Characterization and use of a fiber optic sensor based on PAH/SiO2 film for humidity sensing in ventilator care equipment

Objective: To develop a compact probe that can be used to monitor humidity in ventilator care equipment. A mesoporous film of alternate layers of Poly(allylamine hydrochloride) (PAH) and silica (SiO2) nanoparticles (bilayers), deposited onto an optical fibre was used. The sensing film behaves as a F...

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Main Authors: Hernandez, Francisco U., Morgan, Stephen P., Hayes-Gill, Barrie R., Harvey, Daniel, Kinnear, William, Norris, Andrew, Evans, David, Hardman, J.G., Korposh, Sergiy
Format: Article
Published: IEEE 2016
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Online Access:https://eprints.nottingham.ac.uk/45762/
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author Hernandez, Francisco U.
Morgan, Stephen P.
Hayes-Gill, Barrie R.
Harvey, Daniel
Kinnear, William
Norris, Andrew
Evans, David
Hardman, J.G.
Korposh, Sergiy
author_facet Hernandez, Francisco U.
Morgan, Stephen P.
Hayes-Gill, Barrie R.
Harvey, Daniel
Kinnear, William
Norris, Andrew
Evans, David
Hardman, J.G.
Korposh, Sergiy
author_sort Hernandez, Francisco U.
building Nottingham Research Data Repository
collection Online Access
description Objective: To develop a compact probe that can be used to monitor humidity in ventilator care equipment. A mesoporous film of alternate layers of Poly(allylamine hydrochloride) (PAH) and silica (SiO2) nanoparticles (bilayers), deposited onto an optical fibre was used. The sensing film behaves as a Fabry-Perot cavity of low-finesse where the absorption of water vapour changes the optical thickness and produces a change in reflection proportional to humidity. Methods: The mesoporous film was deposited upon the cleaved tip of an optical fibre using the layer-by-layer method. The sensor was calibrated in a bench model against a commercially available capacitive sensor. The sensitivity and response time were assessed in the range from 5 % relative humidity (RH) to 95 %RH for different numbers of bilayers up to a maximum of nine. Results: The sensitivity increases with the number of bilayers deposited; sensitivity of 2.28 mV/%RH was obtained for nine bilayers. The time constant of the response was 1.13 s ± 0.30 s which is faster than the commercial device (measured as 158 s). After calibration, the optical fibre humidity sensor was utilised in a bench top study employing a mechanical ventilator. The fast response time enabled changes in humidity in individual breaths to be resolved. Conclusion: Optical fibre sensors have the potential to be used to monitor breath to breath humidity during ventilator care. Significance: Control of humidity is an essential part of critical respiratory care and the developed sensor provides a sensitive, compact and fast method of humidity monitoring.
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spelling nottingham-457622020-05-04T20:01:12Z https://eprints.nottingham.ac.uk/45762/ Characterization and use of a fiber optic sensor based on PAH/SiO2 film for humidity sensing in ventilator care equipment Hernandez, Francisco U. Morgan, Stephen P. Hayes-Gill, Barrie R. Harvey, Daniel Kinnear, William Norris, Andrew Evans, David Hardman, J.G. Korposh, Sergiy Objective: To develop a compact probe that can be used to monitor humidity in ventilator care equipment. A mesoporous film of alternate layers of Poly(allylamine hydrochloride) (PAH) and silica (SiO2) nanoparticles (bilayers), deposited onto an optical fibre was used. The sensing film behaves as a Fabry-Perot cavity of low-finesse where the absorption of water vapour changes the optical thickness and produces a change in reflection proportional to humidity. Methods: The mesoporous film was deposited upon the cleaved tip of an optical fibre using the layer-by-layer method. The sensor was calibrated in a bench model against a commercially available capacitive sensor. The sensitivity and response time were assessed in the range from 5 % relative humidity (RH) to 95 %RH for different numbers of bilayers up to a maximum of nine. Results: The sensitivity increases with the number of bilayers deposited; sensitivity of 2.28 mV/%RH was obtained for nine bilayers. The time constant of the response was 1.13 s ± 0.30 s which is faster than the commercial device (measured as 158 s). After calibration, the optical fibre humidity sensor was utilised in a bench top study employing a mechanical ventilator. The fast response time enabled changes in humidity in individual breaths to be resolved. Conclusion: Optical fibre sensors have the potential to be used to monitor breath to breath humidity during ventilator care. Significance: Control of humidity is an essential part of critical respiratory care and the developed sensor provides a sensitive, compact and fast method of humidity monitoring. IEEE 2016-09 Article PeerReviewed Hernandez, Francisco U., Morgan, Stephen P., Hayes-Gill, Barrie R., Harvey, Daniel, Kinnear, William, Norris, Andrew, Evans, David, Hardman, J.G. and Korposh, Sergiy (2016) Characterization and use of a fiber optic sensor based on PAH/SiO2 film for humidity sensing in ventilator care equipment. IEEE Transactions on Biomedical Engineering, 63 (9). pp. 1985-1992. ISSN 0018-9294 Humidity Optical fibers Films Humidity measurement Biomedical measurement Probes Time factors http://ieeexplore.ieee.org/document/7393540/ doi: 10.1109/TBME.2016.2521662 doi: 10.1109/TBME.2016.2521662
spellingShingle Humidity
Optical fibers
Films
Humidity measurement
Biomedical measurement
Probes
Time factors
Hernandez, Francisco U.
Morgan, Stephen P.
Hayes-Gill, Barrie R.
Harvey, Daniel
Kinnear, William
Norris, Andrew
Evans, David
Hardman, J.G.
Korposh, Sergiy
Characterization and use of a fiber optic sensor based on PAH/SiO2 film for humidity sensing in ventilator care equipment
title Characterization and use of a fiber optic sensor based on PAH/SiO2 film for humidity sensing in ventilator care equipment
title_full Characterization and use of a fiber optic sensor based on PAH/SiO2 film for humidity sensing in ventilator care equipment
title_fullStr Characterization and use of a fiber optic sensor based on PAH/SiO2 film for humidity sensing in ventilator care equipment
title_full_unstemmed Characterization and use of a fiber optic sensor based on PAH/SiO2 film for humidity sensing in ventilator care equipment
title_short Characterization and use of a fiber optic sensor based on PAH/SiO2 film for humidity sensing in ventilator care equipment
title_sort characterization and use of a fiber optic sensor based on pah/sio2 film for humidity sensing in ventilator care equipment
topic Humidity
Optical fibers
Films
Humidity measurement
Biomedical measurement
Probes
Time factors
url https://eprints.nottingham.ac.uk/45762/
https://eprints.nottingham.ac.uk/45762/
https://eprints.nottingham.ac.uk/45762/