An Echo-Tracking System for Recording Arterial-Wall Motion

Arteries expand with each heart beat due to the blood pulse pressure. The amount of expansion depends on the mechanical condition of the artery. An ultrasonic echo-tracking device has been developed specifically for recording arterial-wall motion. This instrument may be a useful diagnostic tool for detecting changes in arteries due to disease. The system uses a single voltage pulse to excite a 5-MHz crystal transmitter and an echo from the arterial wall is received. Pulses are generated at a IO-kHz repetition rate and the difference in transit time of consecutive pulses is converted into an analog output that corresponds to movement of the arterial wall. Examples of recordings are given.