Abstract

A cardiac monitoring system easily incorporated into existing electronic digital wristwatches. The self-contained unit monitors the arterial pulse rate by means of a pair of highly directional ultrasonic transducers positioned in a special mounting in the wrist band of the watch. This special mounting also includes an integrated circuit which contains the transmitter and receiver-detector electronics for connection to the transducers. The output signal from the receiver in the special mount is fed via a shielded cable in the wrist band to the processing electronics physically located within the face mounting of the watch. The processing electronics monitors the user's pulse rate and provides a digital output indication thereof if it exceeds pre-established upper and lower threshold limits. The processing circuitry also includes means for detecting an erratic heartbeat, such as a missing pulse or other irregularities, and provides an output alarm indication, both audio and visual, when such is detected. The unit is entirely self-contained and utilizes the wristwatch's standard battery power supply. External select switches are preferably provided for selection of either a time or pulse rate readout.