A multiple range-gated echocardiographic signal processor has been developed for the purpose of converting the complex ultrasonic image of the left ventricular anterior and posterior wall boundaries to equivalent analog signals as a means of estimating stroke volume and computing cardiac output. Two conventional time-analog range-gated modules have been redesigned and synchronized with the initial transmit pulse of 1000 hz, for the purpose of simultaneously gating echocardiographic images of the anterior and posterior left ventricular walls. Each echocardiographic image boundary is selectively gated in the A-Mode and adjusted to a width exceeding the maximum wall motion. The gated echocardiographic boundary of each time-analog channel is processed by a fast-attack envelope detector and a low-pass filter network to produce a D.C. analog signal corresponding to the motion of the left ventricular anterior and posterior wall. These analog signals serve as the basis for the estimation of ventricular stroke volume and the computation of cardiac output.