New method of Doppler angle measurement and flow velocity correction in 3-D space

Since the Doppler angle is hard to measure correctly, current ultrasound blood flow measurement systems can only provide the axial component of the true blood flow velocity. This limitation can be overcome with a new Doppler angle measurement and flow velocity correction method in 3 D space based on electro magnetic position sensor presented in this paper. First, the vessel's structure is reconstructed in 3 D space using the outputs of an electro magnetic position sensor. Then, the Doppler angle and flow velocity are estimated from the orientation between the ultrasound beam and the blood flow. Experiments show that the new method provides good accuracy for Doppler angle measurements and 3 D flow velocity estimates.