Displaying publications 21 - 40 of 51 in total

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  1. Fulltext Investigation of Surface Plasmon Resonance (SPR) in MoS2- and WS2-Protected Titanium Side-Polished Optical Fiber as a Humidity Sensor
    Zakaria R, Zainuddin NAM, Leong TC, Rosli R, Rusdi MF, Harun SW, et al.
    Micromachines (Basel), 2019 Jul 11;10(7).
    PMID: 31336745 DOI: 10.3390/mi10070465
    In this paper, we report the effects of a side-polished fiber (SPF) coated with titanium (Ti) films in different thicknesses, namely 5 nm, 13 nm, and 36 nm, protected by a thin layer of transition metal dichalcogenides (TMDCs) such as molybdenum disulfide (MoS2) and tungsten disulfide (WS2), which provide ultra-sensitive sensor-based surface plasmon resonance (SPR) covering from the visible to mid-infrared region. The SPF deposited with Ti exhibits strong evanescent field interaction with the MoS2 and WS2, and good optical absorption, hence resulting in high-sensitivity performance. Incremental increases in the thickness of the Ti layer contribute to the enhancement of the intensity of transmission with redshift and broad spectra. The findings show that the optimum thickness of Ti with 36 nm combined with MoS2 causes weak redshifts of the longitudinal localized surface plasmon resonance (LSPR) mode, while the same thickness of Ti with WS2 causes large blueshifts. The redshifts are possibly due to a reduced plasmon-coupling effect with the excitonic region of MoS2. The observed blueshifts of the LSPR peak position are possibly due to surface modification between WS2 and Ti. Changing the relative humidity from 58% to 88% only elicited a response in Ti/MoS2. Thus, MoS2 shows more sensitivity on 36-nm thickness of Ti compared with WS2. Therefore, the proposed fiber-optic sensor with integration of 2D materials is capable of measuring humidity in any environment.
    Matched MeSH terms: Fiber Optic Technology
  2. Fulltext Optical Response Analysis at Various Pb2+ Concentration by Using Fiber Optic Displacement Sensor
    Nurul Syafiqah Hirman, Nur Athirah Mohd Taib
    Malaysian Journal of Science, Health & Technology, 2021;7(1):43-48.
    MyJurnal
    A simple and low-cost Fiber Optic Displacement Sensor (FODS) using reflective intensity modulation technique was developed to analyze various concentrations of Pb2+, a compound classified under heavy metal ions. Lead is harmful to the environment including to human but is used in the cosmetic field for beauty without realizing and considering the hazardousness of lead as it would cause a long-term effect. Therefore, a feasible way has been identified in this study to demonstrate the level of Pb2+ concentration in cosmetics field by employing the theory of modulation of intensity as a function of displacement sensor. The permissible limit according to Malaysian Cosmetics Guidelines and ASEAN Cosmetic Directive was 20 ppm. The concentration sensor’s system exhibits 0.0018 V/ppm sensitivity with a linearity of 96% and 94% respectively, for both peaks. Meanwhile, the sensitivity was 0.034 V/ppm for the first peak and 27.72 V/ppm for the second peak, with slope linearity of more than 96% for surface tension parameter. The credibility of these optical response curves data might be useful, especially in the cosmetic’s industrial application.

    Matched MeSH terms: Fiber Optic Technology
  3. Fulltext Classification of reflected signals from cavitated tooth surfaces using an artificial intelligence technique incorporating a fiber optic displacement sensor
    Rahman HA, Harun SW, Arof H, Irawati N, Musirin I, Ibrahim F, et al.
    J Biomed Opt, 2014 May;19(5):057009.
    PMID: 24839996 DOI: 10.1117/1.JBO.19.5.057009
    An enhanced dental cavity diameter measurement mechanism using an intensity-modulated fiber optic displacement sensor (FODS) scanning and imaging system, fuzzy logic as well as a single-layer perceptron (SLP) neural network, is presented. The SLP network was employed for the classification of the reflected signals, which were obtained from the surfaces of teeth samples and captured using FODS. Two features were used for the classification of the reflected signals with one of them being the output of a fuzzy logic. The test results showed that the combined fuzzy logic and SLP network methodology contributed to a 100% classification accuracy of the network. The high-classification accuracy significantly demonstrates the suitability of the proposed features and classification using SLP networks for classifying the reflected signals from teeth surfaces, enabling the sensor to accurately measure small diameters of tooth cavity of up to 0.6 mm. The method remains simple enough to allow its easy integration in existing dental restoration support systems.
    Matched MeSH terms: Fiber Optic Technology/instrumentation; Fiber Optic Technology/methods*
  4. Multi-wavelength laser generation with Bismuthbased Erbium-doped fiber
    Ahmad H, Shahi S, Harun SW
    Opt Express, 2009 Jan 05;17(1):203-7.
    PMID: 19129889
    A multi-wavelength laser comb is demonstrated using a nonlinear effect in a backward pumped Bismuth-based Erbium-doped fiber (Bi-EDF) for the first time. It uses a ring cavity resonator scheme containing a 215 cm long highly nonlinear Bi-EDF, optical isolators, polarisation controller and 10 dB output coupler. The laser generates more than 10 lines of optical comb with a line spacing of approximately 0.41 nm at 1615.5 nm region using 146 mW of 1480 nm pump power.
    Matched MeSH terms: Fiber Optic Technology/instrumentation; Fiber Optic Technology/methods*
  5. Analysis of coupling efficiency on hemispherical fiber lens by method of lines
    Lambak Z, Abdul Rahman F, Mokhtar MR, Tengku IA
    Opt Express, 2009 Feb 16;17(4):2926-37.
    PMID: 19219196
    The method of lines (MoL) has been developed to study coupling efficiency on hemispherical lens. In this paper, the physical shape of the lens is approximated by cascading a number of straight waveguide segments. The perfectly matched layer (PML) is applied as an absorber for the MoL to reduce numerical reflection in the simulation region. Analysis is done by calculating coupling efficiency at the plane of integration where the coupling efficiency is an overlap integral between laser diode field and fiber field. The result of coupling efficiency in this analysis is compared to the experiment and ABCD matrix. It is found that MoL gives good result accuracy.
    Matched MeSH terms: Fiber Optic Technology/instrumentation*; Fiber Optic Technology/methods*
  6. Fulltext Separation and Detection of Escherichia coli and Saccharomyces cerevisiae Using a Microfluidic Device Integrated with an Optical Fibre
    Kamuri MF, Zainal Abidin Z, Yaacob MH, Hamidon MN, Md Yunus NA, Kamarudin S
    Biosensors (Basel), 2019 Mar 14;9(1).
    PMID: 30875829 DOI: 10.3390/bios9010040
    This paper describes the development of an integrated system using a dry film resistant (DFR) microfluidic channel consisting of pulsed field dielectrophoretic field-flow-fractionation (DEP-FFF) separation and optical detection. The prototype chip employs the pulse DEP-FFF concept to separate the cells (Escherichia coli and Saccharomyces cerevisiae) from a continuous flow, and the rate of release of the cells was measured. The separation experiments were conducted by changing the pulsing time over a pulsing time range of 2⁻24 s and a flow rate range of 1.2⁻9.6 μ L min - 1 . The frequency and voltage were set to a constant value of 1 M Hz and 14 V pk-pk, respectively. After cell sorting, the particles pass the optical fibre, and the incident light is scattered (or absorbed), thus, reducing the intensity of the transmitted light. The change in light level is measured by a spectrophotometer and recorded as an absorbance spectrum. The results revealed that, generally, the flow rate and pulsing time influenced the separation of E. coli and S. cerevisiae. It was found that E. coli had the highest rate of release, followed by S. cerevisiae. In this investigation, the developed integrated chip-in-a lab has enabled two microorganisms of different cell dielectric properties and particle size to be separated and subsequently detected using unique optical properties. Optimum separation between these two microorganisms could be obtained using a longer pulsing time of 12 s and a faster flow rate of 9.6 μ L min - 1 at a constant frequency, voltage, and a low conductivity.
    Matched MeSH terms: Fiber Optic Technology/instrumentation; Fiber Optic Technology/methods*
  7. Fulltext Comparison of the Parker flex tip and the unoflex reinforced endotracheal tube for orotracheal fibreoptic intubation in simulated difficult intubation patients
    Narhari R, Nazaruddin Wan Hassan WM, Mohamad Zaini RH, Che Omar S, Abdullah Nik Mohamad N, Seevaunnamtum P
    Anaesthesiol Intensive Ther, 2020;52(5):377-382.
    PMID: 33327695 DOI: 10.5114/ait.2020.101387
    INTRODUCTION: The choice of endotracheal tube (ETT) is important for successful orotracheal fibreoptic intubation (OFI). The aim of this study was to compare the use of the Parker flex tip (PFT) with the unoflex reinforced (UFR) ETT during OFI.

    MATERIAL AND METHODS: A total of 58 patients who underwent elective surgery under general anaesthesia were randomised to two ETT groups, the PFT group (n = 29) and the UFR group (n = 29), for OFI in simulated difficult intubation patients using a rigid cervical collar. After successful standardised induction and relaxation, OFI and railroading of selected ETT were subsequently performed by a similarly experienced practitioner. Ease of insertion, degree of manipulation, time to successful intubation, post-intubation complications and haemodynamic changes were recorded for both groups.

    RESULTS: he percentage of easy intubation was comparable between both groups with a slightly higher percentage in the UFR group than the PFT group (69.0% vs. 62.0%; P = 0.599). Degree of manipulation was also comparable between the two groups; the percentage of cases in which manipulation was not required was slightly higher in the UFR group than the PFT group (69.0% vs. 62.1%; P = 0.849). Time to successful intubation was also comparable between the groups, although the time was slightly shorter for the UFR group than the PFT group (56.9 s ± 39.7 s vs. 63.9 s ± 36.9 s; P = 0.488). There were also no significant differences in other parameters.

    CONCLUSIONS: The Parker flex tip ETT was comparable to the unoflex reinforced ETT for OFI in simulated difficult airway patients.

    Matched MeSH terms: Fiber Optic Technology/instrumentation; Fiber Optic Technology/methods*
  8. Fulltext Chronology of Fabry-Perot interferometer fiber-optic sensors and their applications: a review
    Islam MR, Ali MM, Lai MH, Lim KS, Ahmad H
    Sensors (Basel), 2014;14(4):7451-88.
    PMID: 24763250 DOI: 10.3390/s140407451
    Optical fibers have been involved in the area of sensing applications for more than four decades. Moreover, interferometric optical fiber sensors have attracted broad interest for their prospective applications in sensing temperature, refractive index, strain measurement, pressure, acoustic wave, vibration, magnetic field, and voltage. During this time, numerous types of interferometers have been developed such as Fabry-Perot, Michelson, Mach-Zehnder, Sagnac Fiber, and Common-path interferometers. Fabry-Perot interferometer (FPI) fiber-optic sensors have been extensively investigated for their exceedingly effective, simple fabrication as well as low cost aspects. In this study, a wide variety of FPI sensors are reviewed in terms of fabrication methods, principle of operation and their sensing applications. The chronology of the development of FPI sensors and their implementation in various applications are discussed.
    Matched MeSH terms: Fiber Optic Technology
  9. Real time mass flow rate measurement using multiple fan beam optical tomography
    Abdul Rahim R, Leong LC, Chan KS, Rahiman MH, Pang JF
    ISA Trans, 2008 Jan;47(1):3-14.
    PMID: 17709106
    This paper presents the implementing multiple fan beam projection technique using optical fibre sensors for a tomography system. From the dynamic experiment of solid/gas flow using plastic beads in a gravity flow rig, the designed optical fibre sensors are reliable in measuring the mass flow rate below 40% of flow. Another important matter that has been discussed is the image processing rate or IPR. Generally, the applied image reconstruction algorithms, the construction of the sensor and also the designed software are considered to be reliable and suitable to perform real-time image reconstruction and mass flow rate measurements.
    Matched MeSH terms: Fiber Optic Technology
  10. Tonsillectomy without headlights: a unique solution
    Prepageran N, Omar R, Raman R
    Ear Nose Throat J, 2005 Sep;84(9):564.
    PMID: 16261756
    Matched MeSH terms: Fiber Optic Technology
  11. Determination of percentage depth dose for 6 and 10 MV x-rays using Ge-doped optical fibre and TLD-100
    Abdulla YA, Amin YM, Khoo HB
    J Radiol Prot, 2002 Dec;22(4):417-21.
    PMID: 12546228
    Percentage depth doses for 6 and 10 MV x-ray beams from a linear accelerator were measured using approximately 1 cm long (approximately 0.3 mg) Ge-doped optical fibre as a thermoluminescence dosimeter for two field sizes, 5 x 5 and 10 x 10 cm2. The results indicate that the Ge-doped optical fibre dosimeter is in good agreement with the results from a PTW 30001 cylindrical ionisation chamber and TLD-100. For 6 MV x-ray beams we observe that the depth of maximum dose d(max) is 1.5 and 2 cm for field sizes of 5 x 5 and 10 x 10 cm2 respectively. For 10 MV d(max) is 2 cm for a field size of 5 x 5 cm2 and 2.5 cm for a 10 x 10 cm2 field.
    Matched MeSH terms: Fiber Optic Technology
  12. Fulltext Surface-Mounted Bare and Packaged Fiber Bragg Grating Sensors for Measuring Rock Strain in Uniaxial Testing
    Isah BW, Mohamad H
    Sensors (Basel), 2021 Apr 22;21(9).
    PMID: 33922008 DOI: 10.3390/s21092926
    The paper explores the possibility of using high-resolution fiber Bragg grating (FBG) sensing technology for on-specimen strain measurement in the laboratory. The approach provides a means to assess the surface deformation of the specimen, both the axial and radial, through a chain of FBG sensor (C-FBG), in a basic setup of a uniaxial compression test. The method is cost-effective, straightforward and can be commercialized. Two C-FBG; one was applied directly to the sample (FBGBare), and the other was packaged (FBGPack) for ease of application. The approach measures the local strain with high-resolution and accuracy levels that match up to the existing local strain measuring sensors. The approach enables the evaluation of small-strain properties of the specimen intelligently. The finite element model analysis deployed has proven the adaptability of the technique for measuring material deformation. The adhesive thickness and packaging technique have been shown to influence the sensitivity of the FBG sensors. Owing to the relative ease and low-cost of instrumentation, the suggested method has a great potential to be routinely applied for elemental testing in the laboratory.
    Matched MeSH terms: Fiber Optic Technology
  13. Fulltext Videolaryngoscope-assisted fibreoptic tracheal intubation in a young adolescent with hunter syndrome for posterior cervical fusion
    Zabir, A.F., Frawley, G., Squire, P.
    Journal of Surgical Academia, 2013;3(2):92-96.
    MyJurnal
    We here describe a videolaryngoscope assisted fibreoptic tracheal intubation in a 17-year-old patient with Hunter Syndrome (Mucopolysaccharidosis Type II) and known difficult intubation who required posterior cervical fusion surgery for cervical canal stenosis. The patient had a history of failed nasal and oral fibreoptic intubation. The use of a videolaryngoscope enabled continuous visualization of the tracheal inlet and allowed a straightforward nasal fibreoptic intubation attempt without complications. This report suggests a viable alternative for the management of a known difficult airway in children with mucopolysaccharidosis.
    Matched MeSH terms: Fiber Optic Technology
  14. Fulltext Novel usage of dexmedetomidine in a paediatric patient with giant tongue haemangioma
    Mohd Zulfakar Mazlan, Shamsul Kamalrujan Hassan, Laila Abd Mukmin, Mohd Hasyizan Hassan, Huda Zainal Abiddin, Irfan Mohamad, et al.
    Malaysian Journal of Medicine and Health Sciences, 2016;12(2):46-48.
    MyJurnal
    Giant haemangioma of the tongue is a disease which can
    obstruct the oropharyngeal airway and is presented with
    obstructive symptoms. Due to its vascularity, inserting
    laryngoscope for intubation can cause high risks, such as
    inducing bleeding. Hypoxia and excessive bleeding must be
    anticipated while securing the airway. We present a case of
    novel usage of dexmedetomidine as a conscious sedation agent
    for awake fibre optic intubation in a 9-year-old child with
    obstructive symptoms secondary to a huge tongue
    haemangioma, who was presented for interventional
    sclerotherapy of the lesion.
    Matched MeSH terms: Fiber Optic Technology
  15. Fulltext Comparison of the Air-Q intubating laryngeal mask airway and the Ambu AuraGain laryngeal mask airway as a conduit for fibreoptic assisted endotracheal intubation for simulated cervical spine injury
    Che Omar S, Hardy Mohamad Zaini R, Fui Wong T, Nazaruddin W Hassan WM
    Anaesthesiol Intensive Ther, 2021;53(3):241-245.
    PMID: 34006053 DOI: 10.5114/ait.2021.105759
    INTRODUCTION: Airway management in patients with a cervical spine injury is a difficult and challenging task. The aim of this study was to compare the effectiveness of the Air-Q intubating laryngeal airway and the Ambu AuraGain laryngeal mask airway as a conduit for fibreoptic (FO) assisted endotracheal intubation in adult patients with a simulated cervical spine injury.

    MATERIAL AND METHODS: A total of 66 adult patients underwent elective surgery under general anaes-thesia, and they were randomized to two groups: the Air-Q (AQ) group (n = 33) and the Ambu AuraGain (AA) group (n = 33). A simulated cervical spine injury was created using a cervical collar, which was applied after the induction of general anaesthesia. Ease of insertion, time taken for successful insertion, time taken for successful FO guided endotracheal intubation, oropharyngeal leak pressure (OLP), Brimacombe score for FO laryngeal view, post-intubation complications and haemodynamic changes were recorded for both groups.

    RESULTS: The OLP was significantly higher in the AA group than in the AQ group (34.9 ± 6.4 vs. 28.6 ± 7.8 cm H 2 O; P = 0.001). Otherwise, there were no significant differences in the ease of insertion, time taken for successful insertion, time taken for successful FO guided endotracheal intubation, Brimacombe score for FO laryngeal view, haemodynamic parameters or complication rate between the two groups.

    CONCLUSIONS: Air-Q was comparably effective as Ambu AuraGain as a conduit for FO endotracheal intubation in patients with a simulated cervical spine injury; however, Ambu AuraGain has a better seal with significant OLP.

    Matched MeSH terms: Fiber Optic Technology
  16. Reflection spectra of etched FBGs under the influence of axial contraction and stress-induced index change
    Yang HZ, Lim KS, Qiao XG, Chong WY, Cheong YK, Lim WH, et al.
    Opt Express, 2013 Jun 17;21(12):14808-15.
    PMID: 23787668 DOI: 10.1364/OE.21.014808
    We present a new theoretical model for the broadband reflection spectra of etched FBGs which includes the effects of axial contraction and stress-induced index change. The reflection spectra of the etched FBGs with several different taper profiles are simulated based on the proposed model. In our observation, decaying exponential profile produces a broadband reflection spectrum with good uniformity over the range of 1540-1560 nm. An etched FBG with similar taper profile is fabricated and the experimental result shows good agreement with the theoretical model.
    Matched MeSH terms: Fiber Optic Technology/instrumentation*
  17. Analytical analysis of second-order Stokes wave in Brillouin ring fiber laser
    Al-Asadi HA, Abu Bakar MH, Al-Mansoori MH, Adikan FR, Mahdi MA
    Opt Express, 2011 Dec 5;19(25):25741-8.
    PMID: 22273966 DOI: 10.1364/OE.19.025741
    This paper details a theoretical modeling of Brillouin ring fiber laser which incorporates the interaction between multiple Brillouin Stokes signals. The ring cavity was pumped at several Brillouin pump (BP) powers and the output was measured through an optical coupler with various coupling ratios. The first-order Brillouin Stokes signal was saturated with the presence of the second-order Stokes signal in the cavity as a result of energy transfer between them. The outcome of the study found that the optimum point for the first-order Stokes wave performance is at laser power reduction of 10%. Resultantly, at the optimum output coupling ratio of 90%, the BFL was able to produce 19.2 mW output power at BP power and Brillouin threshold power of 60 and 21.3 mW respectively. The findings also exhibited the feasibility of the theoretical models application to ring-type Brillouin fiber laser of various design parameters.
    Matched MeSH terms: Fiber Optic Technology/instrumentation*
  18. The thermoluminescence response of doped SiO2 optical fibres subjected to fast neutrons
    Hashim S, Bradley DA, Saripan MI, Ramli AT, Wagiran H
    Appl Radiat Isot, 2010 Apr-May;68(4-5):700-3.
    PMID: 19892557 DOI: 10.1016/j.apradiso.2009.10.027
    This paper describes a preliminary study of the thermoluminescence (TL) response of doped SiO(2) optical fibres subjected to (241)AmBe neutron irradiation. The TL materials, which comprise Al- and Ge-doped silica fibres, were exposed in close contact with the (241)AmBe source to obtain fast neutron interactions through use of measurements obtained with and without a Cd filter (the filter being made to entirely enclose the fibres). The neutron irradiations were performed for exposure times of 1-, 2-, 3-, 5- and 7-days in a neutron tank filled with water. In this study, use was also made of the Monte Carlo N-particle (MCNP) code version 5 (V5) to simulate the neutron irradiations experiment. It was found that the commercially available Ge-doped and Al-doped optical fibres show a linear dose response subjected to fast neutrons from (241)AmBe source up to seven days of irradiations. The simulation performed using MCNP5 also exhibits a similar pattern, albeit differing in sensitivity. The TL response of Ge-doped fibre is markedly greater than that of the Al-doped fibre, the total absorption cross section for Ge in both the fast and thermal neutrons region being some ten times greater than that of Al.
    Matched MeSH terms: Fiber Optic Technology/instrumentation*
  19. Tunable range enhancement of Brillouin-erbium fiber laser utilizing Brillouin pump pre-amplification technique
    Al-Mansoori MH, Mahdi MA
    Opt Express, 2008 May 26;16(11):7649-54.
    PMID: 18545472
    We demonstrate an enhanced multiwavelength L-band Brillouin-erbium fiber laser (BEFL), in which the Brillouin pump is pre-amplified before entering the single-mode fiber. The Brillouin pump pre-amplification provided by the Erbium-doped fiber has created higher intensity of Brillouin Stokes line generated in the single-mode fiber that leads to the homogenous gain saturation. Thus the built-up of self-lasing cavity modes is suppressed in a wider wavelength range. In contrary to the conventional linear-cavity BEFL, the number of output channels is enhanced within the same tuning range.
    Matched MeSH terms: Fiber Optic Technology/instrumentation*
  20. Optical fibre chemical sensor for trace vanadium(V) determination based on newly synthesized palm based fatty hydroxamic acid immobilized in polyvinyl chloride membrane
    Isha A, Yusof NA, Ahmad M, Suhendra D, Yunus WM, Zainal Z
    Spectrochim Acta A Mol Biomol Spectrosc, 2007 Aug;67(5):1398-402.
    PMID: 17141557
    Fatty hydroxamic acid (FHA) immobilized in polyvinyl chloride (PVC) has been studied as a sensor element of an optical fibre chemical sensor for V(V). By using this instrument, V(V) in solution has been determined in the log concentration range of 0-2.5 (i.e. 1.0-300 mg/L). The detection limit was 1.0 mg/L. The relative standard deviation (R.S.D.) of the method for the reproducibility study at V(V) concentration of 200 mg/L and 300 mg/L were calculated to be 2.9% and 2.0%, respectively. Interference from foreign ions was also studied at 1:1 mole ratio of V(V):foreign ions. It was found that, Fe(III) ion interfered most in the determination of vanadium(V). Excellent agreement with ICP-AES method was achieved when the proposed method was applied towards determination of V(V).
    Matched MeSH terms: Fiber Optic Technology/instrumentation*
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