201
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Jana K, Sengupta D, Rudra K. Correction of bifurcated river flow measurements from historical data: Paving the way for the Teesta water sharing treaty. Ann Appl Stat 2016. [DOI: 10.1214/16-aoas958] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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202
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Stone KJ, Fryer SM, Ryan T, Stoner L. The validity and reliability of continuous-wave near-infrared spectroscopy for the assessment of leg blood volume during an orthostatic challenge. Atherosclerosis 2016; 251:234-239. [DOI: 10.1016/j.atherosclerosis.2016.06.030] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Revised: 05/23/2016] [Accepted: 06/16/2016] [Indexed: 10/21/2022]
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203
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Panigrahi S, Fade J, Ramachandran H, Alouini M. Theoretical optimal modulation frequencies for scattering parameter estimation and ballistic photon filtering in diffusing media. OPTICS EXPRESS 2016; 24:16066-16083. [PMID: 27410875 DOI: 10.1364/oe.24.016066] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The efficiency of using intensity modulated light for the estimation of scattering properties of a turbid medium and for ballistic photon discrimination is theoretically quantified in this article. Using the diffusion model for modulated photon transport and considering a noisy quadrature demodulation scheme, the minimum-variance bounds on estimation of parameters of interest are analytically derived and analyzed. The existence of a variance-minimizing optimal modulation frequency is shown and its evolution with the properties of the intervening medium is derived and studied. Furthermore, a metric is defined to quantify the efficiency of ballistic photon filtering which may be sought when imaging through turbid media. The analytical derivation of this metric shows that the minimum modulation frequency required to attain significant ballistic discrimination depends only on the reduced scattering coefficient of the medium in a linear fashion for a highly scattering medium.
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204
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Bhatt M, Ayyalasomayajula KR, Yalavarthy PK. Generalized Beer-Lambert model for near-infrared light propagation in thick biological tissues. JOURNAL OF BIOMEDICAL OPTICS 2016; 21:76012. [PMID: 27436050 DOI: 10.1117/1.jbo.21.7.076012] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 06/20/2016] [Indexed: 05/08/2023]
Abstract
The attenuation of near-infrared (NIR) light intensity as it propagates in a turbid medium like biological tissue is described by modified the Beer–Lambert law (MBLL). The MBLL is generally used to quantify the changes in tissue chromophore concentrations for NIR spectroscopic data analysis. Even though MBLL is effective in terms of providing qualitative comparison, it suffers from its applicability across tissue types and tissue dimensions. In this work, we introduce Lambert-W function-based modeling for light propagation in biological tissues, which is a generalized version of the Beer–Lambert model. The proposed modeling provides parametrization of tissue properties, which includes two attenuation coefficients μ0 and η. We validated our model against the Monte Carlo simulation, which is the gold standard for modeling NIR light propagation in biological tissue. We included numerous human and animal tissues to validate the proposed empirical model, including an inhomogeneous adult human head model. The proposed model, which has a closed form (analytical), is first of its kind in providing accurate modeling of NIR light propagation in biological tissues.
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Affiliation(s)
- Manish Bhatt
- Indian Institute of Science, Medical Imaging Group, Department of Computational and Data Sciences, C V Raman Avenue, Bengaluru 560012, India
| | | | - Phaneendra K Yalavarthy
- Indian Institute of Science, Medical Imaging Group, Department of Computational and Data Sciences, C V Raman Avenue, Bengaluru 560012, India
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205
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Abstract
Near infrared spectroscopy (NIRS) utilizes intrinsic optical absorption signals of blood, water, and lipid concentration available in the NIR window (600–1000 nm) as well as a developing array of extrinsic organic compounds to detect and localize cancer. This paper reviews optical cancer detection made possible through high tumor-tissue signal-to-noise ratio (SNR) and providing biochemical and physiological data in addition to those obtained via other methods. NIRS detects cancers in vivo through a combination of blood volume and oxygenation from measurements of oxy- and deoxy-hemoglobin giving signals of tumor angiogenesis and hypermetabolism. The Chance lab tends towards CW breast cancer systems using manually scannable detectors with calibrated low pressure tissue contact. These systems calculate angiogenesis and hypermetabolism by using a pair of wavelengths and referencing the mirror image position of the contralateral breast to achieve high ROC/AUC. Time domain and frequency domain spectroscopy were also used to study similar intrinsic breast tumor characteristics such as high blood volume. Other NIRS metrics are water-fat ratio and the optical scattering coefficient. An extrinsic FDA approved dye, ICG, has been used to measure blood pooling with extravasation, similar to Gadolinium in MRI. A key future development in NIRS will be new Molecular Beacons targeting cancers and fluorescing in the NIR window to enhance in vivo tumor-tissue ratios and to afford biochemical specificity with the potential for effective photodynamic anti-cancer therapies.
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Affiliation(s)
- S Nioka
- University of Pennsylvania, Department of Biochemistry and Biophysics, 250 Anatomy-Chemistry Bldg., Philadelphia, PA 19104-6059, USA
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206
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Fantini S, Heffer EL, Pera VE, Sassaroli A, Liu N. Spatial and Spectral Information in Optical Mammography. Technol Cancer Res Treat 2016; 4:471-82. [PMID: 16173819 DOI: 10.1177/153303460500400502] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
This article reviews our research activities in the area of optical mammography and relates them to the historical developments and the current state and trends in the field. The guiding threads for this article are the roles played in optical mammography by spatial and spectral information. The first feature, spatial information, is limited by the diffusive nature of light propagation but can take advantage of the exceptionally high optical contrast featured by blood vessels and blood-rich areas in the breast. We describe a method to correct for edge effects, a spatial second-derivative algorithm, and a two-dimensional phased-array approach that enhance the image contrast, the spatial resolution, and the depth discrimination in optical mammograms. The second feature, spectral information, is the most powerful and unique capability of optical mammography, and allows for functional measurements associated with hemoglobin concentration and oxygenation, water concentration, lipids content, and the wavelength dependence of tissue scattering. We present oxygenation-index images obtained from multi-wavelength optical data that point to the diagnostic potential of oxygenation information in optical mammography. The optimization of the spatial and spectral information in optical mammography has the potential to create a role for this imaging modality in the detection and monitoring of breast cancer.
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Affiliation(s)
- Sergio Fantini
- Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA 02155, USA.
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207
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Alderliesten T, De Vis JB, Lemmers PMA, van Bel F, Benders MJNL, Hendrikse J, Petersen ET. T 2-prepared velocity selective labelling: A novel idea for full-brain mapping of oxygen saturation. Neuroimage 2016; 139:65-73. [PMID: 27291495 DOI: 10.1016/j.neuroimage.2016.06.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Revised: 06/02/2016] [Accepted: 06/08/2016] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND AND AIM Disturbances in cerebral oxygenation saturation (SO2) have been linked to adverse outcome in adults, children, and neonates. In intensive care, the cerebral SO2 is increasingly being monitored by Near-InfraRed Spectroscopy (NIRS). Unfortunately NIRS has a limited penetration depth. The "modified T2-prepared Blood Imaging of Oxygen Saturation" (T2-BIOS) MR sequence provides a step towards full brain SO2 measurement. MATERIALS AND METHODS Tissue SO2, and venous SO2 (SvO2) were obtained simultaneously by T2-BIOS during a respiratory challenge in ten healthy volunteers. These two measures were compared to SO2 that was obtained by a single probe MR-compatible NIRS setup, and to cerebral blood flow and venous SO2 that were obtained by arterial spin labelling and T2-TRIR, respectively. RESULTS SO2-T2-BIOS and SO2-NIRS had a mean bias of -4.0% (95% CI -21.3% to 13.3%). SvO2-T2-BIOS correlated with SO2-NIRS (R2=0.41, p=0.002) and SvO2-T2-TRIR (R2=0.87, p=0.002). In addition, SO2-NIRS correlated with SvO2-T2-TRIR (R2=0.85, p=0.003) Frontal cerebral blood flow correlated with SO2-T2-BIOS (R2=0.21, p=0.04), but was not significant in relation to SO2-NIRS. DISCUSSION/CONCLUSION Full brain SO2 assessment by any technique may help validating NIRS and may prove useful in guiding the clinical management of patient populations with cerebral injury following hypoxic-ischaemic events. The agreement between NIRS and T2-BIOS provides confidence in measuring cerebral SO2 by either technique. As it stands now, the T2-BIOS represents a novel idea and future work will focus on improvements to make it a reliable tool for SO2 assessment.
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Affiliation(s)
- Thomas Alderliesten
- Department of Neonatology, Wilhelmina Children's Hospital/University Medical Center Utrecht, Room KE04.123.1, PO Box 85090, 3584 AE, Utrecht, The Netherlands.
| | - Jill B De Vis
- Department of Neonatology, Wilhelmina Children's Hospital/University Medical Center Utrecht, Room KE04.123.1, PO Box 85090, 3584 AE, Utrecht, The Netherlands.
| | - Petra M A Lemmers
- Department of Neonatology, Wilhelmina Children's Hospital/University Medical Center Utrecht, Room KE04.123.1, PO Box 85090, 3584 AE, Utrecht, The Netherlands.
| | - Frank van Bel
- Department of Neonatology, Wilhelmina Children's Hospital/University Medical Center Utrecht, Room KE04.123.1, PO Box 85090, 3584 AE, Utrecht, The Netherlands.
| | - Manon J N L Benders
- Department of Neonatology, Wilhelmina Children's Hospital/University Medical Center Utrecht, Room KE04.123.1, PO Box 85090, 3584 AE, Utrecht, The Netherlands.
| | - Jeroen Hendrikse
- Department of Radiology,University Medical Center Utrecht, Room: E.01.132, P.O. Box 85500, 3508 GA Utrecht, The Netherlands.
| | - Esben T Petersen
- Department of Radiology,University Medical Center Utrecht, Room: E.01.132, P.O. Box 85500, 3508 GA Utrecht, The Netherlands; Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Denmark.
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208
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Bravo JJ, Davis SC, Roberts DW, Paulsen KD, Kanick SC. Mathematical model to interpret localized reflectance spectra measured in the presence of a strong fluorescence marker. JOURNAL OF BIOMEDICAL OPTICS 2016; 21:61004. [PMID: 26836297 PMCID: PMC4734982 DOI: 10.1117/1.jbo.21.6.061004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Accepted: 12/31/2015] [Indexed: 06/05/2023]
Abstract
Quantification of multiple fluorescence markers during neurosurgery has the potential to provide complementary contrast mechanisms between normal and malignant tissues, and one potential combination involves fluorescein sodium (FS) and aminolevulinic acid-induced protoporphyrin IX (PpIX). We focus on the interpretation of reflectance spectra containing contributions from elastically scattered (reflected) photons as well as fluorescence emissions from a strong fluorophore (i.e., FS). A model-based approach to extract μa and μ′s in the presence of FS emission is validated in optical phantoms constructed with Intralipid (1% to 2% lipid) and whole blood (1% to 3% volume fraction), over a wide range of FS concentrations (0 to 1000 μg/ml 1000 μg/ml ). The results show that modeling reflectance as a combination of elastically scattered light and attenuation-corrected FS-based emission yielded more accurate tissue parameter estimates when compared with a nonmodified reflectance model, with reduced maximum errors for blood volume (22% versus 90%), microvascular saturation (21% versus 100%), and μs′ (13% versus 207%). Additionally, quantitative PpIX fluorescence sampled in the same phantom as FS showed significant differences depending on the reflectance model used to estimate optical properties (i.e., maximum error 29% versus 86%). These data represent a first step toward using quantitative optical spectroscopy to guide surgeries through simultaneous assessment of FS and PpIX.
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Affiliation(s)
- Jaime J. Bravo
- Dartmouth College, Thayer School of Engineering, 14 Engineering Drive, Hanover, New Hampshire 03755, United States
| | - Scott C. Davis
- Dartmouth College, Thayer School of Engineering, 14 Engineering Drive, Hanover, New Hampshire 03755, United States
- Dartmouth-Hitchcock Medical Center, Norris Cotton Cancer Center, 1 Medical Center Drive, Lebanon, New Hampshire 03756, United States
| | - David W. Roberts
- Dartmouth-Hitchcock Medical Center, Norris Cotton Cancer Center, 1 Medical Center Drive, Lebanon, New Hampshire 03756, United States
- Geisel School of Medicine at Dartmouth, 1 Rope Ferry Road, Hanover, New Hampshire 03755, United States
- Dartmouth-Hitchcock Medical Center, Section of Neurosurgery, 1 Medical Center Drive, Lebanon, New Hampshire 03756, United States
| | - Keith D. Paulsen
- Dartmouth College, Thayer School of Engineering, 14 Engineering Drive, Hanover, New Hampshire 03755, United States
- Dartmouth-Hitchcock Medical Center, Norris Cotton Cancer Center, 1 Medical Center Drive, Lebanon, New Hampshire 03756, United States
- Geisel School of Medicine at Dartmouth, 1 Rope Ferry Road, Hanover, New Hampshire 03755, United States
| | - Stephen C. Kanick
- Dartmouth College, Thayer School of Engineering, 14 Engineering Drive, Hanover, New Hampshire 03755, United States
- Dartmouth-Hitchcock Medical Center, Norris Cotton Cancer Center, 1 Medical Center Drive, Lebanon, New Hampshire 03756, United States
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209
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Vidal-Rosas EE, Billings SA, Chico T, Coca D. Reproducibility of parameters of postocclusive reactive hyperemia measured by diffuse optical tomography. JOURNAL OF BIOMEDICAL OPTICS 2016; 21:66012. [PMID: 27304420 DOI: 10.1117/1.jbo.21.6.066012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Accepted: 05/09/2016] [Indexed: 06/06/2023]
Abstract
The application of near-infrared spectroscopy (NIRS) to assess microvascular function has shown promising results. An important limitation when using a single source-detector pair, however, is the lack of depth sensitivity. Diffuse optical tomography (DOT) overcomes this limitation using an array of sources and detectors that allow the reconstruction of volumetric hemodynamic changes. This study compares the key parameters of postocclusive reactive hyperemia measured in the forearm using standard NIRS and DOT. We show that while the mean parameter values are similar for the two techniques, DOT achieves much better reproducibility, as measured by the intraclass correlation coefficient (ICC). We show that DOT achieves high reproducibility for muscle oxygen consumption (ICC: 0.99), time to maximal HbO2 (ICC: 0.94), maximal HbO2 (ICC: 0.99), and time to maximal HbT (ICC: 0.99). Absolute reproducibility as measured by the standard error of measurement is consistently smaller and close to zero (ideal value) across all parameters measured by DOT compared to NIRS. We conclude that DOT provides a more robust characterization of the reactive hyperemic response and show how the availability of volumetric hemodynamic changes allows the identification of areas of temporal consistency, which could help characterize more precisely the microvasculature.
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Affiliation(s)
- Ernesto E Vidal-Rosas
- University of Sheffield, Department of Automatic Control and Systems Engineering, Mappin Street, Sheffield S1 3JD, United Kingdom
| | - Stephen A Billings
- University of Sheffield, Department of Automatic Control and Systems Engineering, Mappin Street, Sheffield S1 3JD, United Kingdom
| | - Timothy Chico
- University of Sheffield, Department of Cardiovascular Science, Western Bank, Sheffield S10 2TF, United Kingdom
| | - Daniel Coca
- University of Sheffield, Department of Automatic Control and Systems Engineering, Mappin Street, Sheffield S1 3JD, United Kingdom
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210
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Konagaya K, Inagaki T, Kitamura R, Tsuchikawa S. Optical properties of drying wood studied by time-resolved near-infrared spectroscopy. OPTICS EXPRESS 2016; 24:9561-9573. [PMID: 27137569 DOI: 10.1364/oe.24.009561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We measured the optical properties of drying wood with the moisture contents ranging from 10% to 200%. By using time-resolved near-infrared spectroscopy, the reduced scattering coefficient μs' and absorption coefficient μa were determined independent of each other, providing information on the chemical and structural changes, respectively, of wood on the nanometer scale. Scattering from dry pores dominated, which allowed us to determine the drying process of large pores during the period of constant drying rate, and the drying process of smaller pores during the period of decreasing drying rate. The surface layer and interior of the wood exhibit different moisture states, which affect the scattering properties of the wood.
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211
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Thorn CE, Shore AC. The role of perfusion in the oxygen extraction capability of skin and skeletal muscle. Am J Physiol Heart Circ Physiol 2016; 310:H1277-84. [PMID: 27016577 DOI: 10.1152/ajpheart.00047.2016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Accepted: 03/22/2016] [Indexed: 12/19/2022]
Abstract
Oxygen extraction (OE) by all cells is dependent on an adequate supply of oxygen in proximal blood vessels and the cell's need and ability to uptake that oxygen. Here the role of blood flow in regulating OE in skin and skeletal muscle was investigated in lean and obese men. OE was derived by two optical reflectance spectroscopy techniques: 1) from the rate of fall in mean blood saturation during a 4 min below knee arterial occlusion, and thus no blood flow, in calf skin and skeletal muscle and 2) in perfused, unperturbed skin, using the spontaneous falls in mean blood saturation induced by vasomotion in calf and forearm skin of 24 subjects, 12 lean and 12 obese. OE in perfused skin was significantly higher in lean compared with obese subjects in forearm (Mann-Whitney, P < 0.004) and calf (P < 0.001) and did not correlate with OE in unperfused skin (ρ = -0.01, P = 0.48). With arterial occlusion and thus no blood flow, skin OE in lean and obese subjects no longer differed (P = 0.23, not significant). In contrast in skeletal muscle with arterial occlusion and no blood flow, the difference in OE between lean and obese subjects occurred, with obese subjects exhibiting significantly higher OE (P < 0.012). The classic model of metabolic blood flow regulation to support oxygen extraction is evident in perfused skin; OE is perturbed without blood flow and reduced in obesity. In resting skeletal muscle other mechanism(s), independent of blood flow, are implicated in oxygen extraction.
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Affiliation(s)
- Clare E Thorn
- Diabetes and Vascular Medicine, Institute of Biomedical and Clinical Sciences, University of Exeter Medical School and National Institute of Health Research Exeter Clinical Research Facility, Exeter, United Kingdom
| | - Angela C Shore
- Diabetes and Vascular Medicine, Institute of Biomedical and Clinical Sciences, University of Exeter Medical School and National Institute of Health Research Exeter Clinical Research Facility, Exeter, United Kingdom
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212
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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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213
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Marinyuk VV, Sheberstov SV. Finite-size effect in light transmission through highly forward scattering media at grazing angles. OPTICS LETTERS 2016; 41:922-925. [PMID: 26974081 DOI: 10.1364/ol.41.000922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We present a theoretical study of light transmission through a disordered medium with large (compared to the light wavelength) inhomogeneities. Both numerical integration and analytic treatments of the radiative transfer equation are performed. An effect of the single-scattering phase function on the total transmittance is found in a subdiffusion thickness range. The effect reveals itself at grazing angles of incidence and originates from small-angle multiple scattering of light. A simple analytic formula for the total transmittance is derived. Our results are in good agreement with data of independent numerical calculations.
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214
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Kitamura R, Inagaki T, Tsuchikawa S. Determination of true optical absorption and scattering coefficient of wooden cell wall substance by time-of-flight near infrared spectroscopy. OPTICS EXPRESS 2016; 24:3999-4009. [PMID: 26907052 DOI: 10.1364/oe.24.003999] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The true absorption coefficient (μa) and reduced scattering coefficient (μ´s) of the cell wall substance in Douglas fir were determined using time-of-flight near infrared spectroscopy. Samples were saturated with hexane, toluene or quinolone to minimize the multiple reflections of light on the boundary between pore-cell wall substance in wood. μ´s exhibited its minimum value when the wood was saturated with toluene because the refractive index of toluene is close to that of the wood cell wall substance. The optical parameters of the wood cell wall substance calculated were μa = 0.030 mm(-1) and μ´s= 18.4 mm(-1). Monte Carlo simulations using these values were in good agreement with the measured time-resolved transmittance profiles.
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215
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Ganesan G, Cotter JA, Reuland W, Cerussi AE, Tromberg BJ, Galassetti P. Effect of blood flow restriction on tissue oxygenation during knee extension. Med Sci Sports Exerc 2016; 47:185-93. [PMID: 24870580 DOI: 10.1249/mss.0000000000000393] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
PURPOSE Time-resolved near-infrared spectroscopy was used to quantify tissue oxy- and deoxyhemoglobin concentrations ([HbO2] and [HbR]) and O2 saturation (stO2) in the oblique fibers of the vastus medialis muscle and brain prefrontal cortex during knee extension with and without blood flow restriction (BFR). METHODS Six young healthy males performed three sets of knee extensions on a dynamometer (50% one-repetition maximum) separated by 90-s rest periods in three conditions: 1) until fatigue without BFR (fatigue), 2) until fatigue with BFR (100 mm Hg cuff constriction around thigh (BFR)), 3) same number of repetitions from condition 2 without BFR (matched). Each condition was performed on a separate visit. RESULTS BFR was associated with higher [HbR] at the oblique fibers of the vastus medialis muscle (rest 1: 57.8 (BFR) vs 35.0 μM (matched); P < 0.0001) and a significantly lower stO2 during recovery periods between sets (7.5%-11.2 % lower than non-BFR conditions for rest 1 and 2, P < 0.0001). Using a piecewise linear spline method, a spike in [HbR] was observed before the onset of HbR clearance during recovery, causing HbR clearance to begin at a higher concentration (81 (BFR) vs 62 μM (matched), P = 0.029). [HbO2] kinetics during recovery were also affected by BFR, with longer duration (BFR, 51 s; matched, 31 s; P = 0.047) but lower rate of increase (BFR, 58 μM·min; matched, 89 μM·min; P = 0.004) during recovery. In the prefrontal cortex, BFR was associated with increased [HbR], diminished increase in [HbO2], and higher subjective exertion. CONCLUSIONS These findings yield insight into possible physiological mechanisms of BFR and suggest a role of time-resolved near-infrared spectroscopy in monitoring and optimization of BFR exercise on an individual basis.
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Affiliation(s)
- Goutham Ganesan
- 1Beckman Laser Institute and Medical Clinic, School of Medicine, University of California, Irvine, CA; 2Department of Pediatrics, Irvine School of Medicine, University of California, Irvine, CA; 3Department of Orthopedic Surgery, University of California, Irvine, CA; and 4Department of Kinesiology, California State University, Long Beach, CA
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216
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Re R, Contini D, Zucchelli L, Torricelli A, Spinelli L. Effect of a thin superficial layer on the estimate of hemodynamic changes in a two-layer medium by time domain NIRS. BIOMEDICAL OPTICS EXPRESS 2016; 7:264-78. [PMID: 26977338 PMCID: PMC4771447 DOI: 10.1364/boe.7.000264] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Revised: 12/16/2015] [Accepted: 12/16/2015] [Indexed: 05/09/2023]
Abstract
In order to study hemodynamic changes involved in muscular metabolism by means of time domain fNIRS, we need to discriminate in the measured signal contributions coming from different depths. Muscles are, in fact, typically located under other tissues, e.g. skin and fat. In this paper, we study the possibility to exploit a previously proposed method for analyzing time-resolved fNIRS measurements in a two-layer structure with a thin superficial layer. This method is based on the calculation of the time-dependent mean partial pathlengths. We validated it by simulating venous and arterial arm cuff occlusions and then applied it on in vivo measurements.
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Affiliation(s)
- Rebecca Re
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milan, Italy
| | - Davide Contini
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milan, Italy
| | - Lucia Zucchelli
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milan, Italy
| | - Alessandro Torricelli
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milan, Italy
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217
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Di Sieno L, Bettega G, Berger M, Hamou C, Aribert M, Mora AD, Puszka A, Grateau H, Contini D, Hervé L, Coll JL, Dinten JM, Pifferi A, Planat-Chrétien A. Toward noninvasive assessment of flap viability with time-resolved diffuse optical tomography: a preclinical test on rats. JOURNAL OF BIOMEDICAL OPTICS 2016; 21:25004. [PMID: 26836208 DOI: 10.1117/1.jbo.21.2.025004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 12/30/2015] [Indexed: 05/10/2023]
Abstract
The noninvasive assessment of flap viability in autologous reconstruction surgery is still an unmet clinical need. To cope with this problem, we developed a proof-of-principle fully automatized setup for fast time-gated diffuse optical tomography exploiting Mellin-Laplace transform to obtain three-dimensional tomographic reconstructions of oxy- and deoxy-hemoglobin concentrations. We applied this method to perform preclinical tests on rats inducing total venous occlusion in the cutaneous abdominal flaps. Notwithstanding the use of just four source-detector couples, we could detect a spatially localized increase of deoxyhemoglobin following the occlusion (up to 550 μM in 54 min). Such capability to image spatio-temporal evolution of blood perfusion is a key issue for the noninvasive monitoring of flap viability.
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Affiliation(s)
- Laura Di Sieno
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Georges Bettega
- Hôpital d'Annecy, 1 avenue de l'hôpital, Metz Tessy, BP 90074-74374 Pringy cedex 9, FrancecUniversity Grenoble Alpes-site santé, Institut Albert Bonniot, INSERM U1209, Domaine de la merci, 38000, La Tronche, FrancedUniversity Grenoble Alpes, BP53, 38041 G
| | - Michel Berger
- CEA-LETI, Minatec Campus, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
| | - Cynthia Hamou
- University Grenoble Alpes-site santé, Institut Albert Bonniot, INSERM U1209, Domaine de la merci, 38000, La Tronche, FrancedUniversity Grenoble Alpes, BP53, 38041 Grenoble, FrancefCentre Hospitalier Universitaire-Grenoble, Boulevard de la Chantourne, 3870
| | - Marion Aribert
- University Grenoble Alpes-site santé, Institut Albert Bonniot, INSERM U1209, Domaine de la merci, 38000, La Tronche, FrancedUniversity Grenoble Alpes, BP53, 38041 Grenoble, France
| | - Alberto Dalla Mora
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Agathe Puszka
- University Grenoble Alpes-site santé, Institut Albert Bonniot, INSERM U1209, Domaine de la merci, 38000, La Tronche, FrancedUniversity Grenoble Alpes, BP53, 38041 Grenoble, FranceeCEA-LETI, Minatec Campus, 17 rue des Martyrs, 38054 Grenoble Cedex 9, Franc
| | - Henri Grateau
- CEA-LETI, Minatec Campus, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
| | - Davide Contini
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Lionel Hervé
- CEA-LETI, Minatec Campus, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
| | - Jean-Luc Coll
- University Grenoble Alpes-site santé, Institut Albert Bonniot, INSERM U1209, Domaine de la merci, 38000, La Tronche, FrancedUniversity Grenoble Alpes, BP53, 38041 Grenoble, France
| | - Jean-Marc Dinten
- CEA-LETI, Minatec Campus, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
| | - Antonio Pifferi
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milano, ItalygIstituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
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218
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Lindner C, Mora M, Farzam P, Squarcia M, Johansson J, Weigel UM, Halperin I, Hanzu FA, Durduran T. Diffuse Optical Characterization of the Healthy Human Thyroid Tissue and Two Pathological Case Studies. PLoS One 2016; 11:e0147851. [PMID: 26815533 PMCID: PMC4731400 DOI: 10.1371/journal.pone.0147851] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 01/08/2016] [Indexed: 12/17/2022] Open
Abstract
The in vivo optical and hemodynamic properties of the healthy (n = 22) and pathological (n = 2) human thyroid tissue were measured non-invasively using a custom time-resolved spectroscopy (TRS) and diffuse correlation spectroscopy (DCS) system. Medical ultrasound was used to guide the placement of the hand-held hybrid optical probe. TRS measured the absorption and reduced scattering coefficients (μa, μs′) at three wavelengths (690, 785 and 830 nm) to derive total hemoglobin concentration (THC) and oxygen saturation (StO2). DCS measured the microvascular blood flow index (BFI). Their dependencies on physiological and clinical parameters and positions along the thyroid were investigated and compared to the surrounding sternocleidomastoid muscle. The THC in the thyroid ranged from 131.9 μM to 144.8 μM, showing a 25–44% increase compared to the surrounding sternocleidomastoid muscle tissue. The blood flow was significantly higher in the thyroid (BFIthyroid = 16.0 × 10-9 cm2/s) compared to the muscle (BFImuscle = 7.8 × 10-9 cm2/s), while StO2 showed a small (StO2, muscle = 63.8% to StO2, thyroid = 68.4%), yet significant difference. Two case studies with thyroid nodules underwent the same measurement protocol prior to thyroidectomy. Their THC and BFI reached values around 226.5 μM and 62.8 × 10-9 cm2/s respectively showing a clear contrast to the nodule-free thyroid tissue as well as the general population. The initial characterization of the healthy and pathologic human thyroid tissue lays the ground work for the future investigation on the use of diffuse optics in thyroid cancer screening.
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Affiliation(s)
- Claus Lindner
- ICFO - Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona), Spain
- * E-mail:
| | - Mireia Mora
- Department of Endocrinology and Nutrition, Hospital Clínic, Barcelona, Spain
- Institut d’Investigacions Biomèdiques August Pi I Sunyer (IDIBAPS), Barcelona, Spain
| | - Parisa Farzam
- ICFO - Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona), Spain
| | | | - Johannes Johansson
- ICFO - Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona), Spain
| | - Udo M. Weigel
- ICFO - Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona), Spain
- Hemophotonics S.L., Mediterranean Technology Park, Castelldefels (Barcelona), Spain
| | - Irene Halperin
- Department of Endocrinology and Nutrition, Hospital Clínic, Barcelona, Spain
- Institut d’Investigacions Biomèdiques August Pi I Sunyer (IDIBAPS), Barcelona, Spain
| | - Felicia A. Hanzu
- Department of Endocrinology and Nutrition, Hospital Clínic, Barcelona, Spain
- Institut d’Investigacions Biomèdiques August Pi I Sunyer (IDIBAPS), Barcelona, Spain
| | - 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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219
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Hemodynamic Measurements of the Human Adult Head in Transmittance Mode by Near-Infrared Time-Resolved Spectroscopy. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016. [PMID: 26782238 DOI: 10.1007/978-1-4939-3023-4_50] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register]
Abstract
Using a near-infrared time-resolved spectroscopy (TRS) system, we measured the human head in transmittance mode to obtain the optical properties and the hemodynamic changes of deep brain tissues in seven healthy adult volunteers during hyperventilation. For six out of seven volunteers, we obtained the optical signals with sufficient intensity within 10 sec. of sampling. We confirmed that it is possible to non-invasively measure the hemodynamic changes of the human head during hyperventilation, even in the transmittance measurements by the developed TRS system. These results showed that the level of deoxygenated hemoglobin was significantly increased, and the level of oxygenated and total hemoglobin and tissue oxygen saturation were also significantly decreased during hyperventilation. We expect that this TRS technique will be applied to clinical applications for measuring deep brain tissues and deep biological organs.
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220
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Borycki D, Kholiqov O, Chong SP, Srinivasan VJ. Interferometric Near-Infrared Spectroscopy (iNIRS) for determination of optical and dynamical properties of turbid media. OPTICS EXPRESS 2016; 24:329-54. [PMID: 26832264 PMCID: PMC4741353 DOI: 10.1364/oe.24.000329] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
We introduce and implement interferometric near-infrared spectroscopy (iNIRS), which simultaneously extracts optical and dynamical properties of turbid media through analysis of a spectral interference fringe pattern. The spectral interference fringe pattern is measured using a Mach-Zehnder interferometer with a frequency-swept narrow linewidth laser. Fourier analysis of the detected signal is used to determine time-of-flight (TOF)-resolved intensity, which is then analyzed over time to yield TOF-resolved intensity autocorrelations. This approach enables quantification of optical properties, which is not possible in conventional, continuous-wave near-infrared spectroscopy (NIRS). Furthermore, iNIRS quantifies scatterer motion based on TOF-resolved autocorrelations, which is a feature inaccessible by well-established diffuse correlation spectroscopy (DCS) techniques. We prove this by determining TOF-resolved intensity and temporal autocorrelations for light transmitted through diffusive fluid phantoms with optical thicknesses of up to 55 reduced mean free paths (approximately 120 scattering events). The TOF-resolved intensity is used to determine optical properties with time-resolved diffusion theory, while the TOF-resolved intensity autocorrelations are used to determine dynamics with diffusing wave spectroscopy. iNIRS advances the capabilities of diffuse optical methods and is suitable for in vivo tissue characterization. Moreover, iNIRS combines NIRS and DCS capabilities into a single modality.
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Affiliation(s)
- Dawid Borycki
- Biomedical Engineering Department, University of California Davis, Davis, CA 95616,
USA
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudziadzka 5, 87-100 Torun,
Poland
| | - Oybek Kholiqov
- Biomedical Engineering Department, University of California Davis, Davis, CA 95616,
USA
| | - Shau Poh Chong
- Biomedical Engineering Department, University of California Davis, Davis, CA 95616,
USA
| | - Vivek J. Srinivasan
- Biomedical Engineering Department, University of California Davis, Davis, CA 95616,
USA
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221
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Bentz BZ, Chavan AV, Lin D, Tsai EHR, Webb KJ. Fabrication and application of heterogeneous printed mouse phantoms for whole animal optical imaging. APPLIED OPTICS 2016; 55:280-7. [PMID: 26835763 PMCID: PMC5652317 DOI: 10.1364/ao.55.000280] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
This work demonstrates the usefulness of 3D printing for optical imaging applications. Progress in developing optical imaging for biomedical applications requires customizable and often complex objects for testing and evaluation. There is therefore high demand for what have become known as tissue-simulating "phantoms." We present a new optical phantom fabricated using inexpensive 3D printing methods with multiple materials, allowing for the placement of complex inhomogeneities in complex or anatomically realistic geometries, as opposed to previous phantoms, which were limited to simple shapes formed by molds or machining. We use diffuse optical imaging to reconstruct optical parameters in 3D space within a printed mouse to show the applicability of the phantoms for developing whole animal optical imaging methods. This phantom fabrication approach is versatile, can be applied to optical imaging methods besides diffusive imaging, and can be used in the calibration of live animal imaging data.
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222
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Yonezawa T, Nomura K, Onodera T, Ichimura S, Mizoguchi H, Takemura H. Evaluation of venous return in lower limb by passive ankle exercise performed by PHARAD. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2016; 2015:3582-5. [PMID: 26737067 DOI: 10.1109/embc.2015.7319167] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
This paper presents evaluation of venous return, i.e., blood flow volume of vein (BF), in the lower limb after passive exercise performed by our developed "parallel link type human ankle rehabilitation assistive device (PHARAD)". The PHARAD can perform complex passive exercises (plantar flexion/dorsiflexion, inversion/eversion, adduction/abduction, and combination of these motions) by reproducing input motions of a foot plate that is attached to a sole of foot. The passive exercise can be performed for not only rehabilitation but also prevention of deep vein thrombosis (DVT). In this study, we measured the concentration of Total hemoglobin (Total-Hb) using multi-channel near infra-red spectroscopy (NIRS)-based tissue oximeters and calculated a gradient of Total-Hb during a venous occlusion. We defined the gradient as BF and evaluated BF after 3 min passive exercise performed by the PHARAD comparing to BF of resting. Seven healthy young adult people were recruited for the experiment and we assessed passive exercise, active exercise, and walking. Experimental results show that BF after the passive exercises significantly increases compare to BF of resting and this indicates that passive exercises performed by the PHARAD increases BF and has a potential to prevent DVT.
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223
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Turchin IV. Methods of biomedical optical imaging: from subcellular structures to tissues and organs. ACTA ACUST UNITED AC 2016. [DOI: 10.3367/ufnr.2015.12.037734] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
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224
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Wangpraseurt D, Jacques SL, Petrie T, Kühl M. Monte Carlo Modeling of Photon Propagation Reveals Highly Scattering Coral Tissue. FRONTIERS IN PLANT SCIENCE 2016; 7:1404. [PMID: 27708657 PMCID: PMC5030289 DOI: 10.3389/fpls.2016.01404] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 09/02/2016] [Indexed: 05/21/2023]
Abstract
Corals are very efficient at using solar radiation, with photosynthetic quantum efficiencies approaching theoretical limits. Here, we investigated potential mechanisms underlying such outstanding photosynthetic performance through extracting inherent optical properties of the living coral tissue and skeleton in a massive faviid coral. Using Monte Carlo simulations developed for medical tissue optics it is shown that for the investigated faviid coral, the coral tissue was a strongly light scattering matrix with a reduced scattering coefficient of μs' = 10 cm-1 (at 636 nm). In contrast, the scattering coefficient of the coral skeleton was μs' = 3.4 cm-1, which facilitated the efficient propagation of light to otherwise shaded coral tissue layers, thus supporting photosynthesis in lower tissues. Our study provides a quantification of coral tissue optical properties in a massive faviid coral and suggests a novel light harvesting strategy, where tissue and skeletal optics act in concert to optimize the illumination of the photosynthesizing algal symbionts embedded within the living coral tissue.
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Affiliation(s)
- Daniel Wangpraseurt
- Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, SydneyNSW, Australia
- Marine Biological Section, Department of Biology, University of CopenhagenHelsingør, Denmark
- *Correspondence: Daniel Wangpraseurt,
| | - Steven L. Jacques
- Department of Biomedical Engineering, Oregon Health & Science University, PortlandOR, USA
| | - Tracy Petrie
- Department of Biomedical Engineering, Oregon Health & Science University, PortlandOR, USA
| | - Michael Kühl
- Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, SydneyNSW, Australia
- Marine Biological Section, Department of Biology, University of CopenhagenHelsingør, Denmark
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225
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A Clinical Tissue Oximeter Using NIR Time-Resolved Spectroscopy. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 876:427-433. [DOI: 10.1007/978-1-4939-3023-4_54] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
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226
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Wang A, Lu R, Xie L. Finite element modeling of light propagation in turbid media under illumination of a continuous-wave beam. APPLIED OPTICS 2016; 55:95-103. [PMID: 26835627 DOI: 10.1364/ao.55.000095] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Spatially resolved spectroscopy provides a means for measuring the optical properties of biological tissues, based on analytical solutions to diffusion approximation for semi-infinite media under the normal illumination of an infinitely small light beam. The method is, however, prone to error in measurement because the actual boundary condition and light beam often deviate from that used in deriving the analytical solutions. It is therefore important to quantify the effect of different boundary conditions and light beams on spatially resolved diffuse reflectance in order to improve the measurement accuracy of the technique. This research was aimed at using finite element method (FEM) to model light propagation in turbid media, subjected to normal illumination by a continuous-wave beam of infinitely small or finite size. Three types of boundary conditions [i.e., partial current (PCBC), extrapolated (EBC), and zero (ZBC)] were evaluated and compared against Monte Carlo (MC) simulations, since MC could provide accurate fluence rate and diffuse reflectance. The effect of beam size was also investigated. Overall results showed that FEM provided results as accurate as those of the analytical method when an appropriate boundary condition was applied. ZBC did not give satisfactory results in most cases. FEM-PCBC yielded a better fluence rate at the boundary than did FEM-EBC, while they were almost identical in predicting diffuse reflectance. Results further showed that FEM coupled with EBC effectively simulated spatially resolved diffuse reflectance under the illumination of a finite size beam. A large beam introduced more error, especially within the region of illumination. Research also confirmed an earlier finding that a light beam of less than 1 mm diameter should be used for estimation of optical parameters. FEM is effective for modeling light propagation in biological tissues and can be used for improving the optical property measurement by the spatially resolved technique.
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227
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Liemert A, Kienle A. Application of the Laplace transform in time-domain optical spectroscopy and imaging. JOURNAL OF BIOMEDICAL OPTICS 2015; 20:110502. [PMID: 26580698 DOI: 10.1117/1.jbo.20.11.110502] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 10/20/2015] [Indexed: 05/25/2023]
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228
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Yoshizawa N, Ueda Y, Nasu H, Ogura H, Ohmae E, Yoshimoto K, Takehara Y, Yamashita Y, Sakahara H. Effect of the chest wall on the measurement of hemoglobin concentrations by near-infrared time-resolved spectroscopy in normal breast and cancer. Breast Cancer 2015; 23:844-850. [PMID: 26474784 DOI: 10.1007/s12282-015-0650-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 10/04/2015] [Indexed: 10/22/2022]
Abstract
BACKGROUND Optical imaging and spectroscopy using near-infrared light have great potential in the assessment of tumor vasculature. We previously measured hemoglobin concentrations in breast cancer using a near-infrared time-resolved spectroscopy system. The purpose of the present study was to evaluate the effect of the chest wall on the measurement of hemoglobin concentrations in normal breast tissue and cancer. METHODS We measured total hemoglobin (tHb) concentration in both cancer and contralateral normal breast using a near-infrared time-resolved spectroscopy system in 24 female patients with breast cancer. Patients were divided into two groups based on menopausal state. The skin-to-chest wall distance was determined using ultrasound images obtained with an ultrasound probe attached to the spectroscopy probe. RESULTS The apparent tHb concentration of normal breast increased when the skin-to-chest wall distance was less than 20 mm. The tHb concentration in pre-menopausal patients was higher than that in post-menopausal patients. Although the concentration of tHb in cancer tissue was statistically higher than that in normal breast, the contralateral normal breast showed higher tHb concentration than cancer in 9 of 46 datasets. When the curves of tHb concentrations as a function of the skin-to-chest wall distance in normal breast were applied for pre- and post-menopausal patients separately, all the cancer lesions plotted above the curves. CONCLUSIONS The skin-to-chest wall distance affected the measurement of tHb concentration of breast tissue by near-infrared time-resolved spectroscopy. The tHb concentration of breast cancer tissue was more precisely evaluated by considering the skin-to-chest wall distance.
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Affiliation(s)
- Nobuko Yoshizawa
- Department of Diagnostic Radiology and Nuclear Medicine, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashiku, Hamamatsu, Shizuoka, 431-3192, Japan.
| | - Yukio Ueda
- Central Research Laboratory, Hamamatsu Photonics K.K., 5000 Hirakuchi, Hamakitaku, Hamamatsu, Shizuoka, 434-8601, Japan
| | - Hatsuko Nasu
- Department of Diagnostic Radiology and Nuclear Medicine, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashiku, Hamamatsu, Shizuoka, 431-3192, Japan
| | - Hiroyuki Ogura
- Department of Breast Surgery, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashiku, Hamamatsu, Shizuoka, 431-3192, Japan
| | - Etsuko Ohmae
- Central Research Laboratory, Hamamatsu Photonics K.K., 5000 Hirakuchi, Hamakitaku, Hamamatsu, Shizuoka, 434-8601, Japan
| | - Kenji Yoshimoto
- Central Research Laboratory, Hamamatsu Photonics K.K., 5000 Hirakuchi, Hamakitaku, Hamamatsu, Shizuoka, 434-8601, Japan
| | - Yasuo Takehara
- Department of Radiology, Hamamatsu University Hospital, 1-20-1 Handayama, Higashiku, Hamamatsu, Shizuoka, 431-3192, Japan
| | - Yutaka Yamashita
- Central Research Laboratory, Hamamatsu Photonics K.K., 5000 Hirakuchi, Hamakitaku, Hamamatsu, Shizuoka, 434-8601, Japan
| | - Harumi Sakahara
- Department of Diagnostic Radiology and Nuclear Medicine, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashiku, Hamamatsu, Shizuoka, 431-3192, Japan
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229
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Chong SP, Merkle CW, Leahy C, Srinivasan VJ. Cerebral metabolic rate of oxygen (CMRO2) assessed by combined Doppler and spectroscopic OCT. BIOMEDICAL OPTICS EXPRESS 2015; 6:3941-51. [PMID: 26504644 PMCID: PMC4605053 DOI: 10.1364/boe.6.003941] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Revised: 08/28/2015] [Accepted: 09/08/2015] [Indexed: 05/18/2023]
Abstract
A method of measuring cortical oxygen metabolism in the mouse brain that uses independent quantitative measurements of three key parameters: cerebral blood flow (CBF), arteriovenous oxygen extraction (OE), and hemoglobin concentration ([HbT]) is presented. Measurements were performed using a single visible light spectral/Fourier domain OCT microscope, with Doppler and spectroscopic capabilities, through a thinned-skull cranial window in the mouse brain. Baseline metabolic measurements in mice are shown to be consistent with literature values. Oxygen consumption, as measured by this method, did not change substantially during minor changes either in the fraction of inspired oxygen (FiO2) or in the fraction of inspired carbon dioxide (FiCO2), in spite of larger variations in oxygen saturations. This set of experiments supports, but does not prove, the validity of the proposed method of measuring brain oxygen metabolism.
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Affiliation(s)
- Shau Poh Chong
- Biomedical Engineering Department, University of California Davis, Davis, CA 95616, USA
| | - Conrad W Merkle
- Biomedical Engineering Department, University of California Davis, Davis, CA 95616, USA
| | - Conor Leahy
- Biomedical Engineering Department, University of California Davis, Davis, CA 95616, USA
| | - Vivek J Srinivasan
- Biomedical Engineering Department, University of California Davis, Davis, CA 95616, USA
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230
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Mu Y, Niedre M. Fast single photon avalanche photodiode-based time-resolved diffuse optical tomography scanner. BIOMEDICAL OPTICS EXPRESS 2015; 6:3596-3609. [PMID: 26417526 PMCID: PMC4574682 DOI: 10.1364/boe.6.003596] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Revised: 08/17/2015] [Accepted: 08/17/2015] [Indexed: 06/05/2023]
Abstract
Resolution in diffuse optical tomography (DOT) is a persistent problem and is primarily limited by high degree of light scatter in biological tissue. We showed previously that the reduction in photon scatter between a source and detector pair at early time points following a laser pulse in time-resolved DOT is highly dependent on the temporal response of the instrument. To this end, we developed a new single-photon avalanche photodiode (SPAD) based time-resolved DOT scanner. This instrument uses an array of fast SPADs, a femto-second Titanium Sapphire laser and single photon counting electronics. In combination, the overall instrument temporal impulse response function width was 59 ps. In this paper, we report the design of this instrument and validate its operation in symmetrical and irregularly shaped optical phantoms of approximately small animal size. We were able to accurately reconstruct the size and position of up to 4 absorbing inclusions, with increasing image quality at earlier time windows. We attribute these results primarily to the rapid response time of our instrument. These data illustrate the potential utility of fast SPAD detectors in time-resolved DOT.
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Affiliation(s)
- Ying Mu
- Department of Electrical and Computer Engineering, Dana Research Center, Northeastern University, Boston, MA, 02115, USA
| | - Mark Niedre
- Department of Electrical and Computer Engineering, Dana Research Center, Northeastern University, Boston, MA, 02115, USA
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231
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Arefi A, Moghaddam PA, Mollazade K, Hassanpour A, Valero C, Gowen A. Mealiness Detection in Agricultural Crops: Destructive and Nondestructive Tests: A Review. Compr Rev Food Sci Food Saf 2015. [DOI: 10.1111/1541-4337.12152] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Arman Arefi
- Dept. of Biosystems Engineering; Faculty of Agriculture, Urmia Univ; Urmia Iran
| | | | - Kaveh Mollazade
- Dept. of Biosystems Engineering; Faculty of Agriculture, Univ. of Kurdistan; Sanandaj Iran
| | - Ali Hassanpour
- Dept. of Biosystems Engineering; Faculty of Agriculture, Urmia Univ; Urmia Iran
| | | | - Aoife Gowen
- School of Biosystems Engineering; College of Engineering and Architecture, Univ. College Dublin; Ireland
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232
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Abstract
In this work, we introduce an analytical method to solve the diffusion equation in a cylindrical geometry. This method is based on an integral approach to derive the Green's function for specific boundary conditions. Using our approach, we obtain comprehensive analytical solutions with the Robin boundary condition for diffuse optical imaging in both two and three dimensions. The solutions are expressed in terms of the optical properties of tissue and the amplitude and position of the light source. Our method not only works well inside the tissue but provides very accurate results near the tissue boundaries as well. The results obtained by our method are first compared with those obtained by a conventional analytical method then validated using numerical simulations. Our new analytical method allows not only implementation of any boundary condition for a specific problem but also fast simulation of light propagation making it very suitable for iterative image reconstruction algorithms.
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Affiliation(s)
- H Erkol
- Center for Functional Onco Imaging, Department of Radiological Sciences, University of California, Irvine, CA, USA
- Department of Physics, Bogazici University, Bebek, 34342, Istanbul, Turkey
| | - F Nouizi
- Center for Functional Onco Imaging, Department of Radiological Sciences, University of California, Irvine, CA, USA
| | - M B Unlu
- Department of Physics, Bogazici University, Bebek, 34342, Istanbul, Turkey
| | - G Gulsen
- Center for Functional Onco Imaging, Department of Radiological Sciences, University of California, Irvine, CA, USA
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233
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Niemeijer VM, Spee RF, Jansen JP, Buskermolen ABC, van Dijk T, Wijn PFF, Kemps HMC. Test-retest reliability of skeletal muscle oxygenation measurements during submaximal cycling exercise in patients with chronic heart failure. Clin Physiol Funct Imaging 2015; 37:68-78. [DOI: 10.1111/cpf.12269] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 04/27/2015] [Indexed: 01/26/2023]
Affiliation(s)
| | - Ruud F. Spee
- Department of Cardiology; Máxima Medical Centre; Veldhoven The Netherlands
| | - Jasper P. Jansen
- Department of Biomedical Engineering; Eindhoven University of Technology; Eindhoven The Netherlands
| | | | - Thomas van Dijk
- Department of Medical Physics; Máxima Medical Centre; Veldhoven The Netherlands
| | - Pieter F. F. Wijn
- Department of Applied Physics; Eindhoven University of Technology; Eindhoven The Netherlands
- Department of Medical Physics; Máxima Medical Centre; Veldhoven The Netherlands
| | - Hareld M. C. Kemps
- Department of Cardiology; Máxima Medical Centre; Veldhoven The Netherlands
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234
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Baker WB, Parthasarathy AB, Ko TS, Busch DR, Abramson K, Tzeng SY, Mesquita RC, Durduran T, Greenberg JH, Kung DK, Yodh AG. Pressure modulation algorithm to separate cerebral hemodynamic signals from extracerebral artifacts. NEUROPHOTONICS 2015; 2:035004. [PMID: 26301255 PMCID: PMC4524732 DOI: 10.1117/1.nph.2.3.035004] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 07/01/2015] [Indexed: 05/18/2023]
Abstract
We introduce and validate a pressure measurement paradigm that reduces extracerebral contamination from superficial tissues in optical monitoring of cerebral blood flow with diffuse correlation spectroscopy (DCS). The scheme determines subject-specific contributions of extracerebral and cerebral tissues to the DCS signal by utilizing probe pressure modulation to induce variations in extracerebral blood flow. For analysis, the head is modeled as a two-layer medium and is probed with long and short source-detector separations. Then a combination of pressure modulation and a modified Beer-Lambert law for flow enables experimenters to linearly relate differential DCS signals to cerebral and extracerebral blood flow variation without a priori anatomical information. We demonstrate the algorithm's ability to isolate cerebral blood flow during a finger-tapping task and during graded scalp ischemia in healthy adults. Finally, we adapt the pressure modulation algorithm to ameliorate extracerebral contamination in monitoring of cerebral blood oxygenation and blood volume by near-infrared spectroscopy.
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Affiliation(s)
- Wesley B. Baker
- University of Pennsylvania, Department of Physics and Astronomy, 3231 Walnut Street, Philadelphia, Pennsylvania 19104, United States
- Address all correspondence to: Wesley B. Baker, E-mail:
| | - Ashwin B. Parthasarathy
- University of Pennsylvania, Department of Physics and Astronomy, 3231 Walnut Street, Philadelphia, Pennsylvania 19104, United States
| | - Tiffany S. Ko
- University of Pennsylvania, Department of Physics and Astronomy, 3231 Walnut Street, Philadelphia, Pennsylvania 19104, United States
| | - David R. Busch
- University of Pennsylvania, Department of Physics and Astronomy, 3231 Walnut Street, Philadelphia, Pennsylvania 19104, United States
- Children’s Hospital of Philadelphia, Division of Neurology, 3401 Civic Center Boulevard, Philadelphia, Pennsylvania 19104, United States
| | - Kenneth Abramson
- University of Pennsylvania, Department of Physics and Astronomy, 3231 Walnut Street, Philadelphia, Pennsylvania 19104, United States
| | - Shih-Yu Tzeng
- University of Pennsylvania, Department of Physics and Astronomy, 3231 Walnut Street, Philadelphia, Pennsylvania 19104, United States
- National Cheng Kung University, Department of Photonics, No. 1, University Road, Tainan City 701, Taiwan
| | - Rickson C. Mesquita
- University of Campinas, Institute of Physics, 777 R. Sergio Buarque de Holanda, Campinas 13083-859, Brazil
| | - Turgut Durduran
- ICFO-Institut de Ciències Fotòniques, Mediterranean Technology Park, Av. Carl Friedrich Gauss 3, Castelldefels (Barcelona) 08860, Spain
| | - Joel H. Greenberg
- University of Pennsylvania, Department of Neurology, 3450 Hamilton Walk, Philadelphia, Pennsylvania 19104, United States
| | - David K. Kung
- Hospital of the University of Pennsylvania, Department of Neurosurgery, 3400 Spruce Street, Philadelphia, Pennsylvania 19104, United States
| | - Arjun G. Yodh
- University of Pennsylvania, Department of Physics and Astronomy, 3231 Walnut Street, Philadelphia, Pennsylvania 19104, United States
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235
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Akter S, Maejima S, Kawauchi S, Sato S, Hinoki A, Aosasa S, Yamamoto J, Nishidate I. Evaluation of light scattering and absorption properties of in vivo rat liver using a single-reflectance fiber probe during preischemia, ischemia-reperfusion, and postmortem. JOURNAL OF BIOMEDICAL OPTICS 2015; 20:076010. [PMID: 26214615 DOI: 10.1117/1.jbo.20.7.076010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Accepted: 06/25/2015] [Indexed: 05/23/2023]
Abstract
Diffuse reflectance spectroscopy (DRS) has been extensively used for characterization of biological tissues as a noninvasive optical technique to evaluate the optical properties of tissue. We investigated a method for evaluating the reduced scattering coefficient μ(s)', the absorption coefficient μ(a), the tissue oxygen saturation StO₂, and the reduction of heme aa3 in cytochrome c oxidase CcO of in vivo liver tissue using a single-reflectance fiber probe with two source-collector geometries. We performed in vivo recordings of diffuse reflectance spectra for exposed rat liver during the ischemia-reperfusion induced by the hepatic portal (hepatic artery, portal vein, and bile duct) occlusion. The time courses of μ a at 500, 530, 570, and 584 nm indicated the hemodynamic change in liver tissue as well as StO₂. Significant increase in μ(a)(605)/μ(a)(620) during ischemia and after euthanasia induced by nitrogen breathing was observed, which indicates the reduction of heme aa3, representing a sign of mitochondrial energy failure. The time courses of μ(s)' at 500, 530, 570, and 584 nm were well correlated with those of μ(a), which also reflect the scattering by red blood cells. On the other hand, at 700 and 800 nm, a temporary increase in μ(s)' and an irreversible decrease in μ(s)' were observed during ischemia-reperfusion and after euthanasia induced by nitrogen breathing, respectively. The change in μ(s)' in the near-infrared wavelength region during ischemia is indicative of the morphological changes in the cellular and subcellular structures induced by the ischemia, whereas that after euthanasia implies the hepatocyte vacuolation. The results of the present study indicate the potential application of the current DRS system for evaluating the pathophysiological conditions of in vivo liver tissue.
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Affiliation(s)
- Sharmin Akter
- Tokyo University of Agriculture and Technology, Graduate School of Bio-Application and Systems Engineering, 2-24-16, Naka-cho, Koganei, Tokyo 184-8588, Japan
| | - Satoshi Maejima
- National Defense Medical College, Department of Surgery, 3-2, Namiki, Tokorozawa, Saitama 359-8513, Japan
| | - Satoko Kawauchi
- National Defense Medical College Research Institute, Division of Biomedical Information Sciences, 3-2, Namiki, Tokorozawa, Saitama 359-8513, Japan
| | - Shunichi Sato
- National Defense Medical College Research Institute, Division of Biomedical Information Sciences, 3-2, Namiki, Tokorozawa, Saitama 359-8513, Japan
| | - Akinari Hinoki
- National Defense Medical College, Department of Surgery, 3-2, Namiki, Tokorozawa, Saitama 359-8513, Japan
| | - Suefumi Aosasa
- National Defense Medical College, Department of Surgery, 3-2, Namiki, Tokorozawa, Saitama 359-8513, Japan
| | - Junji Yamamoto
- National Defense Medical College, Department of Surgery, 3-2, Namiki, Tokorozawa, Saitama 359-8513, Japan
| | - Izumi Nishidate
- Tokyo University of Agriculture and Technology, Graduate School of Bio-Application and Systems Engineering, 2-24-16, Naka-cho, Koganei, Tokyo 184-8588, Japan
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236
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Li S, Montcel B, Yuan Z, Liu W, Vray D. Multigrid-based reconstruction algorithm for quantitative photoacoustic tomography. BIOMEDICAL OPTICS EXPRESS 2015; 6:2424-2434. [PMID: 26203371 PMCID: PMC4505699 DOI: 10.1364/boe.6.002424] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Revised: 05/08/2015] [Accepted: 06/03/2015] [Indexed: 05/31/2023]
Abstract
This paper proposes a multigrid inversion framework for quantitative photoacoustic tomography reconstruction. The forward model of optical fluence distribution and the inverse problem are solved at multiple resolutions. A fixed-point iteration scheme is formulated for each resolution and used as a cost function. The simulated and experimental results for quantitative photoacoustic tomography reconstruction show that the proposed multigrid inversion can dramatically reduce the required number of iterations for the optimization process without loss of reliability in the results.
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Affiliation(s)
- Shengfu Li
- Université de Lyon, CREATIS ; CNRS UMR5220 ; Inserm U1044 ; INSA-Lyon ; Université Lyon 1, France
- HIT-INSA Sino French Research Center for Biomedical Imaging, Harbin Institute of Technology, Harbin 150001, China
| | - Bruno Montcel
- Université de Lyon, CREATIS ; CNRS UMR5220 ; Inserm U1044 ; INSA-Lyon ; Université Lyon 1, France
| | - Zhen Yuan
- Bioimaging Core, Faculty of Health Sciences, University of Macau, Av. Padre Tomás Pereira, Taipa, Macau SAR, China
| | - Wanyu Liu
- HIT-INSA Sino French Research Center for Biomedical Imaging, Harbin Institute of Technology, Harbin 150001, China
| | - Didier Vray
- Université de Lyon, CREATIS ; CNRS UMR5220 ; Inserm U1044 ; INSA-Lyon ; Université Lyon 1, France
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237
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Liemert A, Kienle A. Explicit solutions of the radiative transport equation in the P3 approximation. Med Phys 2015; 41:111916. [PMID: 25370649 DOI: 10.1118/1.4898097] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Explicit solutions of the monoenergetic radiative transport equation in the P3 approximation have been derived which can be evaluated with nearly the same computational effort as needed for solving the standard diffusion equation (DE). In detail, the authors considered the important case of a semi-infinite medium which is illuminated by a collimated beam of light. METHODS A combination of the classic spherical harmonics method and the recently developed method of rotated reference frames is used for solving the P3 equations in closed form. RESULTS The derived solutions are illustrated and compared to exact solutions of the radiative transport equation obtained via the Monte Carlo (MC) method as well as with other approximated analytical solutions. It is shown that for the considered cases which are relevant for biomedical optics applications, the P3 approximation is close to the exact solution of the radiative transport equation. CONCLUSIONS The authors derived exact analytical solutions of the P3 equations under consideration of boundary conditions for defining a semi-infinite medium. The good agreement to Monte Carlo simulations in the investigated domains, for example, in the steady-state and time domains, as well as the short evaluation time needed suggests that the derived equations can replace the often applied solutions of the diffusion equation for the homogeneous semi-infinite medium.
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Affiliation(s)
- André Liemert
- Institut für Lasertechnologien in der Medizin und Meßtechnik an der Universität Ulm, Helmholtzstr.12, Ulm D-89081, Germany
| | - Alwin Kienle
- Institut für Lasertechnologien in der Medizin und Meßtechnik an der Universität Ulm, Helmholtzstr.12, Ulm D-89081, Germany
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238
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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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239
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Qi H, Ren YT, Chen Q, Ruan LM. Fast method of retrieving the asymmetry factor and scattering albedo from the maximum time-resolved reflectance of participating media. APPLIED OPTICS 2015; 54:5234-5242. [PMID: 26192689 DOI: 10.1364/ao.54.005234] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
This research presents a parametric study of the time-resolved hemispherical reflectance of a semi-infinite plane-parallel slab of homogeneous, nonemitting, absorbing, and anisotropic scattering medium exposed to a collimated Gaussian pulse. The one-dimensional transient radiative transfer equation was solved by using the finite volume method. The internal reflection at the medium-air interface caused by the mismatch of the refractive indices was considered. In particular, this work focused on the maximum diffuse hemispherical reflectance. Three different optical regions were identified according to the dimensionless pulsewidth βctp. The correlation between the normalized maximum hemispherical reflectance and βctp was conformed to the Boltzmann function. The coefficients in the correlating functions of the match and mismatch refractive index cases were fitted as polynomial fitting functions of the single scattering albedo ω and Henyey-Greenstein asymmetric factor g. Thus, ω and g can be simultaneously reconstructed by the semi-empirical correlations without solving the forward model. In conclusion, the proposed method can potentially retrieve the asymmetry factor and single scattering albedo of participating media accurately and efficiently.
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240
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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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241
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Li K, Liu B. Polymer-encapsulated organic nanoparticles for fluorescence and photoacoustic imaging. Chem Soc Rev 2015; 43:6570-97. [PMID: 24792930 DOI: 10.1039/c4cs00014e] [Citation(s) in RCA: 666] [Impact Index Per Article: 74.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Polymer encapsulated organic nanoparticles have recently attracted increasing attention in the biomedical field because of their unique optical properties, easy fabrication and outstanding performance as imaging and therapeutic agents. Of particular importance is the polymer encapsulated nanoparticles containing conjugated polymers (CP) or fluorogens with aggregation induced emission (AIE) characteristics as the core, which have shown significant advantages in terms of tunable brightness, superb photo- and physical stability, good biocompatibility, potential biodegradability and facile surface functionalization. In this review, we summarize the latest advances in the development of polymer encapsulated CP and AIE fluorogen nanoparticles, including preparation methods, material design and matrix selection, nanoparticle fabrication and surface functionalization for fluorescence and photoacoustic imaging. We also discuss their specific applications in cell labeling, targeted in vitro and in vivo imaging, blood vessel imaging, cell tracing, inflammation monitoring and molecular imaging. We specially focus on strategies to fine-tune the nanoparticle property (e.g. size and fluorescence quantum yield) through precise engineering of the organic cores and careful selection of polymer matrices. The review also highlights the merits and limitations of these nanoparticles as well as strategies used to overcome the limitations. The challenges and perspectives for the future development of polymer encapsulated organic nanoparticles are also discussed.
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Affiliation(s)
- Kai Li
- Institute of Materials Research and Engineering, A*STAR, 3 Research Link, Singapore 117602.
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242
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Nirengi S, Yoneshiro T, Sugie H, Saito M, Hamaoka T. Human brown adipose tissue assessed by simple, noninvasive near-infrared time-resolved spectroscopy. Obesity (Silver Spring) 2015; 23:973-80. [PMID: 25866030 DOI: 10.1002/oby.21012] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Accepted: 11/30/2014] [Indexed: 01/30/2023]
Abstract
OBJECTIVE Human brown adipose tissue (BAT) activity has been typically evaluated by (18) F-fluorodeoxyglucose (FDG)-positron emission tomography (PET) combined with computed tomography (CT). However, FDG-PET/CT has serious limitations (e.g., radiation and cold exposure). This study evaluated BAT density using near-infrared time-resolved spectroscopy (NIRTRS ), a simple and noninvasive method of measuring the indices of tissue hemoglobin concentration [total-Hb] and mitochondrial density (µs '). METHODS The NIRTRS parameters at 760, 800, and 830 nm in the supraclavicular region potentially containing BAT were evaluated. First, the NIRTRS parameters were compared at 27 °C and during a 2-h cold exposure (19 °C) in 18 men. Then, NIRTRS parameters at 27 °C were compared with mean standardized uptake values (SUVmean ) assessed by FDG-PET/CT after the 2-h cold exposure (19 °C) in 29 men. RESULTS There was no significant difference between the NIRTRS parameters at 27 °C and 19°C. The [total-Hb] and µs ' were significantly correlated to SUVmean (r = 0.73 and r = 0.64, respectively). A receiver operating characteristic analysis revealed that the sensitivity (75.0-82.4%), specificity (91.7-100%), and accuracy (82.8-86.2%) of the NIRTRS parameters were all good to determine the NIRTRS reliability. CONCLUSIONS Our novel NIRTRS method is noninvasive and simple and can reliably assess human BAT density in the supraclavicular region.
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Affiliation(s)
- Shinsuke Nirengi
- Graduate School of Sport and Health Science, Ritsumeikan University, Kusatsu, Shiga, Japan
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243
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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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244
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Morales-Cruzado B, Pérez-Gutiérrez FG, de Lange DF, Romero-Méndez R. Study of the effect introduced by an integrating sphere on the temporal profile characterization of short laser pulses propagating through a turbid medium. APPLIED OPTICS 2015; 54:2383-2390. [PMID: 25968525 DOI: 10.1364/ao.54.002383] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Accepted: 02/16/2015] [Indexed: 06/04/2023]
Abstract
When a nanosecond laser pulse is transmitted through a highly scattering material, its irradiance decreases as it propagates; this is because of the spatial and temporal pulse profile stretching owing to multiple scattering events. Although the effect of temporal distortion is much less significant than that of the spatial distortion for applications where the laser beam is focused on a subsurface target (writing of waveguides, for example), it becomes significant for applications where the laser pulse must attain certain temporal width after the beam propagated is collimated through a turbid medium (photoacoustic tomography, for example). The objective of this work is to determine the transfer function associated to an integrating sphere measurement of the temporal intensity profile involving turbid media samples. The transfer function is found to be related to the geometrical characteristics of the integrating sphere and the optical properties of the turbid media. This procedure opens a new possibility for optical property characterization and enables the use of an integrating sphere for time-dependent intensity measurements.
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245
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Liemert A, Kienle A. Novel analytical solution for the radiance in an anisotropically scattering medium. APPLIED OPTICS 2015; 54:1963-1969. [PMID: 25968372 DOI: 10.1364/ao.54.001963] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Accepted: 12/11/2014] [Indexed: 06/04/2023]
Abstract
We report on a novel analytical solution of the three-dimensional radiative transport equation for the case of an infinitely extended anisotropically scattering medium that is illuminated by an isotropic point light source. The resulting expression for the radiance can be evaluated efficiently and accurately and exhibits significant improvements with respect to the convergence and the numerical stability compared to the solutions found in the literature so far. The equations obtained were successfully verified by comparisons with the Monte Carlo method.
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246
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Kamran F, Abildgaard OHA, Subash AA, Andersen PE, Andersson-Engels S, Khoptyar D. Computationally effective solution of the inverse problem in time-of-flight spectroscopy. OPTICS EXPRESS 2015; 23:6937-6945. [PMID: 25836913 DOI: 10.1364/oe.23.006937] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Photon time-of-flight (PTOF) spectroscopy enables the estimation of absorption and reduced scattering coefficients of turbid media by measuring the propagation time of short light pulses through turbid medium. The present investigation provides a comparison of the assessed absorption and reduced scattering coefficients from PTOF measurements of intralipid 20% and India ink-based optical phantoms covering a wide range of optical properties relevant for biological tissues and dairy products. Three different models are used to obtain the optical properties by fitting to measured temporal profiles: the Liemert-Kienle model (LKM), the diffusion model (DM) and a white Monte-Carlo (WMC) simulation-based algorithm. For the infinite space geometry, a very good agreement is found between the LKM and WMC, while the results obtained by the DM differ, indicating that the LKM can provide accurate estimation of the optical parameters beyond the limits of the diffusion approximation in a computational effective and accurate manner. This result increases the potential range of applications for PTOF spectroscopy within industrial and biomedical applications.
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247
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Ryser M, Künzi L, Geiser M, Frenz M, Rička J. In situ fiber-optical monitoring of cytosolic calcium in tissue explant cultures. JOURNAL OF BIOPHOTONICS 2015; 8:183-195. [PMID: 24026906 DOI: 10.1002/jbio.201300089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Revised: 07/12/2013] [Accepted: 08/22/2013] [Indexed: 06/02/2023]
Abstract
We present a fluorescence-lifetime based method for monitoring cell and tissue activity in situ, during cell culturing and in the presence of a strong autofluorescence background. The miniature fiber-optic probes are easily incorporated in the tight space of a cell culture chamber or in an endoscope. As a first application we monitored the cytosolic calcium levels in porcine tracheal explant cultures using the Calcium Green-5N (CG5N) indicator. Despite the simplicity of the optical setup we are able to detect changes of calcium concentration as small as 2.5 nM, with a monitoring time resolution of less than 1 s.
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Affiliation(s)
- Manuel Ryser
- Institute of Applied Physics, University of Bern, Sidlerstrasse 5, 3012 Bern, Switzerland
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248
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Alfano RR, Wang WB, Wang L, Gayen SK. Light Propagation in Highly Scattering Turbid Media: Concepts, Techniques, and Biomedical Applications. PHOTONICS 2015. [DOI: 10.1002/9781119011804.ch9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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249
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Horiuchi M, Endo J, Thijssen DHJ. Impact of ischemic preconditioning on functional sympatholysis during handgrip exercise in humans. Physiol Rep 2015; 3:3/2/e12304. [PMID: 25713329 PMCID: PMC4393211 DOI: 10.14814/phy2.12304] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Repeated bouts of ischemia followed by reperfusion, known as ischemic preconditioning (IPC), is found to improve exercise performance. As redistribution of blood from the inactive areas to active skeletal muscles during exercise (i.e., functional sympatholysis) is important for exercise performance, we examined the hypothesis that IPC improves functional sympatholysis in healthy, young humans. In a randomized study, 15 healthy young men performed a 10-min resting period, dynamic handgrip exercise at 10% maximal voluntary contraction (MVC), and 25% MVC. This protocol was preceded by IPC (IPC; 4 × 5-min 220-mmHg unilateral occlusion) or a sham intervention (CON; 4 × 5-min 20-mmHg unilateral occlusion). Near-infrared spectroscopy was used to assess changes in oxygenated hemoglobin and myoglobin in skeletal muscle (HbO2 + MbO2) in response to sympathetic activation (via cold pressor test (CPT)) at baseline and during handgrip exercise (at 10% and 25%). In resting conditions, HbO2 + MbO2 significantly decreased during CPT (−11.0 ± 1.0%), which was significantly larger during the IPC-trial (−13.8 ± 1.2%, P = 0.006). During handgrip exercise at 10% MVC, changes in HbO2 + MbO2 in response to the CPT were blunted after IPC (−8.8 ± 1.5%) and CON (−8.3 ± 0.4%, P = 0.593). During handgrip exercise at 25% MVC, HbO2 + MbO2 in response to the CPT increased (2.0 ± 0.4%), whereas this response was significantly larger when preceded by IPC (4.2 ± 0.6%, P = 0.027). Collectively, these results indicate that IPC-induced different vascular changes at rest and during moderate exercise in response to sympathetic activation. This suggests that, in healthy volunteers, exposure to IPC may alter tissue oxygenation during sympathetic stimulation at rest and during exercise.
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Affiliation(s)
- Masahiro Horiuchi
- Division of Human Environmental Science, Mt. Fuji Research Institute, Fuji-yoshida cityYamanashi, Japan
| | - Junko Endo
- Division of Human Environmental Science, Mt. Fuji Research Institute, Fuji-yoshida cityYamanashi, Japan
| | - Dick H J Thijssen
- Research Institute of Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK Radboud University Medical Center, Radboud Institute for Health Sciences, Nijmegen, Netherlands
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The physiological responses to repeated upper-body sprint exercise in highly trained athletes. Eur J Appl Physiol 2015; 115:1381-91. [DOI: 10.1007/s00421-015-3128-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Accepted: 02/07/2015] [Indexed: 10/24/2022]
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