| 摘要 |
PCT No. PCT/IB95/01055 Sec. 371 Date Aug. 6, 1996 Sec. 102(e) Date Aug. 6, 1996 PCT Filed Nov. 24, 1995 PCT Pub. No. WO96/17549 PCT Pub. Date Jun. 13, 1996Automatic measurement is made of the angle DA enclosed by the direction of ultrasonic echographic excitation and the axis of a vessel in an echographic image on the basis of prior designation of an initial point Pi in the vessel. A first isotropic tracing of rays starting from the initial point Pi is used to produce a histogram of the grey levels of the points of the rays. An algorithm is then applied to the histogram in order to classify the grey levels of selected points. A second tracing of rays is made which is restricted to the walls of the vessel and results in a local mark with triangular sectors from which the slope (a) of a regression line is determined and the calculation of the Doppler angle DA is made as DA=Arc tg(a). |
