth of the sound element. The sweep rate of the frequency shift is less than about 1200 Hz which gives the sound a directional characteristic--resulting in periodic bursts of high intensity sound that is strongly directional. The apparatus may be incorporated into a wide variety of applications where high intensity, power efficient, strongly directional sound is desirable.