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本文介绍了一种新的连续波多普勒仪,它能无创测量病人升主动脉的峰值主动脉血流速度和加速度。该仪器采用一般的连续波多普勒发射器与接收器,工作频率为3.0MHz,用一正交解调器处理多普勒频移信号,以便仅仅检测朝向传感器的血流信号,该定向信号经边带滤波器后送至自动增益电路,使多普勒信号具有等幅度,再送至描迹器,绘出瞬时频率与峰值速度的关系曲线,并将其中最大的速度值确定为峰值速度。为了检验该仪器的精度,对16条开胸的经麻醉的狗进行了实验,比较了用该多普勒仪与电磁血流计所测得的升主动脉血液
This article describes a new continuous wave doppler that provides noninvasive measurement of peak aortic blood flow velocity and acceleration in a patient’s ascending aorta. The instrument uses a generic CW Doppler transmitter and receiver operating at 3.0 MHz and processing the Doppler shift signal with a quadrature demodulator to detect only the blood flow signal toward the sensor, Sideband filter to the automatic gain circuit, the Doppler signal with equal amplitude, and then sent to the tracer, draw the instantaneous frequency and peak velocity curve, and which the maximum speed is determined as the peak speed. In order to test the accuracy of the instrument, 16 thoracotomy anesthetized dogs were tested and compared with ascending aorta blood measured by the Doppler and electromagnetometer