Design And Implementation Of A Virtual Injection Simulation System With Force Feedback

Giving drugs to patients by injection has become an integral part of daily consultation and treatment.The practical objects of injection training for healthcare workers are mostly live animals,silicone arm models,and surgical training kits,which cannot meet the requirements of high repeatability and realism of the materials needed in the training phase of healthcare workers.Therefore,this paper designed and implemented a virtual injection simulation system with force feedback and high re-usability,taking injection operation as the research object from practicality.The main research contents are as follows:(1)Realistic deformation of the arm model.To achieve a realistic deformation effect of the arm model,proposing a deformation modeling algorithm with tetrahedral hybrid extended position dynamics.Firstly,the arm model was tetrahedrally dissected using the Delaunay mesh dissection algorithm that came with Tet Gen software in order to achieve realistic geometric modeling of the arm.Secondly,choosing an extended positional dynamics algorithm as the deformation algorithm for the soft tissue of the arm,and investigated the principles and constraints of the algorithm.Finally,the tetrahedral topology was coupled with the extended positional dynamics algorithm to achieve a realistic deformation of the soft tissue of the arm.(2)Collision detection between surgical instruments and soft tissues of the arm.In order to improve the real-time performance and accuracy of the virtual injection system,proposing a hybrid collision detection algorithm based on the Sphere-AABB bounding box with an octree structure after analyzing the advantages and disadvantages of various collision detection algorithms.Using a top-down search method,a sphere bounding box is used for the surgical instrument and a Sphere-AABB bounding box based on octree was used for the vascular model in the arm,giving a collision detection procedure between the surgical instruments and soft tissues of the arm model,achieving fast and accurate collision detection between them.(3)Implementation of force feedback in the system.Firstly,explaining the principles of force feedback and the kinetic model to achieve a realistic haptic system simulation.Secondly,comparing the commonly used algorithms for force feedback and choosing the mass-spring method with fast solution speed and good real-time performance to solve the force feedback kinetic model to calculate the feedback force.Finally,using the Open Haptics development kit to realize the force rendering of the puncture operation to improve the realistic haptic feedback of virtual injection simulation.(4)Construction of a virtual injection simulation system.A virtual injection simulation system with force feedback was designed and implemented by combining Open GL with the Phantom Premium 1.5 force feedback device.And evaluated the system’s deformation simulation effect,time efficiency,and clinical practicality through experiments.In summary,this paper proposed a virtual injection simulation system with force feedback,and evaluated and analyzed the system.The experimental results show that the system has a realistic deformation effect,the average frame rate can reach 78 frames per second,and meets the requirements of the virtual surgery system in real-time,which has positive significance for the preoperative training of medical and nursing staff.