Research On Preoperative Planning And Intraoperative Positioning Technology For Neurosurgery Navigation System

Neurosurgery Navigation System using modern imaging,stereotactic,advanced computer and other technologies,enables physicians to operate surgery in patients with sufficient preoperative assessment,detail planning paths and solutions.During the operation of surgery,the surgery can be more minimally invasive with surgical instruments' accurate navigation.And after the surgery,surgery evaluation can be made via the recorded data analysis.Therefore,navigation system's application in neurosurgery is of great significance to improve surgery position accuracy,reduce operation damage and optimize the surgery path,and so on.Foreign research for surgery navigation system started relatively early and its technology research has been very mature.In China,the basic research and development of the advanced digital equipment are still weak.Navigation equipment in most large neurosurgery centers are relied on foreign import.With micro invasive neurosurgery concept's extensive promotion at all level hospitals in our country,their demands for navigation technologies are increasing,especially for domestic nerve navigation equipment with advanced technology,convenient operation and low cost.Therefore,the two main functions of navigation system,namely,preoperative surgery planning and intraoperative localization,are studied in this thesis.The main research contents are as follow:Firstly,in the preoperative surgical planning,a multiple modal data registration and fusion method based on a 3D model is applied to acquire comprehensive information of soft tissue and bone tissue.And then the 3D virtual model is set up,which intuitively shows the relationships of all organizational structures.According to the 3D virtual model,the entity anatomical model will be produced through 3D printing technology.Thus it can be used to explore the application of 3D printing technology in the treatment of intracranial tumor disease.Secondly,in the aspect of intraoperative localization,a stereotaxic method based on binocular vision is selected via the comparative analysis of various common navigation stereotaxic methods.And its 3D positioning and stereo matching principle are analyzed.Finally,a simple hardware platform of binocular stereovision system has been built to verify the effeteness.Thirdly,for probe identification and positioning during the navigation,an X corner detection method based on the principle of the saddle point detection is proposed.It can quickly and accurately identify the markers on the probe.The spatial coordinates of the above identified markers are obtained by the matching method based on the feature points.And the probe calibration method based on stereo vision is adopted to get the accurate relationship between the probe tip point and the markers.Finally according to the coordinate transformation relation between the probe tip and the markers,the spatial coordinate of probe tip is obtained,so as to realize the accurate positioning of the probe.Finally,for spatial registration during the navigation,a multi-point automation registration algorithm is proposed.The algorithm unites the 3D virtual model,intraoperative real patient and surgical instruments to a common coordinate system.And through a series experimental results,the influence factor of registration accuracy are discussed,thus to further improve the positioning precision of the navigation system.