Abstract
Several causes of spatial errors in surgical navigation system have been investigated for several systems. These include identification error of the external features used for registration, geometrical distortion in the preoperative images, and tracking error of the surgical instruments. Another potentially important source of error is the patient head position detection retrospectively and concurrent with surgery. The visualization of target zone is carried out according to reference landmark points inside the center of the brain as well as an automatic algorithm for contour recognition (based on 3D segmentation and computer morphometry) was applied to edge the contour. Moreover, the optical navigation system was used to assess the accuracy of determination the position of the surgical instrument inside patient head construction using the "internal map" describing the anatomy of the brain. The major sources of errors occurring in the unit of position detection of the optical navigation system were considered. Furthermore, parts of the errors that could appear were simulated while operating the surgical navigation system. Eventually the research included the possibility of using different filters depending on natural source of noise that was also simulated and analyzed.