Abstract
This paper deals with a system and a method by which echo signals of M-mode echocardiogram obtained using a conventional ultrasonic diagnostic instrument are stored in a video tape and the echo signals transferred to a minicomputer directly from the instrument or through the video tape are processed automatically. For these purposes, a special interface circuit is equipped to connect the ultrasonic instrument to the minicomputer and the video tape recorder, and the emission of a burst of ultrasound is synchronized with the external timing pulse. Using this system the M-mode echocardiogram stored in the video tape can be repeatedly displayed on the oscilloscope of the instrument.
The M-mode echocardiogram for about 1.6 seconds is usually digitized in 256×200 pixels with 8-bit gray level and used as an image to be processed by the minicomputer. After detecting the positions of cardiac structures, i. e., interventricular septum and endocardium and epicardium of the posterior wall of the left ventricle, cardiac information, such as on the change of wall thickness, velocity of circumferential fibre shortening, volume change of the, left ventricle and So on, is obtained. Some clinical results are also shown.
