Portable, low power, 10Mhz continuous wave ultrasonic Doppler blood flowmeter

In this study, working principle of continuous wave Doppler blood flowmeter and signal proccess techniques which are used in blood flowmeters are described in details. Also, electronic circuits which are generate portable, low power, 10MHz continuous wave ultrasonic Doppler blood flowmeter are explained. Designed continuous wave Doppler system, operating on 10MHz frequency and measuring blood flow in superficial small vessels. Continuous wave Doppler system consist of continuous wave Doppler transmitter and receiver which is detected Doppler shifts. Continuous wave Doppler transmitter?s 10MHz frequency signals are produced by crystal oscillator circuit. This signals also applied to the source transducer. In the ultrasonic receiver, demodulation and phase shift processing are done by AD8333 integrated circuit, low pass and high pass filtering are done by AD8021 integrated circuit. This system is different from similar Doppler systems because surface mount integrated circuits and surface mount devices are used for made small size, portable, low power blood flowmeter system. Electronic circuits of designed Doppler system are tested and waveform of outputs are examined in details.