基于法矢跟踪的人工膝关节测量方法研究  

Research on the measurement method of artificial knee joint based on normal vector tracking

作　　者：李琛[1] 朱琳琳 杨旭东[1] 刘磊[1] 张效栋[1] Li Chen;Zhu Linlin;Yang Xudong;Liu Lei;Zhang Xiaodong(State Key Laboratory of Precision Measuring Technology&Instruments,Laboratory of Micro/Nano Manufacturing Technology,Tianjin University,Tianjin 300072,China)

机构地区：[1]天津大学精密测试技术及仪器国家重点实验室,天津大学微纳制造实验室,天津300072

出　　处：《光电工程》2021年第7期32-42,共11页Opto-Electronic Engineering

基　　金：科学挑战计划(TZ2018006-0203-01);国家重点研发计划(2017YFA0701200)。

摘　　要：人工膝关节在改善患者关节病情方面有重要的作用,人工膝关节面型偏差会直接影响患者的治疗效果,因此在投入使用之前需要对人工膝关节面型进行高精度评价。人工膝关节面型复杂倾角变化大,并且不同患者的膝关节面型有较大差异,人工膝关节的复杂性和未知性导致其面型的高精度测量较为困难。对此,本文重点提出了一种基于接触式电感直线位移传感器(LVDT)的法矢跟踪测量方法,并搭建了回转扫描测量系统。该方法对已测点进行曲线拟合,预测待测面型的变化趋势,自适应调整LVDT的采样位姿使其近似沿着采样点法矢方向进行测量,实现对大斜率复杂未知曲面的自适应回转测量。通过对标准球的测量实验,标定系统的测量误差为48.21μm左右;并对人工膝关节模型件进行了测量实验,验证了该方法的可行性。Artificial knee joint plays an important role in improving the joint condition of patients.The surface devia-tion of artificial knee joint will directly affect the treatment effect of patients.Therefore,it is necessary to evaluate the surface of artificial knee joint with high precision before it is put into use.The slope of the artificial knee joint is com-plex and varies greatly,and there are great differences in the knee joint surface among different patients.The com-plexity and unknowability of artificial knee joint make it difficult to measure its surface with high precision.In this paper,a normal vector tracking measurement method based on contact inductance linear displacement sensor(LVDT)is proposed,and a rotary scanning measurement system is built.This method performs curve fitting on the measured points,predicts the changing trend of the measured surface,and adaptively adjusts the sampling position and posture of the LVDT to make it measure approximately along the normal direction of the sampling point,so as to realize the adaptive rotation measurement of the complex and unknown surface with large slope.Through the measurement experiment of the standard ball,the measurement error of the calibration system is about 48.21μm.In addition,the measurement experiment of the artificial knee joint model is carried out to verify the feasibility of the method.

关 键 词：人工膝关节 法矢跟踪 回转测量 未知曲面 

分 类 号：TH772[机械工程—仪器科学与技术] TN247[机械工程—精密仪器及机械]