The Kinematics Model And Simulation Of Flexible Needle Puncturing Soft Tissue

Nowadays, more and more attentions have been paid to the robot auxiliary, especially in the feasibility of minimally invasive surgery, however, most of the clinical were used by rigid needles. Due to the high rigidity and most of the path positioning and directional along the straight line. the rigid needles cannot avoid the vital organs during puncturing operation to reach targeted obstacles. Therefore, exploring for the use of flexible needles to replace the traditional rigid needles have been carried out in the worldwide, because of the flexibility of the flexible needles and the complexity of the deformation of organization make flexible needle biopsy control become complicated, established a more accurate and more simple kinematics model of flexible needle biopsy the soft tissue is a key technology to be solved urgently, it is also treatment method for major disease in urgent such as cancer diagnosis.This thesis adopts robot to control flexible needles to reach the intended targeted in the minimally invasive intervention treatment. Combined the dexterously operating ability of the robot with deformation pose ability of controlling the flexible needle in order to achieve the needle position, attitude, trajectory and accurately motion control for the goal targets. Firstly, the stress-strain relationship is studied when flexible needle is bended and elastic-plastic and failure mechanism of the PVA is analyzed though the bending experiment of the flexible needle and compress the PVA experiment. Secondly, interaction force model is established among cutting force, stiffness force, friction force and deformation of the soft tissue of flexible needle puncture soft tissue based on the balance of the force, and The motion control model of puncturing procedure is established by the analytical theory and cantilever beam theory. Thirdly, the mechanical analysis is proved to be correct by simulating puncture force using ABAQUS software. Finally, analysis was verified through the puncture experiment and kinematics experiment. This article provided the scientific and theoretical basis for clinical surgery by studying the theory of the kinematics modeling and experiment of the robot manipulate flexible needle to puncture soft tissue. Meanwhile, this project combined with the robot that reduced the labor intensity of the doctor, improve the accuracy and security, achieve higher level of minimally invasive surgery, greatly improve the quality and intervention operation efficiency, reduce the patients with pain, and improve the quality of life of patients, and promote the development of minimally invasive medical technology, benefit the whole society.