Quantitative assessment of the phase tracking method for measurement of the elastic characteristics of arterial wall

The minute change in thickness of the arterial wall during one heartbeat is measured by the phase tracking method based on the constraint least squares method that detects displacement of the arterial wall with high precision from the instantaneous phase of the reflected wave, and then the elastic characteristic is detected. However, a propagation-attenuation effect introduces the error due to the shift of the center frequency in the reflected wave. In this paper, using a modified quadrature detection method, the thickness change of the vessel phantom has been measurable by 0.5 /spl mu/m accuracy.