Master-slave Robot-assisted Spinal Puncture Surgery System Based On Force Feedback

Osteoporosis is a common disease which can cause loss of bone massand abnormal bone microstructure. Osteoporosis can lead to seriouscomplications, such as vertebral compression fractures (VCF), hipfractures, distal radius fractures, etc. And osteoporotic vertebralcompression fractures (VCF) which can cause the patient’s center ofgravity forward and spine flexion increases have great harm onpeople.VCF treatment methods include conservative treatment, medicaltreatment, percutaneous vertebroplasty (PVP) and percutaneouskyphoplasty (PKP), etc. And PKP method should be preferred during thetreatment because of the clinical statistics which show that PKP in theclinical treatment of VCF has obvious advantages in achievement ratio ofoperation and cost-effective. However, there are some shortcomings duringPKP process, including surgical procedure incoherent, excessive radiationto the surgeon, etc. In this paper, we put forward using master-slave robotto solve these problems.In this paper, we established the basic design requirements of theoverall system based on the research status of robot-assisted spinalpuncture surgery system. And according to the design requirements, aviable master-slave robot-assisted spinal puncture surgery system was built.The operating side and the surgery side were divided without changing theoperation habits of the surgeon. The slave hand can be precisely controlledby the master hand; meanwhile, to provide force telepresence to thesurgeon, the force information between the slave side and the environmentcan be collected by6-axis force sensor and fed back to the master hand. Therefore, the main works we focus on are as follows:Firstly, different types of master-slave control strategies wereanalyzed to determine taking bilateral control strategy as the generalscheme. According to the requirements of stability and transparency inbilateral control, different types of control models were analyzed. And theoptimum control model was chosen for the robot-assisted spinal puncturesurgery system.Secondly, the position control strategy of the system was studied, inother words, the workspace mapping of heterogeneous robot system wasstudied based on the robot kinematics. The forward kinematics and inversekinematics of6R series robot which meets the Pieper criteria wereobtained, and the optimal inverse kinematics was chosen in accordancewith the best supple law of joints. All the work laid the foundation for theresearch on workspace mapping; further, taking hand-eye coordination as aprecondition, the incremental position control strategy and variableproportions control strategy were used to obtain the workspace mapping,and the ratio between master space and slave workspace can be changedaccording to the requirement; In addition, position feedback is used toimprove control accuracy and decrease the master-slave tracking error.Thirdly, the force feedback algorithm of the system was studied. Thecalibration, gravity compensation and coordinate transformation algorithmwere studied to obtain the actual force information between end-effectorand environment; In addition, the position error between master and slavewas introduced into force feedback strategy, as a result, the position errorcan be further reduced and the safety of surgical procedures can beimproved despite that the transparency of the system is reduced to someextent.Finally, in order to verify the feasibility of the master-slaverobot-assisted spinal puncture surgery system and the effectiveness of thesystem control strategy, some experiments were designed. The experimentresults showed that the positioning accuracy of the master-slave robot-assisted spinal puncture surgery system can meet the need ofpuncture surgery, and the force feedback strategy can provide telepresenceto the surgeon successfully.