Experimental Investigation of Duplex Optical Fiber Sensor for Shoulder Monitoring Application

This paper explores the use of intensity-based fiber optic sensors with embedded u-groove for shoulder joint measurement. Current technologies related to the shoulder measurement devices have several limitations such as small range detection angle, bulky sensor for body attachment and subject to error due to the multiple joint movement directions of the shoulder joint such as rotation, abduction, adduction, flexion and extension. For this purpose, a duplex type plastic optical fiber was modified with a pre-determine dimension of ugroove sections, before the sensor design is tested based on macro-bending effect at abduction and adduction positions. Based on the experimental study, it was found that the proposed sensor design is workable to detect bending angle from 0 deg. to 180 deg. with acceptable resolution and accuracy. The obtained range of detection is sufficient to cover for all range of shoulder motions in clinical application.