Optical Bend Sensing for Wearable Goniometry: Exploring the Comfort/Accuracy Tradeoff

This paper explores some initial variables that impact the sensor signal and accuracy of a garment-integrated bend sensor used to measure the flexion and extension of the knee. An optical fiber bend sensor has been evaluated in garments of 6 sizes on an animatronic running mannequin. The resulting sensor signals are compared for correlation, signal-to-noise ratio, signal variability, and morphology. Subsequently, a knee-brace application is evaluated on the same signal parameters in repetitive donning and doffing trials for consistency between trials. The results show the impact of these variables on the amplitude, variability, and noise in the sensor signal.