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Lacerenza M, Frabasile L, Buttafava M, Spinelli L, Bassani E, Micheloni F, Amendola C, Torricelli A, Contini D. Motor cortex hemodynamic response to goal-oriented and non-goal-oriented tasks in healthy subjects. Front Neurosci 2023; 17:1202705. [PMID: 37539388 PMCID: PMC10394236 DOI: 10.3389/fnins.2023.1202705] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2023] [Accepted: 06/16/2023] [Indexed: 08/05/2023] Open
Abstract
Background Motor disorders are one of the world's major scourges, and neuromotor rehabilitation is paramount for prevention and monitoring plans. In this scenario, exercises and motor tasks to be performed by patients are crucial to follow and assess treatments' progression and efficacy. Nowadays, in clinical environments, quantitative assessment of motor cortex activities during task execution is rare, due to the bulkiness of instrumentation and the need for immobility during measurements [e.g., functional magnetic resonance imaging (MRI)]. Functional near-infrared spectroscopy (fNIRS) can contribute to a better understanding of how neuromotor processes work by measuring motor cortex activity non-invasively in freely moving subjects. Aim Exploit fNIRS to measure functional activation of the motor cortex area during arm-raising actions. Design All subjects performed three different upper limbs motor tasks: arm raising (non-goal-oriented), arm raising and grasping (goal oriented), and assisted arm raising (passive task). Each task was repeated ten times. The block design for each task was divided into 5 seconds of baseline, 5 seconds of activity, and 15 seconds of recovery. Population Sixteen healthy subjects (11 males and 5 females) with an average (+/- standard deviation) of 37.9 (+/- 13.0) years old. Methods Cerebral hemodynamic responses have been recorded in two locations, motor cortex (activation area) and prefrontal cortex (control location) exploiting commercial time-domain fNIRS devices. Haemodynamic signals were analyzed, separating the brain cortex hemodynamic response from extracerebral hemodynamic variations. Results The hemodynamic response was recorded in the cortical motor area for goal-oriented and not-goaloriented tasks, while no response was noticed in the control location (prefrontal cortex position). Conclusions This study provides a basis for canonical upper limb motor cortex activations that can be potentially compared to pathological cerebral responses in patients. It also highlights the potential use of TD-fNIRS to study goal-oriented versus non-goaloriented motor tasks. Impact: the findings of this study may have implications for clinical rehabilitation by providing a better understanding of the neural mechanisms underlying goal-oriented versus non-goal-oriented motor tasks. This may lead to more effective rehabilitation strategies for individuals with motor disorders and a more effective diagnosis of motor dysfunction supported by objective and quantitative neurophysiological readings.
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Affiliation(s)
- Michele Lacerenza
- Dipartimento di Fisica, Politecnico di Milano, Milano, Italy
- PIONIRS s.r.l., Milano, Italy
| | | | | | - Lorenzo Spinelli
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Milano, Italy
| | - Elisa Bassani
- Scuola Universitaria Professionale della Svizzera Italiana, Manno, Switzerland
- Centro Studi Riabilitazione Neurologica, Neuropsicologia e Neuropsicoterapia, Milano, Italy
| | - Francesco Micheloni
- Centro Studi Riabilitazione Neurologica, Neuropsicologia e Neuropsicoterapia, Milano, Italy
| | | | - Alessandro Torricelli
- Dipartimento di Fisica, Politecnico di Milano, Milano, Italy
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Milano, Italy
| | - Davide Contini
- Dipartimento di Fisica, Politecnico di Milano, Milano, Italy
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2
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Re R, Pirovano I, Contini D, Amendola C, Contini L, Frabasile L, Levoni P, Torricelli A, Spinelli L. Reliable Fast (20 Hz) Acquisition Rate by a TD fNIRS Device: Brain Resting-State Oscillation Studies. SENSORS (BASEL, SWITZERLAND) 2022; 23:196. [PMID: 36616792 PMCID: PMC9823873 DOI: 10.3390/s23010196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 12/21/2022] [Accepted: 12/22/2022] [Indexed: 06/17/2023]
Abstract
A high power setup for multichannel time-domain (TD) functional near infrared spectroscopy (fNIRS) measurements with high efficiency detection system was developed. It was fully characterized based on international performance assessment protocols for diffuse optics instruments, showing an improvement of the signal-to-noise ratio (SNR) with respect to previous analogue devices, and allowing acquisition of signals with sampling rate up to 20 Hz and source-detector distance up to 5 cm. A resting-state measurement on the motor cortex of a healthy volunteer was performed with an acquisition rate of 20 Hz at a 4 cm source-detector distance. The power spectrum for the cortical oxy- and deoxyhemoglobin is also provided.
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Affiliation(s)
- Rebecca Re
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci, 32, 20133 Milan, Italy
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Piazza Leonardo da Vinci, 32, 20133 Milan, Italy
| | - Ileana Pirovano
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci, 32, 20133 Milan, Italy
- Istituto di Tecnologie Biomediche, Consiglio Nazionale delle Ricerche, via Fratelli Cervi 93, 20090 Segrate, Italy
| | - Davide Contini
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci, 32, 20133 Milan, Italy
| | - Caterina Amendola
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci, 32, 20133 Milan, Italy
| | - Letizia Contini
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci, 32, 20133 Milan, Italy
| | - Lorenzo Frabasile
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci, 32, 20133 Milan, Italy
| | - Pietro Levoni
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci, 32, 20133 Milan, Italy
| | - Alessandro Torricelli
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci, 32, 20133 Milan, Italy
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Piazza Leonardo da Vinci, 32, 20133 Milan, Italy
| | - Lorenzo Spinelli
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Piazza Leonardo da Vinci, 32, 20133 Milan, Italy
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3
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Lanka P, Yang L, Orive-Miguel D, Veesa JD, Tagliabue S, Sudakou A, Samaei S, Forcione M, Kovacsova Z, Behera A, Gladytz T, Grosenick D, Hervé L, Durduran T, Bejm K, Morawiec M, Kacprzak M, Sawosz P, Gerega A, Liebert A, Belli A, Tachtsidis I, Lange F, Bale G, Baratelli L, Gioux S, Alexander K, Wolf M, Sekar SKV, Zanoletti M, Pirovano I, Lacerenza M, Qiu L, Ferocino E, Maffeis G, Amendola C, Colombo L, Frabasile L, Levoni P, Buttafava M, Renna M, Di Sieno L, Re R, Farina A, Spinelli L, Dalla Mora A, Contini D, Taroni P, Tosi A, Torricelli A, Dehghani H, Wabnitz H, Pifferi A. Multi-laboratory performance assessment of diffuse optics instruments: the BitMap exercise. JOURNAL OF BIOMEDICAL OPTICS 2022; 27:JBO-210373SSR. [PMID: 35701869 PMCID: PMC9199954 DOI: 10.1117/1.jbo.27.7.074716] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 05/05/2022] [Indexed: 05/06/2023]
Abstract
SIGNIFICANCE Multi-laboratory initiatives are essential in performance assessment and standardization-crucial for bringing biophotonics to mature clinical use-to establish protocols and develop reference tissue phantoms that all will allow universal instrument comparison. AIM The largest multi-laboratory comparison of performance assessment in near-infrared diffuse optics is presented, involving 28 instruments and 12 institutions on a total of eight experiments based on three consolidated protocols (BIP, MEDPHOT, and NEUROPT) as implemented on three kits of tissue phantoms. A total of 20 synthetic indicators were extracted from the dataset, some of them defined here anew. APPROACH The exercise stems from the Innovative Training Network BitMap funded by the European Commission and expanded to include other European laboratories. A large variety of diffuse optics instruments were considered, based on different approaches (time domain/frequency domain/continuous wave), at various stages of maturity and designed for different applications (e.g., oximetry, spectroscopy, and imaging). RESULTS This study highlights a substantial difference in hardware performances (e.g., nine decades in responsivity, four decades in dark count rate, and one decade in temporal resolution). Agreement in the estimates of homogeneous optical properties was within 12% of the median value for half of the systems, with a temporal stability of <5 % over 1 h, and day-to-day reproducibility of <3 % . Other tests encompassed linearity, crosstalk, uncertainty, and detection of optical inhomogeneities. CONCLUSIONS This extensive multi-laboratory exercise provides a detailed assessment of near-infrared Diffuse optical instruments and can be used for reference grading. The dataset-available soon in an open data repository-can be evaluated in multiple ways, for instance, to compare different analysis tools or study the impact of hardware implementations.
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Affiliation(s)
- Pranav Lanka
- Politecnico di Milano, Dipartimento di Fisica, Milano, Italy
- Address all correspondence to Pranav Lanka, ; Heidrun Wabnitz,
| | - Lin Yang
- Physikalisch-Technische Bundesanstalt (PTB), Berlin, Germany
| | | | - Joshua Deepak Veesa
- University of Birmingham, School of Computer Science, Birmingham, United Kingdom
| | | | - Aleh Sudakou
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Warsaw, Poland
| | - Saeed Samaei
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Warsaw, Poland
| | - Mario Forcione
- University Hospitals Birmingham, National Institute for Health Research Surgical Reconstruction and Microbiology Research Centre, Birmingham, United Kingdom
| | - Zuzana Kovacsova
- UCL, Department of Medical Physics & Biomedical Engineering, London, United Kingdom
| | - Anurag Behera
- Politecnico di Milano, Dipartimento di Fisica, Milano, Italy
| | - Thomas Gladytz
- Physikalisch-Technische Bundesanstalt (PTB), Berlin, Germany
| | - Dirk Grosenick
- Physikalisch-Technische Bundesanstalt (PTB), Berlin, Germany
| | - Lionel Hervé
- Université Grenoble Alpes, CEA, LETI, DTBS, Grenoble, France
| | - Turgut Durduran
- The Institute of Photonic Sciences (ICFO), Castelldefels, Spain
| | - Karolina Bejm
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Warsaw, Poland
| | - Magdalena Morawiec
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Warsaw, Poland
| | - Michał Kacprzak
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Warsaw, Poland
| | - Piotr Sawosz
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Warsaw, Poland
| | - Anna Gerega
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Warsaw, Poland
| | - Adam Liebert
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Warsaw, Poland
| | - Antonio Belli
- University Hospitals Birmingham, National Institute for Health Research Surgical Reconstruction and Microbiology Research Centre, Birmingham, United Kingdom
| | - Ilias Tachtsidis
- UCL, Department of Medical Physics & Biomedical Engineering, London, United Kingdom
| | - Frédéric Lange
- UCL, Department of Medical Physics & Biomedical Engineering, London, United Kingdom
| | - Gemma Bale
- University of Cambridge, Department of Engineering and Department of Physics, Cambridge, United Kingdom
| | - Luca Baratelli
- University of Strasbourg, ICube Laboratory, Strasbourg, France
| | - Sylvain Gioux
- University of Strasbourg, ICube Laboratory, Strasbourg, France
| | - Kalyanov Alexander
- University Hospital Zurich, Biomedical Optics Research Laboratory, Department of Neonatology, Zurich, Switzerland
| | - Martin Wolf
- University Hospital Zurich, Biomedical Optics Research Laboratory, Department of Neonatology, Zurich, Switzerland
| | | | - Marta Zanoletti
- Politecnico di Milano, Dipartimento di Fisica, Milano, Italy
| | - Ileana Pirovano
- Politecnico di Milano, Dipartimento di Fisica, Milano, Italy
| | | | - Lina Qiu
- South China Normal University, School of Software, Guangzhou, China
| | | | - Giulia Maffeis
- Politecnico di Milano, Dipartimento di Fisica, Milano, Italy
| | | | - Lorenzo Colombo
- Politecnico di Milano, Dipartimento di Fisica, Milano, Italy
| | | | - Pietro Levoni
- Politecnico di Milano, Dipartimento di Fisica, Milano, Italy
| | | | - Marco Renna
- Istituto di Fotonica e Nanotecnologie, Milano, Italy
| | - Laura Di Sieno
- Politecnico di Milano, Dipartimento di Fisica, Milano, Italy
| | - Rebecca Re
- Politecnico di Milano, Dipartimento di Fisica, Milano, Italy
- Politecnico di Milano, Dipartimento di Elettronica, Informazione e Bioingegneria, Milano, Italy
| | - Andrea Farina
- Politecnico di Milano, Dipartimento di Elettronica, Informazione e Bioingegneria, Milano, Italy
| | - Lorenzo Spinelli
- Politecnico di Milano, Dipartimento di Elettronica, Informazione e Bioingegneria, Milano, Italy
| | | | - Davide Contini
- Politecnico di Milano, Dipartimento di Fisica, Milano, Italy
| | - Paola Taroni
- Politecnico di Milano, Dipartimento di Fisica, Milano, Italy
| | - Alberto Tosi
- Istituto di Fotonica e Nanotecnologie, Milano, Italy
| | | | - Hamid Dehghani
- University of Birmingham, School of Computer Science, Birmingham, United Kingdom
| | - Heidrun Wabnitz
- Physikalisch-Technische Bundesanstalt (PTB), Berlin, Germany
- Address all correspondence to Pranav Lanka, ; Heidrun Wabnitz,
| | - Antonio Pifferi
- Politecnico di Milano, Dipartimento di Fisica, Milano, Italy
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4
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Hacker L, Wabnitz H, Pifferi A, Pfefer TJ, Pogue BW, Bohndiek SE. Criteria for the design of tissue-mimicking phantoms for the standardization of biophotonic instrumentation. Nat Biomed Eng 2022; 6:541-558. [PMID: 35624150 DOI: 10.1038/s41551-022-00890-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2020] [Accepted: 02/07/2022] [Indexed: 01/08/2023]
Abstract
A lack of accepted standards and standardized phantoms suitable for the technical validation of biophotonic instrumentation hinders the reliability and reproducibility of its experimental outputs. In this Perspective, we discuss general criteria for the design of tissue-mimicking biophotonic phantoms, and use these criteria and state-of-the-art developments to critically review the literature on phantom materials and on the fabrication of phantoms. By focusing on representative examples of standardization in diffuse optical imaging and spectroscopy, fluorescence-guided surgery and photoacoustic imaging, we identify unmet needs in the development of phantoms and a set of criteria (leveraging characterization, collaboration, communication and commitment) for the standardization of biophotonic instrumentation.
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Affiliation(s)
- Lina Hacker
- Department of Physics, University of Cambridge, Cambridge, UK.,Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge, UK
| | - Heidrun Wabnitz
- Physikalisch-Technische Bundesanstalt (PTB), Berlin, Germany
| | | | | | - Brian W Pogue
- Thayer School of Engineering, Dartmouth, Hanover, NH, USA
| | - Sarah E Bohndiek
- Department of Physics, University of Cambridge, Cambridge, UK. .,Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge, UK.
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5
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Ban HY, Barrett GM, Borisevich A, Chaturvedi A, Dahle JL, Dehghani H, Dubois J, Field RM, Gopalakrishnan V, Gundran A, Henninger M, Ho WC, Hughes HD, Jin R, Kates-Harbeck J, Landy T, Leggiero M, Lerner G, Aghajan ZM, Moon M, Olvera I, Park S, Patel MJ, Perdue KL, Siepser B, Sorgenfrei S, Sun N, Szczepanski V, Zhang M, Zhu Z. Kernel Flow: a high channel count scalable time-domain functional near-infrared spectroscopy system. JOURNAL OF BIOMEDICAL OPTICS 2022; 27:JBO-210278SSR. [PMID: 35043610 PMCID: PMC8765296 DOI: 10.1117/1.jbo.27.7.074710] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 12/23/2021] [Indexed: 05/26/2023]
Abstract
SIGNIFICANCE Time-domain functional near-infrared spectroscopy (TD-fNIRS) has been considered as the gold standard of noninvasive optical brain imaging devices. However, due to the high cost, complexity, and large form factor, it has not been as widely adopted as continuous wave NIRS systems. AIM Kernel Flow is a TD-fNIRS system that has been designed to break through these limitations by maintaining the performance of a research grade TD-fNIRS system while integrating all of the components into a small modular device. APPROACH The Kernel Flow modules are built around miniaturized laser drivers, custom integrated circuits, and specialized detectors. The modules can be assembled into a system with dense channel coverage over the entire head. RESULTS We show performance similar to benchtop systems with our miniaturized device as characterized by standardized tissue and optical phantom protocols for TD-fNIRS and human neuroscience results. CONCLUSIONS The miniaturized design of the Kernel Flow system allows for broader applications of TD-fNIRS.
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Affiliation(s)
- Han Y. Ban
- Kernel, Los Angeles, California, United States
| | | | | | | | | | | | | | | | | | | | | | | | | | - Rong Jin
- Kernel, Los Angeles, California, United States
| | | | - Thanh Landy
- Kernel, Los Angeles, California, United States
| | | | | | | | | | - Isai Olvera
- Kernel, Los Angeles, California, United States
| | | | | | | | | | | | - Nathan Sun
- Kernel, Los Angeles, California, United States
| | | | - Mary Zhang
- Kernel, Los Angeles, California, United States
| | - Zhenye Zhu
- Kernel, Los Angeles, California, United States
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6
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Sudakou A, Lange F, Isler H, Lanka P, Wojtkiewicz S, Sawosz P, Ostojic D, Wolf M, Pifferi A, Tachtsidis I, Liebert A, Gerega A. Time-domain NIRS system based on supercontinuum light source and multi-wavelength detection: validation for tissue oxygenation studies. BIOMEDICAL OPTICS EXPRESS 2021; 12:6629-6650. [PMID: 34745761 PMCID: PMC8548017 DOI: 10.1364/boe.431301] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 08/06/2021] [Accepted: 09/07/2021] [Indexed: 05/15/2023]
Abstract
We present and validate a multi-wavelength time-domain near-infrared spectroscopy (TD-NIRS) system that avoids switching wavelengths and instead exploits the full capability of a supercontinuum light source by emitting and acquiring signals for the whole chosen range of wavelengths. The system was designed for muscle and brain oxygenation monitoring in a clinical environment. A pulsed supercontinuum laser emits broadband light and each of two detection modules acquires the distributions of times of flight of photons (DTOFs) for 16 spectral channels (used width 12.5 nm / channel), providing a total of 32 DTOFs at up to 3 Hz. Two emitting fibers and two detection fiber bundles allow simultaneous measurements at two positions on the tissue or at two source-detector separations. Three established protocols (BIP, MEDPHOT, and nEUROPt) were used to quantitatively assess the system's performance, including linearity, coupling, accuracy, and depth sensitivity. Measurements were performed on 32 homogeneous phantoms and two inhomogeneous phantoms (solid and liquid). Furthermore, measurements on two blood-lipid phantoms with a varied amount of blood and Intralipid provide the strongest validation for accurate tissue oximetry. The retrieved hemoglobin concentrations and oxygen saturation match well with the reference values that were obtained using a commercially available NIRS system (OxiplexTS) and a blood gas analyzer (ABL90 FLEX), except a discrepancy occurs for the lowest amount of Intralipid. In-vivo measurements on the forearm of three healthy volunteers during arterial (250 mmHg) and venous (60 mmHg) cuff occlusions provide an example of tissue monitoring during the expected hemodynamic changes that follow previously well-described physiologies. All results, including quantitative parameters, can be compared to other systems that report similar tests. Overall, the presented TD-NIRS system has an exemplary performance evaluated with state-of-the-art performance assessment methods.
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Affiliation(s)
- Aleh Sudakou
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Warsaw, Poland
| | - Frédéric Lange
- Department of Medical Physics and Biomedical Engineering, University College London, London, UK
| | - Helene Isler
- Department of Neonatology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Pranav Lanka
- Dipartimento di Fisica, Politecnico di Milano, Milano, Italy
| | | | - Piotr Sawosz
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Warsaw, Poland
| | - Daniel Ostojic
- Department of Neonatology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Martin Wolf
- Department of Neonatology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Antonio Pifferi
- Dipartimento di Fisica, Politecnico di Milano, Milano, Italy
| | - Ilias Tachtsidis
- Department of Medical Physics and Biomedical Engineering, University College London, London, UK
| | - Adam Liebert
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Warsaw, Poland
| | - Anna Gerega
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Warsaw, Poland
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7
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Abdalmalak A, Milej D, Norton L, Debicki DB, Owen AM, Lawrence KS. The Potential Role of fNIRS in Evaluating Levels of Consciousness. Front Hum Neurosci 2021; 15:703405. [PMID: 34305558 PMCID: PMC8296905 DOI: 10.3389/fnhum.2021.703405] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 05/31/2021] [Indexed: 12/13/2022] Open
Abstract
Over the last few decades, neuroimaging techniques have transformed our understanding of the brain and the effect of neurological conditions on brain function. More recently, light-based modalities such as functional near-infrared spectroscopy have gained popularity as tools to study brain function at the bedside. A recent application is to assess residual awareness in patients with disorders of consciousness, as some patients retain awareness albeit lacking all behavioural response to commands. Functional near-infrared spectroscopy can play a vital role in identifying these patients by assessing command-driven brain activity. The goal of this review is to summarise the studies reported on this topic, to discuss the technical and ethical challenges of working with patients with disorders of consciousness, and to outline promising future directions in this field.
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Affiliation(s)
- Androu Abdalmalak
- Department of Physiology and Pharmacology, Western University, London, ON, Canada.,Brain and Mind Institute, Western University, London, ON, Canada
| | - Daniel Milej
- Imaging Program, Lawson Health Research Institute, London, ON, Canada.,Department of Medical Biophysics, Western University, London, ON, Canada
| | - Loretta Norton
- Department of Psychology, King's College, Western University, London, ON, Canada
| | - Derek B Debicki
- Brain and Mind Institute, Western University, London, ON, Canada.,Clinical Neurological Sciences, Western University, London, ON, Canada
| | - Adrian M Owen
- Department of Physiology and Pharmacology, Western University, London, ON, Canada.,Brain and Mind Institute, Western University, London, ON, Canada.,Department of Psychology, Western University, London, ON, Canada
| | - Keith St Lawrence
- Imaging Program, Lawson Health Research Institute, London, ON, Canada.,Department of Medical Biophysics, Western University, London, ON, Canada
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8
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Re R, Messenio D, Marano G, Spinelli L, Pirovano I, Contini D, Colombo R, Boracchi P, Biganzoli E, Cubeddu R, Torricelli A. Monitoring the haemodynamic response to visual stimulation in glaucoma patients. Sci Rep 2021; 11:13567. [PMID: 34193904 PMCID: PMC8245402 DOI: 10.1038/s41598-021-92857-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Accepted: 06/16/2021] [Indexed: 11/23/2022] Open
Abstract
In this paper, we used time-domain functional near infrared spectroscopy (TD-fNIRS) to evaluate the haemodynamic response function (HRF) in the occipital cortex following visual stimulation in glaucomatous eyes as compared to healthy eyes. A total of 98 subjects were enrolled in the study and clinically classified as healthy subjects, glaucoma patients (primary open-angle glaucoma) and mixed subjects (i.e. with a different classification for the two eyes). After quality check data were used from HRF of 73 healthy and 62 glaucomatous eyes. The amplitudes of the oxygenated and deoxygenated haemoglobin concentrations, together with their latencies with respect to the stimulus onset, were estimated by fitting their time course with a canonical HRF. Statistical analysis showed that the amplitudes of both haemodynamic parameters show a significant association with the pathology and a significant discriminating ability, while no significant result was found for latencies. Overall, our findings together with the ease of use and noninvasiveness of TD-NIRS, make this technique a promising candidate as a supporting tool for a better evaluation of the glaucoma pathology.
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Affiliation(s)
- R Re
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133, Milan, Italy. .,Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Piazza Leonardo da Vinci 32, 20133, Milan, Italy.
| | - D Messenio
- Department of Clinical Sciences, Eye Clinic, ASST Fatebenefratelli Sacco Hospital, University of Milan, Milan, Italy
| | - G Marano
- Laboratorio di Statistica Medica, Biometria ed Epidemiologia "G.A. Maccacaro", Dipartimento di Scienze Cliniche e di Comunità, Università degli Studi di Milano, Via Vanzetti 5, Milan, Italy
| | - L Spinelli
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Piazza Leonardo da Vinci 32, 20133, Milan, Italy
| | - I Pirovano
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133, Milan, Italy.,Istituto di Tecnologie Biomediche, Consiglio Nazionale delle Ricerche, via Fratelli Cervi 93, 20090, Segrate, MI, Italy
| | - D Contini
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133, Milan, Italy
| | - R Colombo
- Department of Clinical Sciences, Eye Clinic, ASST Fatebenefratelli Sacco Hospital, University of Milan, Milan, Italy
| | - P Boracchi
- Laboratorio di Statistica Medica, Biometria ed Epidemiologia "G.A. Maccacaro", Dipartimento di Scienze Cliniche e di Comunità, Università degli Studi di Milano, Via Vanzetti 5, Milan, Italy
| | - E Biganzoli
- Laboratorio di Statistica Medica, Biometria ed Epidemiologia "G.A. Maccacaro", Dipartimento di Scienze Cliniche e di Comunità, Università degli Studi di Milano, Via Vanzetti 5, Milan, Italy.,Unità di Statistica Medica, Biometria e Bioinformatica, Fondazione IRCCS Istituto Nazionale dei Tumori di Milano, Via Vanzetti 5, Milan, Italy
| | - R Cubeddu
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133, Milan, Italy
| | - A Torricelli
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133, Milan, Italy.,Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Piazza Leonardo da Vinci 32, 20133, Milan, Italy
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9
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Milej D, Abdalmalak A, Rajaram A, Jhajj A, Owen AM, St. Lawrence K. Incorporating early and late-arriving photons to improve the reconstruction of cerebral hemodynamic responses acquired by time-resolved near-infrared spectroscopy. JOURNAL OF BIOMEDICAL OPTICS 2021; 26:056003. [PMCID: PMC8130006 DOI: 10.1117/1.jbo.26.5.056003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 04/28/2021] [Indexed: 06/14/2023]
Abstract
Significance: Despite its advantages in terms of safety, low cost, and portability, functional near-infrared spectroscopy applications can be challenging due to substantial signal contamination from hemodynamics in the extracerebral layer (ECL). Time-resolved near-infrared spectroscopy (tr NIRS) can improve sensitivity to brain activity but contamination from the ECL remains an issue. This study demonstrates how brain signal isolation can be further improved by applying regression analysis to tr data acquired at a single source–detector distance. Aim: To investigate if regression analysis can be applied to single-channel trNIRS data to further isolate the brain and reduce signal contamination from the ECL. Approach: Appropriate regressors for trNIRS were selected based on simulations, and performance was evaluated by applying the regression technique to oxygenation responses recording during hypercapnia and functional activation. Results: Compared to current methods of enhancing depth sensitivity for trNIRS (i.e., higher statistical moments and late gates), incorporating regression analysis using a signal sensitive to the ECL significantly improved the extraction of cerebral oxygenation signals. In addition, this study demonstrated that regression could be applied to trNIRS data from a single detector using the early arriving photons to capture hemodynamic changes in the ECL. Conclusion: Applying regression analysis to trNIRS metrics with different depth sensitivities improves the characterization of cerebral oxygenation signals.
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Affiliation(s)
- Daniel Milej
- Lawson Health Research Institute, Imaging Program, London, Ontario, Canada
- Western University, Department of Medical Biophysics, London, Ontario, Canada
| | - Androu Abdalmalak
- Lawson Health Research Institute, Imaging Program, London, Ontario, Canada
- Western University, Department of Medical Biophysics, London, Ontario, Canada
| | - Ajay Rajaram
- Lawson Health Research Institute, Imaging Program, London, Ontario, Canada
- Western University, Department of Medical Biophysics, London, Ontario, Canada
| | - Amandeep Jhajj
- Western University, Department of Medical Biophysics, London, Ontario, Canada
| | - Adrian M. Owen
- Western University, Brain and Mind Institute, London, Ontario, Canada
| | - Keith St. Lawrence
- Lawson Health Research Institute, Imaging Program, London, Ontario, Canada
- Western University, Department of Medical Biophysics, London, Ontario, Canada
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10
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Di Sieno L, Ferocino E, Conca E, Sesta V, Buttafava M, Villa F, Zappa F, Contini D, Torricelli A, Taroni P, Tosi A, Pifferi A, Dalla Mora A. Time-domain diffuse optics with 8.6 mm 2 fast-gated SiPM for extreme light harvesting. OPTICS LETTERS 2021; 46:424-427. [PMID: 33449045 DOI: 10.1364/ol.413577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 12/15/2020] [Indexed: 06/12/2023]
Abstract
Fast time-gated single-photon detectors demonstrated high depth sensitivity in the detection of localized absorption perturbations inside scattering media, but their use for in vivo clinical applications-such as functional imaging of brain activation-was impaired by their small (<0.04mm2) active area. Here, we demonstrate, both on phantoms and in vivo, the performance of a fast-gated digital silicon photomultiplier (SiPM) that features an overall active area of 8.6mm2, overcoming the photon collection capability of established time-gated single-pixel detectors by orders of magnitude, enabling deep investigations within scattering media and high signal-to-noise ratios at late photon arrival times.
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11
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Di Sieno L, Behera A, Rohilla S, Ferocino E, Contini D, Torricelli A, Krämer B, Koberling F, Pifferi A, Mora AD. Probe-hosted large area silicon photomultiplier and high-throughput timing electronics for enhanced performance time-domain functional near-infrared spectroscopy. BIOMEDICAL OPTICS EXPRESS 2020; 11:6389-6412. [PMID: 33282497 PMCID: PMC7687960 DOI: 10.1364/boe.400868] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 09/21/2020] [Accepted: 10/07/2020] [Indexed: 05/06/2023]
Abstract
Two main bottlenecks prevent time-domain diffuse optics instruments to reach their maximum performances, namely the limited light harvesting capability of the detection chain and the bounded data throughput of the timing electronics. In this work, for the first time to our knowledge, we overcome both those limitations using a probe-hosted large area silicon photomultiplier detector coupled to high-throughput timing electronics. The system performances were assessed based on international protocols for diffuse optical imagers showing better figures with respect to a state-of-the-art device. As a first step towards applications, proof-of-principle in-vivo brain activation measurements demonstrated superior signal-to-noise ratio as compared to current technologies.
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Affiliation(s)
- L. Di Sieno
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - A. Behera
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - S. Rohilla
- PicoQuant Innovation GmbH, Rudower Chaussee 29, 12489 Berlin, Germany
- Charité–Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu and Berlin Institute of Health, Department of Internal Medicine/Infectious Diseases and Respiratory Medicine, Charitéplatz 1, 10117 Berlin, Germany
| | - E. Ferocino
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - D. Contini
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - A. Torricelli
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
- Consiglio Nazionale delle Ricerche, Istituto di Fotonica e Nanotecnologie, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - B. Krämer
- PicoQuant GmbH, Rudower Chaussee 29, 12489 Berlin, Germany
| | - F. Koberling
- PicoQuant GmbH, Rudower Chaussee 29, 12489 Berlin, Germany
| | - A. Pifferi
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
- Consiglio Nazionale delle Ricerche, Istituto di Fotonica e Nanotecnologie, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - A. Dalla Mora
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
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12
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Wabnitz H, Contini D, Spinelli L, Torricelli A, Liebert A. Depth-selective data analysis for time-domain fNIRS: moments vs. time windows. BIOMEDICAL OPTICS EXPRESS 2020; 11:4224-4243. [PMID: 32923038 PMCID: PMC7449728 DOI: 10.1364/boe.396585] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 06/20/2020] [Accepted: 06/22/2020] [Indexed: 05/10/2023]
Abstract
Time-domain measurements facilitate the elimination of the influence of extracerebral, systemic effects, a key problem in functional near-infrared spectroscopy (fNIRS) of the adult human brain. The analysis of measured time-of-flight distributions of photons often relies on moments or time windows. However, a systematic and quantitative characterization of the performance of these measurands is still lacking. Based on perturbation simulations for small localized absorption changes, we compared spatial sensitivity profiles and depth selectivity for moments (integral, mean time of flight and variance), photon counts in time windows and their ratios for different time windows. The influence of the instrument response function (IRF) was investigated for all measurands and for various source-detector separations. Variance exhibits the highest depth selectivity among the moments. Ratios of photon counts in different late time windows can achieve even higher selectivity. An advantage of moments is their robustness against the shape of the IRF and instrumental drifts.
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Affiliation(s)
- Heidrun Wabnitz
- Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin, Germany
| | - Davide Contini
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milan, Italy
| | - Lorenzo Spinelli
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Piazza Leonardo da Vinci 32, 20133 Milan, Italy
| | - Alessandro Torricelli
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milan, Italy
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Piazza Leonardo da Vinci 32, 20133 Milan, Italy
| | - Adam Liebert
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Trojdena 4, 02-109 Warsaw, Poland
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13
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Papadimitriou KI, Vidal Rosas EE, Zhang E, Cooper RJ, Hebden JC, Arridge SR, Powell S. Dual wavelength spread-spectrum time-resolved diffuse optical instrument for the measurement of human brain functional responses. BIOMEDICAL OPTICS EXPRESS 2020; 11:3477-3490. [PMID: 33014545 PMCID: PMC7510926 DOI: 10.1364/boe.393586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 05/07/2020] [Accepted: 05/10/2020] [Indexed: 06/11/2023]
Abstract
Near-infrared spectroscopy has proven to be a valuable method to monitor tissue oxygenation and haemodynamics non-invasively and in real-time. Quantification of such parameters requires measurements of the time-of-flight of light through tissue, typically achieved using picosecond pulsed lasers, with their associated cost, complexity, and size. In this work, we present an alternative approach that employs spread-spectrum excitation to enable the development of a small, low-cost, dual-wavelength system using vertical-cavity surface-emitting lasers. Since the optimal wavelengths and drive parameters for optical spectroscopy are not served by commercially available modules as used in our previous single-wavelength demonstration platform, we detail the design of a custom instrument and demonstrate its performance in resolving haemodynamic changes in human subjects during apnoea and cognitive task experiments.
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Affiliation(s)
- Konstantinos I. Papadimitriou
- Department of Computer Science, University College London, London, WC1E 6BT, UK
- These authors contributed equally to this work
| | - Ernesto E. Vidal Rosas
- Department of Medical Physics and Biomedical Engineering, University College London, London, WC1E 6BT, UK
- These authors contributed equally to this work
| | - Edward Zhang
- Department of Medical Physics and Biomedical Engineering, University College London, London, WC1E 6BT, UK
| | - Robert J. Cooper
- Department of Medical Physics and Biomedical Engineering, University College London, London, WC1E 6BT, UK
| | - Jeremy C. Hebden
- Department of Medical Physics and Biomedical Engineering, University College London, London, WC1E 6BT, UK
| | - Simon R. Arridge
- Department of Computer Science, University College London, London, WC1E 6BT, UK
| | - Samuel Powell
- Faculty of Engineering, University of Nottingham, Nottingham, NG7 2RD, UK
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14
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Optics Based Label-Free Techniques and Applications in Brain Monitoring. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10062196] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Functional near-infrared spectroscopy (fNIRS) has been utilized already around three decades for monitoring the brain, in particular, oxygenation changes in the cerebral cortex. In addition, other optical techniques are currently developed for in vivo imaging and in the near future can be potentially used more in human brain research. This paper reviews the most common label-free optical technologies exploited in brain monitoring and their current and potential clinical applications. Label-free tissue monitoring techniques do not require the addition of dyes or molecular contrast agents. The following optical techniques are considered: fNIRS, diffuse correlations spectroscopy (DCS), photoacoustic imaging (PAI) and optical coherence tomography (OCT). Furthermore, wearable optical brain monitoring with the most common applications is discussed.
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15
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Sudakou A, Wojtkiewicz S, Lange F, Gerega A, Sawosz P, Tachtsidis I, Liebert A. Depth-resolved assessment of changes in concentration of chromophores using time-resolved near-infrared spectroscopy: estimation of cytochrome-c-oxidase uncertainty by Monte Carlo simulations. BIOMEDICAL OPTICS EXPRESS 2019; 10:4621-4635. [PMID: 31565513 PMCID: PMC6757481 DOI: 10.1364/boe.10.004621] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 08/05/2019] [Accepted: 08/06/2019] [Indexed: 06/10/2023]
Abstract
Time-resolved near-infrared spectroscopy (TR-NIRS) measurements can be used to recover changes in concentrations of tissue constituents ( Δ C ) by applying the moments method and the Beer-Lambert law. In this work we carried out the error propagation analysis allowing to calculate the standard deviations of uncertainty in estimation of the Δ C . Here, we show the process of choosing wavelengths for the evaluation of hemodynamic (oxy-, deoxyhemoglobin) and metabolic (cytochrome-c-oxidase (CCO)) responses within the brain tissue as measured with an in-house developed TR-NIRS multi-wavelength system, which measures at 16 consecutive wavelengths separated by 12.5 nm and placed between 650 and 950 nm. Data generated with Monte Carlo simulations on three-layered model (scalp, skull, brain) for wavelengths range from 650 to 950 nm were used to carry out the error propagation analysis for varying choices of wavelengths. For a detector with a spectrally uniform responsivity, the minimal standard deviation of the estimated changes in CCO within the brain layer, σ Δ C CCO brain = 0.40 µM, was observed for the 16 consecutive wavelengths from 725 to 912.5 nm. For realistic a detector model, i.e. the spectral responsivity characteristic is considered, the minimum, σ Δ C CCO brain = 0.47 µM, was observed at the 16 consecutive wavelengths from 688 to 875 nm. We introduce the method of applying the error propagation analysis to data as measured with spectral TR-NIRS systems to calculate uncertainty of recovery of tissue constituents concentrations.
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Affiliation(s)
- Aleh Sudakou
- Nalecz Institute of Biocybernetics and Biomedical Engineering Polish Academy of Sciences, Trojdena 4, 02-109 Warsaw, Poland
| | - Stanislaw Wojtkiewicz
- Nalecz Institute of Biocybernetics and Biomedical Engineering Polish Academy of Sciences, Trojdena 4, 02-109 Warsaw, Poland
- School of Computer Science, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom
| | - Frédéric Lange
- Department of Medical Physics and Biomedical Engineering, University College London, London WC1E 6BT, United Kingdom
| | - Anna Gerega
- Nalecz Institute of Biocybernetics and Biomedical Engineering Polish Academy of Sciences, Trojdena 4, 02-109 Warsaw, Poland
| | - Piotr Sawosz
- Nalecz Institute of Biocybernetics and Biomedical Engineering Polish Academy of Sciences, Trojdena 4, 02-109 Warsaw, Poland
| | - Ilias Tachtsidis
- Department of Medical Physics and Biomedical Engineering, University College London, London WC1E 6BT, United Kingdom
| | - Adam Liebert
- Nalecz Institute of Biocybernetics and Biomedical Engineering Polish Academy of Sciences, Trojdena 4, 02-109 Warsaw, Poland
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16
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Kim JW, Jang H, Kim GH, Jun SW, Kim CS. Multi-spectral laser speckle contrast images using a wavelength-swept laser. JOURNAL OF BIOMEDICAL OPTICS 2019; 24:1-9. [PMID: 31290292 PMCID: PMC6995959 DOI: 10.1117/1.jbo.24.7.076001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 06/06/2019] [Indexed: 06/09/2023]
Abstract
A multi-spectral laser speckle contrast imaging (MS-LSCI) system is proposed using only a single wavelength-swept laser, which provides both highly coherent and multi-spectral outputs to simultaneously generate laser speckle contrast images and multi-spectral images, respectively. Using a laser light swept from 770 to 821 nm at a repetition rate of 5 Hz and a CCD camera of 335 fps, 67 multi-spectral frame images are acquired in 0.76 nm wavebands over 51 nm spectral range. The spectral sub-windowing method of single wavelength-swept laser source is used to solve the lack of spectral information from a few individual light sources, which is a limitation of conventional MS-LSCI systems. In addition to the speckle flow index from the LSCI frames, the multi-spectrally encoded images can generate additional images of spectral absorbance. To further examine the performance of the MS-LSCI system, an in vivo cuff-induced ischemia experiment was conducted to show the real-time imaging of hemodynamic and blood oxygen saturation changes simultaneously over the entire 2.5 cm × 4.5 cm field of view.
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Affiliation(s)
- Jeong Won Kim
- Pusan National University, Department of Cogno-Mechatronics Engineering, Busan, Republic of Korea
| | - Hansol Jang
- Pusan National University, Department of Cogno-Mechatronics Engineering, Busan, Republic of Korea
| | - Gyeong Hun Kim
- Pusan National University, Department of Cogno-Mechatronics Engineering, Busan, Republic of Korea
| | - Seung Won Jun
- Pusan National University, Department of Cogno-Mechatronics Engineering, Busan, Republic of Korea
| | - Chang-Seok Kim
- Pusan National University, Department of Cogno-Mechatronics Engineering, Busan, Republic of Korea
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17
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Lange F, Dunne L, Hale L, Tachtsidis I. MAESTROS: A Multiwavelength Time-Domain NIRS System to Monitor Changes in Oxygenation and Oxidation State of Cytochrome-C-Oxidase. IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS : A PUBLICATION OF THE IEEE LASERS AND ELECTRO-OPTICS SOCIETY 2019; 25:7100312. [PMID: 30450021 PMCID: PMC6054019 DOI: 10.1109/jstqe.2018.2833205] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 04/30/2018] [Accepted: 04/30/2018] [Indexed: 05/17/2023]
Abstract
We present a multiwavelength, multichannel, time-domain near-infrared spectroscopy system named MAESTROS. This instrument can measure absorption and scattering coefficients and can quantify the concentrations of oxy- and deoxy-haemoglobin ([HbO2], [HHb]), and oxidation state of cytochrome-c-oxidase ([oxCCO]). This system is composed of a supercontinuum laser source coupled with two acousto-optic tuneable filters. The light is collected by four photomultipliers tubes, connected to a router to redirect the signal to a single time-correlated single-photon counting card. The interface between the system and the tissue is based on optical fibres. This arrangement allows us to resolve up to 16 wavelengths, within the range of 650-900 nm, at a sampling rate compatible with the physiology (from 0.5 to 2 Hz). In this paper, we describe the system and assess its performance based on two specifically designed protocols for photon migration instruments, the basic instrument protocol and nEUROPt protocols, and on a well characterized liquid phantom based on Intralipid and water. Then, the ability to resolve [HbO2 ], [HHb], and [oxCCO] is demonstrated on a homogeneous liquid phantom, based on blood for [HbO2], [HHb], and yeast for [oxCCO]. In the future, the system could be used to monitor brain tissue physiology.
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Affiliation(s)
- Frederic Lange
- 1Biomedical Optics Research Laboratory Department of Medical Physics and Biomedical Engineering University College London LondonWC1E 6BTU.K
| | - Luke Dunne
- 1Biomedical Optics Research Laboratory Department of Medical Physics and Biomedical Engineering University College London LondonWC1E 6BTU.K
| | - Lucy Hale
- 2Biomedical Optics Research Laboratory Department of Medical Physics and Biomedical Engineering University College London LondonWC1E 6BTU.K
- 3Electronic and Electrical Engineering University College London LondonWC1E 7JEU.K
| | - Ilias Tachtsidis
- 1Biomedical Optics Research Laboratory Department of Medical Physics and Biomedical Engineering University College London LondonWC1E 6BTU.K
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18
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Ancora D, Qiu L, Zacharakis G, Spinelli L, Torricelli A, Pifferi A. Noninvasive optical estimation of CSF thickness for brain-atrophy monitoring. BIOMEDICAL OPTICS EXPRESS 2018; 9:4094-4112. [PMID: 30615703 PMCID: PMC6157767 DOI: 10.1364/boe.9.004094] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 07/06/2018] [Accepted: 07/06/2018] [Indexed: 05/29/2023]
Abstract
Dementia disorders are increasingly becoming sources of a broad range of problems, strongly interfering with the normal daily tasks of a growing number of individuals. Such neurodegenerative diseases are often accompanied with progressive brain atrophy that, at late stages, leads to drastically reduced brain dimensions. Currently, this structural change could be followed with X-ray computed tomography (XCT) or magnetic resonance imaging (MRI), but they share numerous disadvantages in terms of usability, invasiveness and costs. In this work, we aim to retrieve information concerning the brain-atrophy stage and its evolution, proposing a novel approach based on non-invasive time-resolved near infra-red (tr-NIR) measurements. For this purpose, we created a set of virtual human-head atlases in which we eroded the brain as it would happen in a clinical brain-atrophy progression. These realistic meshes were used to simulate a longitudinal tr-NIR study, investigating the effects of an increased amount of cerebral spinal fluid (CSF) in the photon diffusion. The analysis of late photons in the time-resolved reflectance curve-obtained via accurate Monte Carlo simulations-exhibited peculiar slope-changes upon CSF layer increase. The visibility of the effect under several measurement conditions suggested good sensitivity to CSF variation, even in the case of real measurement and under different geometrical models. The robustness of the results might promote the technique as a potential indicator of the dementia progression, relying only on fast and non-invasive optical observations.
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Affiliation(s)
- Daniele Ancora
- Institute of Electronic Structure and Laser, Foundation for Research and Technology - Hellas, Heraklion, Greece
- Department of Materials Science and Technology, University of Crete, Heraklion, Greece
| | - Lina Qiu
- Dipartimento di Fisica, Politecnico di Milano, Milan, Italy
| | - Giannis Zacharakis
- Institute of Electronic Structure and Laser, Foundation for Research and Technology - Hellas, Heraklion, Greece
| | - Lorenzo Spinelli
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Milan, Italy
| | - Alessandro Torricelli
- Dipartimento di Fisica, Politecnico di Milano, Milan, Italy
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Milan, Italy
| | - Antonio Pifferi
- Dipartimento di Fisica, Politecnico di Milano, Milan, Italy
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Milan, Italy
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19
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Papadimitriou KI, Dempsey LA, Hebden JC, Arridge SR, Powell S. A spread spectrum approach to time-domain near-infrared diffuse optical imaging using inexpensive optical transceiver modules. BIOMEDICAL OPTICS EXPRESS 2018; 9:2648-2663. [PMID: 30258680 PMCID: PMC6154193 DOI: 10.1364/boe.9.002648] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 04/23/2018] [Accepted: 04/24/2018] [Indexed: 06/08/2023]
Abstract
We introduce a compact time-domain system for near-infrared spectroscopy using a spread spectrum technique. The proof-of-concept single channel instrument utilises a low-cost commercially available optical transceiver module as a light source, controlled by a Kintex 7 field programmable gate array (FPGA). The FPGA modulates the optical transceiver with maximum-length sequences at line rates up to 10Gb/s, allowing us to achieve an instrument response function with full width at half maximum under 600ps. The instrument is characterised through a set of detailed phantom measurements as well as proof-of-concept in vivo measurements, demonstrating performance comparable with conventional pulsed time-domain near-infrared spectroscopy systems.
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Affiliation(s)
| | - Laura A. Dempsey
- Department of Medical Physics and Biomedical Engineering, University College London, WC1E 6BT, London,
UK
| | - Jeremy C. Hebden
- Department of Medical Physics and Biomedical Engineering, University College London, WC1E 6BT, London,
UK
| | - Simon R. Arridge
- Department of Computer Science, University College London, WC1E 6BT, London,
UK
| | - Samuel Powell
- Department of Medical Physics and Biomedical Engineering, University College London, WC1E 6BT, London,
UK
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20
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Re R, Pirovano I, Contini D, Spinelli L, Torricelli A. Time Domain Near Infrared Spectroscopy Device for Monitoring Muscle Oxidative Metabolism: Custom Probe and In Vivo Applications. SENSORS 2018; 18:s18010264. [PMID: 29342097 PMCID: PMC5795927 DOI: 10.3390/s18010264] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 01/09/2018] [Accepted: 01/15/2018] [Indexed: 11/26/2022]
Abstract
Measurement of muscle oxidative metabolism is of interest for monitoring the training status in athletes and the rehabilitation process in patients. Time domain near infrared spectroscopy (TD NIRS) is an optical technique that allows the non-invasive measurement of the hemodynamic parameters in muscular tissue: concentrations of oxy- and deoxy-hemoglobin, total hemoglobin content, and tissue oxygen saturation. In this paper, we present a novel TD NIRS medical device for muscle oxidative metabolism. A custom-printed 3D probe, able to host optical elements for signal acquisition from muscle, was develop for TD NIRS in vivo measurements. The system was widely characterized on solid phantoms and during in vivo protocols on healthy subjects. In particular, we tested the in vivo repeatability of the measurements to quantify the error that we can have by repositioning the probe. Furthermore, we considered a series of acquisitions on different muscles that were not yet previously performed with this custom probe: a venous-arterial cuff occlusion of the arm muscle, a cycling exercise, and an isometric contraction of the vastus lateralis.
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Affiliation(s)
- Rebecca Re
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci, 32, 20133 Milan, Italy.
| | - Ileana Pirovano
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci, 32, 20133 Milan, Italy.
| | - Davide Contini
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci, 32, 20133 Milan, Italy.
| | - Lorenzo Spinelli
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Piazza Leonardo da Vinci, 32, 20133 Milan, Italy.
| | - Alessandro Torricelli
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci, 32, 20133 Milan, Italy.
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Piazza Leonardo da Vinci, 32, 20133 Milan, Italy.
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21
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Time-Resolved Diffuse Optical Spectroscopy and Imaging Using Solid-State Detectors: Characteristics, Present Status, and Research Challenges. SENSORS 2017; 17:s17092115. [PMID: 28906462 PMCID: PMC5621067 DOI: 10.3390/s17092115] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/23/2017] [Revised: 09/03/2017] [Accepted: 09/06/2017] [Indexed: 02/06/2023]
Abstract
Diffuse optical spectroscopy (DOS) and diffuse optical imaging (DOI) are emerging non-invasive imaging modalities that have wide spread potential applications in many fields, particularly for structural and functional imaging in medicine. In this article, we review time-resolved diffuse optical imaging (TR-DOI) systems using solid-state detectors with a special focus on Single-Photon Avalanche Diodes (SPADs) and Silicon Photomultipliers (SiPMs). These TR-DOI systems can be categorized into two types based on the operation mode of the detector (free-running or time-gated). For the TR-DOI prototypes, the physical concepts, main components, figures-of-merit of detectors, and evaluation parameters are described. The performance of TR-DOI prototypes is evaluated according to the parameters used in common protocols to test DOI systems particularly basic instrumental performance (BIP). In addition, the potential features of SPADs and SiPMs to improve TR-DOI systems and expand their applications in the foreseeable future are discussed. Lastly, research challenges and future developments for TR-DOI are discussed for each component in the prototype separately and also for the entire system.
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Abdalmalak A, Milej D, Diop M, Shokouhi M, Naci L, Owen AM, St. Lawrence K. Can time-resolved NIRS provide the sensitivity to detect brain activity during motor imagery consistently? BIOMEDICAL OPTICS EXPRESS 2017; 8:2162-2172. [PMID: 28736662 PMCID: PMC5516814 DOI: 10.1364/boe.8.002162] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 02/15/2017] [Accepted: 02/27/2017] [Indexed: 05/20/2023]
Abstract
Previous functional magnetic resonance imaging (fMRI) studies have shown that a subgroup of patients diagnosed as being in a vegetative state are aware and able to communicate by performing a motor imagery task in response to commands. Due to the fMRI's cost and accessibility, there is a need for exploring different imaging modalities that can be used at the bedside. A promising technique is functional near infrared spectroscopy (fNIRS) that has been successfully applied to measure brain oxygenation in humans. Due to the limited depth sensitivity of continuous-wave NIRS, time-resolved (TR) detection has been proposed as a way of enhancing the sensitivity to the brain, since late arriving photons have a higher probability of reaching the brain. The goal of this study was to assess the feasibility and sensitivity of TR fNIRS in detecting brain activity during motor imagery. Fifteen healthy subjects were recruited in this study, and the fNIRS results were validated using fMRI. The change in the statistical moments of the distribution of times of flight (number of photons, mean time of flight and variance) were calculated for each channel to determine the presence of brain activity. The results indicate up to an 86% agreement between fMRI and TR-fNIRS and the sensitivity ranging from 64 to 93% with the highest value determined for the mean time of flight. These promising results highlight the potential of TR-fNIRS as a portable brain computer interface for patients with disorder of consciousness.
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Affiliation(s)
- Androu Abdalmalak
- Department of Medical Biophysics, Western University, London, ON, Canada
- Imaging Division, Lawson Health Research Institute, London, ON, Canada
| | - Daniel Milej
- Department of Medical Biophysics, Western University, London, ON, Canada
- Imaging Division, Lawson Health Research Institute, London, ON, Canada
| | - Mamadou Diop
- Department of Medical Biophysics, Western University, London, ON, Canada
- Imaging Division, Lawson Health Research Institute, London, ON, Canada
| | - Mahsa Shokouhi
- Department of Medical Biophysics, Western University, London, ON, Canada
- Imaging Division, Lawson Health Research Institute, London, ON, Canada
| | - Lorina Naci
- Brain and Mind Institute, Western University, London, ON, Canada
| | - Adrian M. Owen
- Brain and Mind Institute, Western University, London, ON, Canada
| | - Keith St. Lawrence
- Department of Medical Biophysics, Western University, London, ON, Canada
- Imaging Division, Lawson Health Research Institute, London, ON, Canada
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Milej D, Abdalmalak A, McLachlan P, Diop M, Liebert A, St. Lawrence K. Subtraction-based approach for enhancing the depth sensitivity of time-resolved NIRS. BIOMEDICAL OPTICS EXPRESS 2016; 7:4514-4526. [PMID: 27895992 PMCID: PMC5119592 DOI: 10.1364/boe.7.004514] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 09/13/2016] [Accepted: 09/14/2016] [Indexed: 05/18/2023]
Abstract
The aim of this study was to evaluate enhancing of the depth sensitivity of time-resolved near-infrared spectroscopy with a subtraction-based approach. Due to the complexity of light propagation in a heterogeneous media, and to prove the validity of the proposed method in a heterogeneous turbid media we conducted a broad analysis taking into account a number of parameters related to the method as well as various parameters of this media. The results of these experiments confirm that the depth sensitivity of the subtraction-based approach is better than classical approaches using continuous-wave or time-resolved methods. Furthermore, the results showed that the subtraction-based approach has a unique, selective sensitivity to a layer at a specific depth. In vivo application of the proposed method resulted in a greater magnitude of the hemodynamic changes during functional activation than with the standard approach.
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Affiliation(s)
- Daniel Milej
- Department of Medical Biophysics, Western University, London, ON, Canada
- Imaging Division, Lawson Health Research Institute, London, ON, Canada
| | - Androu Abdalmalak
- Department of Medical Biophysics, Western University, London, ON, Canada
- Imaging Division, Lawson Health Research Institute, London, ON, Canada
| | - Peter McLachlan
- Department of Medical Biophysics, Western University, London, ON, Canada
- Imaging Division, Lawson Health Research Institute, London, ON, Canada
| | - Mamadou Diop
- Department of Medical Biophysics, Western University, London, ON, Canada
- Imaging Division, Lawson Health Research Institute, London, ON, Canada
| | - Adam Liebert
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Warsaw, Poland
| | - Keith. St. Lawrence
- Department of Medical Biophysics, Western University, London, ON, Canada
- Imaging Division, Lawson Health Research Institute, London, ON, Canada
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Re R, Martinenghi E, Mora AD, Contini D, Pifferi A, Torricelli A. Probe-hosted silicon photomultipliers for time-domain functional near-infrared spectroscopy: phantom and in vivo tests. NEUROPHOTONICS 2016; 3:045004. [PMID: 27752520 PMCID: PMC5061109 DOI: 10.1117/1.nph.3.4.045004] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Accepted: 09/19/2016] [Indexed: 05/23/2023]
Abstract
We report the development of a compact probe for time-domain (TD) functional near-infrared spectroscopy (fNIRS) based on a fast silicon photomultiplier (SiPM) that can be put directly in contact with the sample without the need of optical fibers for light collection. We directly integrated an avalanche signal amplification stage close to the SiPM, thus reducing the size of the detection channel and optimizing the signal immunity to electromagnetic interferences. The whole detection electronics was placed in a plastic screw holder compatible with the electroencephalography standard cap for measurement on brain or with custom probe holders. The SiPM is inserted into a transparent and insulating resin to avoid the direct contact of the scalp with the 100-V bias voltage. The probe was integrated in an instrument for TD fNIRS spectroscopy. The system was characterized on tissue phantoms in terms of temporal resolution, responsivity, linearity, and capability to detect deep absorption changes. Preliminary in vivo tests on adult volunteers were performed to monitor hemodynamic changes in the arm during a cuff occlusion and in the brain cortex during a motor task.
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Affiliation(s)
- Rebecca Re
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, Milano 20133, Italy
| | - Edoardo Martinenghi
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, Milano 20133, Italy
| | - Alberto Dalla Mora
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, Milano 20133, Italy
| | - Davide Contini
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, Milano 20133, Italy
| | - Antonio Pifferi
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, Milano 20133, Italy
- Consiglio Nazionale delle Ricerche, Istituto di Fotonica e Nanotecnologie, Piazza Leonardo da Vinci 32, Milano I-20133, Italy
| | - Alessandro Torricelli
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, Milano 20133, Italy
- Consiglio Nazionale delle Ricerche, Istituto di Fotonica e Nanotecnologie, Piazza Leonardo da Vinci 32, Milano I-20133, Italy
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Milej D, Abdalmalak A, Janusek D, Diop M, Liebert A, St Lawrence K. Time-resolved subtraction method for measuring optical properties of turbid media. APPLIED OPTICS 2016; 55:1507-13. [PMID: 26974605 DOI: 10.1364/ao.55.001507] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Near-infrared spectroscopy is a noninvasive optical method used primarily to monitor tissue oxygenation due to the absorption properties of hemoglobin. Accurate estimation of hemoglobin concentrations and other light absorbers requires techniques that can separate the effect of absorption from the much greater effect of light scattering. One of the most advanced methods is time-resolved near-infrared spectroscopy (TR-NIRS), which measures the absorption and scattering coefficients of a turbid medium by modeling the recorded distribution time of flight of photons. A challenge with TR-NIRS is that it requires accurate characterization of the dispersion caused by the system. In this study, we present a method for circumventing this problem by applying statistical moment analysis to two time-of-flight distributions measured at separated source-detector distances. Simulations based on analytical models and Monte Carlo code, and tissue-mimicking phantoms, were used to demonstrate its accuracy for source-detector distances typically used in neuroimaging applications. The simplicity of the approach is well suited to real-time applications requiring accurate quantification of the optical properties of a turbid medium.
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Pifferi A, Torricelli A, Cubeddu R, Quarto G, Re R, Sekar SKV, Spinelli L, Farina A, Martelli F, Wabnitz H. Mechanically switchable solid inhomogeneous phantom for performance tests in diffuse imaging and spectroscopy. JOURNAL OF BIOMEDICAL OPTICS 2015. [PMID: 26220211 DOI: 10.1117/1.jbo.20.12.121304] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
A mechanically switchable solid inhomogeneous phantom simulating localized absorption changes was developed and characterized. The homogeneous host phantom was made of epoxy resin with black toner and titanium dioxide particles added as absorbing and scattering components, respectively. A cylindrical rod, movable along a hole in the block and made of the same material, has a black polyvinyl chloride cylinder embedded in its center. By varying the volume and position of the black inclusion, absorption perturbations can be generated over a large range of magnitudes. The phantom has been characterized by various time-domain diffuse optics instruments in terms of absorption and scattering spectra, transmittance images, and reflectance contrast. Addressing a major application of the phantom for performance characterization for functional near-infrared spectroscopy of the brain, the contrast was measured in reflectance mode while black cylinders of volumes from ≈20 mm3 to ≈270 mm3 were moved in lateral and depth directions, respectively. The new type of solid inhomogeneous phantom is expected to become a useful tool for routine quality check of clinical instruments or implementation of industrial standards provided an experimental characterization of the phantom is performed in advance.
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Affiliation(s)
- Antonio Pifferi
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, Milano 20133, Italy
| | - Alessandro Torricelli
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, Milano 20133, Italy
| | - Rinaldo Cubeddu
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, Milano 20133, ItalybIstituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Piazza Leonardo da Vinci 32, Milano 20133, Italy
| | - Giovanna Quarto
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, Milano 20133, Italy
| | - Rebecca Re
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, Milano 20133, Italy
| | - Sanathana K V Sekar
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, Milano 20133, Italy
| | - Lorenzo Spinelli
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Piazza Leonardo da Vinci 32, Milano 20133, Italy
| | - Andrea Farina
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Piazza Leonardo da Vinci 32, Milano 20133, Italy
| | - Fabrizio Martelli
- Università degli Studi di Firenze, Dipartimento di Fisica e Astronomia, Via G. Sansone 1, Firenze, Sesto Fiorentino 50019, Italy
| | - Heidrun Wabnitz
- Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, Berlin 10587, Germany
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27
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Mora AD, Martinenghi E, Contini D, Tosi A, Boso G, Durduran T, Arridge S, Martelli F, Farina A, Torricelli A, Pifferi A. Fast silicon photomultiplier improves signal harvesting and reduces complexity in time-domain diffuse optics. OPTICS EXPRESS 2015; 23:13937-46. [PMID: 26072763 DOI: 10.1364/oe.23.013937] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
We present a proof of concept prototype of a time-domain diffuse optics probe exploiting a fast Silicon PhotoMultiplier (SiPM), featuring a timing resolution better than 80 ps, a fast tail with just 90 ps decay time-constant and a wide active area of 1 mm2. The detector is hosted into the probe and used in direct contact with the sample under investigation, thus providing high harvesting efficiency by exploiting the whole SiPM numerical aperture and also reducing complexity by avoiding the use of cumbersome fiber bundles. Our tests also demonstrate high accuracy and linearity in retrieving the optical properties and suitable contrast and depth sensitivity for detecting localized inhomogeneities. In addition to a strong improvement in both instrumentation cost and size with respect to legacy solutions, the setup performances are comparable to those of state-of-the-art time-domain instrumentation, thus opening a new way to compact, low-cost and high-performance time-resolved devices for diffuse optical imaging and spectroscopy.
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28
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Mora AD, Contini D, Arridge S, Martelli F, Tosi A, Boso G, Farina A, Durduran T, Martinenghi E, Torricelli A, Pifferi A. Towards next-generation time-domain diffuse optics for extreme depth penetration and sensitivity. BIOMEDICAL OPTICS EXPRESS 2015; 6:1749-60. [PMID: 26137377 PMCID: PMC4467698 DOI: 10.1364/boe.6.001749] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Revised: 03/20/2015] [Accepted: 03/20/2015] [Indexed: 05/18/2023]
Abstract
Light is a powerful tool to non-invasively probe highly scattering media for clinical applications ranging from oncology to neurology, but also for molecular imaging, and quality assessment of food, wood and pharmaceuticals. Here we show that, for a paradigmatic case of diffuse optical imaging, ideal yet realistic time-domain systems yield more than 2-fold higher depth penetration and many decades higher contrast as compared to ideal continuous-wave systems, by adopting a dense source-detector distribution with picosecond time-gating. Towards this aim, we demonstrate the first building block made of a source-detector pair directly embedded into the probe based on a pulsed Vertical-Cavity Surface-Emitting Laser (VCSEL) to allow parallelization for dense coverage, a Silicon Photomultiplier (SiPM) to maximize light harvesting, and a Single-Photon Avalanche Diode (SPAD) to demonstrate the time-gating capability on the basic SiPM element. This paves the way to a dramatic advancement in terms of increased performances, new high impact applications, and availability of devices with orders of magnitude reduction in size and cost for widespread use, including quantitative wearable imaging.
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Affiliation(s)
- Alberto Dalla Mora
- Dipartimento di Fisica, Politecnico di Milano,
Italy
- These authors contributed equally to this work
| | - Davide Contini
- Dipartimento di Fisica, Politecnico di Milano,
Italy
- These authors contributed equally to this work
| | - Simon Arridge
- Department of Computer Science, University College London,
United Kingdom
| | - Fabrizio Martelli
- Dipartimento di Fisica e Astronomia, Università degli Studi di Firenze,
Italy
| | - Alberto Tosi
- Dipartimento di Elettronica Informazione e Bioingegneria, Politecnico di Milano,
Italy
| | - Gianluca Boso
- Dipartimento di Elettronica Informazione e Bioingegneria, Politecnico di Milano,
Italy
| | - Andrea Farina
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche,
Italy
| | | | | | | | - Antonio Pifferi
- Dipartimento di Fisica, Politecnico di Milano,
Italy
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche,
Italy
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29
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Milej D, Kruczkowski M, Kacprzak M, Sawosz P, Maniewski R, Liebert A. Estimation of light detection efficiency for different light guides used in time-resolved near-infrared spectroscopy. Biocybern Biomed Eng 2015. [DOI: 10.1016/j.bbe.2015.05.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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30
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Wabnitz H, Jelzow A, Mazurenka M, Steinkellner O, Macdonald R, Milej D, Żołek N, Kacprzak M, Sawosz P, Maniewski R, Liebert A, Magazov S, Hebden J, Martelli F, Di Ninni P, Zaccanti G, Torricelli A, Contini D, Re R, Zucchelli L, Spinelli L, Cubeddu R, Pifferi A. Performance assessment of time-domain optical brain imagers, part 2: nEUROPt protocol. JOURNAL OF BIOMEDICAL OPTICS 2014; 19:086012. [PMID: 25121480 DOI: 10.1117/1.jbo.19.8.086012] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Accepted: 07/21/2014] [Indexed: 05/18/2023]
Abstract
The nEUROPt protocol is one of two new protocols developed within the European project nEUROPt to characterize the performances of time-domain systems for optical imaging of the brain. It was applied in joint measurement campaigns to compare the various instruments and to assess the impact of technical improvements. This protocol addresses the characteristic of optical brain imaging to detect, localize, and quantify absorption changes in the brain. It was implemented with two types of inhomogeneous liquid phantoms based on Intralipid and India ink with well-defined optical properties. First, small black inclusions were used to mimic localized changes of the absorption coefficient. The position of the inclusions was varied in depth and lateral direction to investigate contrast and spatial resolution. Second, two-layered liquid phantoms with variable absorption coefficients were employed to study the quantification of layer-wide changes and, in particular, to determine depth selectivity, i.e., the ratio of sensitivities for deep and superficial absorption changes. We introduce the tests of the nEUROPt protocol and present examples of results obtained with different instruments and methods of data analysis. This protocol could be a useful step toward performance tests for future standards in diffuse optical imaging.
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Affiliation(s)
- Heidrun Wabnitz
- Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin, Germany
| | - Alexander Jelzow
- Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin, Germany
| | - Mikhail Mazurenka
- Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin, Germany
| | - Oliver Steinkellner
- Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin, Germany
| | - Rainer Macdonald
- Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin, Germany
| | - Daniel Milej
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, ul. Trojdena 4, 02-109 Warsaw, Poland
| | - Norbert Żołek
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, ul. Trojdena 4, 02-109 Warsaw, Poland
| | - Michal Kacprzak
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, ul. Trojdena 4, 02-109 Warsaw, Poland
| | - Piotr Sawosz
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, ul. Trojdena 4, 02-109 Warsaw, Poland
| | - Roman Maniewski
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, ul. Trojdena 4, 02-109 Warsaw, Poland
| | - Adam Liebert
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, ul. Trojdena 4, 02-109 Warsaw, Poland
| | - Salavat Magazov
- University College London, Department of Medical Physics and Biomedical Engineering, Gower Street, London WC1E 6BT, United Kingdom
| | - Jeremy Hebden
- University College London, Department of Medical Physics and Biomedical Engineering, Gower Street, London WC1E 6BT, United Kingdom
| | - Fabrizio Martelli
- Dipartimento di Fisica e Astronomia dell'Università degli Studi di Firenze, Via G. Sansone 1, 50019 Sesto Fiorentino, Firenze, Italy
| | - Paola Di Ninni
- Dipartimento di Fisica e Astronomia dell'Università degli Studi di Firenze, Via G. Sansone 1, 50019 Sesto Fiorentino, Firenze, Italy
| | - Giovanni Zaccanti
- Dipartimento di Fisica e Astronomia dell'Università degli Studi di Firenze, Via G. Sansone 1, 50019 Sesto Fiorentino, Firenze, Italy
| | - Alessandro Torricelli
- Politecnico di Milano-Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Davide Contini
- Politecnico di Milano-Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Rebecca Re
- Politecnico di Milano-Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Lucia Zucchelli
- Politecnico di Milano-Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Lorenzo Spinelli
- Istituto di Fotonica e Nanotecnologie, CNR, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Rinaldo Cubeddu
- Politecnico di Milano-Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milano, ItalyfIstituto di Fotonica e Nanotecnologie, CNR, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Antonio Pifferi
- Politecnico di Milano-Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milano, ItalyfIstituto di Fotonica e Nanotecnologie, CNR, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
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31
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Wabnitz H, Taubert DR, Mazurenka M, Steinkellner O, Jelzow A, Macdonald R, Milej D, Sawosz P, Kacprzak M, Liebert A, Cooper R, Hebden J, Pifferi A, Farina A, Bargigia I, Contini D, Caffini M, Zucchelli L, Spinelli L, Cubeddu R, Torricelli A. Performance assessment of time-domain optical brain imagers, part 1: basic instrumental performance protocol. JOURNAL OF BIOMEDICAL OPTICS 2014; 19:086010. [PMID: 25121479 DOI: 10.1117/1.jbo.19.8.086010] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Accepted: 07/21/2014] [Indexed: 05/20/2023]
Abstract
Performance assessment of instruments devised for clinical applications is of key importance for validation and quality assurance. Two new protocols were developed and applied to facilitate the design and optimization of instruments for time-domain optical brain imaging within the European project nEUROPt. Here, we present the "Basic Instrumental Performance" protocol for direct measurement of relevant characteristics. Two tests are discussed in detail. First, the responsivity of the detection system is a measure of the overall efficiency to detect light emerging from tissue. For the related test, dedicated solid slab phantoms were developed and quantitatively spectrally characterized to provide sources of known radiance with nearly Lambertian angular characteristics. The responsivity of four time-domain optical brain imagers was found to be of the order of 0.1 m² sr. The relevance of the responsivity measure is demonstrated by simulations of diffuse reflectance as a function of source-detector separation and optical properties. Second, the temporal instrument response function (IRF) is a critically important factor in determining the performance of time-domain systems. Measurements of the IRF for various instruments were combined with simulations to illustrate the impact of the width and shape of the IRF on contrast for a deep absorption change mimicking brain activation.
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Affiliation(s)
- Heidrun Wabnitz
- Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin, Germany
| | | | - Mikhail Mazurenka
- Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin, Germany
| | - Oliver Steinkellner
- Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin, Germany
| | - Alexander Jelzow
- Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin, Germany
| | - Rainer Macdonald
- Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin, Germany
| | - Daniel Milej
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, ul. Trojdena 4, 02-109 Warsaw, Poland
| | - Piotr Sawosz
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, ul. Trojdena 4, 02-109 Warsaw, Poland
| | - Michał Kacprzak
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, ul. Trojdena 4, 02-109 Warsaw, Poland
| | - Adam Liebert
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, ul. Trojdena 4, 02-109 Warsaw, Poland
| | - Robert Cooper
- University College London, Department of Medical Physics and Biomedical Engineering, Gower Street, London WC1E 6BT, United Kingdom
| | - Jeremy Hebden
- University College London, Department of Medical Physics and Biomedical Engineering, Gower Street, London WC1E 6BT, United Kingdom
| | - Antonio Pifferi
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milano, ItalyeIstituto di Fotonica e Nanotecnologie, CNR, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Andrea Farina
- Istituto di Fotonica e Nanotecnologie, CNR, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Ilaria Bargigia
- Istituto Italiano di Tecnologia, Center for Nano Science and Technology @ PoliMi, via Pascoli 70/3, 20133 Milano, Italy
| | - Davide Contini
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Matteo Caffini
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Lucia Zucchelli
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Lorenzo Spinelli
- Istituto di Fotonica e Nanotecnologie, CNR, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Rinaldo Cubeddu
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milano, ItalyeIstituto di Fotonica e Nanotecnologie, CNR, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Alessandro Torricelli
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
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Hong KS, Nguyen HD. State-space models of impulse hemodynamic responses over motor, somatosensory, and visual cortices. BIOMEDICAL OPTICS EXPRESS 2014; 5:1778-98. [PMID: 24940540 PMCID: PMC4052911 DOI: 10.1364/boe.5.001778] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Revised: 05/03/2014] [Accepted: 05/03/2014] [Indexed: 05/20/2023]
Abstract
THE PAPER PRESENTS STATE SPACE MODELS OF THE HEMODYNAMIC RESPONSE (HR) OF FNIRS TO AN IMPULSE STIMULUS IN THREE BRAIN REGIONS: motor cortex (MC), somatosensory cortex (SC), and visual cortex (VC). Nineteen healthy subjects were examined. For each cortex, three impulse HRs experimentally obtained were averaged. The averaged signal was converted to a state space equation by using the subspace method. The activation peak and the undershoot peak of the oxy-hemoglobin (HbO) in MC are noticeably higher than those in SC and VC. The time-to-peaks of the HbO in three brain regions are almost the same (about 6.76 76 ± 0.2 s). The time to undershoot peak in VC is the largest among three. The HbO decreases in the early stage (~0.46 s) in MC and VC, but it is not so in SC. These findings were well described with the developed state space equations. Another advantage of the proposed method is its easy applicability in generating the expected HR to arbitrary stimuli in an online (or real-time) imaging. Experimental results are demonstrated.
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Affiliation(s)
- Keum-Shik Hong
- Department of Cogno-Mechatronics Engineering, Pusan National University; 2 Busandaehak-ro, Geumjeong-gu, Busan 609-735, South Korea
- School of Mechanical Engineering, Pusan National University; 2 Busandaehak-ro, Geumjeong-gu, Busan 609-735, South Korea
| | - Hoang-Dung Nguyen
- Department of Cogno-Mechatronics Engineering, Pusan National University; 2 Busandaehak-ro, Geumjeong-gu, Busan 609-735, South Korea
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Cooper RJ, Magee E, Everdell N, Magazov S, Varela M, Airantzis D, Gibson AP, Hebden JC. MONSTIR II: a 32-channel, multispectral, time-resolved optical tomography system for neonatal brain imaging. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2014; 85:053105. [PMID: 24880351 DOI: 10.1063/1.4875593] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
We detail the design, construction and performance of the second generation UCL time-resolved optical tomography system, known as MONSTIR II. Intended primarily for the study of the newborn brain, the system employs 32 source fibres that sequentially transmit picosecond pulses of light at any four wavelengths between 650 and 900 nm. The 32 detector channels each contain an independent photo-multiplier tube and temporally correlated photon-counting electronics that allow the photon transit time between each source and each detector position to be measured with high temporal resolution. The system's response time, temporal stability, cross-talk, and spectral characteristics are reported. The efficacy of MONSTIR II is demonstrated by performing multi-spectral imaging of a simple phantom.
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Affiliation(s)
- Robert J Cooper
- Biomedical Optics Research Laboratory, Department of Medical Physics and Bioengineering, University College London, London WC1E 6BT, United Kingdom
| | - Elliott Magee
- Biomedical Optics Research Laboratory, Department of Medical Physics and Bioengineering, University College London, London WC1E 6BT, United Kingdom
| | - Nick Everdell
- Biomedical Optics Research Laboratory, Department of Medical Physics and Bioengineering, University College London, London WC1E 6BT, United Kingdom
| | - Salavat Magazov
- Biomedical Optics Research Laboratory, Department of Medical Physics and Bioengineering, University College London, London WC1E 6BT, United Kingdom
| | - Marta Varela
- Biomedical Optics Research Laboratory, Department of Medical Physics and Bioengineering, University College London, London WC1E 6BT, United Kingdom
| | - Dimitrios Airantzis
- Biomedical Optics Research Laboratory, Department of Medical Physics and Bioengineering, University College London, London WC1E 6BT, United Kingdom
| | - Adam P Gibson
- Biomedical Optics Research Laboratory, Department of Medical Physics and Bioengineering, University College London, London WC1E 6BT, United Kingdom
| | - Jeremy C Hebden
- Biomedical Optics Research Laboratory, Department of Medical Physics and Bioengineering, University College London, London WC1E 6BT, United Kingdom
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