Study On The Characteristics Of The Vascular Interventional Surgery Robot In A Simulated Vascular Environment

With the rapid development of sensor technology and intelligent technology,robotic surgery has been introduced into the field of minimally invasive surgery.It has been highly valued by doctors with its high accuracy and better assistance.It has become a hot research field at home and abroad.Minimally invasive surgery robot system is to feedback visual information and tactile information to doctors through operation interface and tactile feedback.The doctor controls the operating rod to complete the operation.This greatly improves the flexibility,convenience and safety and accuracy of the surgeon's operation.However,there are still some problems such as lack of feedback and poor detection precision in the existing vascular interventional operation robot.Moreover,most of the researchers evaluated the performance of the vascular interventional robot system in a static vascular model environment without considering the influence of the flow characteristics of the human blood on the system.Therefore,this paper has carried out the related research on the vascular interventional robotic in the simulated vascular environment,which are as follows.Firstly,the system structure and design principle of the vascular interventional surgery robot used in this study are described in detail.According to the overall structure of the vascular interventional robot,we established its dynamic model,and the dynamic model of axial and radial motion of the slave manipulator was established.And then we used the kinematic method to analyze the positive and negative kinematics of the interventional catheter.The scope of the working space that the catheter can reach was explored and its kinematic inverse and Jacobi matrix were solved.This provides a reference for the better control of the movement of the catheter position accuracy.In the meantime,a safe control method of the catheter operation was put forward for the way that the system controls the catheter.Secondly,the vascular model established in the three-dimensional software is numerically simulated by using the fluid mechanics method,and the deformation equation and force expression of the vascular wall are obtained.The hemodynamic analysis of the vascular model was carried out in the finite element software ANSYS,and the flow characteristics of branches in different flow velocity environment and the stress and deformation of the vascular wall were studied.It can provide optimal hemodynamic parameters for vascular interventional operation,improve the success rate of operation,and guarantee the long-term effectiveness of surgery,which can provide strong theoretical support for the optimization of surgical instruments.Finally,this study evaluated the motion characteristics and force feedback characteristics of surgical robotic system on a simulated vascular environment experimental platform.The effect of liquid flow velocity on the force and motion of the interventional catheter and the performance of the master and slave force feedback of the robot system under different velocity conditions are analyzed.The result of force feedback experiment shows that the average error between the feedback force at the master and the slave detection force is within 7mN,which shows that the robot system has good force feedback performance By comparing the catheter collision force with the maximum stress value of the vessel wall,we can know that the control of the contact force between the catheter and the blood vessel is within the safe force range of the blood vessel wall.The axial and radial motion experiments show that the average error of the axial displacement of the master manipulator and the slave manipulator of this system is less than 1mm,and the average error of the rotation angle is within 5 degrees,indicating that the robot system has good controllability and synchronization follow-up performance.