Abstract:The efficiency of the extracorporeal shock wave lithotripsy treatment depends to a great extent on the capability to focus the shock waves on the stone, so to achieve this goal, recognition of the stone and tracking it is essential for good treatment. Two algorithms were proposed to track the renal stone; their results were compared, to determine the most successful among them. The proposed tracking algorithms for the stone contain four main stages; the preprocessing stage that includes enhancing the ultrasound image and reducing to a great extent the effect of the correlated speckle that is considered as the main challenging issue when dealing with ultrasound images. The second stage includes segmenting the obtained image by using one of the two proposed methods, the first method was the application of canny edge detection, and the second method is by using fuzzy c-means. The third step includes the application of Morphology operations to correct the resulted image and make it more suitable for easily finding the centroid. The fourth step then determines the centroid of the stone, and accordingly the focus of the shockwave generator is set to be directed to the center of the stone. (MATLAB 7.6.0 R2008a) was used to build a program that do all of the stages of the algorithm, while different renal ultrasound images that have different qualities were used, to ensure that the proposed methods can fit each case.