| 摘要 |
PURPOSE:To exactly execute the picture display of low velocity information such as the heart wall or valve as well by providing a switch to change over and output either a filter output or a difference computing element output and selectively obtaining the low velocity information and high velocity information. CONSTITUTION:For a received signal obtained in a receiver 14, a frequency component is taken out by an orthogonal detection part 16 and a Doppler signal is formed by a composite signal. The outputs of A/D converters 18a and 18b are supplied to high-pass filters 20a and 20b and delay lines 22a and 22b and only the Doppler signal at high speed is taken out of the high-pass filter 20. In a subtracter 24, the output of the filter is subtracted from the output of the delay line and only the low velocity information are taken out. This selection of the high velocity information and low velocity information is executed by switches 26a and 26b to be interlocked. When this switch 26 is changed over to terminals A and A' side, the blood stream of the heart is superimposed on the tomogram picture of the heart samely as a conventional device and the picture display is executed two-dimensionally. |
