| 摘要 |
PURPOSE:To provide an ultrasonic diagnostic system excellent in S/N without impairing resolution and a contrast resolving power extending over a wide range with simplified constitution. CONSTITUTION:In this ultrasonic diagnostic system, ultrasonic waves are transmitted to an examinee, a reception signal is obtained by converting an ultrasonic echo reflected inside the examinee to an electrical signal, and the reception signal is level-compressed by a successive saturation type logarithmic amplifier 20, then image is displayed. The system is provided with a waveform processing circuit 4 which handles an input signal to the specific stage ST3 of the logarithmic amplifier 20 in such a way that a reception signal ¦Vi¦ is set as a signal passing a low-pass filter when it is smaller than a prescribed level Vth, and sets it as a signal which sets the output of the stage ST3 at a saturated level when the signal exceeds the prescribed level Vth. |
