Evaluation of a visual matching registration technique for intra-operative surgery support

In the field of image-guided surgery, registration of pre- and intra-operative images is all important, yet some times cumbersome procedure. Visual matching, consisting of a manual alignment of such images call improve the efficiency of registration. In this paper we investigate the accuracy of a visual matching system. A number of tests, including mono and stereo visualization of real and virtual objects, was set up. Seven test subjects were asked to register pre-and intra-operative images while accuracy and registration time were measured. The error analysis led to the conclusion that one can accurately match a virtual phantom with a real one in directions perpendicular to the viewing direction. The depth accuracy though is insufficient for registration purposes, even when using stereo perception. We conclude that visual matching call be complementary to more automatic registration methods or even a valuable alternative in applications where the viewing directions are nearly perpendicular as in bi-plane fluoroscopy.