Ultrasonic blood flow sensing apparatus

An ultrasonic Doppler blood flow sensing apparatus comprises a probe for sending an ultrasonic wave into a living body and receiving echoes, an ultrasonic diagnosing device for processing the echoes received to provide a tomogram signal, an ultrasonic Doppler blood flow meter for processing the echoes received to provide blood flow data, an electrocardiographic circuit, a gate for producing a sampling signal in response to an electrocardiographic signal from the electrocardiograph circuit, a random access memory for sampling and storing blood flow data sensed by the blood flow meter in response to the sampling signal from the gate, detectors for detecting a radius r of a blood vessel and a cosine of theta , where theta is an angle of direction of an ultrasonic beam with respect to a direction of blood flow at a part of the living body to be measured on the basis of the tomogram data derived from the diagnosing device, an arithmetic logic unit for calculating an average blood flow during a most recent one minute or for one or several most recent cardiac cycles on the basis of the sampled blood flow data stored in the RAM, the detected cos theta from the cosine detector and the radius r of the blood vessel from the r detector, and a monitor for displaying a tomogram defined by the tomogram data from the diagnosing device and an average blood flow from the arithmetic logic unit.