Extracting of the ultrasound fetal heart rate signal based on wavelet packet mix node threshold

Clinically, fetal heart rate, to a certain extent, reflects the health of the fetus. Therefore, how to extract the fetal heart rate signals in ultrasound fetal heart rate signal processing has been a key issue. In this paper, a new wavelet packet mix node threshold (WPMNT) denoising algorithm based on the maximum wavelet packet energy entropy is proposed. Moreover, based on the threshold given by the new algorithm, a new wavelet packet threshold function is constructed for ultrasound fetal heart rate signal denoising. Experimental results show that this algorithm gives better signal noise ratio (SNR) gains and mean square error (MSE) performance than traditional algorithms.