A Study On Key Techniques Of Intraoperative Imaging Guidance In Stereotactic Neurosurgery

Neurosurgery stereotactic navigation system, developes rapidly in recent years, is one of focuses in biomedical engineering. Neurosurgery stereotactic navigation system mainly includes three modules: preoperation planning, navigation registeration and intraoperative therapy. Among them, navigation registeration not only determines the accuracy of operative location and a successful neurosurgery, but also the main point of this study.The present investigation is supported by the national high technology research and development program"Stereotactic neurosurgical navigation and the treatment system based on near infrared spectroscopy". The main aspects are as follows: (1) research on locating position of markers on patient's skull utilizing electromagnetic poisoning system, obtain real-time spatial position of surgical markers in the surgical spatial coordinate system with reference to preoperative imaging; (2) propose a new image interpolation algorithm to preprocess medical images and realize 3 dimensional visualization, then obtain position of surgical markers in the computerized spatial coordinate system; (3) introduce an algorithm to calculate the optimal transformation matrix derived from real-time surgical spatial coordinate system to computerized spatial coordinate system according to unit-quaternion and matrix principle during operative registeration, thus improve accuracy of operative registeration. Since surgical navigation is the inverse transformation of surgical registeration, it can start real-time navigating as soon as completion of surgical registration; (4) adopt Aurora locater producted by NDI Corporation, and develop a set of cerebral stereotactic neurosurgical navigation system software instructed by NIRS imaging utilizing VTK toolbox based on VC++ development platform. This software involves such functions: data preparation, surgical planning, model error correction, surgical registeration and real-time navigation etc.The main innovations of this study are as follows: (1) propose a new medical imaging interpolation agorithm based on wavelet-fractal adaptation matching interpolation, and its results correspond to requirements of medical imaging 3 dimensional visualizaition and surgical navigation better; (2) pose an algorithm used to calcuatle look-ahead distance of surgical planning; (3) put forward an algorithm to calculate the optimal transformation matrix derived from real-time surgical spatial coordinate system to computerized spatial coordinate system according to unit-quaternion and matrix principle.