Plastic optical fiber respiration sensor based on in-fiber microholes

Abstract

This paper presents a novel respiration sensor based on multiple in-fiber microholes drilled along a plastic optical fiber (POF) that is stitched to a waist-band wrapped around the patient's abdomen. The bending loss of a POF with a single microhole is analyzed in order to enhance the sensor sensitivity. Several sensors were fabricated using a 1.5 mm-diameter POF with different numbers and spacing of 0.7 mm-diameter microholes. The sensitivity of the respiration sensor increased when increasing the number and spacing of the microholes, where the POF respiration sensor with seven 0.7 mm-diameter in-fiber microholes spaced at 15 mm showed the highest sensitivity and sufficient strength for respiratory monitoring. Thus, the experimental results confirmed that a POF sensor based on in-fiber microholes can be effectively used to monitor the respiration of patients. ? 2018 The Authors. Microwave and Optical Technology Letters published by Wiley Periodicals, Inc.