| 1. |
- Aad, G, et al.
(author)
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- 2015
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swepub:Mat__t
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| 2. |
- Aaron, F. D., et al.
(author)
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Combined measurement and QCD analysis of the inclusive e(+/-)p scattering cross sections at HERA
- 2010
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In: Journal of High Energy Physics. - 1029-8479. ; :1
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Journal article (peer-reviewed)abstract
- A combination is presented of the inclusive deep inelastic cross sections measured by the H1 and ZEUS Collaborations in neutral and charged current unpolarised e(+/-)p scattering at HERA during the period 1994-2000. The data span six orders of magnitude in negative four-momentum-transfer squared, Q(2), and in Bjorken x. The combination method used takes the correlations of systematic uncertainties into account, resulting in an improved accuracy. The combined data are the sole input in a NLO QCD analysis which determines a new set of parton distributions, HERAPDF1.0, with small experimental uncertainties. This set includes an estimate of the model and parametrisation uncertainties of the fit result.
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| 3. |
- Aaron, F. D., et al.
(author)
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Events with an isolated lepton and missing transverse momentum and measurement of W production at HERA
- 2010
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In: Journal of High Energy Physics. - 1029-8479. ; 2010:3, s. 1-19
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Journal article (peer-reviewed)abstract
- A search for events containing an isolated electron or muon and missing trans verse momentum produced in e(+/-)p collisions is performed with the H1 and ZEUS detectors at HERA. The data were taken in the period 1994-2007 and correspond to an integrated luminosity of 0.98 fb(-1). The observed event yields are in good overall agreement with the Standard Model prediction, which is dominated by single W production. In the e(+)p data, at large hadronic transverse momentum P-T(X) > 25GeV, a total of 23 events are observed compared to a prediction of 14.0 +/- 1.9. The total single W boson production cross section is measured as 1.06 +/- 0.16 (stat.) +/- 0.07 (sys.) pb, in agreement with an Standard Model (SM) expectation of 1.26 +/- 0.19 pb.
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| 4. |
- Aaron, F. D., et al.
(author)
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Multi-leptons with high transverse momentum at HERA
- 2009
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In: Journal of High Energy Physics. - : Springer Science and Business Media LLC. - 1029-8479. ; :10
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Journal article (peer-reviewed)abstract
- Events with at least two high transverse momentum leptons (electrons or muons) are studied using the H1 and ZEUS detectors at HERA with an integrated luminosity of 0.94 fb(-1). The observed numbers of events are in general agreement with the Standard Model predictions. Seven di- and tri-lepton events are observed in e(+)p collision data with a scalar sum of the lepton transverse momenta above 100 GeV while 1.94 +/- 0.17 events are expected. Such events are not observed in e(-)p collisions for which 1.19 +/- 0.12 are predicted. Total visible and differential di-electron and di-muon photoproduction cross sections are extracted in a restricted phase space dominated by photon-photon collisions.
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| 5. |
- Aaron, F. D., et al.
(author)
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Combined inclusive diffractive cross sections measured with forward proton spectrometers in deep inelastic ep scattering at HERA
- 2012
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In: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 72:10
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Journal article (peer-reviewed)abstract
- A combination of the inclusive diffractive cross section measurements made by the H1 and ZEUS Collaborations at HERA is presented. The analysis uses samples of diffractive deep inelastic ep scattering data at a centre-of-mass energy root s = 318 GeV where leading protons are detected by dedicated spectrometers. Correlations of systematic uncertainties are taken into account, resulting in an improved precision of the cross section measurement which reaches 6 % for the most precise points. The combined data cover the range 2.5 < Q(2) < 200 GeV2 in photon virtuality, 0.00035 < x(P) < 0.09 in proton fractional momentum loss, 0.09 < vertical bar t vertical bar < 0.55 GeV2 in squared four-momentum transfer at the proton vertex and 0.0018 < beta < 0.816 in beta = x/x(P), where x is the Bjorken scaling variable.
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| 6. |
- Abramowicz, H., et al.
(author)
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Combination and QCD analysis of charm production cross section measurements in deep-inelastic ep scattering at HERA
- 2013
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In: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 73:2
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Journal article (peer-reviewed)abstract
- Measurements of open charm production cross sections in deep-inelastic ep scattering at HERA from the H1 and ZEUS Collaborations are combined. Reduced cross sections sigma(c (c) over bar)(red) for charm production are obtained in the kinematic range of photon virtuality 2.5 <= Q(2) <= 2000 GeV2 and Bjorken scaling variable 3 . 10(-5) <= x <= 5 . 10(-2). The combination method accounts for the correlations of the systematic uncertainties among the different data sets. The combined charm data together with the combined inclusive deep-inelastic scattering cross sections from HERA are used as input for a detailed NLO QCD analysis to study the influence of different heavy flavour schemes on the parton distribution functions. The optimal values of the charm mass as a parameter in these different schemes are obtained. The implications on the NLO predictions for W-+/- and Z production cross sections at the LHC are investigated. Using the fixed flavour number scheme, the running mass of the charm quark is determined.
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| 7. |
- Dellenmark-Blom, Michaela, 1983, et al.
(author)
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Establishment of a condition-specific quality-of-life questionnaire for children born with esophageal atresia aged 2-7 across 14 countries
- 2023
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In: Frontiers in Pediatrics. - 2296-2360. ; 11
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Journal article (peer-reviewed)abstract
- BackgroundEsophageal atresia (EA) is a rare congenital anomaly characterized by a discontinuity of the esophagus. Following surgical repair, survival rates have improved dramatically the past decenniums and today exceed 90%, but the children commonly present with esophageal and respiratory morbidity. In 2018, a condition-specific quality-of-life questionnaire for children with esophageal atresia (EA) aged 2-7 in Sweden-Germany was finalized (The EA-QOL questionnaire). The study aim was to describe the evaluation of the new translations across 12 new countries in Europe, Asia, Africa, Central-and North America.MethodsFollowing forward-backward translation into the new languages, the 17-item EA-QOL questionnaire was tested in cognitive debriefing interviews with parents of children with EA aged 2-7. Parents rated if each item was easy to understand (clarity) and sensitive to answer (interference with personal integrity). They could skip responding to a non-applicable/problematic item and give open comments. Predefined psychometric criteria were used; item clarity >= 80%/item sensitive to answer <= 20%/item feasibility <= 5% missing item responses. The decision to modify the translation was based on native expert, patient stakeholder, and instrument developer review, and the need for harmonization between translations.ResultsSimilar to findings in the Swedish-German cognitive debriefing, the cross-cultural analysis of input from 116 parents from 12 new countries (4-14 parents, median 9 parents/country) showed that all items in the EA-QOL questionnaire fulfilled the criteria for item clarity >= 80% and sensitive to answer (ranging from 1%-4.5%), although results varied between countries. Four items had missing responses between 5.2% and 13.4%, three within the same domain and were in line with parents' explanations. Poor translations and feasibility were improved.ConclusionsBased on parent input, the collaboration between native experts, patient stakeholders, and instrument developers, a linguistic version of the EA-QOL questionnaire for children aged 2-7 for use in and across 14 countries has been established. These efforts have set the conditions for a cross-cultural field test of the EA-QOL questionnaire and will open the doors for a new chapter in outcome research, registries, and clinical practice concerning children with EA. In the long-term, this will help increase knowledge of the disease's burden, promote patient-centeredness, exchange of information between nations, and strengthen evidence-based treatments for children born with EA.
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| 8. |
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| 9. |
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| 10. |
- Ponticorvo, A., et al.
(author)
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529 Evaluating Clinical Observation, Spatial Frequency Domain Imaging (SFDI) and Laser Speckle Imaging (LSI) for the Assessment of Burns
- 2018
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In: Journal of Burn Care & Research. - : Oxford University Press. - 1559-047X .- 1559-0488. ; 39:Suppl_1, s. S238-S239
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Journal article (peer-reviewed)abstract
- IntroductionThe current standard for diagnosis of burn severity and subsequent wound healing is through clinical examination, which is highly subjective. Several new technologies focus on burn care in an attempt to help clinicians quantify burn severity earlier and more accurately. Laser Speckle Imaging (LSI) is a technique that quantifies perfusion to assess burn wounds while Spatial Frequency Domain Imaging (SFDI) can quantify the structural damage caused by burns. Here we test each system’s ability to categorize burn wounds and compare their performance.MethodsClinical assessment of a Yorkshire pig (n=3) graded burn model was performed at 24 hours after burn injury. A commercial LSI (Periscan PIM 3, Perimed Inc.) and SFDI (OxImager RS, MI Inc.) device were used to measure hemodynamic (blood flow) and structural (reduced scattering coefficient) properties of the burn wounds. Burn severity was confirmed by histology. Additionally, both devices were used to collect preliminary data on clinical patients.ResultsClinical assessments in the swine model were 83% percent accurate, while the LSI and SFDI systems were 81% and 85% percent accurate respectively. In addition to being more accurate than LSI in this study, SFDI data suggests that it can spatially resolve the heterogeneity of burn severity within a burn wound. This was not observed using the commercial LSI device. Preliminary results on clinical patients also showed both devices were capable of non-invasively predicting burn regions that would eventually require grafting.ConclusionsThe testing of these different imaging modalities in a controlled environment allows a direct comparison. Here we show that SFDI is capable of categorizing burn wounds in a swine model of histologically confirmed graded burn severity more accurately than clinical assessment or LSI. SFDI is also able to resolve spatial heterogeneity of burn severity within a wound. SFDI has the potential to improve clinical care with additional information related to tissue structure and function, thus aiding clinicians to make decisions on how to treat burn wounds accurately at earlier time points. Additionally, these noninvasive imaging technologies have the potential to enhance tracking of wound progression and treatment efficacy.Applicability of Research to PracticeBy improving diagnostic accuracy of which burn areas will require grafting, these devices may aid clinicians make appropriate treatment decisions sooner.
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| 11. |
- Torabzadeh, Mohammad, et al.
(author)
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hyperspectral characterization of tissue simulating phantoms using a supercontinuum laser in a spatial frequency domain imaging instrument
- 2018
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In: Proceedings Volume 10486, Design and Quality for Biomedical Technologies XI; 104860G (2018). - : SPIE - International Society for Optical Engineering.
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Conference paper (peer-reviewed)abstract
- Hyperspectral Imaging (HSI) is a growing field in tissue optics due to its ability to collect continuous spectral features of a sample without a contact probe. Spatial Frequency Domain Imaging (SFDI) is a non-contact wide-field spectral imaging technique that is used to quantitatively characterize tissue structure and chromophore concentration. In this study, we designed a Hyperspectral SFDI (H-SFDI) instrument which integrated a supercontinuum laser source to a wavelength tuning optical configuration and a sCMOS camera to extract spatial (Field of View: 2cm×2cm) and broadband spectral features (580nm-950nm). A preliminary experiment was also performed to integrate the hyperspectral projection unit to a compressed single pixel camera and Light Labeling (LiLa) technique.
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| 12. |
- Pham, T. H, et al.
(author)
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Quantifying the optical properties and chromophore concentrations of turbid media by chemometric analysis of hyperspectral diffuse reflectance data collected using a fourier interferometric imaging system
- 2001
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In: Applied Spectroscopy. - : SAGE Publications. - 1943-3530 .- 0003-7028. ; 55:8, s. 1035-1045
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Journal article (peer-reviewed)abstract
- A non-contact Fourier transform interferometric imaging system was used to collect hyperspectral images of the steady-state diffuse reflectance from a point source in turbid media for the spectral range of 550-850 nm. Steady-state diffuse reflectance profiles were generated from the hyperspectral images, and partial least-squares (PLS) regression was performed on the diffuse reflectance profiles to quantify absorption (mu (alpha)) and reduced scattering (mu (s)') properties of turbid media. The feasibility of using PLS regression to predict optical properties was examined for two different sets of spatially-resolved diffuse reflectance data. One set of data was collected from 40 turbid phantoms, while the second set was generated by convolving Monte Carlo simulations with the instrument response of the imaging system. Study results show that PLS prediction of mu (alpha) and mu (s)' was accurate to within +/-8% and +/-5%, respectively, when the model was trained on turbid phantom data. Moreover, PLS prediction of optical properties was considerably faster and more efficient than direct least-squares fitting of spatially-resolved profiles. When the PLS model was trained on Monte Carlo simulated data and subsequently used to predict mu (alpha) and mu (s)' from the diffuse reflectance of turbid phantom, the percent accuracies degraded to +/-12% and +/-5%, respectively. These accuracy values are applicable to homogenous, semi-infinite turbid phantoms with optical property ranges comparable to tissues.
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| 13. |
- Ponticorvo, Adrien, et al.
(author)
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Quantitative long term measurements of burns in a rat model using spatial frequency domain imaging and laser speckle imaging (Conference Presentation)
- 2016
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In: Proceedings Volume 9711, Imaging, Manipulation, and Analysis of Biomolecules, Cells, and Tissues IX; 971102 (2016). - : SPIE - International Society for Optical Engineering.
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Conference paper (peer-reviewed)abstract
- The ability to accurately assess burn wound severity in a timely manner is a critical component of wound management as it dictates the course of treatment. While full thickness and superficial burns can be easily diagnosed through visual inspection, burns that fall in between these categories are difficult to classify. Additionally, the ability to better quantify different stages of wound healing from a burn of any severity would be important for evaluating the efficacy of different treatment options. Here we present a longitudinal (28 day) study that employs spatial frequency domain imaging (SFDI) and laser speckle imaging (LSI) as non-invasive technologies to characterize in-vivo burn wounds and healing in a murine model. Burn wounds were created using an established technique of a brass comb heated to a given temperature and applied for a set amount of time. They were imaged immediately after the initial injury and then at 2, 4, 7, 14, 21, and 28 days following the injury. Biopsies were taken on the day of the injury in order to verify the extent of the burn damage as well as at different time points after the injury in order to visualize different stages of inflammation and healing. The results of this study suggest that the reduced scattering coefficient measured using SFDI and blood flow as measured using LSI have the potential to provide useful metrics for quantifying the severity of burn injuries as well as track the different stages associated with wound healing progression.
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| 14. |
- Saager, Rolf B., 1974-, et al.
(author)
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A Light Emitting Diode (LED) Based Spatial Frequency Domain Imaging System for Optimization of Photodynamic Therapy of Nonmelanoma Skin Cancer : Quantitative Reflectance Imaging
- 2013
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In: Lasers in Surgery and Medicine. - : John Wiley & Sons. - 0196-8092 .- 1096-9101. ; 45:4, s. 207-215
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Journal article (peer-reviewed)abstract
- BackgroundPhotodynamic therapy (PDT) offers the potential for enhanced treatment of nonmelanoma skin cancer (NMSC) with minimal scarring. Yet, PDT has not achieved consistent long term effectiveness to gain widespread clinical acceptance for treatment of skin cancer. Therapeutic response varies between practitioners, patients and lesions. One important contributing factor is the absence of quantitative tools to perform in vivo dosimetry. To this end, we have developed a new quantitative imaging device that can be used to investigate parameters related to optimizing dosimetry.MethodsWe present a spatial frequency domain imaging (SFDI) based device designed to: (1) determine the optical properties at the therapeutic wavelength, which can inform variations in light penetration depth and (2) measure the spatially resolved oxygen saturation of the skin cancer lesions and surrounding tissue. We have applied this system to a preliminary clinical study of nine skin cancer lesions.ResultsOptical properties vary greatly both spatially [101%, 48% for absorption and reduced scattering, respectively] and across patients [102%, 57%]. Blood volume maps determined using visible wavelengths (460, 525, and 630 nm) represent tissue volumes within ∼1 mm in tissue (1.17 ± 0.3 mm). Here the average total hemoglobin concentration is approximately three times greater in the lesion than that detected in normal tissue, reflecting increased vasculature typically associated with tumors. Data acquired at near infrared wavelengths (730 and 850 nm) reports tissue blood concentrations and oxygenations from the underlying dermal microvasculature (volumes reaching 4.36 ± 1.32 mm into tissue).ConclusionsSFDI can be used to quantitatively characterize in vivo tissue optical properties that could be useful for better informing PDT treatment parameters. Specifically, this information provides spatially resolved insight into light delivery into tissue and local tissue oxygenation, thereby providing more quantitative and controlled dosimetry specific to the lesion. Ultimately, by optimizing the execution of PDT, this instrument has the potential to positively improve treatment outcomes. Lasers Surg. Med. 9999:XX–XX, 2013. © 2013 Wiley Periodicals, Inc.
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| 15. |
- Saager, Rolf B., 1974-, et al.
(author)
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Impact of hemoglobin breakdown products in the spectral analysis of burn wounds using spatial frequency domain spectroscopy
- 2019
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In: Journal of Biomedical Optics. - : SPIE - International Society for Optical Engineering. - 1083-3668 .- 1560-2281. ; 24:2
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Journal article (peer-reviewed)abstract
- Burn wounds and wound healing invoke several biological processes that may complicate the interpretation of spectral imaging data. Through analysis of spatial frequency domain spectroscopy data (450 to 1000 nm) obtained from longitudinal investigations using a graded porcine burn wound healing model, we have identified features in the absorption spectrum that appear to suggest the presence of hemoglobin breakdown products, e.g., methemoglobin. Our results show that the calculated concentrations of methemoglobin directly correlate with burn severity, 24 h after the injury. In addition, tissue parameters such as oxygenation (StO2) and water fraction may be underestimated by 20% and 78%, respectively, if methemoglobin is not included in the spectral analysis.
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| 16. |
- Saager, Rolf B., 1974-, et al.
(author)
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Low-cost tissue simulating phantoms with adjustable wavelength-dependent scattering properties in the visible and infrared ranges
- 2016
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In: Journal of Biomedical Optics. - : SPIE - International Society for Optical Engineering. - 1083-3668 .- 1560-2281. ; 21:6
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Journal article (peer-reviewed)abstract
- We present a method for low-cost fabrication of polydimethylsiloxane (PDMS) tissue simulating phantoms with tunable scattering spectra, spanning visible, and near-infrared regimes. These phantoms use optical polishing agents (aluminum oxide powders) at various grit sizes to approximate in vivo tissue scattering particles across multiple size distributions (range: 17 to 3 μm). This class of tunable scattering phantoms is used to mimic distinct changes in wavelength-dependent scattering properties observed in tissue pathologies such as partial thickness burns. Described by a power-law dependence on wavelength, the scattering magnitude of these phantoms scale linearly with particle concentration over a physiologic range [μ's=(0.5 to 2.0 mm−1)] whereas the scattering spectra, specific to each particle size distribution, correlate to distinct exponential coefficients (range: 0.007 to 0.32). Aluminum oxide powders used in this investigation did not detectably contribute to the absorption properties of these phantoms. The optical properties of these phantoms are verified through inverse adding-doubling methods and the tolerances of this fabrication method are discussed.
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| 17. |
- Saager, Rolf B., 1974-, et al.
(author)
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Low-cost tissue simulating phantoms with tunable, wavelength-dependent scattering properties (Conference Presentation)
- 2016
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In: Proceedings Volume 9700, Design and Quality for Biomedical Technologies IX; 970005 (2016). - : SPIE - International Society for Optical Engineering.
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Conference paper (peer-reviewed)abstract
- Tissue-simulating phantoms provide the opportunity to evaluate the performance of optical and spectroscopic instruments under controlled experimental conditions. Recent efforts have advanced phantom fabrication methods to provide more tissue realistic phantoms, both in terms of a) incorporating absorbing agents that more faithfully mimic in vivo tissue chromophores spanning visible and near infrared regimes and b) accounting for multi-layer tissue structures with distinct optical properties. The spectral scattering properties in these phantoms, however, are typically based only on a single scattering agent, thereby locking the spectral scattering properties to a single particle size distribution. However, in both healthy tissue as well as pathologic tissue, regions of distinct and differentiated scattering may be present. With differing mean size and distribution of scattering objects in these tissue regions, the relative wavelength-dependent scattering spectra may vary. For example, partial thickness burns exhibit significant cellular damage and collagen denaturation that will significantly alter the wavelength-dependent scattering properties resembling large Mie-like scatterer distributions in both visible and near infrared regimes. We present a low-cost method to fabricate silicone tissue-simulating phantoms with tunable scattering spectra properties that span visible and near infrared wavelengths. We use optical polishing agents (white aluminum oxides powders) at various grit sizes to approximate Mie scattering across multiple mean particle sizes. Mean particle sizes used in this study range from 17-3 micron. The optical properties of these phantoms are verified using an integrating sphere in combination with inverse adding-doubling methods. The tolerances of this fabrication method will be discussed.
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| 18. |
- Saager, Rolf B., 1974-, et al.
(author)
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Method using in vivo quantitative spectroscopy to guide design and optimization of low-cost, compact clinical imaging devices : emulation and evaluation of multispectral imaging systems
- 2018
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In: Journal of Biomedical Optics. - : SPIE - International Society for Optical Engineering. - 1083-3668 .- 1560-2281. ; 23:4
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Journal article (peer-reviewed)abstract
- With recent proliferation in compact and/or low-cost clinical multispectral imaging approaches and commercially available components, questions remain whether they adequately capture the requisite spectral content of their applications. We present a method to emulate the spectral range and resolution of a variety of multispectral imagers, based on in-vivo data acquired from spatial frequency domain spectroscopy (SFDS). This approach simulates spectral responses over 400 to 1100 nm. Comparing emulated data with full SFDS spectra of in-vivo tissue affords the opportunity to evaluate whether the sparse spectral content of these imagers can (1) account for all sources of optical contrast present (completeness) and (2) robustly separate and quantify sources of optical contrast (crosstalk). We validate the approach over a range of tissue-simulating phantoms, comparing the SFDS-based emulated spectra against measurements from an independently characterized multispectral imager. Emulated results match the imager across all phantoms (<3 % absorption, <1 % reduced scattering). In-vivo test cases (burn wounds and photoaging) illustrate how SFDS can be used to evaluate different multispectral imagers. This approach provides an in-vivo measurement method to evaluate the performance of multispectral imagers specific to their targeted clinical applications and can assist in the design and optimization of new spectral imaging devices.
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| 19. |
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