| 摘要 |
PROBLEM TO BE SOLVED: To allow quick signal processing without using a high-speed processing filter circuit and reduce the cost by converting the ultrasonic reception signal into the base band complex signal by orthogonal detection processing, processing it with a complex filter, and changing the filter characteristic of the complex filter along the time series. SOLUTION: This ultrasonic diagnostic device is provided with a dynamic filter 5 applying filter processing to the ultrasonic reception signal received by a transmitting/receiving circuit and A/D-converted by an A/D converter 4 and extracting only the signal in the required band. The output signal of the filter 5 is fed to a digital scan converter via a logarithmic amplifier 6 and a rectifying circuit 7. The dynamic filter 5 is provided with an orthogonal detecting circuit 10 applying orthogonal detection to the reception signal after A/D conversion and generating base-band complex signals I, Q, applies complex filter processing to the complex signals I, Q with the complex filter 11, and changes the filter characteristic of the complex filter 11 along the time series. |
