CARDIOTACHOMETER

摘要

A pair of doppler type ultrasonic transmitters and receiving devices are employed, one operating at a frequency lower than the other. Each of the devices are connected to a demodulator to produce first and second doppler frequency signals, one indicative of vascular blood flow, the other indicative of movement of the vascular wall. The doppler frequencies are fed to a signal processing circuit and a reference stage received as its input, the output of the signal processors. The reference stage produces an output signal on coincidence of the two input signals which is indicative of the heart-beat frequency.