An Eight-channel ultrasonic displacement meter was developed to evaluate the effect of left ventricular assist devices (LVAD) on the performance of a natural heart. A pair of miniature ultrasonic sensors of 2 or 2. 5 mm in diameter made of piezoelectric ceramic of 6 MHz were used for each channel. Ultrasonic pulse waves are emitted from one of two sensors at the rate of 1. 95 kHz and received by the other. The transit time is proportional to the distance between two sensors. In acute experiments, LVADs were implanted in mongrel dogs between the left atrium and the descending aorta. Pairs of ultrasonic sensors were installed in the left ventricular wall to measure dimensional changes of ventricular length in the short and long axes as well as of segmental length of cardiac muscle. It has been shown that this system is very useful for studying the effect of LVADs on the performance of the natural heart.
|Japanese journal of medical electronics and biological engineering
|Published - 1984 4月 1
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