| 摘要 |
PURPOSE:To measure displacement with high accuracy by reducing a computed variable by calculating the displacement of a tissue in a direction along a scanning line based on an autocorrelation coefficient in a frequency direction for the product of one of one-dimensional Fourier transformed signals and the complex conjugate of the other signal at received signal parts segmented from two received signals provided at different time. CONSTITUTION:Data segmenting means 15 and 16 segment the received signal parts from two received signals, which are provided at two kinds of time of transmission timing, along the scanning line. The respective segmented received signal parts are inputted to Fourier transforming means 20 and 21, and Fourier transformed signals are inputted to a complex multiplying means 23. Besides, the complex conjugate is calculated by a complex conjugate arithmetic means 22, and complex multiplication is performed by the complex multiplying means 23. Then, the complex conjugate product is inputted to a complex autocorrelation arithmetic means 41, the complex auto-correlation of the complex conjugate product in the frequency direction is calculated, and the complex autocorrelation coefficient is calculated. Then, a phase arithmetic means 42 calculates a phase and a multiplying means 43 calculates the displacement in a depth direction. |
