Research On Soft Tissue Model In Telemedicine Simulation Syste

With the steady improvement of telemedicine technology and the continuous development of computer related technologies such as 5G,telemedicine simulation systems play an important role in solving the treatment of infectious diseases and the uneven distribution of medical resources.It can break through the geographical and technological constraints of traditional surgery,providing a new surgical approach for modern medicine,and therefore,the research on telemedicine has far-reaching significance,it is a hot and cutting-edge topic in the medical field.The flexible body deformation model is the most critical research in the field of telemedicine.It is related to the real-time and realistic simulation of the deformation process of tissues and organs,and it is a key factor for the success of doctors’ surgery.However,due to the extremely complex deformation process of flexible bodies during contact,it is difficult to vividly simulate,resulting in very difficult research.As the most critical part of telemedicine,how to simultaneously meet the requirements of model accuracy,interactive real-time,and visual fidelity is an urgent research challenge.Therefore,this article focuses on the two issues of satisfying the balance between accuracy and real-time performance of flexible body models,as well as the requirements for visual fidelity of model simulation.It in-depth studies the deformation process of soft tissue models in remote surgery,and carries out model optimization.The main research work of this article is as follows:(1)To solve the balance between model accuracy and interactive real-time,this paper proposes a finite element model based on the variable step size fourth order Runge Kutta method,which improves performance from both accuracy and real-time aspects.Firstly,a three-dimensional physical modeling of the lung was performed by combining a finite element model with a single step high accuracy variable step size fourth order Runge Kutta numerical calculation method.Compared with the optimized implicit Euler method,its single step accuracy is two orders of magnitude higher.In addition,due to the increase in the number of solving steps,the calculation amount will increase,and the calculation process of traditional methods is complex and time-consuming.A single solution optimization algorithm is proposed to solve the step size selection problem.The relationship between truncation errors is skillfully utilized to quickly solve the step size that meets the accuracy requirements,thereby saving the time for traditional methods to repeatedly halve or double the step size.In addition,the steepest descent method is prone to a sawtooth phenomenon when approaching the minimum point.In order to further improve real-time performance,in the early stage of this article,the steepest descent method was used to iterate to the vicinity of the minimum point,and then the Newton iteration method was used to accelerate convergence,in conjunction with GPU acceleration.This can effectively solve the problem of slow convergence near the minimum point when only using the steepest descent method,to improve the computational efficiency of deformation calculations.(2)Aiming at the problem that a single finite element model cannot meet visual fidelity,this paper proposes a high fidelity virtual model incorporating biological characteristics.From the perspective of simulating the unique biological characteristics of soft tissue,it is the first time to incorporate multiple biological characteristics such as viscoelasticity,nonlinearity,and anisotropy into the liver model,in order to obtain a virtual liver model with higher fidelity.The simulation of various biological characteristics of the liver makes the deformation process of virtual liver tissue during surgery more vivid and realistic,to enhance the doctor’s experience of surgery.In addition,when simulating the resection of the diseased liver,the model will undergo a plastic deformation process that loses elasticity due to excessive deformation,but has not yet reached the fracture threshold.Due to the fact that only considering viscoelastic models cannot well simulate the entire process of liver creep before being cut and fractured,viscoplastic properties were first attempted to be added to the model during surgical cutting in order to simulate the characteristics of virtual liver tissue before being cut and fractured,making the simulation process more dynamic and complete,and improving the fidelity of the model.By building a simulation experimental platform for telemedicine surgery,the corresponding flexible tissue deformation simulation was performed using the above methods,and the performance of the model was verified with the help of a haptic force feedback device,PHANTOM OMNI hand controller.The experimental results show that the flexible body deformation model proposed in this paper not only improves the computational accuracy,but also improves the real-time performance of surgical simulation,better simulates the surgical operations of stretching and compressing flexible body tissue,but also simulates the biological characteristics of soft tissue,further improving fidelity,ensuring a more realistic and natural deformation effect,providing strong support for the implementation of remote surgery.