Research On Model And Sensing Of The Steerable Catheter For Radiofrequency Cardiac Ablation

As the mortality of the patients caused by cardiovascular disease is increased year by year in the world,arrhythmia become the common clinical manifestations of vascular disease.The cardiac radiofrequency ablation surgery has become the main minimally invasive surgery for the treatment of the disease.Conventional catheters remain to be promoted about flexible controllability of interventional instruments,the capacity of positioning distal catheter precisely and the security of melting operation.This paper designed flexible cardiac radiofrequency ablation catheter and driving mechanism,established mechanical model of silk coupling flexible catheter,developed force sensor with multi degrees of freedom,and carried out verified experiment.The work includes the followings:The flexible catheters based on elastic skeleton and multi degrees of freedom catheter driving mechanism were developed.The catheter prototype based on the spring skeleton and nickel titanium alloy plate skeleton were designed and developed,3 degrees of freedom driving mechanism which integrated double wires drive and catheter rotational degree of freedom were designed and developed at the same time.The mechanical model of flexible catheter based on beam theory was established,the introduced interaction model of silk coupling was introduced at the same time.Cosserat beam theory was described the large deformation characteristics of the flexible skeleton,nonlinear finite element method was used to analyze bending deformation of the coupling flexible catheter,and the accuracy of theoretical model and finite element model was verified by experiment.The distal catheter force feedback sensor based on the principle of fiber Bragg grating(FBG)sensing strain was developed.The axial force sensor based on the preliminary draft of FBG and spring type elastomer was designed and developed,the lateral force sensor based on the three FBGs and 3D printing elastomerswere designed,and the developed experiment used to verify the accuracy of these force sensors.The designed flexible catheter prototype,the multidimensional driving platform and the catheter mechanical model were used to make the target tracking experiment,the driving mechanism completed the precise positioning of multiple targets.The research in this paper is in-depth study of cardiac radiofrequency ablation robotic assistant technology,which is of great significance for manipulability of catheter and accurate sensing.