骨关节角度数字化测量与功能评估系统设计

Design of joint angle digital measuring and functional assessing system

为了实现对骨关节空间角度的数字化测量与功能客观评价,建立了骨关节角度数字化测量与功能评估系统。对该系统所采用的骨关节空间角度测量、功能评估算法进行研究。首先,根据Kinect数据采集原理及空间向量计算方法介绍了骨关节空间角度测量算法,即在Kinect深度数据流基础上将骨关节点空间位置信息转换为对应的三维空间坐标,根据空间向量夹角公式计算骨关节空间角度。然后,在分析比较分类评价方法的性能基础上,说明了采用K-means聚类方法进行骨关节功能评估的算法。实验结果表明,系统可以为用户提供骨关节的数字化测量与功能评估结果,评估指标purity、RI与F-meaures等能稳定在0.8及其以上,基本满足骨关节功能评价的非接触、客观高效、适应能力强、准确度高、操作简便和成本低等要求。

In order to realize digital measurement and objective function assessment for joint angle, an joint angle digital measuring and functional assessing system is established and its applied algorithms is investigated. Firstly, based on Kinect data acquisition principles and calculation method of space vectors, the joint angle measuring algorithm is presented. The space points of joint on the basis of the depth data of Kinect are converted to the corresponding three-dimensional coordinates which will be used to calcu-late the Euclidean distance between each key point, and the joint space angles are calculated according to the angle formula of space vector. Then after the performance of several clustering methods is compared, the algorithm of function assessing by K-means is analyzed. Experimental results indicate that the system can realize the digital measuring and assessing, and the precision of the clustering indexes of purity, RI and F-meaures can be stabled in 0. 8 and above. It can satisfy the system requirements of non-contact, objective, effective, higher precision and strong adaptability, as well as user-friendly control and low cost.