| 摘要 |
<p>An ultrasonic device for measuring the acceleration of a moving reflective member that is useful in ultrasonic image diagnosis. The device transmits an ultrasonic wave into a living organism and upon receiving the wave reflected by a moving reflective member in the organism, calculates and visually displays the acceleration of the moving reflective member. The device consists of a complex signal converter for transmitting a periodic pulse modulated wave into a living organism, receiving a reflected signal from a moving reflective member in the living organism and converting the received signal into a complex signal, and an acceleration measurement means having a plurality of complex delay lines with delay times equal to an integral multiple of the pulse period, said acceleration measurement means calculating the acceleration of the moving reflective member from the signals output by the complex signal converter and the signals output by the complex delay lines. The acceleration measurement means is an acceleration calculator consisting of a velocity calculator and a difference calculator. The acceleration of the moving reflective member is derived from the argument of the triple-complex product, or from the difference in the velocities represented by the output of the velocity calculator at two different instants. In either case, the acceleration can be calculated without need to differentiate the velocity. Moreover, in the case of using the triple-complex multiplier, a highly accurate measured value can be obtained. whereas in the case of using a velocity calculator and an acceleration calculator, the structure of the device can be simplified.</p> |
