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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: 8] [Impact Index Per Article: 2.7] [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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2
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The Use of Supercontinuum Laser Sources in Biomedical Diffuse Optics: Unlocking the Power of Multispectral Imaging. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11104616] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Optical techniques based on diffuse optics have been around for decades now and are making their way into the day-to-day medical applications. Even though the physics foundations of these techniques have been known for many years, practical implementation of these technique were hindered by technological limitations, mainly from the light sources and/or detection electronics. In the past 20 years, the developments of supercontinuum laser (SCL) enabled to unlock some of these limitations, enabling the development of system and methodologies relevant for medical use, notably in terms of spectral monitoring. In this review, we focus on the use of SCL in biomedical diffuse optics, from instrumentation and methods developments to their use for medical applications. A total of 95 publications were identified, from 1993 to 2021. We discuss the advantages of the SCL to cover a large spectral bandwidth with a high spectral power and fast switching against the disadvantages of cost, bulkiness, and long warm up times. Finally, we summarize the utility of using such light sources in the development and application of diffuse optics in biomedical sciences and clinical applications.
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Lacerenza M, Buttafava M, Renna M, Mora AD, Spinelli L, Zappa F, Pifferi A, Torricelli A, Tosi A, Contini D. Wearable and wireless time-domain near-infrared spectroscopy system for brain and muscle hemodynamic monitoring. BIOMEDICAL OPTICS EXPRESS 2020; 11:5934-5949. [PMID: 33149997 PMCID: PMC7587270 DOI: 10.1364/boe.403327] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 09/09/2020] [Accepted: 09/11/2020] [Indexed: 05/04/2023]
Abstract
We present a wearable time-domain near infrared spectroscopy (TD-NIRS) system (two wavelengths, one detection channel), which fits in a backpack and performs real-time hemodynamic measurements on the brain and muscle tissues of freely moving subjects. It can provide concentration values of oxygenated hemoglobin (O2Hb), deoxygenated hemoglobin (HHb), total hemoglobin (tHb = O2Hb + HHb) and tissue oxygen saturation (StO2). The system is battery-operated and can be wirelessly controlled. By following established characterization protocols for performance assessment of diffuse optics instruments, we achieved results comparable with state-of-the-art research-grade TD-NIRS systems. We also performed in-vivo measurements such as finger tapping (motor cortex monitoring), breath holding (prefrontal cortex monitoring and forearm muscle monitoring), and outdoor bike riding (vastus lateralis muscle monitoring), in order to test the system capabilities in evaluating both muscle and brain hemodynamics.
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Affiliation(s)
| | - Mauro Buttafava
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, 20133 Milano, Italy
| | - Marco Renna
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, 20133 Milano, Italy
| | | | - Lorenzo Spinelli
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, 20133 Milano, Italy
| | - Franco Zappa
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, 20133 Milano, Italy
| | - Antonio Pifferi
- Dipartimento di Fisica, Politecnico di Milano, 20133 Milano, Italy
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, 20133 Milano, Italy
| | - Alessandro Torricelli
- Dipartimento di Fisica, Politecnico di Milano, 20133 Milano, Italy
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, 20133 Milano, Italy
| | - Alberto Tosi
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, 20133 Milano, Italy
| | - Davide Contini
- Dipartimento di Fisica, Politecnico di Milano, 20133 Milano, Italy
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4
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Quantitative analysis of fat and protein concentrations of milk based on fibre-optic evaluation of back scattering intensity. Int Dairy J 2020. [DOI: 10.1016/j.idairyj.2020.104743] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Helton M, Mycek MA, Vishwanath K. Direct estimation of the reduced scattering coefficient from experimentally measured time-resolved reflectance via Monte Carlo based lookup tables. BIOMEDICAL OPTICS EXPRESS 2020; 11:4366-4378. [PMID: 32923049 PMCID: PMC7449726 DOI: 10.1364/boe.398256] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 07/02/2020] [Accepted: 07/07/2020] [Indexed: 06/11/2023]
Abstract
A heuristic method for estimating the reduced scattering coefficient (µs') of turbid media using time-resolved reflectance is presented. The technique requires measurements of the distributions of times-of-flight (DTOF) of photons arriving at two identical detection channels placed at unique distances relative to a source. Measured temporal shifts in DTOF peak intensities at the two channels were used to estimate µs' of the medium using Monte Carlo (MC) simulation-based lookup tables. MC simulations were used to compute temporal shifts in modeled reflectance at experimentally employed source-detector separations (SDS) for media spanning a wide range of optical properties to construct look up tables. Experiments in Intralipid (IL) phantoms demonstrated that we could retrieve µs' with errors ranging between 6-25% of expected (literature) values, using reflectance measured across 650-800 nm and SDS of 5-15 mm. Advantages of the technique include direct processing of measured data without requiring iterative non-linear curve fitting. We also discuss applicability of this approach for media with low scattering coefficients where the commonly employed diffusion theory analysis could be inaccurate, with practical recommendations for use.
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Affiliation(s)
- Michael Helton
- Applied Physics Program, University of Michigan, Ann Arbor, MI 48109, USA
| | - Mary-Ann Mycek
- Applied Physics Program, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
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Performance assessment of high-density diffuse optical topography regarding source-detector array topology. PLoS One 2020; 15:e0230206. [PMID: 32208433 PMCID: PMC7092988 DOI: 10.1371/journal.pone.0230206] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 02/24/2020] [Indexed: 11/19/2022] Open
Abstract
Recent advances in optical neuroimaging systems as a functional interface enhance our understanding of neuronal activity in the brain. High density diffuse optical topography (HD-DOT) uses multi-distance overlapped channels to improve the spatial resolution of images comparable to functional magnetic resonance imaging (fMRI). The topology of the source and detector (SD) array directly impacts the quality of the hemodynamic reconstruction in HD-DOT imaging modality. In this work, the effect of different SD configurations on the quality of cerebral hemodynamic recovery is investigated by presenting a simulation setup based on the analytical approach. Given that the SD arrangement determines the elements of the Jacobian matrix, we conclude that the more individual components in this matrix, the better the retrieval quality. The results demonstrate that the multi-distance multi-directional (MDMD) arrangement produces more unique elements in the Jacobian array. Consequently, the inverse problem can accurately retrieve the brain activity of diffuse optical topography data.
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Pirovano I, Re R, Candeo A, Contini D, Torricelli A, Spinelli L. Instrument response function acquisition in reflectance geometry for time-resolved diffuse optical measurements. BIOMEDICAL OPTICS EXPRESS 2020; 11:240-250. [PMID: 32010513 PMCID: PMC6968769 DOI: 10.1364/boe.380996] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 12/06/2019] [Accepted: 12/06/2019] [Indexed: 05/21/2023]
Abstract
In time-domain diffuse optical spectroscopy, the simultaneous acquisition of the time-of-flight distribution (DTOF) of photons traveling in a diffusive medium and of the instrument response function (IRF) is necessary to perform quantitative measurements of optical properties (absorption and reduced scattering coefficients) while taking into account the non-idealities of a real system (e.g. temporal resolution and time delays). The IRF acquisition can be a non-trivial and time-consuming operation that requires directly facing the injection and collection fibers. Since this operation is not always possible, a new IRF measurement scheme is here proposed where the IRF is acquired in reflectance geometry from a corrugate reflective surface. Validation measurements on a set of reference homogenous phantoms have been performed, resulting in an error in the optical properties estimation lower than 10% with respect to the typical IRF configuration. Thus, the proposed method proved to be a reliable approach that after a preliminary calibration can be exploited in a laboratory and clinical set-ups, leading to faster and more accurate measurements and reducing the operator-dependent performance.
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Affiliation(s)
- Ileana Pirovano
- 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
- Consiglio Nazionale delle Ricerche, Istituto di Fotonica e Nanotecnologie, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Alessia Candeo
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
- Central Laser Facility, Science and Technology Facility Council (STFC), Rutherford Appleton Laboratory, Research Complex at Harwell, Didcot, OX11 0QX, United Kingdom
| | - Davide Contini
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Alessandro 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
| | - Lorenzo Spinelli
- Consiglio Nazionale delle Ricerche, Istituto di Fotonica e Nanotecnologie, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
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Broadband Time Domain Diffuse Optical Reflectance Spectroscopy: A Review of Systems, Methods, and Applications. APPLIED SCIENCES-BASEL 2019. [DOI: 10.3390/app9245465] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
This review presents recent developments and a wide overview of broadband time domain diffuse optical spectroscopy (TD-DOS). Various topics including physics of photon migration, advanced instrumentation, methods of analysis, applications covering multiple domains (tissue chromophore, in vivo studies, food, wood, pharmaceutical industry) are elaborated. The key role of standardization and recent studies in that direction are discussed. Towards the end, a brief outlook is presented on the current status and future trends in broadband TD-DOS.
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9
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Sekar SKV, Pacheco A, Martella P, Li H, Lanka P, Pifferi A, Andersson-Engels S. Solid phantom recipe for diffuse optics in biophotonics applications: a step towards anatomically correct 3D tissue phantoms. BIOMEDICAL OPTICS EXPRESS 2019; 10:2090-2100. [PMID: 31061772 PMCID: PMC6484985 DOI: 10.1364/boe.10.002090] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 02/19/2019] [Accepted: 02/19/2019] [Indexed: 05/19/2023]
Abstract
We present a tissue mimicking optical phantom recipe to create robust well tested solid phantoms. The recipe consists of black silicone pigment (absorber), silica microspheres (scatterer) and silicone rubber (SiliGlass, bulk material). The phantom recipe was characterized over a broadband spectrum (600-1100 nm) for a wide range of optical properties (absorption 0.1-1 cm-1, reduced scattering 5-25 cm-1) that are relevant to human organs. The results of linearity show a proper scaling of optical properties as well as the absence of coupling between the absorber and scatterer at different concentrations. A reproducibility of 4% among different preparations was obtained, with a similar grade of spatial homogeneity. Finally, a 3D non-scattering mock-up phantom of an infant torso made with the same recipe bulk material (SiliGlass) was presented to project the futuristic aspect of our work that is 3D printing human organs of biomedical relevance.
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Affiliation(s)
| | - Andrea Pacheco
- Biophotonics@Tyndall, IPIC, Tyndall National Institute, Lee Maltings, Dyke Parade, Cork, Ireland
- Department of Physics, University College Cork, College Road, Cork, T12 K8AF, Ireland
| | - Pierluigi Martella
- Biophotonics@Tyndall, IPIC, Tyndall National Institute, Lee Maltings, Dyke Parade, Cork, Ireland
- Department of Electrical, Computer and Biomedical Engineering, University of Pavia, Pavia, Italy
| | - Haiyang Li
- Biophotonics@Tyndall, IPIC, Tyndall National Institute, Lee Maltings, Dyke Parade, Cork, Ireland
- School of Mechanical Engineering and Automation, Northeastern University, China
| | - Pranav Lanka
- Dipartimento di Fisica, Politecnico di Milano, Milano, Italy
| | - Antonio Pifferi
- Dipartimento di Fisica, Politecnico di Milano, Milano, Italy
- Consiglio Nazionale delle Ricerche, Istituto di Fotonica e Nanotecnologie, Milano, Italy
| | - Stefan Andersson-Engels
- Biophotonics@Tyndall, IPIC, Tyndall National Institute, Lee Maltings, Dyke Parade, Cork, Ireland
- Department of Physics, University College Cork, College Road, Cork, T12 K8AF, Ireland
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Katsumata T, Aizawa H, Komuro S, Ito S, Matsumoto T. Non-destructive evaluation of tomato based on optical scattering. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2019; 90:043102. [PMID: 31043008 DOI: 10.1063/1.5082869] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Accepted: 03/10/2019] [Indexed: 06/09/2023]
Abstract
Equipment for the non-destructive evaluations of a tomato has been developed based on the scattering spectra, the angular distributions of the scattering intensities, and the scattering images from the specimens. The sugar concentrations of tomato can be estimated optically based on the scattering intensities using a halogen lamp, a white light-emitting diode (white LED), a yellow LED, a red LED, and near infrared LEDs (λ = 850 nm and 940 nm) as the incident lights. The scattering intensity is found to vary linearly with sugar concentrations of tomato with any wavelengths at which the scattering light can be observed. The gradient of calibration lines of the sugar concentrations against the scattering intensities varies with scattering angles, θ. Evaluations at around θ = 160° are found to be suitable because of the large gradient and good linearity with the correlation coefficient, R, close to 1.
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Affiliation(s)
- Toru Katsumata
- Faculty of Science and Engineering, Toyo University, 2100 Kujirai, Kawagoe, Saitama 350-8585, Japan
| | - Hiroaki Aizawa
- Faculty of Science and Engineering, Toyo University, 2100 Kujirai, Kawagoe, Saitama 350-8585, Japan
| | - Shuji Komuro
- Faculty of Science and Engineering, Toyo University, 2100 Kujirai, Kawagoe, Saitama 350-8585, Japan
| | - Shigeo Ito
- Faculty of Science and Engineering, Toyo University, 2100 Kujirai, Kawagoe, Saitama 350-8585, Japan
| | - Takeshi Matsumoto
- Matsumoto Precision Co., Ltd, 3-2-17 Kagiyama, Iruma, Saitama 350, Japan
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Alayed M, Palubiak DP, Deen MJ. Characterization of a Time-Resolved Diffuse Optical Spectroscopy Prototype Using Low-Cost, Compact Single Photon Avalanche Detectors for Tissue Optics Applications. SENSORS 2018; 18:s18113680. [PMID: 30380688 PMCID: PMC6263510 DOI: 10.3390/s18113680] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 10/19/2018] [Accepted: 10/24/2018] [Indexed: 01/09/2023]
Abstract
Time-resolved diffuse optical spectroscopy (TR-DOS) is an increasingly used method to determine the optical properties of diffusive media, particularly for medical applications including functional brain, breast and muscle measurements. For medical imaging applications, important features of new generation TR-DOS systems are low-cost, small size and efficient inverse modeling. To address the issues of low-cost, compact size and high integration capabilities, we have developed free-running (FR) single-photon avalanche diodes (SPADs) using 130 nm silicon complementary metal-oxide-semiconductor (CMOS) technology and used it in a TR-DOS prototype. This prototype was validated using assessments from two known protocols for evaluating TR-DOS systems for tissue optics applications. Following the basic instrumental performance protocol, our prototype had sub-nanosecond total instrument response function and low differential non-linearity of a few percent. Also, using light with optical power lower than the maximum permissible exposure for human skin, this prototype can acquire raw data in reflectance geometry for phantoms with optical properties similar to human tissues. Following the MEDPHOT protocol, the absolute values of the optical properties for several homogeneous phantoms were retrieved with good accuracy and linearity using a best-fitting model based on the Levenberg-Marquardt method. Overall, the results of this study show that our silicon CMOS-based SPAD detectors can be used to build a multichannel TR-DOS prototype. Also, real-time functional monitoring of human tissue such as muscles, breasts and newborn heads will be possible by integrating this detector with a time-to-digital converter (TDC).
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Affiliation(s)
- Mrwan Alayed
- School of Biomedical Engineering, McMaster University, Hamilton, ON L8S 4L8, Canada.
- National Nanotechnology Center, King Abdul Aziz City for Science and Technology (KACST), Riyadh 11442, Saudi Arabia.
| | - Darek P Palubiak
- Department of Electrical and Computer Engineering, McMaster University, Hamilton, ON L8S 4L8, Canada.
| | - M Jamal Deen
- School of Biomedical Engineering, McMaster University, Hamilton, ON L8S 4L8, Canada.
- Department of Electrical and Computer Engineering, McMaster University, Hamilton, ON L8S 4L8, Canada.
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12
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Chung C, Chen YP, Leu TH, Sun CW. Near-infrared bone densitometry: A feasibility study on distal radius measurement. JOURNAL OF BIOPHOTONICS 2018; 11:e201700342. [PMID: 29451366 DOI: 10.1002/jbio.201700342] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 02/13/2018] [Indexed: 06/08/2023]
Abstract
Osteoporosis, defined as decreased bone mineral density (BMD), poses patients in dangers for fracture risk and has become a major public health problem worldwide because of is associated morbidity, mortality and costs. Without doubt, early detection and timely intervention are important to successfully manage osteoporosis and its associated complications. The dual-energy x-ray absorptiometry (DXA) is the most popular and standard method to measure BMD. However, limitations including radiation exposure and availability restrict its application for osteoporosis screening among general population. In this study, we developed a simple method to detect human distal radius bone density based on near infrared (NIR) image system. Among 10 volunteers (including 5 young and 5 elderly participants) receiving bone density measurement using our NIR image system at the ultradistal part of bilateral distal radius, we demonstrated a strong correlation between the optical attenuation and BMD measured with DXA, which may facilitate predicting bone density status. We hope our potential NIR image system may open a new avenue for development of osteoporosis screening facilities and help in prevention of osteoporosis related fracture and its associated complications in the near future. Pearson's correlations between BMD values from the DXA and light intensity of NIR system.
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Affiliation(s)
- Chun Chung
- Biomedical Optical Imaging Lab, Department of Photonics, College of Electrical and Computer Engineering, National Chiao Tung University, Hsinchu, Taiwan
| | - Yu-Pin Chen
- Department of Orthopaedic Surgery, Wan Fang Hospital, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Tsai-Hsueh Leu
- Department of Orthopaedic Surgery, Wan Fang Hospital, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Chia-Wei Sun
- Biomedical Optical Imaging Lab, Department of Photonics, College of Electrical and Computer Engineering, National Chiao Tung University, Hsinchu, Taiwan
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13
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Stocker S, Foschum F, Kienle A. Spatially Resolved Lateral Transmission Measurements to Characterize Changes in the Scattering Coefficient and the Anisotropy Factor. APPLIED SPECTROSCOPY 2018; 72:757-764. [PMID: 29464961 DOI: 10.1177/0003702818757520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
A new setup is described to characterize the scattering coefficient and the scattering phase function of liquid media. The setup utilizes the basic idea of a spatially resolved reflectance measurement combined with a sophisticated illumination geometry. The sample is illuminated parallel and close to the interface of the sample and a glass window to get information from single scattered and multiple scattered light. By illuminating the sample with a fiber orientated with the axis parallel to the glass surface, small distances to the source can be examined unimpeded by the illumination beam. The derived information is, for example, not only sensitive to the concentration of the scatterers but also to the size of the scattering particles. We present the setup including the theory to describe the light propagation in the whole configuration using Monte Carlo simulations. The validation has been done with polystyrene microsphere dispersions with different scattering coefficients. As application for the developed setup, we show measurements of different milk samples which vary in concentration of fat, protein, and in fat droplet size during homogenization process. By measuring milk, we show the ability of the sensor to determine information about the scattering phase function without diluting the sample. For sensors in the dairy industry, a measurement with no pre-processing and no diluting of the sample is worthwhile, because this can be used to determine the fat and protein concentration on-line.
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Affiliation(s)
- Sabrina Stocker
- Institut für Lasertechnologien in der Medizin und Meßtechnik, Ulm, Germany
| | - Florian Foschum
- Institut für Lasertechnologien in der Medizin und Meßtechnik, Ulm, Germany
| | - Alwin Kienle
- Institut für Lasertechnologien in der Medizin und Meßtechnik, Ulm, Germany
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14
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Ferocino E, Martinenghi E, Dalla Mora A, Pifferi A, Cubeddu R, Taroni P. High throughput detection chain for time domain optical mammography. BIOMEDICAL OPTICS EXPRESS 2018; 9:755-770. [PMID: 29552410 PMCID: PMC5854076 DOI: 10.1364/boe.9.000755] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 12/16/2017] [Accepted: 01/09/2018] [Indexed: 05/04/2023]
Abstract
A novel detection chain, based on 8 Silicon Photomultipliers (forming a wide-area custom-made detection probe) and on a time-to-digital converter, was developed to improve the signal level in multi-wavelength (635-1060 nm) time domain optical mammography. The performances of individual components and of the overall chain were assessed using established protocols (BIP and MEDPHOT). The photon detection efficiency was improved by up to 3 orders of magnitude, and the maximum count rate level was increased by a factor of 10 when compared to the previous system, based on photomultiplier tubes and conventional time-correlated single-photon counting boards. In the estimate of optical parameters, the novel detection chain provides performances comparable to the previous system, widely validated in clinics, but with higher signal level, higher robustness, and at a lower price per channel, thus targeting important requirements for clinical applications.
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Affiliation(s)
- Edoardo Ferocino
- Politecnico di Milano, Department of Physics, Piazza Leonardo da Vinci, 32, 20133, Milan, Italy
| | - Edoardo Martinenghi
- Politecnico di Milano, Department of Physics, Piazza Leonardo da Vinci, 32, 20133, Milan, Italy
| | - Alberto Dalla Mora
- Politecnico di Milano, Department of Physics, Piazza Leonardo da Vinci, 32, 20133, Milan, Italy
| | - Antonio Pifferi
- Politecnico di Milano, Department of Physics, Piazza Leonardo da Vinci, 32, 20133, Milan, Italy
- CNR-Istituto di Fotonica e Nanotecnologie, Piazza Leonardo da Vinci, 32, 20133, Milan, Italy
| | - Rinaldo Cubeddu
- Politecnico di Milano, Department of Physics, Piazza Leonardo da Vinci, 32, 20133, Milan, Italy
| | - Paola Taroni
- Politecnico di Milano, Department of Physics, Piazza Leonardo da Vinci, 32, 20133, Milan, Italy
- CNR-Istituto di Fotonica e Nanotecnologie, Piazza Leonardo da Vinci, 32, 20133, Milan, Italy
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Alayed M, Naser MA, Aden-Ali I, Deen MJ. Time-resolved diffuse optical tomography system using an accelerated inverse problem solver. OPTICS EXPRESS 2018; 26:963-979. [PMID: 29401984 DOI: 10.1364/oe.26.000963] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
A computationally efficient time-resolved diffuse optical tomography (TR-DOT) prototype was demonstrated using an accelerated inverse problem solver to reconstruct high quality 3D images of highly scattering media such as tissues. The inverse problem solver utilizes seven well-defined points on each experimentally recorded histogram of the distribution time-of-flight (DToF). In this work, the accuracy of the recovered optical properties, and the computational load and time of TR-DOT prototype were investigated using cylindrical turbid phantoms. These phantoms were measured using transmittance geometry under different conditions in multiple experiments to evaluate the performance of this prototype. Overall, the results of evaluation are important in the realization of a real-time and highly accurate TR-DOT system for diffuse optical imaging applications.
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16
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Pagliazzi M, Sekar SKV, Colombo L, Martinenghi E, Minnema J, Erdmann R, Contini D, Mora AD, Torricelli A, Pifferi A, Durduran T. Time domain diffuse correlation spectroscopy with a high coherence pulsed source: in vivo and phantom results. BIOMEDICAL OPTICS EXPRESS 2017; 8:5311-5325. [PMID: 29188122 PMCID: PMC5695972 DOI: 10.1364/boe.8.005311] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 10/12/2017] [Accepted: 10/24/2017] [Indexed: 05/18/2023]
Abstract
Diffuse correlation spectroscopy (DCS), combined with time-resolved reflectance spectroscopy (TRS) or frequency domain spectroscopy, aims at path length (i.e. depth) resolved, non-invasive and simultaneous assessment of tissue composition and blood flow. However, while TRS provides a path length resolved data, the standard DCS does not. Recently, a time domain DCS experiment showed path length resolved measurements for improved quantification with respect to classical DCS, but was limited to phantoms and small animal studies. Here, we demonstrate time domain DCS for in vivo studies on the adult forehead and the arm. We achieve path length resolved DCS by means of an actively mode-locked Ti:Sapphire laser that allows high coherence pulses, thus enabling adequate signal-to-noise ratio in relatively fast (~1 s) temporal resolution. This work paves the way to the translation of this approach to practical in vivo use.
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Affiliation(s)
- M. Pagliazzi
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
| | | | - L. Colombo
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
- Politecnico di Milano, Dipartimento di Fisica, 20133 Milano, Italy
| | - E. Martinenghi
- Politecnico di Milano, Dipartimento di Fisica, 20133 Milano, Italy
| | - J. Minnema
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
| | | | - D. Contini
- Politecnico di Milano, Dipartimento di Fisica, 20133 Milano, Italy
| | - A. Dalla Mora
- Politecnico di Milano, Dipartimento di Fisica, 20133 Milano, Italy
| | - A. Torricelli
- Politecnico di Milano, Dipartimento di Fisica, 20133 Milano, Italy
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, 20133 Milano, Italy
| | - A. Pifferi
- Politecnico di Milano, Dipartimento di Fisica, 20133 Milano, Italy
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, 20133 Milano, Italy
| | - T. Durduran
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), 08015 Barcelona, Spain
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17
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Non-invasive optical estimate of tissue composition to differentiate malignant from benign breast lesions: A pilot study. Sci Rep 2017; 7:40683. [PMID: 28091596 PMCID: PMC5238417 DOI: 10.1038/srep40683] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 11/28/2016] [Indexed: 12/22/2022] Open
Abstract
Several techniques are being investigated as a complement to screening mammography, to reduce its false-positive rate, but results are still insufficient to draw conclusions. This initial study explores time domain diffuse optical imaging as an adjunct method to classify non-invasively malignant vs benign breast lesions. We estimated differences in tissue composition (oxy- and deoxyhemoglobin, lipid, water, collagen) and absorption properties between lesion and average healthy tissue in the same breast applying a perturbative approach to optical images collected at 7 red-near infrared wavelengths (635–1060 nm) from subjects bearing breast lesions. The Discrete AdaBoost procedure, a machine-learning algorithm, was then exploited to classify lesions based on optically derived information (either tissue composition or absorption) and risk factors obtained from patient’s anamnesis (age, body mass index, familiarity, parity, use of oral contraceptives, and use of Tamoxifen). Collagen content, in particular, turned out to be the most important parameter for discrimination. Based on the initial results of this study the proposed method deserves further investigation.
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Konugolu Venkata Sekar S, Pagliazzi M, Negredo E, Martelli F, Farina A, Dalla Mora A, Lindner C, Farzam P, Pérez-Álvarez N, Puig J, Taroni P, Pifferi A, Durduran T. In Vivo, Non-Invasive Characterization of Human Bone by Hybrid Broadband (600-1200 nm) Diffuse Optical and Correlation Spectroscopies. PLoS One 2016; 11:e0168426. [PMID: 27997565 PMCID: PMC5172608 DOI: 10.1371/journal.pone.0168426] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2016] [Accepted: 11/30/2016] [Indexed: 11/19/2022] Open
Abstract
Non-invasive in vivo diffuse optical characterization of human bone opens a new possibility of diagnosing bone related pathologies. We present an in vivo characterization performed on seventeen healthy subjects at six different superficial bone locations: radius distal, radius proximal, ulna distal, ulna proximal, trochanter and calcaneus. A tailored diffuse optical protocol for high penetration depth combined with the rather superficial nature of considered tissues ensured the effective probing of the bone tissue. Measurements were performed using a broadband system for Time-Resolved Diffuse Optical Spectroscopy (TRS) to assess mean absorption and reduced scattering spectra in the 600-1200 nm range and Diffuse Correlation Spectroscopy (DCS) to monitor microvascular blood flow. Significant variations among tissue constituents were found between different locations; with radius distal rich of collagen, suggesting it as a prominent location for bone related measurements, and calcaneus bone having highest blood flow among the body locations being considered. By using TRS and DCS together, we are able to probe the perfusion and oxygen consumption of the tissue without any contrast agents. Therefore, we predict that these methods will be able to evaluate the impairment of the oxygen metabolism of the bone at the point-of-care.
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Affiliation(s)
| | - Marco Pagliazzi
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona, Spain
| | - Eugènia Negredo
- Lluita contra la Sida Foundation, Germans Trias i Pujol University Hospital, Badalona, Spain. Universitat Autònoma de Barcelona, Barcelona, Spain
- Universitat de Vic-Universitat Central de Catalunya, Vic, Barcelona, Spain
| | - Fabrizio Martelli
- Dipartimento di Fisica e Astronomia, Università degli Studi di Firenze, Sesto Fiorentino, Firenze, Italy
| | - Andrea Farina
- Dipartimento di Fisica, Politecnico di Milano, Milano, Italy
- Consiglio Nazionale delle Ricerche - Istituto di Fotonica e Nanotecnologie, Milano, Italy
| | | | - Claus Lindner
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona, Spain
| | - Parisa Farzam
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona, Spain
| | - Núria Pérez-Álvarez
- Lluita contra la Sida Foundation, Germans Trias i Pujol University Hospital, Badalona, Spain. Universitat Autònoma de Barcelona, Barcelona, Spain
- Statistics and Operations Research Department, Universitat Politècnica de Catalunya, Barcelona, Spain
| | - Jordi Puig
- Lluita contra la Sida Foundation, Germans Trias i Pujol University Hospital, Badalona, Spain. Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Paola Taroni
- Dipartimento di Fisica, Politecnico di Milano, Milano, Italy
| | - Antonio Pifferi
- Dipartimento di Fisica, Politecnico di Milano, Milano, Italy
| | - Turgut Durduran
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
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Pifferi A, Contini D, Mora AD, Farina A, Spinelli L, Torricelli A. New frontiers in time-domain diffuse optics, a review. JOURNAL OF BIOMEDICAL OPTICS 2016; 21:091310. [PMID: 27311627 DOI: 10.1117/1.jbo.21.9.091310] [Citation(s) in RCA: 106] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2016] [Accepted: 05/24/2016] [Indexed: 05/20/2023]
Abstract
The recent developments in time-domain diffuse optics that rely on physical concepts (e.g., time-gating and null distance) and advanced photonic components (e.g., vertical cavity source-emitting laser as light sources, single photon avalanche diode, and silicon photomultipliers as detectors, fast-gating circuits, and time-to-digital converters for acquisition) are focused. This study shows how these tools could lead on one hand to compact and wearable time-domain devices for point-of-care diagnostics down to the consumer level and on the other hand to powerful systems with exceptional depth penetration and sensitivity.
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Affiliation(s)
- Antonio Pifferi
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, Milan I-20133, ItalybIstituto di Fotonica e Nanotecnologie, Consiglio Nazionale per le Ricerche, Piazza Leonardo da Vinci 32, Milan I-20133, Italy
| | - Davide Contini
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, Milan I-20133, Italy
| | - Alberto Dalla Mora
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, Milan I-20133, Italy
| | - Andrea Farina
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale per le Ricerche, Piazza Leonardo da Vinci 32, Milan I-20133, Italy
| | - Lorenzo Spinelli
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale per le Ricerche, Piazza Leonardo da Vinci 32, Milan I-20133, Italy
| | - Alessandro Torricelli
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, Milan I-20133, ItalybIstituto di Fotonica e Nanotecnologie, Consiglio Nazionale per le Ricerche, Piazza Leonardo da Vinci 32, Milan I-20133, Italy
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20
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Taroni P, Quarto G, Pifferi A, Abbate F, Balestreri N, Menna S, Cassano E, Cubeddu R. Breast tissue composition and its dependence on demographic risk factors for breast cancer: non-invasive assessment by time domain diffuse optical spectroscopy. PLoS One 2015; 10:e0128941. [PMID: 26029912 PMCID: PMC4452361 DOI: 10.1371/journal.pone.0128941] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2015] [Accepted: 05/01/2015] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Breast tissue composition is recognized as a strong and independent risk factor for breast cancer. It is a heritable feature, but is also significantly affected by several other elements (e.g., age, menopause). Nowadays it is quantified by mammographic density, thus requiring the use of ionizing radiation. Optical techniques are absolutely non-invasive and have already proved effective in the investigation of biological tissues, as they are sensitive to tissue composition and structure. METHODS Time domain diffuse optical spectroscopy was performed at 7 wavelengths (635-1060 nm) on 200 subjects to derive their breast tissue composition (in terms of water, lipid and collagen content), blood parameters (total hemoglobin content and oxygen saturation level), and information on the microscopic structure (scattering amplitude and power). The dependence of all optically-derived parameters on age, menopausal status, body mass index, and use of oral contraceptives, and the correlation with mammographic density were investigated. RESULTS Younger age, premenopausal status, lower body mass index values, and use of oral contraceptives all correspond to significantly higher water, collagen and total hemoglobin content, and lower lipid content (always p < 0.05 and often p < 10-4), while oxygen saturation level and scattering parameters show significant dependence only on some conditions. Even when age-adjusted groups of subjects are compared, several optically derived parameters (and in particular always collagen and total hemoglobin content) remain significantly different. CONCLUSIONS Time domain diffuse optical spectroscopy can probe non-invasively breast tissue composition and physiologic blood parameters, and provide information on tissue structure. The measurement is suitable for in vivo studies and monitoring of changes in breast tissue (e.g., with age, lifestyle, chemotherapy, etc.) and to gain insight into related processes, like the origin of cancer risk associated with breast density.
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Affiliation(s)
- Paola Taroni
- Dipartimento di Fisica, Politecnico di Milano, Milano, Italy
- * E-mail:
| | - Giovanna Quarto
- Dipartimento di Fisica, Politecnico di Milano, Milano, Italy
| | - Antonio Pifferi
- Dipartimento di Fisica, Politecnico di Milano, Milano, Italy
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Milano, Italy
| | - Francesca Abbate
- European Institute of Oncology, Breast Imaging Unit, Milano, Italy
| | - Nicola Balestreri
- European Institute of Oncology, Department of Radiology, Milano, Italy
| | - Simona Menna
- European Institute of Oncology, Breast Imaging Unit, Milano, Italy
| | - Enrico Cassano
- European Institute of Oncology, Breast Imaging Unit, Milano, Italy
| | - Rinaldo Cubeddu
- Dipartimento di Fisica, Politecnico di Milano, Milano, Italy
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Milano, Italy
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21
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Lemaillet P, Bouchard JP, Hwang J, Allen DW. Double-integrating-sphere system at the National Institute of Standards and Technology in support of measurement standards for the determination of optical properties of tissue-mimicking phantoms. JOURNAL OF BIOMEDICAL OPTICS 2015; 20:121310. [PMID: 26505172 DOI: 10.1117/1.jbo.20.12.121310] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Accepted: 09/29/2015] [Indexed: 05/22/2023]
Abstract
There is a need for a common reference point that will allow for the comparison of the optical properties of tissue-mimicking phantoms. After a brief review of the methods that have been used to measure the phantoms for a contextual backdrop to our approach, this paper reports on the establishment of a standardized double-integrating-sphere platform to measure absorption and reduced scattering coefficients of tissue-mimicking biomedical phantoms. The platform implements a user-friendly graphical user interface in which variations of experimental configurations and model-based analysis are implemented to compute the coefficients based on a modified inverse adding-doubling algorithm allowing a complete uncertainty evaluation. Repeatability and validation of the measurement results of solid phantoms are demonstrated for three samples of different thicknesses, d = 5.08 mm, 7.09 mm, and 9.92 mm, with an absolute error estimate of 4.0% to 5.0% for the absorption coefficient and 11% to 12% for the reduced scattering coefficient (k = 2). The results are in accordance with those provided by the manufacturer. Measurements with different polarization angles of the incident light are also presented, and the resulting optical properties were determined to be equivalent within the estimated uncertainties.
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Affiliation(s)
- Paul Lemaillet
- National Institute of Standards and Technology, Physical Measurement Laboratory, 100 Bureau Drive, Gaithersburg, Maryland 20899, United States
| | | | - Jeeseong Hwang
- National Institute of Standards and Technology, Physical Measurement Laboratory, 325 Broadway Street, Boulder, Colorado 80305, United States
| | - David W Allen
- National Institute of Standards and Technology, Physical Measurement Laboratory, 100 Bureau Drive, Gaithersburg, Maryland 20899, United States
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22
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Sieno LD, Mora AD, Boso G, Tosi A, Pifferi A, Cubeddu R, Contini D. Diffuse optics using a dual window fast-gated counter. APPLIED OPTICS 2014; 53:7394-401. [PMID: 25402904 DOI: 10.1364/ao.53.007394] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
In this paper we demonstrate the advantages of a fast-gated counter in achieving high count-rate and reducing costs of timing equipment in a time-resolved diffuse optical spectroscopy setup. We experimentally prove the equivalence between the fast-gated counter we developed and a traditional time-correlated single-photon counting setup in terms of depth sensitivity and signal-to-noise ratio. Additionally, we show the suitability of this device for bilayer analysis and to estimate the absorption coefficient of homogeneous diffusing media. Finally, we present a proof-of-principle arterial occlusion measurement on a healthy volunteer to validate the proposed approach in a real application. Fast-gated counters can dramatically reduce both costs and complexity in time-resolved multichannel systems, while achieving high count-rate, thus offering a great advantage in applications like brain and muscle functional imaging.
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23
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Khoptyar D, Subash AA, Johansson S, Saleem M, Sparén A, Johansson J, Andersson-Engels S. Broadband photon time-of-flight spectroscopy of pharmaceuticals and highly scattering plastics in the VIS and close NIR spectral ranges. OPTICS EXPRESS 2013; 21:20941-53. [PMID: 24103967 DOI: 10.1364/oe.21.020941] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
We present extended spectroscopic analysis of pharmaceutical tablets in the close near infrared spectral range performed using broadband photon time-of-flight (PTOF) absorption and scattering spectra measurements. We show that the absorption spectra can be used to perform evaluation of the chemical composition of pharmaceutical tablets without need for chemo-metric calibration. The spectroscopic analysis was performed using an advanced PTOF spectrometer operating in the 650 to 1400 nm spectral range. By employing temporal stabilization of the system we achieve the high precision of 0.5% required to evaluate the concentration of tablet ingredients. In order to further illustrate the performance of the system, we present the first ever reported broadband evaluation of absorption and scattering spectra from pure and doped Spectralon®.
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24
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Farina A, Bargigia I, Taroni P, Pifferi A. Note: Comparison between a prism-based and an acousto-optic tunable filter-based spectrometer for diffusive media. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2013; 84:016109. [PMID: 23387715 DOI: 10.1063/1.4789312] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
This paper compares two continuously tunable systems for time-resolved spectroscopy of diffusive media based on a supercontinuum laser source. Two approaches for spectral selection are considered relying either on a dispersive prism or on a commercial acoustic-optic tunable filter (AOTF) device. The comparison was performed first in terms of extracted power and spectral response function, then in terms of distortions introduced in the retrieved absorption and scattering spectra. Simulations and experiments on diffusive phantoms confirmed that, besides narrower FWHM in the AOTF bandpass, the prism solution is superior with respect to the distortions produced on the recovered spectra.
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Affiliation(s)
- A Farina
- Consiglio Nazionale delle Ricerche, Istituto di Fotonica e Nanotecnologie, Piazza L. da Vinci 32, I-20133 Milano, Italy.
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25
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Bargigia I, Tosi A, Bahgat Shehata A, Della Frera A, Farina A, Bassi A, Taroni P, Dalla Mora A, Zappa F, Cubeddu R, Pifferi A. Time-resolved diffuse optical spectroscopy up to 1700 nm by means of a time-gated InGaAs/InP single-photon avalanche diode. APPLIED SPECTROSCOPY 2012; 66:944-50. [PMID: 22800436 DOI: 10.1366/11-06461] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
We present a new compact system for time-domain diffuse optical spectroscopy of highly scattering media operating in the wavelength range from 1100 nm to 1700 nm. So far, this technique has been exploited mostly up to 1100 nm: we extended the spectral range by means of a pulsed supercontinuum light source at a high repetition rate, a prism to spectrally disperse the radiation, and a time-gated InGaAs/InP single-photon avalanche diode working up to 1700 nm. A time-correlated single-photon counting board was used as processing electronics. The system is characterized by linear behavior up to absorption values of about 3.4 cm(-1) where the relative error is 17%. A first measurement performed on lipids is presented: the absorption spectrum shows three major peaks at 1200 nm, 1400 nm, and 1700 nm.
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Affiliation(s)
- Ilaria Bargigia
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milano, Italy.
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26
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Foschum F, Kienle A. Broadband absorption spectroscopy of turbid media using a dual step steady-state method. JOURNAL OF BIOMEDICAL OPTICS 2012; 17:037009. [PMID: 22502581 DOI: 10.1117/1.jbo.17.3.037009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
We present a method for the determination of the absorption coefficient of turbid media in a broad wavelength range with high spectral resolution using a dual step method. First, the reduced scattering coefficient is determined for a few wavelengths with spatially resolved reflectance measurements. The reduced scattering coefficient for the intermediate wavelengths is interpolated by fitting a power law. Second, the absorption coefficient is obtained from measurements of the total reflectance using the a priori knowledge of the reduced scattering coefficient. By applying a white light source and a spectrometer to measure the total reflectance, the absorption coefficient is determined with a high spectral resolution. The methodology is verified by comparing the absorption coefficients determined by the spatially resolved reflectance measurements with those obtained by the dual step method. The influence of an unknown refractive index and phase function on the determination of the optical properties is investigated. In addition, the optical properties of Intralipid/ink phantoms and the fat layer of porcine rind were determined. The absorption coefficient of the investigated phantoms varying by four orders of magnitude could be determined with an average error of less than 10%.
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Affiliation(s)
- Florian Foschum
- Institut für Lasertechnologien in der Medizin und Messtechnik an der Universität Ulm, Helmholtzstrasse 12, 89081 Ulm, Germany.
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27
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Foschum F, Jäger M, Kienle A. Fully automated spatially resolved reflectance spectrometer for the determination of the absorption and scattering in turbid media. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2011; 82:103104. [PMID: 22047277 DOI: 10.1063/1.3648120] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
We describe a fully automated setup which is based on measurements of the spatially resolved reflectance for the determination of the reduced scattering and absorption coefficients in semi-infinite turbid media. The sample is illuminated with a xenon light source in combination with a monochromator enabling the scan of the wavelength from 450 nm to 950 nm. Reflected light from the sample is detected with a CCD camera providing a high spatial resolution. The essential steps for signal processing including, e.g., the consideration of the optical transfer function and the correct treatment of the background subtraction, are presented. The solutions of the diffusion theory and of the radiative transfer theory are investigated regarding the exact detection and illumination geometry. Systematic errors caused by using the different theories for fitting the optical parameters are characterized. The system was validated using liquid phantoms which contain Intralipid 20% and ink, and the measurement range of the system is specified. Further, we carefully characterized the optical properties of Intralipid 20% in the wavelength range between 450 nm and 950 nm.
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Affiliation(s)
- F Foschum
- Institut für Lasertechnologien in der Medizin und Meßtechnik an der Universität Ulm, Ulm, Germany.
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28
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Hass R, Reich O. Photon density wave spectroscopy for dilution-free sizing of highly concentrated nanoparticles during starved-feed polymerization. Chemphyschem 2011; 12:2572-5. [PMID: 21887842 DOI: 10.1002/cphc.201100323] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2011] [Indexed: 11/08/2022]
Affiliation(s)
- Roland Hass
- Physical Chemistry, innoFSPEC Potsdam, University of Potsdam, Germany
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29
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Ducros N, D’Andrea C, Bassi A, Peyrin F. Fluorescence diffuse optical tomography: Time-resolved versus continuous-wave in the reflectance configuration. Ing Rech Biomed 2011. [DOI: 10.1016/j.irbm.2011.04.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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30
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Cubeddu R, Bassi A, Comelli D, Cova S, Farina A, Ghioni M, Rech I, Pifferi A, Spinelli L, Taroni P, Torricelli A, Tosi A, Valentini G, Zappa F. Photonics for Life. IEEE Pulse 2011; 2:16-23. [DOI: 10.1109/mpul.2011.941519] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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31
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Taroni P, Bassi A, Spinelli L, Cubeddu R, Pifferi A. Time-resolved diffuse optical spectroscopy: a differential absorption approach. APPLIED SPECTROSCOPY 2010; 64:1220-6. [PMID: 21073789 DOI: 10.1366/000370210793334981] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
A method is presented for the estimate of spectral changes in the absorption properties of turbid media from time-resolved diffuse optical spectroscopy. The method relies on the hypothesis of constant scattering over the wavelength range of interest, but no limitations come from the sample size and shape as the method is derived directly from the Beer-Lambert law. The effects of a moderate spectral dependence of the scattering properties and of the non-ideal instrument response function were investigated theoretically, and the results were confirmed experimentally, showing that the method can be profitably applied in cases of practical interest.
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Affiliation(s)
- Paola Taroni
- Dipartimento di Fisica, Politecnico di Milano, piazza Leonardo da Vinci 32, 20133 Milan, Italy.
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32
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Guyon L, da Silva A, Planat-Chrétien A, Rizo P, Dinten JM. Chi2 analysis for estimating the accuracy of optical properties derived from time resolved diffuse-reflectance. OPTICS EXPRESS 2009; 17:20521-20537. [PMID: 19997281 DOI: 10.1364/oe.17.020521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Weighted residuals and the reduced chi(2) (chi(R) (2)) value are investigated with regard to their relevance for assessing optical property estimates using the diffusion equation for time-resolved measurements in turbid media. It is shown and explained, for all photon counting experiments including lifetime estimation, why chi(R) (2) increases linearly with the number of photons when there is a model bias. Only when a sufficient number of photons has been acquired, chi(R) (2) is a pertinent value for assessing the accuracy of mu(a) and mu(s)' estimates. It was concluded that chi(R) (2) is of particular interest for cases of small interfiber separation, low-level scattering, strong absorption and incorrect measurement of instrument response function. It was also found that chi(R) (2) is less pertinent for judging mu(a) in case of air boundary effects.
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Affiliation(s)
- Laurent Guyon
- CEA, LETI, Département Technologies pour la Biologie et la Santé, F-38054 Grenoble, France.
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Taroni P, Bassi A, Comelli D, Farina A, Cubeddu R, Pifferi A. Diffuse optical spectroscopy of breast tissue extended to 1100 nm. JOURNAL OF BIOMEDICAL OPTICS 2009; 14:054030. [PMID: 19895132 DOI: 10.1117/1.3251051] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The feasibility of in vivo measurements in the range of 1000 to 1100 nm and the potential benefits of operation in that wavelength range for diagnostic applications are investigated. To this purpose, an existing system for time-resolved diffuse spectroscopy is modified to enable in vivo studies to be carried out continuously from 600 to 1100 nm. The optical characterization of collagen powder is extended to 1100 nm and an accurate measurement of the absorption properties of lipid is carried out over the entire spectral range. Finally, the first in vivo absorption and scattering spectra of breast tissue are measured from 10 healthy volunteers between 600 and 1100 nm and tissue composition is evaluated in terms of blood parameters and water, lipid, and collagen content using a spectrally constrained global fitting procedure.
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Affiliation(s)
- Paola Taroni
- Politecnico di Milano, Dipartimento di Fisica and Consiglio Nazionale delle Ricerche, Istituto di Fotonica e Nanotecnologie, Piazza Leonardo da Vinci 32, Milan, 20133, Italy.
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Taroni P, Pifferi A, Salvagnini E, Spinelli L, Torricelli A, Cubeddu R. Seven-wavelength time-resolved optical mammography extending beyond 1000 nm for breast collagen quantification. OPTICS EXPRESS 2009; 17:15932-46. [PMID: 19724592 DOI: 10.1364/oe.17.015932] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Our multi-wavelength time-resolved optical mammograph was upgraded to improve its overall performances and extend its spectral coverage up to 1060 nm, with the aim of increasing the measurement sensitivity to the content of collagen in breast tissue. Late-gated intensity and reduced scattering images are routinely displayed for diagnostic purposes. Maps of tissue constituents (lipid, water and collagen) and blood parameters (total hemoglobin content and blood oxygenation) are built to highlight spatial changes due to physiological and pathological reasons. The upgraded instrument was tested on tissue phantoms. Then images were collected at 7 wavelengths (635-1060 nm) from 10 healthy volunteers. Average collagen content correlated with breast density whenever x-ray mammograms were available (6 subjects).
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Affiliation(s)
- Paola Taroni
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milan, Italy.
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Svensson T, Alerstam E, Khoptyar D, Johansson J, Folestad S, Andersson-Engels S. Near-infrared photon time-of-flight spectroscopy of turbid materials up to 1400 nm. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2009; 80:063105. [PMID: 19566194 DOI: 10.1063/1.3156047] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Photon time-of-flight spectroscopy (PTOFS) is a powerful tool for analysis of turbid materials. We have constructed a time-of-flight spectrometer based on a supercontinuum fiber laser, acousto-optical tunable filtering, and an InP/InGaAsP microchannel plate photomultiplier tube. The system is capable of performing PTOFS up to 1400 nm, and thus covers an important region for vibrational spectroscopy of solid samples. The development significantly increases the applicability of PTOFS for analysis of chemical content and physical properties of turbid media. The great value of the proposed approach is illustrated by revealing the distinct absorption features of turbid epoxy resin. Promising future applications of the approach are discussed, including quantitative assessment of pharmaceuticals, powder analysis, and calibration-free near-infrared spectroscopy.
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Affiliation(s)
- Tomas Svensson
- Department of Physics, Lund University, P.O. Box 118, S-221 00 Lund, Sweden
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Cletus B, Künnemeyer R, Martinsen P, McGlone A, Jordan R. Characterizing liquid turbid media by frequency-domain photon-migration spectroscopy. JOURNAL OF BIOMEDICAL OPTICS 2009; 14:024041. [PMID: 19405769 DOI: 10.1117/1.3119282] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We present a wavelength-tunable frequency-domain instrument for the characterization of liquid turbid media. The instrument employs a tunable titanium-sapphire laser modulated by an acousto-optic modulator. The absorption and reduced scattering coefficient of Intralipid(R) 20%, diluted to concentrations of 0.94 to 4.00%, are measured over the wavelength range 710 to 850 nm at 10-nm intervals. The standard measurement errors for the absorption and reduced scattering coefficients are 1 and 2.5%, respectively. Extrapolation to 0% Intralipid(R) concentration gives an absorption coefficient that closely follows that of water, overestimating the absorption of pure water by less than 10%. The reduced scattering coefficient is compared at 750 nm with published results and is found consistent within the experimental error. We compare the reduced scattering coefficient to an estimate based on Mie theory and find the reduced scattering coefficient underestimated the Mie theory result by about 9%.
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Affiliation(s)
- Biju Cletus
- The University of Waikato, Hillcrest Road, Hamilton, Waikato 3210, New Zealand.
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Farina A, Bassi A, Pifferi A, Taroni P, Comelli D, Spinelli L, Cubeddu R. Bandpass effects in time-resolved diffuse spectroscopy. APPLIED SPECTROSCOPY 2009; 63:48-56. [PMID: 19146718 DOI: 10.1366/000370209787169795] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
This paper discusses the spectral distortions occurring when time-resolved spectroscopy of diffusive media is performed illuminating with a wide bandpass. It is shown that the spectral region within the bandpass that exhibits the lowest absorption will dominate the resulting time-resolved curve, leading to significant underestimations of absorption as well as distortions in the spectral shape (including shifts in peak positions). Due to the nonlinear behavior of absorption, this effect becomes even more pronounced when including longer and longer photon path lengths. First, a theoretical treatment of the problem is given, and then the distortion is described by time-resolved reflectance simulations and experimental measurements of lipid and water samples. A spectrally constrained data analysis is proposed that takes into account the spectrum of the light injected into the sample, used to overcome the distortion and improve the accuracy of the estimation of chromophore concentrations from absorption spectra. Measurements on a lipid sample show a reduction of the error from 30% to 6%.
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Affiliation(s)
- A Farina
- IIT, CNR-INFM and CNR-IFN, Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy.
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Kienle A, D'Andrea C, Foschum F, Taroni P, Pifferi A. Light propagation in dry and wet softwood. OPTICS EXPRESS 2008; 16:9895-9906. [PMID: 18575559 DOI: 10.1364/oe.16.009895] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Light propagation in dry and wet softwood (silver fir) was investigated experimentally and theoretically. The spatially and time resolved reflectance from softwood was measured. Light propagation was modeled with Monte Carlo simulations considering the microstructure of softwood. By comparing the spatially resolved reflectance we found that all characteristics of the experimentally obtained iso-intensity contour lines were recovered by the theory. In addition, the reduced scattering and the absorption coefficients were determined in the time domain by fitting a solution of the diffusion equation to Monte Carlo simulations and to measurements. Good qualitative agreement was obtained between the experimentally and theoretically derived optical properties.
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Affiliation(s)
- Alwin Kienle
- Institut für Lasertechnologien in der Medizin und Messtechnik, Helmholtzstr.12, D-89081 Ulm, Germany.
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D'Andrea C, Farina A, Comelli D, Pifferi A, Taroni P, Valentini G, Cubeddu R, Zoia L, Orlandi M, Kienle A. Time-resolved optical spectroscopy of wood. APPLIED SPECTROSCOPY 2008; 62:569-574. [PMID: 18498699 DOI: 10.1366/000370208784344424] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We have proposed and experimentally demonstrated that picosecond time-resolved optical spectroscopy in the visible/near-infrared (NIR) region (700-1040 nm) is a useful technique for noninvasive characterization of wood. This technique has been demonstrated on both softwood and hardwood samples treated in different ways simulating the aging process suffered by waterlogged woods. In all the cases, alterations of absorption and scattering spectra were observed, revealing changes of chemical and structural composition.
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Affiliation(s)
- C D'Andrea
- CNR-INFM and CNR-IFN, Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy.
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Torricelli A, Spinelli L, Contini D, Vanoli M, Rizzolo A, Eccher Zerbini P. Time-resolved reflectance spectroscopy for non-destructive assessment of food quality. ACTA ACUST UNITED AC 2008. [DOI: 10.1007/s11694-008-9036-2] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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