| 摘要 |
PURPOSE:To stably observe the tomographic image of a lumen by operating the center-of-gravity position of an ultrasonic tomographic image and superposing the same on the center position of a screen. CONSTITUTION:The echo data stored in an echo data memory 17 is stored in a display memory 19 through a DSC circuit 18. The DSC circuit 18 performs the coordinates transformation from an orthogonal coordinate system to a polar coordinate system. The center of an ultrasonic probe (the origin of radial scanning) is altered corresponding to the displacement of the relative position of a lumen and the ultrasonic probe. This displacement is detected by detecting the shift of the center of gravity of a tomographic image from the echo data. The shift quantity of the center of gravity of the tomographic image to the origin is calculated as a center-of-gravity position. Then, the origin is calculated at every frame from the center-of-gravity position of the detected tomographic image and the position of the center point of the screen on the display memory 19 according to a predetermined formula. By converting the center-of-gravity position of the tomographic image, the shift of the center of gravity of the tomographic image in the display memory is corrected. |
