Research On Accurate Craniotomy And Skull Repair Technology By Surgical Navigation

Because of the complex internal structure and plenty of important functional tissues of the brain,intracranial tumor usually causes harm to patients,therefore the technique of neurosurgery is high demanding.It is necessary to minimize the patient's intraoperative trauma so that improves the postoperative recovery speed and reduces the occurrence of surgical complications.Surgical trauma usually occurs during craniotomy and lesion removal,and the effect of skull defect repair affects the prognosis of patients.Therefore,accurate intraoperative location of the lesion area,craniotomy incision planning and intraoperative skull reconstruction are important research issues in current neurosurgery.In order to solve the above problems in neurosurgery,we studied combined with the optical surgical navigation equipment.The research contents are as follows:(1)The markless space registration technology based on patient's facial information.In order to achieve accurate intraoperative navigation,we proposed an accurate matching method to get the transformation relationship between operation space and image space with the patient surface information in both spaces.Then we verified the accuracy of the method through head model experiment and simulated human experiment.The experimental results showed that the error of the matched points is less than 1mm and the target registration error(TRE)is 1.81 mm,which meets the clinical requirements.In addition,this method avoids the consumption of medical disposable materials,and reduces the operation steps for surgery.(2)Craniotomy incision planning technology based on intracranial lesion area.In order to reduce the trauma caused by craniotomy and assist the doctor to determine the location and size of the craniotomy incision,we designed a craniotomy incision planning technique,which can plan the craniotomy incision preoperatively or intraoperatively and modify the incision according to the doctor's planning.The experimental results showed that the incision shape could generate according to the shape of the lesion and the projection direction,smooth and scale operations could be carried out as required.Moreover,the projection of the incision shape to the scalp was more than 10 times faster than the traditional method,which reduced the time spent in the incision planning step.(3)Reconstruction technique of skull defect patch in craniotomy.In order to reduce the incidence of postoperative complications caused by skull repairing,we designed an accurate reconstruction method of skull defect patch.The first step of the method is to design and produce the patch with preoperative scanned medical images.Then the actual defect edge is obtained by of the optical navigation system so that we can calculate the corresponding defect edge in image space.After the patch registration step is performed,the defect edge on the patch can be obtained.Then the patch can be tailored along the edge so that the patch can be constructed into the same structure of the actual defect.The method was verified by animal experiment,and the experimental results showed that the patch was consistent with the edge of skull defect,and the animals recovered well after surgery.The verification results showed that the proposed markless space registration techniques can locate lesion accurately during surgery;the proposed craniotomy incision planning technology can realize personalized planning according to the structure and location of the craniotomy and the requirement of the doctor;the reconstruction technique of skull defect patch technology can get the skull defect patch with the same structure of actual defect.