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 wave (CW) fNIRS system able to monitor haemodynamic signals. Our prototype consists of 64 LED sources and 128 photodetectors. It is based on a scalable architecture composed by 8 modular probes, realized on flexible stand in order to fit the head shape as close as possible, each one hosting 4 bi-color LEDs, 16 photo-detectors and a temperature sensor. Hardware novelty lies in adopting Silicon PhotoMultiplier (SiPM) as optical solid-state sensors, which are featured by significant properties in terms of gain, Signal to Noise Ratio, ruggedness and compactness. Such hardware structure allows to easily set up several relevant parameters thanks to a programmable ARM microcontroller, such as: the switching time and the optical power radiated by each LED, the acquisition process and the working voltage of each SiPM. Furthermore, it is possible to configure the portion of cerebral cortex to be analysed, by choosing the proper LED-SiPM couples that will be involved in the measurement. In addition to the electronics boards, a graphical user interface has been developed in order to acquire and display the haemoglobin changes induced by brain activity (or possible disease). Several preliminary tests have been successfully carried out, thus achieving very encouraging results.
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 wave (CW) fNIRS system able to monitor haemodynamic signals. Our prototype consists of 64 LED sources and 128 photodetectors. It is based on a scalable architecture composed by 8 modular probes, realized on flexible stand in order to fit the head shape as close as possible, each one hosting 4 bi-color LEDs, 16 photo-detectors and a temperature sensor. Hardware novelty lies in adopting Silicon PhotoMultiplier (SiPM) as optical solid-state sensors, which are featured by significant properties in terms of gain, Signal to Noise Ratio, ruggedness and compactness. Such hardware structure allows to easily set up several relevant parameters thanks to a programmable ARM microcontroller, such as: the switching time and the optical power radiated by each LED, the acquisition process and the working voltage of each SiPM. Furthermore, it is possible to configure the portion of cerebral cortex to be analysed, by choosing the proper LED-SiPM couples that will be involved in the measurement. In addition to the electronics boards, a graphical user interface has been developed in order to acquire and display the haemoglobin changes induced by brain activity (or possible disease). Several preliminary tests have been successfully carried out, thus achieving very encouraging results.
Agro', .Progettazione e realizzazione di un sistema Continuous Wave fNIRS basato su tecnologia SiPM.
Progettazione e realizzazione di un sistema Continuous Wave fNIRS basato su tecnologia SiPM
AGRO', Diego
Abstract
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 wave (CW) fNIRS system able to monitor haemodynamic signals. Our prototype consists of 64 LED sources and 128 photodetectors. It is based on a scalable architecture composed by 8 modular probes, realized on flexible stand in order to fit the head shape as close as possible, each one hosting 4 bi-color LEDs, 16 photo-detectors and a temperature sensor. Hardware novelty lies in adopting Silicon PhotoMultiplier (SiPM) as optical solid-state sensors, which are featured by significant properties in terms of gain, Signal to Noise Ratio, ruggedness and compactness. Such hardware structure allows to easily set up several relevant parameters thanks to a programmable ARM microcontroller, such as: the switching time and the optical power radiated by each LED, the acquisition process and the working voltage of each SiPM. Furthermore, it is possible to configure the portion of cerebral cortex to be analysed, by choosing the proper LED-SiPM couples that will be involved in the measurement. In addition to the electronics boards, a graphical user interface has been developed in order to acquire and display the haemoglobin changes induced by brain activity (or possible disease). Several preliminary tests have been successfully carried out, thus achieving very encouraging results.
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