| 摘要 |
PURPOSE:To digitize a filter circuit without enlarging a circuit scale. CONSTITUTION:An ultrasonic reflection signal obtained from a living body is converted to a digital signal by an A/D converter 12, and inputted to one terminal of a digital adder 13 of a filter circuit 11. The digital adder 13 inputs a part which is outputted to the other terminal of the digital adder 13 through a D/A converter 14, a low-pass filter 15 and an addition A/D converter 16. The digital adder 13 adds a digital signal from the addition A/D converter 16 to the digital signal inputted from the A/D converter 12, and outputs it to a post-stage side. In such a way, the whole filter circuit 11 works as a high-pass filter. A DSC converts a passing signal of the filter circuit to a TV scan and outputs it to a display part. An ultrasonic image whose contour is emphasized is displayed on the display part. |
