Doppler Pulse Detection

多普勒脉冲检测

The Doppler effect in an ultrasonic pulse probe detects the reflected sound from moving blood. The frequency of the reflected sound is different, and the beat frequency between the direct and reflected sounds can be amplified and used in earphones to hear the pulse sound.

多普勒效应在超声脉冲探头中用于检测移动血液反射的声波。反射声的频率不同，直接声与反射声之间的拍频可以放大并用于耳phones听到脉冲声。

Further discussion

进一步讨论

Doppler arterial scan

多普勒动脉扫描

Index

Traveling wave concepts

行波概念索引

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Doppler Pulse Probe

多普勒脉冲探针

The pulse of a premature infant may be very difficult to detect with a stethoscope since the sound produced is extremely faint. A sensitive Doppler pulse probe can be used to advantage because it detects the movement of the blood through an artery. The ultrasonic echo from the moving blood can be mixed with the source frequency to produce a beat frequency. As the blood surges with the pumping action of the heart, the beat frequency signal changes in frequency and amplitude.
Remarkably, in clinical Doppler pulse detectors the sound output is similar in nature to what you hear with a stethoscope; you immediately recognize it as a pulse sound.
令人惊讶的是，在临床多普勒脉搏检测器中，其声音输出的性质与你用听诊器听到的相似；你立刻就能识别出这是脉搏音。

早产儿的脉搏可能很难用听诊器检测到，因为产生的声音非常微弱。使用灵敏的多普勒脉搏探头可以发挥优势，因为它可以检测动脉中血液的流动。来自运动血液的超声回波可以与源频率混合，产生拍频。当血液随着心脏泵血动作 surge 时，拍频信号的频率和幅度会发生变化。

Index

Traveling wave concepts

Doppler concepts

索引波动概念多普勒概念

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