A simulator with an elastic guidewire and vascular system for minimally invasive vascular surgery

Simulators play an important role in minimally invasive vascular surgery training. A challenging task for the simulator is to model an elastic guidewire and an elastic vascular system, both of which are important aspects for vascular surgery. However, many simulators treat the virtual vascular system as a rigid object, which reduces the immersion of operators. In this study, a virtual guidewire is first modeled based on Cosserat rod theory. Second, the stretching and bending constraints are introduced into the mass-spring vascular model according to the conservation of linear and angular momentum, making the model more stable and the deformation of blood vessels more realistic. Furthermore, the traditional dihedral angle constraint is replaced by our new bending constraint, which simplifies the complexity of the calculation. Finally, some experiments are conducted to demonstrate the effectiveness and accuracy of our vascular and guidewire models. Introduction. Simulators based on virtual reality are becoming continually more popular in the medical training domain. Furthermore, a training simulator for minimally invasive vascular surgery, which is an effective aid for treating coronary heart disease, can overcome many drawbacks of traditional training methods. The modeling of deformable objects presents a challenging task for such a training system. Zhang et al. [1] proposed a layered rhombus chain-connected haptic deformation model, and later in [2] a non-uniform regularizer was applied to perform the deformation smoothly. Sharei et al. [3] reviewed computerbased models in surgery training systems, and emphasized the importance of the deformation of the vascular system in the training system. However, this is not considered in many studies. In [4], virtual surgery based on rigid vascular and elastic guidewire models was introduced. In order to increase the immersion of doctors, an elastic massspring-based vascular model is proposed in this paper. Wang et al. [5] developed a method to identify the spring coefficient in a mass-spring model, and proved that the coefficient of elasticity is related to the radius of the blood vessel. In the original mass-spring model, a virtual spring with linear elasticity is assumed. However, this may result in a large deformation. Duan et al. [6] introduced new constraints to improve the accuracy of the deformation. In this study, we apply a length constraint and a new angular constraint to our mass-spring vascular model. Physical model. An overview of our simulator is presented in Figure 1(a). The guidewire and vas-