Three-dimensional modelling for an intraoperative stereo-vision system

Success rates of scoliosis surgery are very dependent on the skill and experience of the surgeon. An objective measurement tool would provide surgeons with insight into the successes and failures of these surgeries. This work continues the development of an Operating Room Imaging System (ORIS) capable of tracking the three-dimensional (3D) motion of artificial markers rigidly attached to vertebrae during the surgical correction of scoliosis.;Accuracy experiments were conducted on ORIS. Small predetermined displacements and rotations were made to artificial markers mounted on the spinous processes of vertebra while results were recorded by the stereo-vision system. The system was determined to have an accuracy of ;Because ORIS detects the position and orientation of artificial markers, a model was developed to relate the artificial markers to the vertebrae for visualization. Geometry, vector analysis, and stereo-radiographs were used to relate the artificial markers to the vertebrae. Experiments were done using stereo-radiographs and an electromagnetic digitizer to determine the orientation and position of vertebrae in a simulated operating room (OR) environment. Results demonstrated that the model performed as expected when supplied accurate data from an electromagnetic digitizer. Stereo-radiographs however were deemed too inaccurate to provide the necessary data for the model.;Additional tools were added to the visualization stage of ORIS. Multiple simultaneous views of the spine were added. The user can view successive stages of the surgery also. Various 3D computer models of vertebra were developed to investigate optimal spine graphical representation. Surgeons were asked which model was most useful to them as a tool in spinal visualization. They favoured the more detailed models despite the longer rendering times.