Development Of Robotic Slave Manipulator And Sensors For Minimally Invasive Vascular Interventional Surgery

Focusing on the low efficiency of traditional vascular interventional surgery and the lack of safety due to force feedback,a minimally invasive vascular intervention robot for guidewire catheter access was developed to solve the problem of manual intubation in traditional surgery.This work proposes a proximal sensor for measuring force/torque signals,a displacement sensor for catheter movement speed,and a threedimensional force sensor at the end of the catheter,which is used to monitor the interaction force between the catheter and human tissue during vascular interventional procedures.The specific research content is as follows:Firstly,this chapter proposes a design of a minimally invasive vascular interventional surgery robot slave manipulator,which combines a miniaturized and low-cost push device drive method to improve the stability and accuracy of the device’s movement.Meanwhile,the performance parameters of the whole machine were analyzed to explore its ability to operate the guidewire and catheter,which proved the feasibility of the proposed push device.Secondly,proximal force/torque sensors and displacement/angular displacement sensing devices based on the Laser Doppler principle were developed to measure force/torque and displacement information,respectively.The proposed sensor is based on a multi-layer cross beam and ortho-planar springs structure,which has the characteristics of compact structure,large displacement and deformation,and excellent linearity.The coupling design of the flexure and the laser sensor can realize highresolution force/torque signal detection at low levels in vascular interventional surgery.To perform digital performance analysis on the proposed structure,a finite element method is implemented to characterize its performance indicators.Then,the FBG-based distal three-dimensional force sensor was proposed to be used in vascular robots to obtain the interaction force between the catheter tip and the tissue at the lesion during surgery.The flexure is based on a multi-layer parallel groove structure and a hollow cylindrical structure.The “two-point” FBG configuration allows the FBG element to be axially compressed or stretched,achieves improved sensitivity and repeatability,and avoids FBG chirping,compared with the traditional FBG gluing method.To improve the performance of the designed force sensor,simulation-enabled optimization has been implemented to achieve optimal structural parameters,and the static and dynamic performance simulations of the optimized sensor have been carried out to verify the feasibility of the designed force sensor.Finally,the proposed interventional surgery robot and sensors are prototyped and their performance parameters are tested through designed experiments.The experimental results show that the proximal force/torque sensor has achieved a resolution of 90 m N and 2.45 N·mm in the force measurement range of [-2.5,2.5 N]and the torque measurement range of [-60,60 N·mm],and three-dimensional force sensor achieves a resolution of 0.75 m N,0.76 m N,and 5.6 m N in the X,Y,and Z directions.The designed proximal force/torque sensor is integrated into the robot to carry out the access experiment of the vascular interventional surgery model,which verifies the practicality of the designed sensor.