Search results for "nirS"

Design and realization of a portable continuous wave fNIRS

2015

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…

Continuous Wave fNIRS with Silicon Photomultiplier

2015

This work is focused on the development of a Continuous Wave (CW) NIRS integrated system with multi-wavelength LED sources between 700 and 950 nm and a Silicon Photomultiplier detector (SiPM) developed by STMicroelectronics. The Signal Noise Rate (SNR), measured placing the LEDs and an SiPM in a direct contact with the surface of a plastic phantom mimicking a real human head, results higher than the calculated minimum, required to detect small variation in the HbO2 and HHb concentration, till a source detector separation (SDS) of 6 cm.

Motor Cortex Function in Fibromyalgia: A Study by Functional Near-Infrared Spectroscopy

2019

Previous studies indicated changes of motor cortex excitability in fibromyalgia (FM) patients and the positive results of transcranial stimulation techniques. The present study aimed to explore the metabolism of motor cortex in FM patients, in resting state and during slow and fast finger tapping, using functional Near-Infrared Spectroscopy (fNIRS), an optical method which detects in real time the metabolism changes in the cortical tissue. We studied 24 FM patients and 24 healthy subjects. We found a significant slowness of motor speed in FM patients compared to controls. During resting state and slow movement conditions, the metabolism of the motor areas was similar between groups. The oxy…

Functional Near Infrared Spectroscopy System Validation for Simultaneous EEG-FNIRS Measurements

2019

Functional near-infrared spectroscopy (fNIRS) applied to brain monitoring has been gaining increasing relevance in the last years due to its not invasive nature and the capability to work in combination with other well–known techniques such as the EEG. The possible use cases span from neural-rehabilitation to early diagnosis of some neural diseases. In this work a wireline FPGA–based fNIRS system, that use SiPM sensors and dual-wavelength LED sources, has been designed and validated to work with a commercial EEG machine without reciprocal interference.

Behavioral and hemodynamic effects of prefrontal anodal stimulation in healthy older adults: a simultaneous tDCS/fNIRS study

2019

Effects of Transcranial Direct Current Stimulation on Baseline and Slope of Prefrontal Cortex Hemodynamics During a Spatial Working Memory Task

2020

Background: Transcranial direct current stimulation (tDCS) has been shown to be an inexpensive, safe, and effective way of augmenting a variety of cognitive abilities. Relatively recent advances in neuroimaging technology have provided the ability to measure brain activity concurrently during active brain stimulation rather than after stimulation. The effects on brain activity elicited by tDCS during active tDCS reported by initial studies have been somewhat conflicted and seemingly dependent on whether a behavioral improvement was observed. Objective: The current study set out to address questions regarding behavioral change, within and between-participant designs as well as differentiatin…

Can differences in microbial abundances help explain enhanced N2O emissions in a permanent grassland under elevated atmospheric CO2?

2011

Mogućnosti i granice montaže modela čeljusti orijentiranih prema šarnirskoj osi

1988

Terminalna šarnirska os može se odrediti na dva načina: egzaktna (točna metoda) i metoda prosječne šarnirske osi. Za točnu lokalizaciju šarnirske osi u ovom je istraživanju upotrijebljen Lauritzen - pribor i SAM obrazni luk s metalnim pločicama i milimetarskim papirom. Ispitivalo se s kojom je točnošću moguće odrediti šarnirsku os i s kojom inkongruencijom šarnirske osi i osi artikulatora treba računati pri primjeni metode prosječne šarnirske osi. Dobivene vrijednosti pri montaži donjih modela prema točno određenoj šarnirskoj osi varirale su ± 0,8 mm od srednje vrijednosti u sagitalnoj i vertikalnoj ravnini. Prosječno odstupanje dobivenih vrijednosti pri montaži modela prema prosječnoj šarn…