Study On A Novel Robotic Catheter System For Vascular Interventional Surgery

Vascular diseases have become serious diseases which threaten human life and health. More than 16.7 million people loss thire lives because of vascular diseases worldwide each year. Vascular Interventional Surgery(VIS) is the main method for diagnosis and treatment of endovascular diseases. However, the surgeon operates the surgery with hands in conventional VIS, which need the surgeons exposed to X-ray radiation with long time. The operation of the Vascular Interventional Surgery is long time processing, which will lead to fatigue of the doctor and the patient, and the doctor’s attention will be reduced. The technich is hard to master because the lack of training method, and the amount of doctors who can operate the surgery couldn’t meet the needs of patients. The using of robotic catheter system can solve these problems effectively. To solve the isuues in related researches, this paper researches on vascular interventional catheter robot system with the consideration of ergonomic. And a novel master-slave robotic catheter system was desgined.To solve the problem of the big differences on the manipulation method on master side campared with conventional vascular interventional surgery, a novel master manipulater was designed in this paper, which allows the surgeon to operate a real catheter similar to conventional vascular interventional surgery. And this method can make full use of the operating skills and methods which is accumulated in the conventioanl operation. With the damper based on intelligent material magnetorheological fluid, the operating force of the slave manipulator could feedback to the surgeon’s hand with the real catheter he oprated. The realization of the force feedback is a kind of passive force feedback, operating resistance produced only in the situation of the surgeon operats the catheter. Therefore, it is not like the using of motor which existing the problem of inertia. The axial motion information of the catheter operated by the surgeon is acquired with linear displacement sensor based on magnetic induction, then additional resistance can be reduced effectively.To solve the problem of catheter operation of the slave manipulator may bring damage to the catheter or exists large error during the operation, a novle slave manipulator which can imitate the the surgeon’s operation was designed. The grasper in the front of the the slave manipulator can clamp the catheter just like the surgeon’s hand. A force sensor was installed on the grasper to detect the clamping force for avoiding damage to the catheter. When the catherer is clamped by the grasper, the slide platform drives the catheter to move in axial deraction, which imitates the pushing and pulling operation of the surgeon. And the rotation motor drives the graper to rotat for imitating the rotating operation of the surgeon. The axial operation force and radial torque of the slave manipulator were acquired and transmited to master side as the basis of force feedback device.This paper has analyzed the importance of the contact force detection at catheter tip, and fully learned about the need of the catheter tip force detection. An optical fiber force sensor was used to detect the contact force between the catheter tip and blood vessel, which can improve the safty of the surgery. A novle tactile sensor array with pressure sensitive rubber was developed, which can detect the magnitude and position of the contacting force between the catheter sidewall and blood vessel.The movement tracking experiment was carried out to verify the designed master-slave robot catheter system. The damping force calibration experient of magnetorheological fluid damper force has been done, which could verify that the application of magnetorheological fluid damper can be used for realizing the force feedback on master side of the robotic catheter system.