Study and Implementation of a Signal Processing Algorithm for Doppler Ultrasound Fetal Heart Signals

The Doppler ultrasound fetal heart signals are weak and complex, while the background noise is strong. It results in many problems for household integrated Doppler fetal heart monitors, such as low sensitivity, small measuring area, low accuracy of fetal heart rates, and self-excited howling. A fetal heart signal processing algorithm is proposed in this paper, which includes the adaptive denoising method based on spectral subtraction and the non-linear self-excitation suppression processing algorithm. The measuring results in a Doppler ultrasound fetal heart simulator and pregnant women show that the good denoising effect can been achieved and the signal-to-noise of the signals can been greatly enhanced by the proposed algorithm. Also, the sensitivity of fetal heart measurement is improved and the self-excited howling is eliminated effectively.