Signals from the human body are stochastic, complicated and with strong environmental noise. In this paper, the quantitative blood flow velocity detection using the Doppler ultrasound technique was firstly presented .Then several new theories and approaches of the modern information processing were introduced into the medical ultrasound field, which provided new means to extract the characteristic of the medical ultrasound information. These theories include the fractal, the morphology, the quantification theory, the wavelet transform, the pole track, the transmission line of the vessel, and so on. Finally, three application systems were designed using these new methods as the technology cores： the non-invasive detection system for hemodynamic parameters of the pulmonary circulation, the color-encoded spectrogram analyzer and the ultrasound quantitative detection system for the blood flow velocity.