Seon Geun KIM¹, Kyoung Won JANG¹, Wook Jae YOO¹, Sang Hun SHIN¹, Seunghyun CHO², and Bongsoo LEE^1*

¹School of Biomedical Engineering, Research Institute of Biomedical Engineering, Konkuk University, Chungju 380-701, Korea
²Department of Organic Materials & Fiber Engineering, College of Engineering, Soongsil University, Seoul 156-743, Korea

(Received April 1, 2014; Revised June 11, 2014; Accepted June 12, 2014)

In this study, we fabricated a fiber-optic goniometer using a plastic optical fiber, a light-emitting diode, and a photodiode. The cladding of the plastic optical fiber was removed at 0.5–3 mm intervals regularly to increase the bending loss of the plastic optical fiber. Also, the output voltages of the photodiode based on light intensity that measured using the fiber-optic goniometer were measured light intensities using the fiber-optic goniometer were measured to evaluate the linearity of the fiber-optic goniometer. Finally, we measured the responses of the fiber-optic goniometer for gait speeds of 3, 5, and 10 km/h using a data acquisition board and a LabVIEW program.

Key words: fiber-optic sensor, goniometer, knee joint angle

^*E-mail address: bslee@kku.ac.kr