静脉穿刺机械臂穿刺与挑针动作

Puncture and Needle Picking Action of Venipuncture Manipulator

目的提出一种新型多关节串联静脉穿刺系统,探究其穿刺过程中进针、挑针动作涉及的以力学、运动学为基础的相关控制问题,验证此系统的可行性。方法搭建穿刺机械臂实物,结合穿刺力学模型提出进针位移控制算法。利用DH法进行正运动学解算,得到末端针尖坐标,再利用几何法进行逆运动学解算,正逆过程联系紧密。采用运动学正解-逆解-再正解方法比较挑针前后的末端坐标位置误差,最后结合实物进行实验验证与仿真。结果经过仿真及实验,验证理论模型的准确性。利用该进针算法可以实现一针见血,为机械臂动作的控制提供理论依据。挑针前后末端位置误差可以控制在1 mm以内。机械臂在挑针过程中末端针尖几乎保持固定,故此套挑针方案可行,基本可以验证机械臂挑针动作满足精度与安全要求。结论该静脉穿刺机械臂真实模拟穿刺过程的进针、挑针动作,能够安全、准确地实现进针穿刺和以针尖为定点的挑针动作,具有一定的临床使用价值。

Objective To propose a new multi-joint series venipuncture system,explore the mechanics and kinematics-based related control problems involved in needle insertion and needle picking during the puncture process,and verify feasibility of this system.Methods A puncture manipulator was built,and needle displacement control algorithm was proposed by combing with the puncture mechanics model.The the forward kinematics was calculated by using DH method,so as to obtain the tip coordinates.Then the inverse kinematics was calculated by using the geometric method.The forward and inverse processes were closely connected.The position error of the end coordinates before and after needle picking was compared by using the method of kinematics positive solution-inverse solution-re-positive solution.Finally,experimental verification and simulation were conducted by combining with the physical object.Results Through simulation and experiments,accuracy of the theoretical model was verified.The needle insertion algorithm could be used to achieve success with only one needle insertion,which provided theoretical basis for the control of robot arm.The position error before and after needle picking could be controlled within 1 mm from the end trajectory.The end needle tip of robot arm was almost kept fixed during the needle picking process.Therefore,this needle picking scheme was feasible and could basically verify that the needle picking action of robot arm met the accuracy and safety requirements.Conclusions The venipuncture manipulator truly simulates the needle insertion and needle picking action during the puncture process,and can safely and accurately realize the needle insertion and needle picking action with needle tip as the fixed point,indicating that it has certain clinical values.