The Research Of Expansion And Operation Technology For Endovascular Surgical Robot

With the development of society and the improvement of technology, people propose increasingly high demands on the means of diagnosis and treatment The emergence of minimally invasive surgery subverts the traditional open surgery to a certain extent, and greatly reduces the wound healing time. The technology of endovascular surgical robotic based on the minimally invasive surgery is willing to expand the scope of application of minimally invasive surgery and promote the further development of the technology. However, the development of endovascular surgical robot is just begin, and there are still many technical difficulties to be resolved. So, few practical endovascular surgical robots are in use. This thesis does some research on the two major technical difficulties exist in the field of cavity robotics.Based on the needs of surgery, this thesis designs an endovascular surgical robotic with the function of expansion and operation. The expander can enter into the internal of organs, and the organs can be stretched by the expander in order to obtain adequate vision and operating space. The operator can enter into the internal of organs to do some observation, sampling, surgical diagnosis and treatment With the help of three-dimensional design software which called solidworks, this thesis designs the expander, tensioning mechanism, operator, and tendon-sheath transmission system which compose the entire cavity robot Then, the prototype is made. Distraction rods of the expander are combined with many multi-cells, and they are both flexible and rigid. The tensioning mechanism uses a pulley structure to tension ropes. So that, just a single power source can guarantee the pulling force of six ropes approximately equal. The operator uses the pre-bending titanium-nickel alloy wire to drive the endoscope to swing. The pre-bent elastic tube can drive surgical instruments to do some surgery.Upon completion of the structural design of this robot, this thesis models and simulates the expender and operator. In the process of the expender modeling, this thesis firstly models the tendon-sheath transmission system according to the reference, and determines the relationship between input and output. And then this thesis analyses the deformation of the expander after uploading and obtained the relationships between the different initial pulling force and the dilator size. According to the underlying assumptions, this thesis analyses the interaction between the organ and the expander. Finally, matlab is used to simulate the mathematical model. In the process of the analysis of operator’s kinematics, this thesis firstly establishes the manipulator’s coordinate according to the D-H method. On this basis, this thesis establishes the manipulator’s forward kinematics and inverse kinematics and analyses the operating space according to the Monte Carlo method. At last, the pose of pre-bending titanium-nickel alloy wire and lesion localization is analyzed, which determines the feasibility of operator’s function by theory.Finally, this thesis designs the special force sensor for lasso transmission and builds the pulling force acquisition system. Then, the pulling force of the rope is measured by the system during the expansion process. On this basis, in order to verify the functionality, this thesis does some surgical experiments, and the experiments are successful.