The utilisation of signal processing techniques in nondestructive testing especially in ultrasonics, is widespread. Many signal processing algorithms have been used to analyze ultrasonic Doppler signals. The Wavelet Transform (WT) is the most recent technique for processing signals with time-varying spectra. The WT allows better time-frequency resolution than the conventional signal processing techniques, and the WT efficiently detect fluctuations in signals. So, because Doppler ultrasound signals is non-stationary, in this work, the WT is utilised to improve reconstruction of the Doppler ultrasound signal. The signal is measured from Carotid Artery. In this work, orthogonal wavelet transform is applied in the signal.