Measuring Elemental Time and Duty Cycle Using Automated Video Processing

摘要

A marker-less 2D video algorithm measured hand kinematics (location, velocity, and acceleration) in a paced repetitive laboratory task for varying hand activity levels (HAL). The decision tree (DT) algorithm identified the trajectory of the hand using spatiotemporal relationships during the exertion and rest states. The feature vector training (FVT) method utilized the k-nearest neighborhood classifier, trained using a set of samples or the first cycle. The average duty cycle error using the DT algorithm was 2.7%. The FVT algorithm had an average 3.3% error when trained using the first cycle sample of each repetitive task, and had a 2.8% average error when trained using several representative repetitive cycles. Error for HAL was 0.1 for both algorithms, which was considered negligible. Elemental time, stratified by task and subject, were not statistically different from ground truth (p < .05). Both algorithms performed well for automatically measuring elapsed time, duty cycle and HAL.