Research On The Spatial Positioning And Needle Insertion Planning Of The Robotic Arm Assisted Lumbar Puncture System

The purpose of this research is to explore a medical puncture method of robotic arm based on optical positioning guidance.The thesis explored the accuracy of structured light visual positioning in robotic arm puncture guidance,established a pose constraint method based on intraoperative requirements,and designed a method to avoid some singular points.Experiments was designed to verify and discuss the above methods.According to the analysis of research status at home and abroad in related fields,combined with laboratory conditions,a model of a six-degree-of-freedom UR3 robotic arm was used to achieve the purpose of puncture planning of the robotic arm in this study.A mathematical model of the robotic arm was established by the D-H parameter method to perform kinematic analysis,and Monte Carlo method was used to analyze the reachable working space of the robotic arm,which provided a theoretical basis for subsequent research on the control of the robotic arm.Based on the selection and control of the robotic arm,this study explored the accuracy and feasibility of structured light vision as an optical positioning guide robotic arm puncture.Intel’s structured light camera was used as the visual positioning hardware device,and its internal and external parameters were calibrated.The "eye on hand" method of robotic arm visual positioning was used to complete the hand-eye calibration.The twodimensional code mark in the ArUco library was used to compare the camera positioning and mechanical positioning of the experimental positioning points on the surface of the lumbar gel model to calculate the positioning error of the structured light-guided robotic arm based on the mechanical positioning.At the same time,this research carried out a study on the location of singular points and pose constraints based on the puncture end device.According to the human-computer interaction scene of the intraoperative puncture system,a pose constraint method based on the puncture direction and the puncture end structure design was established,and the corresponding spatial pose calculation mathematical model was established through the analysis of the space vector.In order to effectively avoid some singular points,a method was designed to provide multiple sets of poses by rotating at a small angle along a fixed axis,and the mathematical model of the method is established by the Rodriguez formula.By setting the puncture path at different angles,and using mechanical positioning to obtain the needle entry point and target point of puncture,the above method was experimentally verified.The experimental results show that,according to the obtained multiple sets of robotic arm puncture postures,the possible singular points could be effectively avoided,which proved the feasibility of the constraint method.Through the above experiments,this research has realized the puncture planning based on structured light space positioning and guiding the robotic arm,designed a "eyein-hand" visual aid puncture module,and established a new pose constraint method model.Due to factors such as vision module selection and calibration and processing accuracy,there is still room for improvement in positioning accuracy.Pose constraints and guidance can be further optimized under a large number of experiments.Compared with traditional positioning methods and optical positioning products,the structured light-based robotic arm puncture guidance system established in this study has certain feasibility and clinical application prospects.