The superluminescent diode based differential absorption frequency domain low-coherence interferometry (FD-DALCI) technique is proposed and demonstrated for sensing physiological concentrations of glucose (0–250 mg/dl) in oral mucosa simulating phantoms (intralipid of concentrations 0.25–0.50%) with wavelengths at 1589 and 1310 nm. The proposed technique allows simultaneous measurements of refractive index based spectral shift and estimation of physiological concentration of glucose in intralipid with scattering characteristics using the differential absorption approach. The sensitivity of the glucose concentration obtained by spectral shift measurement was ≈0.016 nm∕mg∕dl, irrespective of the intralipid concentration. The resolution of the glucose level was estimated to be ≈15 mg∕dl in 0.25% intralipid and ≈19 mg∕dl in 0.5% intralipid using the FD-DALCI technique. © 2017 Optical Society of America.

Nilesh Jayanthilal Vasa

Department of Engineering Design

Pauline John

Sujatha Narayanan Unni

Suresh Ranga Rao

Fiber optic sensors

Finite difference method

glucose

Interferometry

physiology

Refractive index

Wave interference

Differential absorption

Frequency domains

Glucose concentration

LOW COHERENCE INTERFEROMETRY

PHYSIOLOGICAL CONCENTRATIONS

SCATTERING CHAR-ACTERISTICS

Simultaneous measurement

SUPERLUMINESCENT DIODE

Frequency domain analysis

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Glucose sensing in oral mucosa simulating phantom using differential absorption based frequency domain low-coherence interferometry.

Applied Optics

The proposed technique based on frequency domain dual wavelength low coherence interferometry (FD-DWLCI) is demonstrated for sensing glucose in ex-vivo human gingival tissue, with preliminary studies performed on solid bilayer gingival tissue phantom and saline. A broad band supercontinuum source filtered using bandpass filters with centre wavelengths at 1300, 1580 (corresponding to the first overtone region), and 2100 nm (corresponding to the combination band of glucose) was employed for the studies. Enhanced glucose resolutions of 11 and 15 mg/dl were estimated for the ratio of relative reflectivity of wavelengths 2100 /1300 nm, in the gingival tissue phantom and ex-vivo human gingival tissue, respectively. © 2001-2012 IEEE.

IEEE Sensors Journal

Glucose sensing in ex-vivo human gingival tissue with enhanced sensitivity in combination band

Supercontinuum source based dual wavelength low coherence interferometry (DWLCI) technique is proposed to measure glucose in the aqueous humor of the eye. Studies were conducted in the second overtone region, first overtone region and combination band to determine the favourable wavelength region for glucose measurement. Bandpass filters at centre wavelengths 1300 nm, 1580 nm, 2100 nm and 2250 nm were used to filter out appropriate bands of interest for the study from the broad wavelength range of 900–2800 nm. In the studies, human eye model was used to simulate the anterior chamber of the eye containing artificial aqueous humor with varying physiological concentrations of glucose ranging from 0 to 250 mg/dl. Studies based on spectral shift measurements and relative reflectivity were conducted. Enhancement in the resolution of glucose was obtained in the combination band at 2100 nm compared to the first overtone region at 1580 nm, due to the increase in the absorption of glucose in the combination band. Glucose resolution of ≈10.3 mg/dl was estimated in the first overtone region. Whereas, an enhancement in the resolution of glucose of ≈2.4 mg/dl was attained in the combination band. © 2019

Fulltext

Sensing and Bio-Sensing Research

Glucose sensing in the anterior chamber of the human eye model using supercontinuum source based dual wavelength low coherence interferometry

Differential absorption based frequency domain optical coherence tomography (FD-DAOCT) technique is proposed and demonstrated for sensing glucose in saline and in ex vivo human gingival tissue. A broad band supercontinuum source at wavelengths 1580 nm and 1300 nm is employed in the proposed study. © 2018 IEEE.

Proceedings of IEEE Sensors

Glucose Sensing in Human Gingival Tissue Using Supercontinuum Source Based Differential Absorption Optical Coherence Tomography

This work presents a combination of differential absorption technique and frequency domain optical coherence tomography for detection of glucose, which is an important analyte in medical diagnosis of diabetes. Differential absorption technique is used to detect glucose selectively in the presence of interfering species especially water and frequency domain optical coherence tomography (FDOCT) helps to obtain faster acquisition of depth information. Two broadband super-luminescent diode (SLED) sources with centre wavelengths 1586 nm (wavelength range of 1540 to 1640 nm) and 1312 nm (wavelength range of 1240 to 1380 nm) and a spectral width of 60nm (FWHM) are used. Preliminary studies on absorption spectroscopy using various concentrations of aqueous glucose solution gave promising results to distinguish the absorption characteristics of glucose at two wavelengths 1310 nm (outside the absorption band of glucose) and 1625 nm (within the absorption band of glucose). In order to mimic the optical properties of biological skin tissue, 2% and 10% of 20% intralipid with various concentrations of glucose (0 to 4000 mg/dL) was prepared and used as sample. Using OCT technique, interference spectra were obtained using an optical spectrum analyzer with a resolution of 0.5 nm. Further processing of the interference spectra provided information on reflections from the surfaces of the cuvette containing the aqueous glucose sample. Due to the absorption of glucose in the wavelength range of 1540 nm to 1640 nm, a trend of reduction in the intensity of the back reflected light was observed with increase in the concentration of glucose. © 2015 SPIE.

Progress in Biomedical Optics and Imaging - Proceedings of SPIE

Aqueous glucose measurement using differential absorption-based frequency domain optical coherence tomography at wavelengths of 1310 nm and 1625 nm

A high-field Asymmetric Waveform Ion Mobility Spectrometry (FA-IMS) with ultra-violet (UV) photo-ionization source is proposed and demonstrated for measurement of trace amounts of volatile organic compound (VOC) gases. Experimental studies performed with the sensor using a high frequency asymmetrical waveform differential field for detection of acetone, hexane and acetone-hexane mixture in trace concentrations are discussed. The detection limit as estimated for a signal-to-noise ratio of 3 is of the order of 100 ppb for acetone and hexane. Experimental studies clearly show that selective sensing of a gas in a mixture of gases is also possible by appropriate value for the compensation voltage. Numerical Simulation is also performed using two-dimensional fluid-flow equations to estimate the motion of ions in an electric field. The study also demonstrated influence of parameters such as flow velocity, duty-ratio, on compensation voltage for detection of trace VOC gases with asymmetrical high-frequency electric field. Results based on theoretical study are in agreement with the experimental studies. © 2014 Elsevier B.V.

Sensors and Actuators, B: Chemical

UV photo-ionization based asymmetric field differential ion mobility sensor for trace gas detection

Sensors

Current and Emerging Technology for Continuous Glucose Monitoring

Journal of Biomedical Optics

Optical coherence tomography for blood glucose monitoringin vitrothrough spatial and temporal approaches

IEEE Journal of Selected Topics in Quantum Electronics

Refractive Index Sensing in Rectangular Glass Micro-Capillaries by Spectral Reflectivity Measurements

Glucose sensing in oral mucosa simulating phantom using differential absorption based frequency domain low-coherence interferometry

Journal	Data powered by TypesetApplied Optics
Publisher	Data powered by TypesetOSA - The Optical Society
ISSN	1559128X
Impact Factor	1.230
Open Access	No
Citation Style	unsrt
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