Blar i NTNU Open på forfatter "Hjelme, Dag Roar"
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Feasibility of supercontinuum sources for use in glucose sensing by absorption spectroscopy
Fuglerud, Silje Skeide; Milenko, Karolina Barbara; Ellingsen, Reinold; Aksnes, Astrid; Hjelme, Dag Roar (Journal article; Peer reviewed, 2019)Diabetes mellitus 1 requires tight control of the blood glucose levels to avoid harmful effects of either too high (hyperglycemia) or too low (hypoglycemia) blood sugar. Due to the availability of low-cost components, ... -
Fibre Bragg Grating Temperature Sensor for Thermodilution
Edvardsen, Sara (Master thesis, 2021) -
First step towards an interferometric and localized surface plasmon fiber optic sensor
Muri, Harald Ian; Bano, Andon; Hjelme, Dag Roar (Journal article; Peer reviewed, 2017)We present a first demonstration of a novel multi-parameter fiber optic (FO) sensor concept based on gold nanoparticles (GNP) embedded in a stimuli-responsive hydrogel material. A hemispherical hydrogel immobilized on the ... -
Food intake monitoring using neural networks based on swallowing sound data
Isifan, Ahmed (Master thesis, 2022)Kunstig Bukspyttkjertel systemer er avhengige av Kontinuerlig Glukose Overvåkningssystemer til å måle blodsukkernivået, og basert på denne målingen beregnes insulindosen og avgis via en insulinpumpe. Disse systemer er ... -
Generation, and nonlinear Parameter Estimation, of Reflection Spectra from an Intravascular Fabry-Perót Sensor, for detecting Temperature and Glucose Concentrations
Rokkones, Didrik (Master thesis, 2017)GlucoSet AS has developed an intravascular Fabry-Perót (FP) glucose sensor. The sensor consists of a hydrogel cast on an optical fiber cut, representing a low finesse FP cavity. The cavity changes length with respect to ... -
Glucose sensing by absorption spectroscopy using lensed optical fibers
Fuglerud, Silje Skeide; Milenko, Karolina Barbara; Ellingsen, Reinold; Aksnes, Astrid; Hjelme, Dag Roar (Journal article; Peer reviewed, 2019)The bulkiness of common transmission spectroscopy probes prevents applicability at remote locations such as within the body. We present the fabrication and characterization of lensed fibers for transmission spectroscopy ... -
Ice formation and growth in supercooled water–alcohol mixtures: Theory and experiments with dual fiber sensors
Wahl, Markus Solberg; Aasen, Ailo; Hjelme, Dag Roar; Wilhelmsen, Øivind (Peer reviewed; Journal article, 2020)Increased knowledge on fluid-solid phase transitions is needed, both when they are undesired and can impair processes operation, and when strict control is required in fields such as food technology, the pharmaceutical ... -
Infrared measurements of glucose in peritoneal fluid with a tuneable quantum cascade laser
Jernelv, Ine Larsen; Hjelme, Dag Roar; Aksnes, Astrid (Peer reviewed; Journal article, 2020)Fast and accurate continuous glucose monitoring is needed in future systems for control of blood glucose levels in type 1 diabetes patients. Direct spectroscopic measurement of glucose in the peritoneal cavity is an ... -
Infrared Spectroscopy with a Fiber-Coupled Quantum Cascade Laser for Attenuated Total Reflection Measurements Towards Biomedical Applications
Jernelv, Ine Larsen; Strøm, Karina; Hjelme, Dag Roar; Aksnes, Astrid (Journal article; Peer reviewed, 2019)The development of rapid and accurate biomedical laser spectroscopy systems in the mid-infrared has been enabled by the commercial availability of external-cavity quantum cascade lasers (EC-QCLs). EC-QCLs are a preferable ... -
Interferometric and localized surface plasmon based fiber optic sensor
Muri, Harald Ian Di; Bano, Andon; Hjelme, Dag Roar (Journal article; Peer reviewed, 2017)We demonstrate a novel single point, multi-parameter, fiber optic sensor concept based on a combination of interferometric and plasmonic sensor modalities on an optical fiber end face. The sensor consists of a microFabry-Perot ... -
Investigation of the effect of clinically relevant interferents on glucose monitoring using near‐infrared spectroscopy
Fuglerud, Silje Skeide; Ellingsen, Reinold; Aksnes, Astrid; Hjelme, Dag Roar (Peer reviewed; Journal article, 2021)Near infrared spectroscopy (NIR) is a promising technique for continuous blood glucose monitoring for diabetic patients. Four interferents, at physiological concentrations, were introduced to study how the glucose predictions ... -
Low-energy pyroelectric motion detection
Mithassel, Benedikt Andreas (Master thesis, 2023)Eksisterende løsninger for bevegelsesdeteksjon har et høyt energikonsum, hvilket gjør dem mindre egnet til IoT (Tingenes internett) applikasjoner. Denne masteroppgaven beskriver en ny alternativ måte å måle signalet, med ... -
LSPR and Interferometric Sensor Modalities Combined Using a Double-Clad Optical Fiber
Muri, Harald Ian; Bano, Andon; Hjelme, Dag Roar (Journal article; Peer reviewed, 2018)We report on characterization of an optical fiber-based multi-parameter sensor concept combining localized surface plasmon resonance (LSPR) signal and interferometric sensing using a double-clad optical fiber. The sensor ... -
LSPR Coupling and Distribution of Interparticle Distances between Nanoparticles in Hydrogel on Optical Fiber End Face
Muri, Harald Ian; Hjelme, Dag Roar (Journal article; Peer reviewed, 2017)We report on a new localized surface plasmon resonance (LSPR)-based optical fiber (OF) architecture with a potential in sensor applications. The LSPR-OF system is fabricated by immobilizing gold nanoparticles (GNPs) in a ... -
Mapping nanoparticles in hydrogels: A comparison of preparation methods for electron microscopy
Muri, Harald Ian; Hoang, Linh; Hjelme, Dag Roar (Journal article; Peer reviewed, 2018)The distribution of noble metal nanoparticles (NMNPs) in hydrogels influences their nanoplasmonic response and signals used for biosensor purposes. By controlling the particle distribution in NMNP-nanocomposite hydrogels, ... -
Meal type classification using a neural network model trained on chewing audio data
Klavins, Davis Guntars (Master thesis, 2022)Diabetes er en av de mest utbredte sykdommene i verden. Millioner av pasienter er avhengige av invasive og ugunstige behandlinger for å opprettholde optimal daglig funksjon. Forskning i alternative behandlinger har ført ... -
Metodologi for synkronisering av hyperspektral klassifisering med sorteringsmaskiner
Mørenskog, Erik Rundhovde (Master thesis, 2020)Hyperspektral avbildning har vist seg å være et nyttig verktøy for fjernmåling i laboratorie-, felt-, luftbårne og industrielle applikasjoner. Teknikken gir høy spektral oppløsning i det synlige og infrarøde spekteret, som ... -
Micro-lensed negative-curvature fibre probe for raman spectroscopy
Milenko, Karolina Barbara; Yerolatsitis, Stephanos; Aksnes, Astrid; Hjelme, Dag Roar; Stone, James M. (Peer reviewed; Journal article, 2021)We developed a novel miniature micro-lensed fibre probe for Raman spectroscopy. The fibre probe consists of a single negative-curvature fibre (NCF) and a spliced, cleaved, micro-lensed fibre cap. Using a single NCF, we ... -
Micro-lensed optical fibers for a surface-enhanced Raman scattering sensing probe
Milenko, Karolina Barbara; Fuglerud, Silje Skeide; Kjeldby, Snorre B; Ellingsen, Reinold; Aksnes, Astrid; Hjelme, Dag Roar (Journal article; Peer reviewed, 2018)We present the fabrication and characterization of a novel sensing configuration based on surface-enhanced Raman scattering (SERS) and two micro-lensed optical fibers. The first micro-lensed fiber is used to excite surface ... -
Mid-infrared spectroscopy with a fiber-coupled tuneable quantum cascade laser for glucose sensing
Jernelv, Ine Larsen; Strøm, Karina; Hjelme, Dag Roar; Aksnes, Astrid (Peer reviewed; Journal article, 2020)A fiber-coupled transmission spectroscopy setup using a pulsed external-cavity quantum cascade laser (EC-QCL, 1200-900 cm−1 ) has been developed and demonstrated for measurements of aqueous solutions. The system has been ...