Research and Development Center, Hitachi Medical Corporation
To display the blood flow pattern, some real time frequency analysis technic is used popularly. These are FFT (Fast Fourier Transformation), CZT (Chirp Z Transformation) and heterodyne method for time compression. But, by any real time frequency analysis technic, the blood flow pattern is delayed with other display i.e., M-mode, ECG or PCG. I have analyzed this delay time by simulation and experimentation. The good agreement is obtained in the simulation and experimental result.