Host: Japan Society for Fuzzy Theory and Intelligent Informatics (SOFT)
This paper describes an ultrasonic registration system for locating screw hole positions of intramedullary nail. Currently, X-ray has been used for visualizing the nail into the femur. However, it has serious problem of X-ray exposure. We propose a locating method of the screw hole positions by doing a image registration. We perform an experiment by one-direction manual scanning using an ultrasonic array probe. In our method, first, we extract screw hole regions by calculating two fuzzy degrees: average of the intensity of eight neighborhood and variance of the intensity along long axis of the nail using fuzzy inference. Next, we do a registration between the obtained image with the exact image, where the exact image is the truth image of the nail. The position of screw holes in the obtained image is calculated by moving from coordinate of screw holes in the exact image using the translation matrix. As the result, we could locate the screw holes on center axis of the nail and calculate the center distance of two screw holes within an error of 1.0 mm.
