TISSUE DISPLACEMENT MEASUREMENT USING ULTRASONIC WAVE ADAPTIVE DIGITAL DETECTION METHOD

We have developed an internal small-displacement measurement system ba sed on the ultrasonic wave pulsed Doppler technique. In the system, th e ultrasonic wave Doppler frequency shift due to tissue movement is de tected by using either an analog-type quadrature detector or digital d etection algorithm. In this paper,we propose an adaptive digital detec tion algorithm which can derive a Doppler frequency shift signal with higher precision and with higher Signal-to-noise ratio than the conven tional method. The comparison between the proposed method and the conv entional method is shown through both numerical analysis and basic exp erimentation.