Research On Preoperative Path Planning Of Craniotomy Robot

The craniotomy in neurosurgery is an important surgical method for the treatment of patients with brain tumors and head trauma.According to investigations and studies,the annual number of craniotomy operations in Beijing Tiantan Hospital has reached14,000.Traditional craniotomy surgery has a high surgical risk factor,doctors have deviations in determining the patient’s scalp incision and skull bone window.Craniotomy are highly dependent on the doctor’s surgical experience.It takes at least two hours from cutting the skin to opening the bone window.A craniotomy robot is needed to help the doctor complete the craniotomy operation and save the doctor’s energy to complete the intracranial tumor resection.Therefore,it has important practical significance to plan the contour of the skull bone window and the scalp incision before operation.This paper focuses on the preoperative path planning for craniotomy.It is proposed a preoperative path planning strategy.This paper studies the threedimensional reconstruction of the patient’s head medical image,the RRT path planning algorithm as a basic research algorithm,and the recognition of the characteristic points of the skull,the main research contents are as follows:Firstly,according to the clinical requirements of craniotomy,the preoperative path planning strategy for craniotomy is proposed,the routine craniotomy procedure and the preoperative path planning procedure in this paper were introduced.The planning is carried out from the inside to the outside.A method for calculating the area of the bone window and a strategy to determine the area of the bone window S and the position of the surgical approach combined with the size and depth of the tumor are proposed.The related algorithms of global path planning and local path planning are studied and their shortcomings are analyzed.Secondly,under the VTK visualization mechanism,the CT image of the patient is read through the MC algorithm,and the patient’s skull model is reconstructed in three dimensions.The MRI image of the patient is read through the RC algorithm,and the patient’s head model is reconstructed.Thirdly,based on the sampling-based RRT path planning algorithm,the RRT*algorithm is developed,and the shortcomings of the RRT* algorithm were pointed out.The idea of target point-to-expansion is introduced to the RRT* algorithm,and it is verified that the space domain of the path search is significantly reduced after introducing the idea of target point-to-expansion.A three-dimensional path planning environment model was created,and the improved RRT* algorithm was trimmed and smoothed to improve the quality of path planning,so that the smooth path planned by the algorithm in the three-dimensional environment could meet the requirements of surgical incision.Finally,in view of the problem that the preoperative path planning is planned on the skull and head models,the surface of the model is irregular curved surface,and the model is parameterized.The position of the main feature points on the skull surface distribution was defined.According to the characteristics of the loaded STL 3D model,the surface curvature of the model and the included angle of vector geometry were calculated,and the identification of the feature points was completed to determine the location of the skull drilling points.The points with large curvature can describe the geometric structure of the 3D model contour and reflect the geometric structure information of the surface around the determined points on the model.The location of the tumor,the skull area and location of the drilling point and the area of the bone window S were determined preoperatively to complete the planning of the skull bone window and the planning of the scalp incision.