Study On A Micro Stereotactic Frame Creating Algorithm For Deep Brain Stimulation

Deep brain stimulation(DBS) electrode placement has been a well-established technique in treating Parkinson’s disease and epilepsy. It is performed through delivery of a tiny current at high frequency into certain basal ganglia region structures deep in the brain and achieves its effect by modifying neuronal activitiesIn order to perform DBS surgery, neurosurgeons need the help of stereotaxy. The traditional frame-based stereotaxis needs a set of complicated instruments and brings lots of inconvenience to the patients. Patients are kept awake during the prolonged surgical procedures and many of them find it difficult to tolerate the heavy and restraining frame. Based on this situation, this paper presents a stereotactic system and describes the algorithm used to create the micro stereotactic frame. The details are as follows:(1) Medical Image processing. The stereotactic system could read DICOM files and display the CT and MR images. Volum images will be interpolated when they are imported into the software system. The system could also fuse the CT and MR images after registration.(2) Algorithm for creating the stereotactic frame. A stereotactic coordinate system was created and the coordinates of the targets, entry points and screw points were got based on the stereotactic coordinate system. An algorithm was designed to reconstruct the 3D model of the frame based on Open GL, and the model was stored to STL file.(3) Skull model experiment. We designed an experiment based on a clinical skull model. A frame was manufactured based on the model. A usb-drived micro camera was mounted in the skull model to film the whole procedure of the operator pushing the steel needle to the target.The results of the experiment showed that the algorithm was able to use Open GL to create a 3D model based on the the medical image acquired from patient’s head. When the frame was manufactured by 3D printer, it could help the surgeon to navigate the insertion of the needle in the DBS surgery. The mean offset error is 0.76 0.05 mm, vector error is1.68 0.33. This error meets the requirements of DBS surgery.