Research On Modeling And Control Methods Of Spiral Vascular Robot

With the development of modern society,people's living standards have been continuously improved,but the number of patients suffering from cardiovascular and cerebrovascular diseases in China has increased year by year.For cardiovascular and cerebrovascular diseases,the traditional therapy is to control the catheter by doctors to dredge blood vessels or expand blood vessels to achieve the therapeutic effect.However,in the process of treatment,doctors are often exposed to radiation,which has a certain impact on doctors' health.In recent years,minimally invasive surgery has gradually become the key point of modern medical concern due to its advantages such as small wound and quick recovery.The emergence of micro robot has opened people's horizons.The combination of minimally invasive surgery and robot technology is the inevitable trend of medical development.Vascular robot is a micro robot working in human blood vessels.Using vascular robots to treat cardiovascular and cerebrovascular diseases can make doctors avoid radiation damage.Therefore,vascular robots will become another method for treating cardiovascular and cerebrovascular diseases.In this paper,spiral vascular robot is selected as the research object and the modeling and geometric parameters of spiral vascular robot are optimized,and the effective three-dimensional trajectory tracking control method is studied.In this paper,the research status of the vascular robot at home and abroad is introduced,and the current driving modes of vascular robots are summarized.In order to reduce the volume of the vascular robot,the external three-dimensional rotating magnetic field is chosen to provide energy for the robot.Then the blood environment of the spiral vascular robot is analyzed,including the influence of three common vascular shapes(irregular vessel in diameter,curved vessel and branched vessel)on the pressure of vessel wall,blood velocity and wall shear stress of the vessel,and the changes of hemorheological parameters.Considering the effects of different vascular shapes on blood velocity,the kinematics and dynamics model of spiral vascular robot is established.In order to make the spiral vascular robot move effectively in the vessel,the relationship between the robot's geometric parameters and robot motion is analyzed.Based on genetic algorithm,the geometric parameters of the vascular robot are optimized,and it provides a basis for establishing the motion control of the spiral vascular robot.At present,the research of trajectory tracking for vascular robots still stays on two-dimensional plane.In fact,when the robot performs tasks in the blood vessel,there are many kinds of state,including forward and backward translation,pitch motion,and rotation.Only studying the two-dimensional motion of the robot does not represent the actual movement of the robot.Therefore,the three-dimensional trajectory control method of the spiral vascular robot is studied in this paper.In order to make the spiral vascular robot to travel along the desired trajectory,the idea of tracking trajectory is analyzed.By controlling the attitude angle of the vascular robot,the cerebellar model neural network control scheme is proposed,which makes the vascular robot to track the three-dimensional motion trajectory in the three kinds of vascular models established before.Simulation researches are carried out by using PID control and cerebellar model neural network control.The results show that the cerebellar model neural network control method has higher tracking accuracy and faster convergence speed.