Deformable organ model using the sphere-filled method for virtual surgery

The authors have been developing a virtual surgery simulation system that uses virtual reality techniques. In order to perform real-time simulation, they have to develop a deformable organ model. They made a method to create an elastic organ model by the name of 'sphere-filled model'. This model is suited for real-time simulation and quantitative deformation. Furthermore, the authors equipped this model with a sense of touch and a sense of force by connecting it to a force feedback device. With a patient's 3D image reconstructed from MRI, one will be able to perform virtual surgery while taking into account individual differences in organ shape, blood vessel structures and so on. Normally, manipulations of an organ model were limited to the basic surgical maneuvers. However, the model in initial stage becomes unmanageable when faced with complicated incisions. Therefore, the authors modified this model by using a new algorithm for organ deformation which permits various, complicated incisions. The modified sphere-filled model provided the system with a more realistic simulation of various organ manipulations in virtual space.