For patients under Magnetic Resonance Imaging (MRI) spontaneous respiration is constantly at risk of being impaired by anesthetic drugs or by upper airway obstruction. Therefore, continuous monitoring of the breathing activity is needed to assess adequate ventilation or to detect specific obstruction patterns. The paper describes three MRI compatible respiration sensors based on pure optical technologies developed within the EU FP6 project OFSETH. The sensors are based on fiber Bragg gratings, optical time-domain reflectometry and macrobending effects. The developed smart medical textiles can sense elongation up to 3% while maintaining the stretching properties of the textile substrates for patient's comfort. The OFSETH harness allows a continuous measurement of abdominal and thoracic respiration movement while all vitals organs are free for medical staff actions. The sensors were tested in MRI environment and on healthy adults.
We report on three respiration sensors based on pure optical technologies developed during the FP6 EU project
OFSETH. The developed smart medical textiles can sense elongation up to 3%, while maintaining the stretching
properties of the textile substrates for a good comfort of the patient. The sensors, based on silica and polymer fibre, are
developed for monitoring of patients during MRI examination. The OFSETH harness allows a continuous measurement
of respiration movements while all vitals organs are free for medical staff actions. The sensors were tested in MRI
environment and on healthy adults.
We investigated sensing properties of single mode poly methyl methacrylate (PMMA) microstructured polymer optical
fibres (MPOF) with mechanically imprinted long period gratings (LPG). After preparation of the MPOF end-faces the
samples were elongated with silica fibres. These samples were used to measure the influence of strain to the LPG
wavelength which showed the viscoelastic nature of PMMA. We also measured the influence of temperature and
humidity. The results show that MPOF LPGs are well suited for strain sensing. One MPOF LPG was stitched to a
textile. Using this textile we measured a simulated respiratory motion.