A method for early detection of the initiation of sit-to-stand posture transitions
A method for early detection of the initiation of sit-to-stand posture transitions
复制标题
DOI：
10.1088/0967-3334/37/4/515
复制
发表时间：
2016-04-01
影响因子：
3.2
通讯作者：
Sazonov, Edward
中科院分区：
文献类型：
--
作者：
Doulah, Abul;Shen, Xiangrong;Sazonov, Edward
动力下肢矫形支具可能用于在日常活动中辅助体弱的老年人。本文提出了一种早期检测从坐到站（SiSt）姿势转换起始的方法，该方法可用于动力矫形器的控制。与假肢装置中依赖表面肌电图（EMG）的方法不同，所提出的方法仅使用嵌入连接到肢体的矫形支具中的传感器。该方法是使用来自10个人的人体研究数据开发和验证的。每个人体试验包括源自各种初始姿势的不同组的坐、站和行走活动。从传感器信号中提取特征并在滞后时段中聚合，以纳入时间历程。主成分分析（PCA）用于减少特征集。然后以留一法的方式使用主成分来训练线性支持向量机（SVM）分类器，以对SiSt姿势转换进行早期检测。所提出的方法在无假阳性的试验中达到了100%的灵敏度和92.94%的特异性。在转换开始后平均检测时间（DT）为0.1341±0.3310秒，这表明对SiSt转换起始的早期识别。
A powered lower extremity orthotic brace can potentially be used to assist frail elderly during daily activities. This paper presents a method for an early detection of the initiation of sit-to-stand (SiSt) posture transition that can be used in the control of the powered orthosis. Unlike the methods used in prosthetic devices that rely on surface electromyography (EMG), the proposed method uses only sensors embedded into the orthosis brace attached to the limb. The method was developed and validated using data from a human study with 10 individuals. Each human trial included different sets of sitting, standing and walking activities originating from various initial postures. Features from the sensor signal were extracted and aggregated in lagged epochs to incorporate the time history. Principal component analysis (PCA) was used to reduce the feature set. The principal components were then used in a leave-one-out manner to train a linear support vector machine (SVM) classifier to perform early detection of the SiSt posture transition. The proposed method achieved the sensitivity of 100% and the specificity 92.94% of trials without false positives. The average detection time (DT) of 0.1341 +/- 0.3310 s following the start of transition demonstrated early recognition of the initiation of SiSt transition.