Modeling And Simulation Of Minimally Invasive Surgical Robot Brain Surgical Force Telepresence System

During minimally invasive surgery, the doctor’s surgical operation is often limited to anarrow space, the doctor with the surgical instruments through the working channel, richvisual and force information like open surgery is lost. The bandwidth of the manpower tactileinformation generally about1000HZ, through the absorption of the elastic deformation of thesurgical instruments and systems gap, the bandwidth of the tactile information only dozens ofHZ, perception channel is obstructed obviously. It is prone to malfunction of operation andreliability is reduced greatly because of the vagueness of the information. Especially forhuman tissue like the brain of such a complicated structure, the small error in the time ofsurgery may result in patients with lifelong disabilities. It is provided more fortwo-dimensional image of CT, MRI formerly, the medical observation and analysis is notvery intuitive, it is unsafe to the complex brain surgery. This article focus on thethree-dimensional modeling of brain tissue and the reproduction of the tactile information, itis based on the full study of minimally invasive surgery, robotics, virtual surgery, medicalimage modeling, force telepresence system and other related technologies at home and abroad,which provide an intuitive and force telepresence simulation system for the brain theminimally invasive surgical, and it provides an effective technical means to ensure the safetyand reliability of the surgical operation.The design of the force telepresence system includes the two parts of three-dimensionalgeometric modeling and virtual surgery simulation scenarios. In the brain organ modeling, thefirst step using the weighted average method to the image to grayscale conversion，which isfacilitated subsequent processing; the second step using smoothing linear filters for imagefiltering enhancement to filter image noise and smooth the signal; the third step is to take thedual-threshold to do the image sementation and then use the manual segmentation method,mathematical morphology method for the compensation; the fourth step is geometricmodeling by the surface rendering algorithm based on the surface model. Surgicalinstruments modeling by selected Pro/E software. The virtual surgery simulation scenarios isdesigned by the haptic rendering engine Chai3d, the manipulator omega.6the SDK, whichfocused on the key part design of model import, collision detection, haptic computing in thepaper. The model import was described in detail based on programming in Chai3d, to achievethe rapid import of the model; collision detection is based on bounding volume hierarchy treealgorithm, axial bounding box is selected as the type of bounding box, a fast collision detection is achieved; haptic computing by using spring mass damping model, the model issimple, fast, force telepresence in the virtual environment is simulated realistically.Force display and3D modeling of the human brain organs and surgical instruments isachieved in paper. The system can be used simulation studies in the preoperative repeatly bythe doctor,.and the rotation, amplification, collision of human organs under the external forceof the surgical instruments is simulated realistically. So the doctor can acquires the reliableoperation path and developes the more rational surgery program. Then using theself-monitoring mode of the teleoperation technology planned a set of commands to thesurgical robot and to complete the operation of the brain minimally invasive surgery. Theteleoperation command through the pre-simulation to prove no problem, and then distributeto the minimally invasive surgical robot to operate and improve the safety and reliability ofthe surgical operation effectively.