Respiratory monitoring using fibre long period grating sensors

Abstract

We demonstrate the use of a series of in-line fibre long period grating curvature sensors on a garment, used to monitor the thoracic and abdominal volumetric tidal movements of a human subject. These results are used to obtain volumetric tidal changes of the human torso showing reasonable agreement with a spirometer used simultaneously to record the volume at the mouth during breathing. The curvature sensors are based upon long period gratings written in a progressive three layered fibre that are insensitive to refractive index changes. The sensor platform consists of the long period grating laid upon a carbon fibre ribbon, which is encapsulated in a low temperature curing silicone rubber.

Fiber-optic sensors for monitoring patient physiological parameters: a review of applicable technologies and relevance to use during magnetic resonance imaging procedures

“…124,125 Preliminary studies of longperiod gratings (LPGs), a variation of Bragg gratings, for recording ventilatory movements and/or volumes have been performed because these gratings are particularly sensitive to any deformations in the LPG section. [126][127][128][129][130][131][132] Change in thorax curvature is sensed as bending of an LPG attached to the thorax. Bending induces strain and stress across the fiber and, in consequence, a change in its refractive index via the strain-optic effect, which manifests as a change in position, shape and amplitude of resonant bands in the transmission spectrum.…”

Medizinische Textilien mit integrierten polymeroptischen Fasern zur AtmungssensorikMedicinal Textiles with Integrated Polymer-Optical Fibers for Respiration Monitoring

“…Dies unterscheidet die Sensorentwicklungen von den meist glasfaserbasierten, bereits existierenden faseroptischen Sensoren [6][7][8][9][10][11].…”