title: Recent Improvement of Medical Optical Fibre Pressure and Temperature Sensors.
abstract: This investigation describes a detailed analysis of the fabrication and testing of optical fibre pressure and temperature sensors (OFPTS). The optical sensor of this research is based on an extrinsic Fabry-Perot interferometer (EFPI) with integrated fibre Bragg grating (FBG) for simultaneous pressure and temperature measurements. The sensor is fabricated exclusively in glass and with a small diameter of 0.2 mm, making it suitable for volume-restricted bio-medical applications. Diaphragm shrinking techniques based on polishing, hydrofluoric (HF) acid and femtosecond (FS) laser micro-machining are described and analysed. The presented sensors were examined carefully and demonstrated a pressure sensitivity in the range of sp = 2-10 nm/kPa and a resolution of better than ΔP = 10 Pa protect (0.1 cm H2O). A static pressure test in 38 cm H2O shows no drift of the sensor in a six-day period. Additionally, a dynamic pressure analysis demonstrated that the OFPTS never exceeded a drift of more than 130 Pa (1.3 cm H2O) in a 12-h measurement, carried out in a cardiovascular simulator. The temperature sensitivity is given by k = 10.7 pm/K, which results in a temperature resolution of better than ΔT = 0.1 K. Since the temperature sensing element is placed close to the pressure sensing element, the pressure sensor is insensitive to temperature changes.
authors.affiliation: Optical Fibre Sensors Research Centre-University of Limerick, Limerick MS1019, Ireland. Sven@Poeggel.eu.
authors.forename: Sven
authors.initials: S
authors.lastname: Poeggel
authors.affiliation: Optical Fibre Sensors Research Centre-University of Limerick, Limerick MS1019, Ireland. ddineshbabu@hotmail.com.
authors.forename: Dineshbabu
authors.initials: D
authors.lastname: Duraibabu
authors.affiliation: Nanophotonics Research Laboratory, Cyprus University of Technology, Lemesos 3036, Cyprus. kkalli@cytanet.com.cy.
authors.forename: Kyriacos
authors.initials: K
authors.lastname: Kalli
authors.affiliation: Optical Fibre Sensors Research Centre-University of Limerick, Limerick MS1019, Ireland. Gabriel.leen@ul.ie.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Leen
authors.affiliation: Optical Fibre Sensors Research Centre-University of Limerick, Limerick MS1019, Ireland. gerard.dooly@ul.ie.
authors.forename: Gerard
authors.initials: G
authors.lastname: Dooly
authors.affiliation: Optical Fibre Sensors Research Centre-University of Limerick, Limerick MS1019, Ireland. Elfed.Lewis@ul.ie.
authors.forename: Elfed
authors.initials: E
authors.lastname: Lewis
authors.affiliation: University of Limerick, Chemical & Environmental Science, Limerick MS1019, Ireland. James.kelly@ul.ie.
authors.forename: Jimmy
authors.initials: J
authors.lastname: Kelly
authors.affiliation: University of Limerick, Chemical & Environmental Science, Limerick MS1019, Ireland. Maria.Munroe@ul.ie.
authors.forename: Maria
authors.initials: M
authors.lastname: Munroe
mesh_terms: D005336:Fiber Optic Technology / Q000379:methods / Q000592:standards; D008962:Models, Theoretical; D055100:Optical Fibers; D011312:Pressure; D012680:Sensitivity and Specificity; D013696:Temperature
keywords: Fabry–Perot interferometer; optical fibre sensors; pressure sensors