A new optical technique to monitor joint motion using position sensitive detector

Abstract

BACKGROUND: Evaluation of joint movements is essential to choose an appropriate rehabilitation protocol for a patient. OBJECTIVE: The aim of this study is to suggest an alternative optical technique for measurement of joint angle which is convenient, inexpensive, and can be operated in real time. METHODS: According to the principle of the triangulation method, position sensitive detector (PSD) converts reflected light signals into distance-related voltages. Various parameters were investigated to increase detection range and resolution of joint angle measurements. RESULTS: The accuracy of the suggested optical sensor was verified by comparing with a commercial goniometer and 3D motion capture system. CONCLUSIONS: This method can be applied to monitor recovery progress for the patient in rehabilitation and sport science.