Abstract: A monitoring system for a bed patient comprising a binary signal generating means to provide a first signal when the patient is in the bed and a second signal when the patient is out of the bed. An alternating electrical power supply passes to a frequency divider so that electrical pulses of selected time spacing are derived by means of which time can be measured. These pulses go to a signal delay means with adjustments possible for any selected delay and then to a latch means. Alarm control means are provided responsive to the operation of the latch for controlling the nature of the alarm signal. The alarm control means alternately provides electrical alarm signals of various sorts, such as a single short pulse or an indefinitely long pulse or an alternating signal. Each of these could separately control a visual or audible alarm means. This invention is compatible with normal call equipment and alarms in hospitals.

Abstract: A switch placed in a bed under a patient comprises two spaced parallel strips of insulating material carrying contact means therebetween. When the strips are straight the switch is closed, and when the strips are bent into an arc the switch is open. The closing of the switch starts an electrical oscillator, which activates a counter, and at a selected count a latch is set to actuate an alarm.

Abstract: A switch placed in a bed under a patient, includes contacts which can make or break a connection to a signal processing circuit. The signal processing circuit charges a capacitor at a selected rate, when the switch is in a first state and discharges the capacitor when the switch is in a second state. A latch is set to actuate a signal when the voltage of the capacitor reaches a selected high value. By controlling the rates of charge and discharge of the capacitor it is possible to provide an indication of the degree of restlessness of the patient, the presence of the patient in bed, and whether the patient is out of bed.