Design and characteristics evaluation of a novel VR-based robot-assisted catheterization training system with force feedback for vascular interventional surgery

Vascular interventional surgery has been become a specialized surgical technique because it can minimize the trauma and shorten the recovery time, but it needs more accurate operation and image to guide the surgery. In the meantime, it needs that the doctor has a great deal of experience. Moreover, it needs to train the novice because of the lack of experienced neurosurgeons. In order to solve aforementioned problems, the training system for vascular interventional surgery was proposed. A novel VR-based robot-assisted catheterization training system is designed to solve these problems. This system is composed of the virtual environment and the haptic device. The virtual environment included a catheter model and a vascular model to realize the synchronous movement with the haptic device. In order to imitate soft tissue deformation, mass-spring model has been proposed in physical modeling. In this paper we established a dynamics equation of the moving catheter. We analyzed the elasticity distribution of the wall of vascular according to the previous research. The haptic interaction device based on magneto-rheological fluid as the master manipulator was applied to control the movement of the catheter model in the virtual environment and realize haptic feedback. At the same time, a force feedback calculation model for the novel master manipulator has been proposed. Ten times experiments both in axial movement direction and in radial movement respectively, are carried out, there was within 0.74 mm error in axial movement direction and 3.5° error in radial movement direction. When the moving speed of the catheter is 5 mm/s, the force error between the virtual environment and the feedback force of the damper is within 0.3 mN. The error is in the range which is permitted during VIS. The proposed method improved accurate operability and traceability in this novel VR robotic catheter training system. It offers users better visualization and control. The experimental results indicate that the performance of the synchronous movement and the force feedback can meet our design requirement. The developed training system can be used to train novice for VIS.