Motion sensor

Abstract

A motion detection monitor for patient movement, comprising a sensor for viding signals in response to patient movement to provide an alarm under predetermined conditions of patient movement. A processor, including an oscillator, is provided for receiving signals from the sensor, to provide oscillator interrupt signals proportional to active signals. The interrupt signals are observed within a contiguous series at time windows. The alarm condition is satisfied when interrup signals are detected within each window. The sensor preferably includes a conductive sphere in a cylinder having an interior portion locating the sphere therein with conductive end plates and conductive inner surfaces, the inner surfaces being tapered to direct the sphere to an at rest condition in contact with at least one surface and at least a part of the inner surface in any orientation of the sensor. The motion detection device further includes jumper circuits for adjusting the parameters used to distinguish from casual motion and for providing a visible alarm. The motion detection device further includes a remote, tetherless receiver for receiving the alarm signal, the transmitter means repeatedly providing the alarm signal over a periodic interval until the processor is reset by an operator. The visible alarm is pulsed with relatively short pulses sufficient to activate the alarm, the short pulses being less than sufficient to activate the receiver.