Search results for "Near infrared spectroscopy"
showing 10 items of 20 documents
Progettazione e realizzazione di un sistema Continuous Wave fNIRS basato su tecnologia SiPM
Optical techniques represent a suitable tool for in vivo and non-invasive diagnosis of human brain and tissues. Functional Near InfraRed Spectroscopy (fNIRS) is revealing as an emerging neuroimaging technology, since it is safe, relatively inexpensive and little cumbersome. fNIRS relies on the measurement of the oxygen concentration in the blood by means of light beams impinging on the tissues under test. Haemoglobin concentration variations (oxygenated/deoxygenated) can provide very important information on brain activity and allow to discriminate the main brain area involved during tests. Herein, we present the design and development of an innovative solution for a portable continuous wav…
Design of a portable (CW) fNIRS embedded system
2014
Near infrared spectroscopic study on the adsorption of methanol on silica gel
2013
Author's version of an article in the journal: Advanced Materials Research. Also available from the publisher at: http://dx.doi.org/10.4028/www.scientific.net/AMR.650.150 The silanol groups on Silica gel surface are sites for adsorption of polar molecules. Alcohols and other polar molecules are easily adsorbed by forming hydrogen bondings with OH groups on silica gel surface. A study on the adsorption of methanol on silica gel was carried out by using NIR spectroscopy in combination with ssecond derivative techniques. Four of the well characterised silica gel samples were used in this study. Each of the silica gel (0.25g) samples with different surface areas and silanol number was pressed i…
The Nature of Rest Silanol Groups on the Surfaces of Silica Based Solid Phase Extraction Materials
2013
Author's version of an article in the journal: Advanced Materials Research. Also available from the publisher at: http://dx.doi.org/10.4028/www.scientific.net/AMR.650.66 Chemically bonded solid phase materials are very important in separation chemistry. The chemically modified silica gel contains rest silanol groups that can affect the retention properties when they are used for separation of compounds. Some commercially available solid phase extraction (SPE) materials based on silica gel were analysed for rest silanol groups by near infrared spectroscopy. The combination frequency of the water molecules in the 5500- 5000 cm -1 region was used in identifying the nature of water molecules on…
Determination of fatty acids and lipid classes in salmon oil by near infrared spectroscopy
2017
International audience; Near-infrared (NIR) spectroscopy was evaluated as a rapid method for the determination of oleic, palmitic, linoleic and linolenic acids as well as omega-3, omega-6, and to predict polyunsaturated, monounsaturated and saturated fatty acids, together with triacylglycerides, diglycerides, free fatty acids and ergosterol in salmon oil. To do it, Partial Least Squares (PLS) regression models were applied to correlate NIR spectra with aforementioned fatty acids and lipid classes. Results obtained were validated in front of reference procedures based on high performance thin layer and gas chromatography. PLS-NIR has a good predictive capability with relative root mean squar…
Design and development of a continuous wave functional near infrared spectroscopy system
2014
Functional Near InfraRed Spectroscopy uses light sources and optical detectors for human brain monitoring. In this paper, a portable, low cost, battery-operated, multi-channel, continuous wave fNIRS embedded system, hosting up to 64 LED sources and 128 Silicon PhotoMultiplier optical detectors, is reported on. The designed system is based on a scalable architecture, in which each probe consists of 8 modular and flexible stands, able to host 4 bi-color LEDs as light sources, 16 silicon photomultipliers as photodetectors and a temperature sensor. The hardware structure allows to easily set up several relevant parameters: the timing of the LEDs, the optical power emitted by the LEDs; the acqui…
Design and realization of a portable multichannel continuous wave fNIRS
2014
A design and implementation of a portable functional Near InfraRed Spectroscopy embedded system prototype is described. In this theoretical and experimental work, we present an embedded system hosting 64 LED sources and 128 Silicon PhotoMultiplier detectors (SiPM). The elementary part of the structure is a flexible probe “leaf” consisting of 16 SiPMs, 4 couples of LEDs, each operating at two wavelengths, and a temperature sensor. The hardware system is based on an ARM main microcontroller that allows to perform both the switching time of LEDs and the acquisition of the SiPM outputs. The performed preliminary experimental tests achieved very promising results, thus demonstrating the effectiv…
Design and development of a fNIRS system prototype based on SiPM detectors
2014
Functional Near Infrared Spectroscopy (fNIRS) uses near infrared sources and detectors to measure changes in absorption due to neurovascular dynamics in response to brain activation. The use of Silicon Photomultipliers (SiPMs) in a fNIRS system has been estimated potentially able to increase the spatial resolution. Dedicated SiPM sensors have been designed and fabricated by using an optimized process. Electrical and optical characterizations are presented. The design and implementation of a portable fNIRS embedded system, hosting up to 64 IR-LED sources and 128 SiPM sensors, has been carried out. The system has been based on a scalable architecture whose elementary leaf is a flexible board …