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Ni D, Karmann N, Hohmann M. Reconstruction of Optical Properties in Turbid Media: Omitting the Need of the Collimated Transmission for an Integrating Sphere Setup. SENSORS (BASEL, SWITZERLAND) 2024; 24:4807. [PMID: 39123853 PMCID: PMC11314773 DOI: 10.3390/s24154807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2024] [Revised: 07/15/2024] [Accepted: 07/16/2024] [Indexed: 08/12/2024]
Abstract
Currently, the most reliable approach to reconstruct optical properties, namely absorption coefficient, reduced scattering coefficient, scattering coefficient and asymmetry factor, of turbid media is through inverse Monte Carlo simulation. To determine these optical properties, three measurements are required: total transmission, total reflection and collimated transmission. However, the accurate determination of the collimated transmission is very difficult. To overcome the difficulty of measuring the collimated transmission, it is proposed to measure the total transmission and total reflection of the same sample with two different thicknesses instead. To prove this alternative solution, machine learning is used to prove that the repeated measurement for two different thicknesses carries all the necessary information. As a result, all four optical properties can be measured with high accuracy, particularly for interpolation problems where the test data fall within the range of the training data. For extrapolation problems, high accuracy can be achieved in the determination of at least the absorption coefficient, reduced scattering coefficient and scattering coefficient. Hence, these results allow that in the future, an easier and therefore more precise reconstruction of the optical properties is possible, potentially even with inverse Monte Carlo simulations as the current standard.
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Affiliation(s)
- Dongqin Ni
- Institute of Photonic Technologies (LPT), Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Konrad-Zuse-Straße 3/5, 91052 Erlangen, Germany; (D.N.)
- Erlangen Graduate School in Advanced Optical Technologies (SAOT), Paul-Gordon-Straße 6, 91052 Erlangen, Germany
| | - Niklas Karmann
- Institute of Photonic Technologies (LPT), Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Konrad-Zuse-Straße 3/5, 91052 Erlangen, Germany; (D.N.)
| | - Martin Hohmann
- Institute of Photonic Technologies (LPT), Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Konrad-Zuse-Straße 3/5, 91052 Erlangen, Germany; (D.N.)
- Erlangen Graduate School in Advanced Optical Technologies (SAOT), Paul-Gordon-Straße 6, 91052 Erlangen, Germany
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Sarkar M, Perez-Liva M, Renault G, Tavitian B, Gateau J. Motion Rejection and Spectral Unmixing for Accurate Estimation of In Vivo Oxygen Saturation Using Multispectral Optoacoustic Tomography. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2023; 70:1671-1681. [PMID: 37603493 DOI: 10.1109/tuffc.2023.3306592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/23/2023]
Abstract
Multispectral optoacoustic tomography (MSOT) uniquely enables spatial mapping in high resolution of oxygen saturation (SO2), with potential applications in studying pathological complications and therapy efficacy. MSOT offers seamless integration with ultrasonography, by using a common ultrasound (US) detector array. However, MSOT relies on multiple successive acquisitions of optoacoustic (OA) images at different optical wavelengths and the low frame rate of OA imaging makes the MSOT acquisition sensitive to body/respiratory motion. Moreover, the estimation of SO2 is highly sensitive to noise, and artifacts related to the respiratory motion of the animal were identified as the primary source of noise in MSOT. In this work, we propose a two-step image processing method for SO2 estimation in deep tissues. First, to mitigate motion artifacts, we propose a method of selection of OA images acquired only during the respiratory pause of the animal, using ultrafast ultrasound (US) images acquired immediately after each OA acquisition (US image acquisition duration of 1.4 ms and a total delay of 7 ms). We show that gating is more effective using US images than OA images at different optical wavelengths. Second, we propose a novel method that can estimate directly the SO2 value of a pixel and at the same time evaluate the amount of noise present in that pixel. Hence, the method can efficiently eliminate the pixels dominated by noise from the final SO2 map. Our postprocessing method is shown to outperform conventional methods for SO2 estimation, and the method was validated by in vivo oxygen challenge experiments.
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Qi J, Tatla T, Nissanka-Jayasuriya E, Yuan AY, Stoyanov D, Elson DS. Surgical polarimetric endoscopy for the detection of laryngeal cancer. Nat Biomed Eng 2023; 7:971-985. [PMID: 37012312 PMCID: PMC10427430 DOI: 10.1038/s41551-023-01018-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 02/23/2023] [Indexed: 04/05/2023]
Abstract
The standard-of-care for the detection of laryngeal pathologies involves distinguishing suspicious lesions from surrounding healthy tissue via contrasts in colour and texture captured by white-light endoscopy. However, the technique is insufficiently sensitive and thus leads to unsatisfactory rates of false negatives. Here we show that laryngeal lesions can be better detected in real time by taking advantage of differences in the light-polarization properties of cancer and healthy tissues. By measuring differences in polarized-light retardance and depolarization, the technique, which we named 'surgical polarimetric endoscopy' (SPE), generates about one-order-of-magnitude greater contrast than white-light endoscopy, and hence allows for the better discrimination of cancerous lesions, as we show with patients diagnosed with squamous cell carcinoma. Polarimetric imaging of excised and stained slices of laryngeal tissue indicated that changes in the retardance of polarized light can be largely attributed to architectural features of the tissue. We also assessed SPE to aid routine transoral laser surgery for the removal of a cancerous lesion, indicating that SPE can complement white-light endoscopy for the detection of laryngeal cancer.
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Affiliation(s)
- Ji Qi
- Research Center for Humanoid Sensing, Zhejiang Lab, Hangzhou, China.
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences, University College London, London, UK.
- Department of Computer Science, University College London, London, UK.
- Centre For Medical Image Computing, University College London, London, UK.
- Hamlyn Centre for Robotic Surgery, Imperial College London, London, UK.
- Department of Surgery and Cancer, Imperial College London, London, UK.
| | - Taranjit Tatla
- Hamlyn Centre for Robotic Surgery, Imperial College London, London, UK
- Northwick Park Hospital, London North West University Healthcare NHS Trust, London, UK
| | | | - Alan Yilun Yuan
- Department of Electrical and Electronic Engineering, Imperial College London, London, UK
| | - Danail Stoyanov
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences, University College London, London, UK.
- Department of Computer Science, University College London, London, UK.
- Centre For Medical Image Computing, University College London, London, UK.
| | - Daniel S Elson
- Hamlyn Centre for Robotic Surgery, Imperial College London, London, UK.
- Department of Surgery and Cancer, Imperial College London, London, UK.
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Sudakou A, Wabnitz H, Liemert A, Wolf M, Liebert A. Two-layered blood-lipid phantom and method to determine absorption and oxygenation employing changes in moments of DTOFs. BIOMEDICAL OPTICS EXPRESS 2023; 14:3506-3531. [PMID: 37497481 PMCID: PMC10368065 DOI: 10.1364/boe.492168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 05/29/2023] [Accepted: 05/29/2023] [Indexed: 07/28/2023]
Abstract
Near-infrared spectroscopy (NIRS) is an established technique for measuring tissue oxygen saturation (StO2), which is of high clinical value. For tissues that have layered structures, it is challenging but clinically relevant to obtain StO2 of the different layers, e.g. brain and scalp. For this aim, we present a new method of data analysis for time-domain NIRS (TD-NIRS) and a new two-layered blood-lipid phantom. The new analysis method enables accurate determination of even large changes of the absorption coefficient (Δµa) in multiple layers. By adding Δµa to the baseline µa, this method provides absolute µa and hence StO2 in multiple layers. The method utilizes (i) changes in statistical moments of the distributions of times of flight of photons (DTOFs), (ii) an analytical solution of the diffusion equation for an N-layered medium, (iii) and the Levenberg-Marquardt algorithm (LMA) to determine Δµa in multiple layers from the changes in moments. The method is suitable for NIRS tissue oximetry (relying on µa) as well as functional NIRS (fNIRS) applications (relying on Δµa). Experiments were conducted on a new phantom, which enabled us to simulate dynamic StO2 changes in two layers for the first time. Two separate compartments, which mimic superficial and deep layers, hold blood-lipid mixtures that can be deoxygenated (using yeast) and oxygenated (by bubbling oxygen) independently. Simultaneous NIRS measurements can be performed on the two-layered medium (variable superficial layer thickness, L), the deep (homogeneous), and/or the superficial (homogeneous). In two experiments involving ink, we increased the nominal µa in one of two compartments from 0.05 to 0.25 cm-1, L set to 14.5 mm. In three experiments involving blood (L set to 12, 15, or 17 mm), we used a protocol consisting of six deoxygenation cycles. A state-of-the-art multi-wavelength TD-NIRS system measured simultaneously on the two-layered medium, as well as on the deep compartment for a reference. The new method accurately determined µa (and hence StO2) in both compartments. The method is a significant progress in overcoming the contamination from the superficial layer, which is beneficial for NIRS and fNIRS applications, and may improve the determination of StO2 in the brain from measurements on the head. The advanced phantom may assist in the ongoing effort towards more realistic standardized performance tests in NIRS tissue oximetry. Data and MATLAB codes used in this study were made publicly available.
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Affiliation(s)
- Aleh Sudakou
- Nałęcz Institute of Biocybernetics and Biomedical Engineering Polish Academy of Sciences, Warsaw, Poland
| | - Heidrun Wabnitz
- Physikalisch-Technische Bundesanstalt (PTB), Berlin, Germany
| | - André Liemert
- Institut für Lasertechnologien in der Medizin und Meßtechnik an der Universität Ulm, Germany
| | - Martin Wolf
- Department of Neonatology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Adam Liebert
- Nałęcz Institute of Biocybernetics and Biomedical Engineering Polish Academy of Sciences, Warsaw, Poland
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Walter AB, Jansen ED. Development of a platform for broadband, spectra-fitted, tissue optical phantoms. JOURNAL OF BIOMEDICAL OPTICS 2023; 28:025001. [PMID: 36814953 PMCID: PMC9940728 DOI: 10.1117/1.jbo.28.2.025001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 01/24/2023] [Indexed: 06/18/2023]
Abstract
SIGNIFICANCE Current methods of producing optical phantoms are incapable of accurately capturing the wavelength-dependent properties of tissue critical for many optical modalities. AIM We aim to introduce a method of producing solid, inorganic phantoms whose wavelength-dependent optical properties can be matched to those of tissue over the wavelength range of 370 to 950 nm. APPROACH The concentration-dependent optical properties of 20 pigments were characterized and used to determine combinations that result in optimal fits compared to the target properties over the full spectrum. Phantoms matching the optical properties of muscle and nerve, the diffuse reflectance of pale and melanistic skin, and the chromophore concentrations of a computational skin model with varying oxygen saturation ( StO 2 ) were made with this method. RESULTS Both optical property phantoms were found to accurately mimic their respective tissues' absorption and scattering properties across the entire spectrum. The diffuse reflectance phantoms were able to closely approximate skin reflectance regardless of skin type. All three computational skin phantoms were found to have emulated chromophore concentrations close to the model, with an average percent error for the StO 2 of 4.31%. CONCLUSIONS This multipigment phantom platform represents a powerful tool for creating spectrally accurate tissue phantoms, which should increase the availability of standards for many optical techniques.
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Affiliation(s)
- Alec B. Walter
- Vanderbilt University, Department of Biomedical Engineering, Nashville, Tennessee, United States
- Vanderbilt University, Biophotonics Center, Nashville, Tennessee, United States
| | - E. Duco Jansen
- Vanderbilt University, Department of Biomedical Engineering, Nashville, Tennessee, United States
- Vanderbilt University, Biophotonics Center, Nashville, Tennessee, United States
- Vanderbilt University Medical Center, Department of Neurosurgery, Nashville, Tennessee, United States
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Anthropomorphic Polydimethylsiloxane silicone-based phantom for Diffuse Optical Imaging. Heliyon 2022; 8:e10308. [PMID: 36033332 PMCID: PMC9404336 DOI: 10.1016/j.heliyon.2022.e10308] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 07/06/2022] [Accepted: 08/11/2022] [Indexed: 11/24/2022] Open
Abstract
This work presents a method for constructing phantoms suitable for diffuse optical mammography. They are based on Polydimethylsiloxane silicones, with the characteristic of being anthropomorphic, and having similar mechanical and optical properties as a real breast. These phantoms are useful for testing the performance of diffuse optical imaging devices in the near infrared, both in transmittance and reflectance geometries, since they can be constructed containing inclusions, to simulate breast tumors. An alternative component to be used as scattering agent, that is easier to handle than traditional scattering agents, is also studied. The optical properties of the phantoms were tested varying the concentration of scattering and absorbing agents, while their mechanical properties were modified by adding a silicone fluid to the basic mixture. Finally, the phantoms were tested by Diffuse Optical Imaging experiments, and these images were compared to the ones obtained by conventional ultrasound techniques. Results show that the constructed anthropomorphic phantoms properly reproduce the optical and mechanical characteristics of human breasts, and are suitable to be used in Diffuse Optical Imaging. We constructed anthropomorphic phantoms for Diffuse Optical Imaging. They simulate the optical and mechanical characteristics of a human breast. A new scattering agent was successfully introduced. Results of Diffuse Optical images are compared to Ultrasound images.
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Muhammad M, Prakash J, Liapis E, Ntziachristos V, Jüstel D. Weighted model-based optoacoustic reconstruction for partial-view geometries. JOURNAL OF BIOPHOTONICS 2022; 15:e202100334. [PMID: 35133073 DOI: 10.1002/jbio.202100334] [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: 10/29/2021] [Revised: 01/22/2022] [Accepted: 02/07/2022] [Indexed: 06/14/2023]
Abstract
Acoustic heterogeneities in biological samples are known to cause artifacts in tomographic optoacoustic (photoacoustic) image reconstruction. A statistical weighted model-based reconstruction approach was previously introduced to mitigate such artifacts. However, this approach does not reliably provide high-quality reconstructions for partial-view imaging systems, which are common in preclinical and clinical optoacoustics. In this article, the capability of the weighted model-based algorithm is extended to generate optoacoustic reconstructions with less distortions for partial-view geometry data. This is achieved by manipulating the weighting scheme based on the detector geometry. Using partial-view optoacoustic tomography data from a tissue-mimicking phantom containing a strong acoustic reflector, tumors grafted onto mice, and a mouse brain with intact skull, the proposed partial-view-corrected weighted model-based algorithm is shown to mitigate reflection artifacts in reconstructed images without distorting structures or boundaries, compared with both conventional model-based and the weighted model-based algorithms. It is also demonstrated that the partial-view-corrected weighted model-based algorithm has the additional advantage of suppressing streaking artifacts due to the partial-view geometry itself in the presence of a very strong optoacoustic chromophore. Due to its enhanced performance, the partial-view-corrected weighted model-based algorithm may prove useful for improving the quality of partial-view multispectral optoacoustic tomography, leading to enhanced visualization of functional parameters such as tissue oxygenation.
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Affiliation(s)
- Marwan Muhammad
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
- Chair of Biological Imaging at the Center for Translational Cancer Research (TranslaTUM), School of Medicine, Technical University of Munich, Munich, Germany
| | - Jaya Prakash
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
- Chair of Biological Imaging at the Center for Translational Cancer Research (TranslaTUM), School of Medicine, Technical University of Munich, Munich, Germany
| | - Evangelos Liapis
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
- Chair of Biological Imaging at the Center for Translational Cancer Research (TranslaTUM), School of Medicine, Technical University of Munich, Munich, Germany
| | - Vasilis Ntziachristos
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
- Chair of Biological Imaging at the Center for Translational Cancer Research (TranslaTUM), School of Medicine, Technical University of Munich, Munich, Germany
- Munich Institute of Robotics and Machine Intelligence (MIRMI), Technical University of Munich, Munich, Germany
| | - Dominik Jüstel
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
- Chair of Biological Imaging at the Center for Translational Cancer Research (TranslaTUM), School of Medicine, Technical University of Munich, Munich, Germany
- Institute of Computational Biology, Helmholtz Zentrum München, Neuherberg, Germany
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Schädel-Ebner S, Hirsch O, Gladytz T, Gutkelch D, Licha K, Berger J, Grosenick D. 3D-printed tissue-simulating phantoms for near-infrared fluorescence imaging of rheumatoid diseases. JOURNAL OF BIOMEDICAL OPTICS 2022; 27:074702. [PMID: 35711096 PMCID: PMC9201974 DOI: 10.1117/1.jbo.27.7.074702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 05/26/2022] [Indexed: 06/15/2023]
Abstract
SIGNIFICANCE Fluorescence imaging of rheumatoid diseases with indocyanine green (ICG) is an emerging technique with unique potential for diagnosis and therapy. Device characterization, monitoring of the performance, and further developments of the technique require tissue-equivalent fluorescent phantoms of high stability with appropriate anatomical shapes. AIM Our investigations aim at the development of a three-dimensional (3D) printing technique to fabricate hand and finger models with appropriate optical properties in the near-infrared spectral range. These phantoms should have fluorescence properties similar to ICG, and excellent photostability and durability over years. APPROACH We modified a 3D printing methacrylate photopolymer by adding the fluorescent dye Lumogen IR 765 to the raw material. Reduced scattering and absorption coefficients were adjusted to values representative of the human hand by incorporating titanium dioxide powder and black ink. The properties of printed phantoms of various compositions were characterized using UV/Vis and fluorescence spectroscopy, and time-resolved measurements. Photostability and bleaching were investigated with a hand imager. For comparison, several phantoms with ICG as fluorescent dye were printed and characterized as well. RESULTS The spectral properties of Lumogen IR 765 are very similar to those of ICG. By optimizing the concentrations of Lumogen, titanium dioxide, and ink, anatomically shaped hand and vessel models with properties equivalent to in vivo investigations with a fluorescence hand imager could be printed. Phantoms with Lumogen IR 765 had an excellent photostability over up to 4 years. In contrast, phantoms printed with ICG showed significant bleaching and degradation of fluorescence over time. CONCLUSIONS 3D printing of phantoms with Lumogen IR 765 is a promising method for fabricating anatomically shaped fluorescent tissue models of excellent stability with spectral properties similar to ICG. The phantoms are well-suited to monitor the performance of hand imagers. Concepts can easily be transferred to other fluorescence imaging applications of ICG.
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Affiliation(s)
| | - Ole Hirsch
- Hochschule für angewandte Wissenschaft und Kunst Hildesheim/Holzminden/Göttingen (HAWK), Fakultät Ingenieurwissenschaften und Gesundheit, Göttingen, Germany
| | - Thomas Gladytz
- Physikalisch-Technische Bundesanstalt (PTB), Berlin, Germany
- Max-Delbrück-Centrum für Molekulare Medizin in der Helmholtz-Gemeinschaft (MDC), Berlin, Germany
| | - Dirk Gutkelch
- Physikalisch-Technische Bundesanstalt (PTB), Berlin, Germany
| | - Kai Licha
- FEW Chemicals GmbH, Bitterfeld-Wolfen, Germany
| | | | - Dirk Grosenick
- Physikalisch-Technische Bundesanstalt (PTB), Berlin, Germany
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Hacker L, Wabnitz H, Pifferi A, Pfefer TJ, Pogue BW, Bohndiek SE. Criteria for the design of tissue-mimicking phantoms for the standardization of biophotonic instrumentation. Nat Biomed Eng 2022; 6:541-558. [PMID: 35624150 DOI: 10.1038/s41551-022-00890-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2020] [Accepted: 02/07/2022] [Indexed: 01/08/2023]
Abstract
A lack of accepted standards and standardized phantoms suitable for the technical validation of biophotonic instrumentation hinders the reliability and reproducibility of its experimental outputs. In this Perspective, we discuss general criteria for the design of tissue-mimicking biophotonic phantoms, and use these criteria and state-of-the-art developments to critically review the literature on phantom materials and on the fabrication of phantoms. By focusing on representative examples of standardization in diffuse optical imaging and spectroscopy, fluorescence-guided surgery and photoacoustic imaging, we identify unmet needs in the development of phantoms and a set of criteria (leveraging characterization, collaboration, communication and commitment) for the standardization of biophotonic instrumentation.
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Affiliation(s)
- Lina Hacker
- Department of Physics, University of Cambridge, Cambridge, UK.,Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge, UK
| | - Heidrun Wabnitz
- Physikalisch-Technische Bundesanstalt (PTB), Berlin, Germany
| | | | | | - Brian W Pogue
- Thayer School of Engineering, Dartmouth, Hanover, NH, USA
| | - Sarah E Bohndiek
- Department of Physics, University of Cambridge, Cambridge, UK. .,Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge, UK.
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Bachir W, Abo Dargham F. Feasibility of 830 nm laser imaging for vein localization in dark skin tissue-mimicking phantoms. Phys Eng Sci Med 2022; 45:135-142. [PMID: 34982404 DOI: 10.1007/s13246-021-01096-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 12/25/2021] [Indexed: 10/19/2022]
Abstract
Accessing blood vessels by medical professionals has been a challenge in healthcare centers worldwide. The main objective of this work is to investigate the localization of blood vessels in dark skin based on near infrared laser imaging. An 830 nm diode laser was used as a light source to irradiate dark skin mimicking optical phantoms. Phantoms were constructed to simulate dark skin with embedded polymer tubes filled with human blood to mimic subcutaneous veins. Appropriate image processing techniques were also used to enhance the detection and depth resolved differentiation of the vein phantoms. Results show that a linear regression model can represent the relation between the grey level in subcutaneous vein images and the depth of vessels down to 3 mm or deeper (n = 15, R2 = 0.88, P < 0.001). The effect of laser power on the system performance is also discussed. Analysis of the collected images demonstrates the feasibility of 830 nm laser imaging for differentiating vein depths under dark skin surface. The proposed method would enhance the localization of invisible subcutaneous veins. This, in turn, would further improve the success rate of related medical procedures such as blood sampling, drawing, in the dark skin population.
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Affiliation(s)
- Wesam Bachir
- Biomedical Photonics Laboratory, Higher Institute for Laser Research and Applications, Damascus University, Damascus, Syria. .,Faculty of Informatics Engineering, Al-Sham Private University, Damascus, Syria.
| | - Farah Abo Dargham
- Biomedical Photonics Laboratory, Higher Institute for Laser Research and Applications, Damascus University, Damascus, Syria.,Faculty of Informatics Engineering, Aljazeera Private University, Damascus, Syria
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11
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Zaytsev SM, Amouroux M, Khairallah G, Bashkatov AN, Tuchin VV, Blondel W, Genina EA. Impact of optical clearing on ex vivo human skin optical properties characterized by spatially resolved multimodal spectroscopy. JOURNAL OF BIOPHOTONICS 2022; 15:e202100202. [PMID: 34476912 DOI: 10.1002/jbio.202100202] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 08/26/2021] [Accepted: 08/30/2021] [Indexed: 06/13/2023]
Abstract
A spatially resolved multimodal spectroscopic device was used on a two-layered "hybrid" model made of ex vivo skin and fluorescent gel to investigate the effect of skin optical clearing on the depth sensitivity of optical spectroscopy. Time kinetics of fluorescence and diffuse reflectance spectra were acquired in four experimental conditions: with optical clearing agent (OCA) 1 made of polyethylene glycol 400 (PEG-400), propylene glycol and sucrose; with OCA 2 made of PEG-400 and dimethyl sulfoxide (DMSO); with saline solution as control and a "dry" condition. An increase in the gel fluorescence back reflected intensity was measured after optical clearing. Effect of OCA 2 turned out to be stronger than that of OCA 1, possibly due to DMSO impact on the stratum corneum keratin conformation. Complementary experimental results showed increased light transmittance through the skin and confirmed that the improvement in the depth sensitivity of the multimodal spectroscopic approach is related not only to the dehydration and refractive indices matching due to optical clearing, but also to the mechanical compression of tissues caused by the application of the spectroscopic probe.
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Affiliation(s)
- Sergey M Zaytsev
- Université de Lorraine, CNRS, CRAN UMR 7039, Vandoeuvre-lès-Nancy, France
- Saratov State University, Institute of Physics, Department of Optics and Biophotonics, Saratov, Russian Federation
| | - Marine Amouroux
- Université de Lorraine, CNRS, CRAN UMR 7039, Vandoeuvre-lès-Nancy, France
| | - Grégoire Khairallah
- Université de Lorraine, CNRS, CRAN UMR 7039, Vandoeuvre-lès-Nancy, France
- Department of Plastic, Aesthetic and Reconstructive Surgery, Metz-Thionville Regional Hospital, Ars-Laquenexy, France
| | - Alexey N Bashkatov
- Saratov State University, Institute of Physics, Department of Optics and Biophotonics, Saratov, Russian Federation
- National Research Tomsk State University, Interdisciplinary Laboratory of Biophotonics, Tomsk, Russian Federation
| | - Valery V Tuchin
- Saratov State University, Institute of Physics, Department of Optics and Biophotonics, Saratov, Russian Federation
- National Research Tomsk State University, Interdisciplinary Laboratory of Biophotonics, Tomsk, Russian Federation
- Institute of Precision Mechanics and Control RAS, Laboratory of Laser Diagnostics of Technical and Living Systems, Saratov, Russian Federation
| | - Walter Blondel
- Université de Lorraine, CNRS, CRAN UMR 7039, Vandoeuvre-lès-Nancy, France
| | - Elina A Genina
- Saratov State University, Institute of Physics, Department of Optics and Biophotonics, Saratov, Russian Federation
- National Research Tomsk State University, Interdisciplinary Laboratory of Biophotonics, Tomsk, Russian Federation
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12
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Goldfain AM, Lemaillet P, Allen DW, Briggman KA, Hwang J. Polydimethylsiloxane tissue-mimicking phantoms with tunable optical properties. JOURNAL OF BIOMEDICAL OPTICS 2021; 27:JBO-210209SSRR. [PMID: 34796707 PMCID: PMC8601433 DOI: 10.1117/1.jbo.27.7.074706] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 10/25/2021] [Indexed: 05/05/2023]
Abstract
SIGNIFICANCE The polymer, polydimethylsiloxane (PDMS), has been increasingly used to make tissue simulating phantoms due to its excellent processability, durability, flexibility, and limited tunability of optical, mechanical, and thermal properties. We report on a robust technique to fabricate PDMS-based tissue-mimicking phantoms where the broad range of scattering and absorption properties are independently adjustable in the visible- to near-infrared wavelength range from 500 to 850 nm. We also report on an analysis method to concisely quantify the phantoms' broadband characteristics with four parameters. AIM We report on techniques to manufacture and characterize solid tissue-mimicking phantoms of PDMS polymers. Tunability of the absorption (μa ( λ ) ) and reduced scattering coefficient spectra (μs'(λ)) in the wavelength range of 500 to 850 nm is demonstrated by adjusting the concentrations of light absorbing carbon black powder (CBP) and light scattering titanium dioxide powder (TDP) added into the PDMS base material. APPROACH The μa ( λ ) and μs'(λ) of the phantoms were obtained through measurements with a broadband integrating sphere system and by applying an inverse adding doubling algorithm. Analyses of μa ( λ ) and μs'(λ) of the phantoms, by fitting them to linear and power law functions, respectively, demonstrate that independent control of μa ( λ ) and μs'(λ) is possible by systematically varying the concentrations of CBP and TDP. RESULTS Our technique quantifies the phantoms with four simple fitting parameters enabling a concise tabulation of their broadband optical properties as well as comparisons to the optical properties of biological tissues. We demonstrate that, to a limited extent, the scattering properties of our phantoms mimic those of human tissues of various types. A possible way to overcome this limitation is demonstrated with phantoms that incorporate polystyrene microbead scatterers. CONCLUSIONS Our manufacturing and analysis techniques may further promote the application of PDMS-based tissue-mimicking phantoms and may enable robust quality control and quality checks of the phantoms.
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Affiliation(s)
- Aaron M. Goldfain
- National Institute of Standards and Technology, Sensor Science Division, Gaithersburg, Maryland, United States
| | - Paul Lemaillet
- National Institute of Standards and Technology, Sensor Science Division, Gaithersburg, Maryland, United States
| | - David W. Allen
- National Institute of Standards and Technology, Sensor Science Division, Gaithersburg, Maryland, United States
| | - Kimberly A. Briggman
- National Institute of Standards and Technology, Applied Physics Division, Boulder, Colorado, United States
| | - Jeeseong Hwang
- National Institute of Standards and Technology, Applied Physics Division, Boulder, Colorado, United States
- Address all correspondence to Jeeseong Hwang,
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Orfanakis M, Tserevelakis GJ, Zacharakis G. A Cost-Efficient Multiwavelength LED-Based System for Quantitative Photoacoustic Measurements. SENSORS 2021; 21:s21144888. [PMID: 34300627 PMCID: PMC8309896 DOI: 10.3390/s21144888] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 06/30/2021] [Accepted: 07/15/2021] [Indexed: 01/13/2023]
Abstract
The unique ability of photoacoustic (PA) sensing to provide optical absorption information of biomolecules deep inside turbid tissues with high sensitivity has recently enabled the development of various novel diagnostic systems for biomedical applications. In many cases, PA setups can be bulky, complex, and costly, as they typically require the integration of expensive Q-switched nanosecond lasers, and also presents limited wavelength availability. This article presents a compact, cost-efficient, multiwavelength PA sensing system for quantitative measurements, by utilizing two high-power LED sources emitting at central wavelengths of 444 and 628 nm, respectively, and a single-element ultrasonic transducer at 3.5 MHz for signal detection. We investigate the performance of LEDs in pulsed mode and explore the dependence of PA responses on absorber's concentration and applied energy fluence using tissue-mimicking phantoms demonstrating both optical absorption and scattering properties. Finally, we apply the developed system on the spectral unmixing of two absorbers contained at various relative concentrations in the phantoms, to provide accurate estimations with absolute deviations ranging between 0.4 and 12.3%. An upgraded version of the PA system may provide valuable in-vivo multiparametric measurements of important biomarkers, such as hemoglobin oxygenation, melanin concentration, local lipid content, and glucose levels.
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Affiliation(s)
- Michalis Orfanakis
- Foundation for Research and Technology Hellas, Institute of Electronic Structure and Laser, N. Plastira 100, GR-70013 Heraklion, Greece; (M.O.); (G.J.T.)
- School of Medicine, University of Crete, GR-71003 Heraklion, Greece
| | - George J. Tserevelakis
- Foundation for Research and Technology Hellas, Institute of Electronic Structure and Laser, N. Plastira 100, GR-70013 Heraklion, Greece; (M.O.); (G.J.T.)
| | - Giannis Zacharakis
- Foundation for Research and Technology Hellas, Institute of Electronic Structure and Laser, N. Plastira 100, GR-70013 Heraklion, Greece; (M.O.); (G.J.T.)
- Correspondence:
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Sahlstrom T, Pulkkinen A, Leskinen J, Tarvainen T. Computationally Efficient Forward Operator for Photoacoustic Tomography Based on Coordinate Transformations. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2021; 68:2172-2182. [PMID: 33600313 DOI: 10.1109/tuffc.2021.3060175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Photoacoustic tomography (PAT) is an imaging modality that utilizes the photoacoustic effect. In PAT, a photoacoustic image is computed from measured data by modeling ultrasound propagation in the imaged domain and solving an inverse problem utilizing a discrete forward operator. However, in realistic measurement geometries with several ultrasound transducers and relatively large imaging volume, an explicit formation and use of the forward operator can be computationally prohibitively expensive. In this work, we propose a transformation-based approach for efficient modeling of photoacoustic signals and reconstruction of photoacoustic images. In the approach, the forward operator is constructed for a reference ultrasound transducer and expanded into a general measurement geometry using transformations that map the formulated forward operator in local coordinates to the global coordinates of the measurement geometry. The inverse problem is solved using a Bayesian framework. The approach is evaluated with numerical simulations and experimental data. The results show that the proposed approach produces accurate 3-D photoacoustic images with a significantly reduced computational cost both in memory requirements and time. In the studied cases, depending on the computational factors, such as discretization, over the 30-fold reduction in memory consumption was achieved without a reduction in image quality compared to a conventional approach.
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Piao D, Sun T. Diffuse photon remission from thick opaque media of the high absorption/scattering ratio beyond what is accountable by the Kubelka-Munk function. OPTICS LETTERS 2021; 46:1225-1228. [PMID: 33720153 DOI: 10.1364/ol.415650] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 02/07/2021] [Indexed: 06/12/2023]
Abstract
The Kubelka-Munk (KM) theory of diffuse photon remission from opaque media is widely applied to quality-control processes. Recent works based on radiative transfer revealed that the KM function as the backbone parameter of the method may saturate at strong absorption to cause the KM approach to be unfit to predict the change of diffuse reflectance from the medium at strong absorption. We demonstrate by empirical means based on Monte Carlo results that diffuse photon remission from a strong-absorbing medium depends simply upon the absorption/scattering ratio when evaluated over a large area centered at the point of illumination differing in geometry from those convenient for the KM approach. Our empirical prediction gives ∼11% mean errors of the diffuse photon remission from thick opaque medium having an absorption coefficient ranging 0.001 to up to 1000 times stronger than the reduced-scattering coefficient. A slight modification to the KM function in terms of the absorption weighting and absorption-scattering coupling for use within the KM approach also noticeably improves the prediction of diffuse photon remission from thick opaque medium of strong absorption. Our empirical model and the KM approach using the modified KM function were compared against measurements from a thick opaque medium, of which the absorption coefficient was changed over four orders of magnitude.
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Chandramoorthi S, Thittai AK. Extending Imaging Depth in PLD-Based Photoacoustic Imaging: Moving Beyond Averaging. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2021; 68:549-557. [PMID: 32784132 DOI: 10.1109/tuffc.2020.3015130] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Pulsed laser diodes (PLDs) promise to be an attractive alternative to solid-state laser sources in photoacoustic tomography (PAT) due to their portability, high-pulse repetition frequency (PRF), and cost effectiveness. However, due to their lower energy per pulse, which, in turn, results in lower fluence required per photoacoustic signal generation, PLD-based photoacoustic systems generally have maximum imaging depth that is lower in comparison to solid-state lasers. Averaging of multiple frames is usually employed as a common practice in high PRF PLD systems to improve the signal-to-noise ratio of the PAT images. In this work, we demonstrate that by combining the recently described approach of subpitch translation on the receive-side ultrasound transducer alongside averaging of multiple frames, it is feasible to increase the depth sensitivity in a PLD-based PAT imaging system. Here, experiments on phantom containing diluted India ink targets were performed at two different laser energy level settings, that is, 21 and [Formula: see text]. Results obtained showed that the imaging depth improves by ~38.5% from 9.1 to 12.6 mm for 21- [Formula: see text] energy level setting and by ~33.3% from 10.8 to 14.4 mm for 27- [Formula: see text] energy level setting by using λ /4-pitch translation and average of 128 frames in comparison to λ -pitch data acquired with the average of 128 frames. However, the achievable frame rate is reduced by a factor of 2 and 4 for λ /2 and λ /4 subpitch translation, respectively.
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Blaney G, Donaldson R, Mushtak S, Nguyen H, Vignale L, Fernandez C, Pham T, Sassaroli A, Fantini S. Dual-Slope Diffuse Reflectance Instrument for Calibration-Free Broadband Spectroscopy. APPLIED SCIENCES (BASEL, SWITZERLAND) 2021; 11. [PMID: 35719895 PMCID: PMC9204805 DOI: 10.3390/app11041757] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
This work presents the design and validation of an instrument for dual-slope broadband diffuse reflectance spectroscopy. This instrument affords calibration-free, continuous-wave measurements of broadband absorbance of optically diffusive media, which may be translated into absolute absorption spectra by adding frequency-domain measurements of scattering at two wavelengths. An experiment on a strongly scattering liquid phantom (milk, water, dyes) confirms the instrument’s ability to correctly identify spectral features and measure absolute absorption. This is done by sequentially adding three dyes, each featuring a distinct spectral absorption, to the milk/water phantom. After each dye addition, the absorption spectrum is measured, and it is found to reproduce the spectral features of the added dye. Additionally, the absorption spectrum is compared to the absorption values measured with a commercial frequency-domain instrument at two wavelengths. The measured absorption of the milk/water phantom quantitatively agrees with the known water absorption spectrum (R2 = 0.98), and the measured absorption of the milk/water/dyes phantom quantitatively agrees with the absorption measured with the frequency-domain instrument in six of eight cases. Additionally, the measured absorption spectrum correctly recovers the concentration of one dye, black India ink, for which we could accurately determine the extinction spectrum (i.e., the specific absorption per unit concentration). The instrumental methods presented in this work can find applications in quantitative spectroscopy of optically diffusive media, and particularly in near-infrared spectroscopy of biological tissue.
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Lascaud J, Dash P, Würl M, Wieser HP, Wollant B, Kalunga R, Assmann W, Clevert DA, Ferrari A, Sala P, Savoia AS, Parodi K. Enhancement of the ionoacoustic effect through ultrasound and photoacoustic contrast agents. Sci Rep 2021; 11:2725. [PMID: 33526802 PMCID: PMC7851171 DOI: 10.1038/s41598-021-81964-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 01/12/2021] [Indexed: 11/09/2022] Open
Abstract
The characteristic depth dose deposition of ion beams, with a maximum at the end of their range (Bragg peak) allows for local treatment delivery, resulting in better sparing of the adjacent healthy tissues compared to other forms of external beam radiotherapy treatments. However, the optimal clinical exploitation of the favorable ion beam ballistic is hampered by uncertainties in the in vivo Bragg peak position. Ionoacoustics is based on the detection of thermoacoustic pressure waves induced by a properly pulsed ion beam (e.g., produced by modern compact accelerators) to image the irradiated volume. Co-registration between ionoacoustics and ultrasound imaging offers a promising opportunity to monitor the ion beam and patient anatomy during the treatment. Nevertheless, the detection of the ionoacoustic waves is challenging due to very low pressure amplitudes and frequencies (mPa/kHz) observed in clinical applications. We investigate contrast agents to enhance the acoustic emission. Ultrasound microbubbles are used to increase the ionoacoustic frequency around the microbubble resonance frequency. Moreover, India ink is investigated as a possible mean to enhance the signal amplitude by taking advantage of additional optical photon absorption along the ion beam and subsequent photoacoustic effect. We report amplitude increase of up to 200% of the ionoacoustic signal emission in the MHz frequency range by combining microbubbles and India ink contrast agents.
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Affiliation(s)
- Julie Lascaud
- Department for Medical Physics, Ludwig-Maximilians-Universität München (LMU Munich), 85748, Garching b. München, Germany.
| | - Pratik Dash
- Department for Medical Physics, Ludwig-Maximilians-Universität München (LMU Munich), 85748, Garching b. München, Germany
| | - Matthias Würl
- Department for Medical Physics, Ludwig-Maximilians-Universität München (LMU Munich), 85748, Garching b. München, Germany
| | - Hans-Peter Wieser
- Department for Medical Physics, Ludwig-Maximilians-Universität München (LMU Munich), 85748, Garching b. München, Germany
| | - Benjamin Wollant
- Department for Medical Physics, Ludwig-Maximilians-Universität München (LMU Munich), 85748, Garching b. München, Germany
| | - Ronaldo Kalunga
- Department for Medical Physics, Ludwig-Maximilians-Universität München (LMU Munich), 85748, Garching b. München, Germany
| | - Walter Assmann
- Department for Medical Physics, Ludwig-Maximilians-Universität München (LMU Munich), 85748, Garching b. München, Germany
| | - Dirk-André Clevert
- Interdisciplinary Ultrasound-Center, Department of Radiology, University of Munich-Grosshadern Campus, Munich, Germany
| | - Alfredo Ferrari
- Universitätsklinikum, Heidelberg, Germany
- Gangneu-Wonju National University, Gangneung, Wonju, South Korea
| | - Paola Sala
- Italian National Institute for Nuclear Physics (INFN), 20133, Milan, Italy
| | | | - Katia Parodi
- Department for Medical Physics, Ludwig-Maximilians-Universität München (LMU Munich), 85748, Garching b. München, Germany.
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Yang L, Wabnitz H, Gladytz T, Sudakou A, Macdonald R, Grosenick D. Space-enhanced time-domain diffuse optics for determination of tissue optical properties in two-layered structures. BIOMEDICAL OPTICS EXPRESS 2020; 11:6570-6589. [PMID: 33282509 PMCID: PMC7687957 DOI: 10.1364/boe.402181] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 09/18/2020] [Accepted: 09/28/2020] [Indexed: 05/05/2023]
Abstract
A novel methodology for solving the inverse problem of diffuse optics for two-layered structures is proposed to retrieve the absolute quantities of optical absorption and reduced scattering coefficients of the layers simultaneously. A liquid phantom with various optical absorption properties in the deep layer is prepared and experimentally investigated using the space-enhanced time-domain method. Monte-Carlo simulations are applied to analyze the different measurements in time domain, space domain, and by the new methodology. The deviations of retrieved values from nominal values of both layers' optical properties are simultaneously reduced to a very low extent compared to the single-domain methods. The reliability and uncertainty of the retrieval performance are also considerably improved by the new methodology. It is observed in time-domain analyses that for the deep layer the retrieval of absorption coefficient is almost not affected by the scattering properties and this kind of "deep scattering neutrality" is investigated and overcome as well.
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Affiliation(s)
- Lin Yang
- Physikalisch-Technische Bundesanstalt (PTB), Abbestr. 2-12, 10587 Berlin, Germany
- Institute of Optics and Atomic Physics, Technical University of Berlin, Strasse des 17. Juni 135, 10623 Berlin, Germany
| | - Heidrun Wabnitz
- Physikalisch-Technische Bundesanstalt (PTB), Abbestr. 2-12, 10587 Berlin, Germany
| | - Thomas Gladytz
- Physikalisch-Technische Bundesanstalt (PTB), Abbestr. 2-12, 10587 Berlin, Germany
| | - Aleh Sudakou
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Trojdena 4, 02-109 Warsaw, Poland
| | - Rainer Macdonald
- Physikalisch-Technische Bundesanstalt (PTB), Abbestr. 2-12, 10587 Berlin, Germany
- Institute of Optics and Atomic Physics, Technical University of Berlin, Strasse des 17. Juni 135, 10623 Berlin, Germany
| | - Dirk Grosenick
- Physikalisch-Technische Bundesanstalt (PTB), Abbestr. 2-12, 10587 Berlin, Germany
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Belcastro L, Jonasson H, Strömberg T, Saager RB. Handheld multispectral imager for quantitative skin assessment in low-resource settings. JOURNAL OF BIOMEDICAL OPTICS 2020; 25:1-12. [PMID: 32755076 PMCID: PMC7399474 DOI: 10.1117/1.jbo.25.8.082702] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Accepted: 07/06/2020] [Indexed: 05/28/2023]
Abstract
SIGNIFICANCE Spatial frequency domain imaging (SFDI) is a quantitative imaging method to measure absorption and scattering of tissue, from which several chromophore concentrations (e.g., oxy-/deoxy-/meth-hemoglobin, melanin, and carotenoids) can be calculated. Employing a method to extract additional spectral bands from RGB components (that we named cross-channels), we designed a handheld SFDI device to account for these pigments, using low-cost, consumer-grade components for its implementation and characterization. AIM With only three broad spectral bands (red, green, blue, or RGB), consumer-grade devices are often too limited. We present a methodology to increase the number of spectral bands in SFDI devices that use RGB components without hardware modification. APPROACH We developed a compact low-cost RGB spectral imager using a color CMOS camera and LED-based mini projector. The components' spectral properties were characterized and additional cross-channel bands were calculated. An alternative characterization procedure was also developed that makes use of low-cost equipment, and its results were compared. The device performance was evaluated by measurements on tissue-simulating optical phantoms and in-vivo tissue. The measurements were compared with another quantitative spectroscopy method: spatial frequency domain spectroscopy (SFDS). RESULTS Out of six possible cross-channel bands, two were evaluated to be suitable for our application and were fully characterized (520 ± 20 nm; 556 ± 18 nm). The other four cross-channels presented a too low signal-to-noise ratio for this implementation. In estimating the optical properties of optical phantoms, the SFDI data have a strong linear correlation with the SFDS data (R2 = 0.987, RMSE = 0.006 for μa, R2 = 0.994, RMSE = 0.078 for μs'). CONCLUSIONS We extracted two additional spectral bands from a commercial RGB system at no cost. There was good agreement between our device and the research-grade SFDS system. The alternative characterization procedure we have presented allowed us to measure the spectral features of the system with an accuracy comparable to standard laboratory equipment.
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Affiliation(s)
- Luigi Belcastro
- Linköping University, Department of Biomedical Engineering, Linköping, Sweden
| | - Hanna Jonasson
- Linköping University, Department of Biomedical Engineering, Linköping, Sweden
| | - Tomas Strömberg
- Linköping University, Department of Biomedical Engineering, Linköping, Sweden
| | - Rolf B. Saager
- Linköping University, Department of Biomedical Engineering, Linköping, Sweden
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Nomoni M, May JM, Kyriacou PA. Novel Polydimethylsiloxane (PDMS) Pulsatile Vascular Tissue Phantoms for the In-Vitro Investigation of Light Tissue Interaction in Photoplethysmography. SENSORS (BASEL, SWITZERLAND) 2020; 20:E4246. [PMID: 32751541 PMCID: PMC7435705 DOI: 10.3390/s20154246] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 07/27/2020] [Accepted: 07/28/2020] [Indexed: 11/22/2022]
Abstract
Currently there exists little knowledge or work in phantoms for the in-vitro evaluation of photoplethysmography (PPG), and its' relationship with vascular mechanics. Such phantoms are needed to provide robust, basic scientific knowledge, which will underpin the current efforts in developing new PPG technologies for measuring or estimating blood pressure, blood flow and arterial stiffness, to name but a few. This work describes the design, fabrication and evaluation of finger tissue-simulating pulsatile phantoms with integrated custom vessels. A novel technique has been developed to produce custom polydimethylsiloxane (PDMS) vessels by a continuous dip-coating process. This process can accommodate the production of different sized vessel diameters (1400-2500 µm) and wall thicknesses (56-80 µm). These vessels were embedded into a mould with a solution of PDMS and India ink surrounding them. A pulsatile pump experimental rig was set up to test the phantoms, where flow rate (1-12 L·min-1), heart rate (40-120 bpm), and total resistance (0-100% resistance clamps) could be controlled on demand. The resulting flow profiles approximates human blood flow, and the detected contact PPG signal (red and infrared) from the phantom closely resembles the morphology of in-vivo PPG waveforms with signal-to-noise ratios of 38.16 and 40.59 dB, for the red and infrared wavelengths, respectively. The progress made by this phantom development will help in obtaining new knowledge in the behaviour of PPG's under differing flow conditions, optical tissue properties and differing vessel stiffness.
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Affiliation(s)
- Michelle Nomoni
- Research Centre for Biomedical Engineering, City, University of London, London EC1V 0HB, UK; (J.M.M.); (P.A.K.)
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Fujii H, Tsang L, Zhu J, Nomura K, Kobayashi K, Watanabe M. Photon transport model for dense polydisperse colloidal suspensions using the radiative transfer equation combined with the dependent scattering theory. OPTICS EXPRESS 2020; 28:22962-22977. [PMID: 32752548 DOI: 10.1364/oe.398582] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 07/10/2020] [Indexed: 06/11/2023]
Abstract
In near-infrared imaging and spectroscopy, high-fidelity modeling of photon transport for dense polydisperse colloidal suspensions is crucial. We developed photon transport models using the radiative transfer equation (RTE) with the dependent scattering theory (DST) at volume fractions up to 20%. The polydispersity and interference effects strongly influence results of the scattering properties and the RTE in cases of small mean diameter and large variance of the particle size distribution. We compared the RTE-results for the Henyey-Greenstein (conventional) function with those for the phase function using the DST. The RTE-results differ between both functions at low volume fractions for forward scattering media, suggesting the limitation of the conventional function.
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Han CM, Waks E, Shapiro B. Mathematical modeling and experimental validation for expression microdissection. APPLIED OPTICS 2020; 59:5870-5880. [PMID: 32672729 DOI: 10.1364/ao.395864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 06/02/2020] [Indexed: 06/11/2023]
Abstract
Using laser excitation, expression microdissection (xMD) can selectively heat cancer cells targeted via immunohistochemical staining to enable their selective retrieval from tumor tissue samples, thus reducing misdiagnoses caused by contamination of noncancerous cells. Several theoretical models have been validated for the photothermal effect in highly light absorbing and scattering media. However, these models are not generally applicable to the physics behind the process of xMD. In this study, we propose a thermal model that can analyze the transient temperature distribution and heat melt zone in an xMD sample medium composed of a thermoplastic film and a tumor tissue sample sandwiched between two glass slides. Furthermore, we experimentally examined the model using an ink layer with controllable optical properties to serve as a microscale-thin, tissue-mimicking phantom and found the experimentally measured film temperature is in good agreement with the model predictions. The validated model can help researchers to optimize cell retrieval by xMD for improved diagnostics of cancer and other diseases.
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Chamberlain S, Bellnier D, Yendamuri S, Lindenmann J, Demmy T, Nwogu C, Ramer M, Tworek L, Oakley E, Mallory M, Carlsen L, Sexton S, Curtin L, Shafirstein G. An Optical Surface Applicator for Intraoperative Photodynamic Therapy. Lasers Surg Med 2020; 52:523-529. [PMID: 31587314 PMCID: PMC7131890 DOI: 10.1002/lsm.23168] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/20/2019] [Indexed: 02/06/2023]
Abstract
BACKGROUND AND OBJECTIVES Intraoperative photodynamic therapy (IO-PDT) is typically administered by a handheld light source. This can result in uncontrolled distribution of light irradiance that impacts tissue and tumor response to photodynamic therapy. The objective of this work was to characterize a novel optical surface applicator (OSA) designed to administer controlled light irradiance in IO-PDT. STUDY DESIGN/MATERIALS AND METHODS An OSA was constructed from a flexible silicone mesh applicator with multiple cylindrically diffusing optical fibers (CDF) placed into channels of the silicone. Light irradiance distribution, at 665 nm, was evaluated on the OSA surface and after passage through solid tissue-mimicking optical phantoms by measurements from a multi-channel dosimetry system. As a proof of concept, the light administration of the OSA was tested in a pilot study by conducting a feasibility and performance test with 665-nm laser light to activate 2-(1'-hexyloxyethyl) pyropheophorbide-a (HPPH) in the thoracic cavity of adult swine. RESULTS At the OSA surface, the irradiance distribution was non-uniform, ranging from 128 to 346 mW/cm2 . However, in the tissue-mimicking phantoms, beam uniformity improved markedly, with irradiance ranges of 39-153, 33-87, and 12-28 mW/cm2 measured at phantom thicknesses of 3, 5, and 10 mm, respectively. The OSA safely delivered the prescribed light dose to the thoracic cavities of four swine. CONCLUSIONS The OSA can provide predictable light irradiances for administering a well-defined and potentially effective therapeutic light in IO-PDT. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.
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Affiliation(s)
- Sarah Chamberlain
- Photodynamic Therapy Center, Department of Cell Stress Biology, Roswell Park Comprehensive Cancer Center (Roswell Park), Buffalo, New York
| | - David Bellnier
- Photodynamic Therapy Center, Department of Cell Stress Biology, Roswell Park Comprehensive Cancer Center (Roswell Park), Buffalo, New York
| | - Sai Yendamuri
- Department of Thoracic Surgery, Roswell Park, Buffalo, New York
| | - Joerg Lindenmann
- Division of Thoracic and Hyperbaric Surgery, Medical University Graz, Austria
| | - Todd Demmy
- Department of Thoracic Surgery, Roswell Park, Buffalo, New York
| | | | - Max Ramer
- Photodynamic Therapy Center, Department of Cell Stress Biology, Roswell Park Comprehensive Cancer Center (Roswell Park), Buffalo, New York
| | - Larry Tworek
- Photodynamic Therapy Center, Department of Cell Stress Biology, Roswell Park Comprehensive Cancer Center (Roswell Park), Buffalo, New York
| | - Emily Oakley
- Photodynamic Therapy Center, Department of Cell Stress Biology, Roswell Park Comprehensive Cancer Center (Roswell Park), Buffalo, New York
| | - Matthew Mallory
- Photodynamic Therapy Center, Department of Cell Stress Biology, Roswell Park Comprehensive Cancer Center (Roswell Park), Buffalo, New York
| | - Lindsey Carlsen
- Photodynamic Therapy Center, Department of Cell Stress Biology, Roswell Park Comprehensive Cancer Center (Roswell Park), Buffalo, New York
| | - Sandra Sexton
- Laboratory Animal Shared Resource, Roswell Park, Buffalo, New York
| | - Leslie Curtin
- Laboratory Animal Shared Resource, Roswell Park, Buffalo, New York
| | - Gal Shafirstein
- Photodynamic Therapy Center, Department of Cell Stress Biology, Roswell Park Comprehensive Cancer Center (Roswell Park), Buffalo, New York
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Naglič P, Zelinskyi Y, Rogelj L, Stergar J, Milanič M, Novak J, Kumperščak B, Bürmen M. Optical properties of PlatSil SiliGlass tissue-mimicking phantoms. BIOMEDICAL OPTICS EXPRESS 2020; 11:3753-3768. [PMID: 33014564 PMCID: PMC7510920 DOI: 10.1364/boe.391720] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 05/08/2020] [Accepted: 06/05/2020] [Indexed: 06/11/2023]
Abstract
In this work, we revise the preparation procedure and conduct an in depth characterization of optical properties for the recently proposed silicone-based tissue-mimicking optical phantoms in the spectral range from 475 to 925 nm. The optical properties are characterized in terms of refractive index and its temperature dependence, absorption and reduced scattering coefficients and scattering phase function related quantifiers. The scattering phase function and related quantifiers of the optical phantoms are first assessed within the framework of the Mie theory by using the measured refractive index of SiliGlass and size distribution of the hollow silica spherical particles that serve as scatterers. A set of purely absorbing optical phantoms in cuvettes is used to evaluate the linearity of the absorption coefficient with respect to the concentration of black pigment that serves as the absorber. Finally, the optical properties in terms of the absorption and reduced scattering coefficients and the subdiffusive scattering phase function quantifier γ are estimated for a subset of phantoms from spatially resolved reflectance using deep learning aided inverse models. To this end, an optical fiber probe with six linearly arranged optical fibers is used to collect the backscattered light at small and large distances from the source fiber. The underlying light propagation modeling is based on the stochastic Monte Carlo method that accounts for all the details of the optical fiber probe.
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Affiliation(s)
- Peter Naglič
- University of Ljubljana, Faculty of Electrical Engineering, Tržaška cesta 25, 1000 Ljubljana, Slovenia
| | - Yevhen Zelinskyi
- University of Ljubljana, Faculty of Electrical Engineering, Tržaška cesta 25, 1000 Ljubljana, Slovenia
| | - Luka Rogelj
- University of Ljubljana, Faculty of Mathematics and Physics, Jadranska ulica 19, 1000 Ljubljana, Slovenia
| | - Jošt Stergar
- University of Ljubljana, Faculty of Mathematics and Physics, Jadranska ulica 19, 1000 Ljubljana, Slovenia
| | - Matija Milanič
- University of Ljubljana, Faculty of Mathematics and Physics, Jadranska ulica 19, 1000 Ljubljana, Slovenia
- Jozef Stefan Institute, Jamova cesta 39, 1000 Ljubljana, Slovenia
| | - Jure Novak
- Dia-Vit d.o.o., Litijska cesta 186e, 1000 Ljubljana, Slovenia
| | | | - Miran Bürmen
- University of Ljubljana, Faculty of Electrical Engineering, Tržaška cesta 25, 1000 Ljubljana, Slovenia
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Lu H, Floris F, Rensing M, Andersson-Engels S. Fluorescence Spectroscopy Study of Protoporphyrin IX in Optical Tissue Simulating Liquid Phantoms. MATERIALS (BASEL, SWITZERLAND) 2020; 13:E2105. [PMID: 32370118 PMCID: PMC7254220 DOI: 10.3390/ma13092105] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 04/27/2020] [Accepted: 04/28/2020] [Indexed: 11/16/2022]
Abstract
Fluorescence spectroscopy has been extensively investigated for disease diagnosis. In this framework, optical tissue phantoms are widely used for validating the biomedical device system in a laboratory environment outside of clinical procedures. Moreover, it is fundamental to consider that there are several scattering components and chromophores inside biological tissues and the interplay between scattering and absorption may result in a distortion of the emitted fluorescent signal. In this work, the photophysical behaviour of a set of liquid, tissue-like phantoms containing different compositions was analysed: phosphate buffer saline (PBS) was used as the background medium, low fat milk as a scatterer, Indian ink as an absorber and protoporphyrin IX (PpIX) dissolved in dimethyl formamide (DMF) as a fluorophore. We examined the collected data in terms of the impact of surfactant Tween-20 on the background medium, scattering effects and combination of scattering and absorption within a luminescent body on PpIX. The results indicated that the intrinsic emission peaks are red shifted by the scattering particles or surfactant, whilst the scattering agent and the absorbent can alter the emission intensity substantially. We corroborated that phantoms containing higher surfactant content (>0.5% Tween 20) are essential to prepare stable aqueous phantoms.
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Affiliation(s)
- Huihui Lu
- Biophotonics @ Tyndall, IPIC, Tyndall National Institute, University College Cork, T12 R5CP Cork, Ireland;
| | - Francesco Floris
- Photonics Packaging Group, IPIC, Tyndall National Institute, University College Cork, T12 R5CP Cork, Ireland; (F.F.); (M.R.)
| | - Marc Rensing
- Photonics Packaging Group, IPIC, Tyndall National Institute, University College Cork, T12 R5CP Cork, Ireland; (F.F.); (M.R.)
| | - Stefan Andersson-Engels
- Biophotonics @ Tyndall, IPIC, Tyndall National Institute, University College Cork, T12 R5CP Cork, Ireland;
- Department of Physics, University College Cork, T12 K8AF Cork, Ireland
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27
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Ioussoufovitch S, Morrison LB, Desjardins L, Hadway JA, Lawrence KS, Lee TY, Beier F, Diop M. Quantification of joint blood flow by dynamic contrast-enhanced near-infrared spectroscopy: application to monitoring disease activity in a rat model of rheumatoid arthritis. JOURNAL OF BIOMEDICAL OPTICS 2020; 25:1-10. [PMID: 31939225 PMCID: PMC6983648 DOI: 10.1117/1.jbo.25.1.015003] [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: 05/08/2019] [Accepted: 12/06/2019] [Indexed: 05/11/2023]
Abstract
Significance Current guidelines for rheumatoid arthritis (RA) management recommend early treatment with disease modifying antirheumatic drugs (DMARDs). However, DMARD treatment fails in 30% of patients and current monitoring methods can only detect failure after 3 to 6 months of therapy. Aim We investigated whether joint blood flow (BF), quantified using dynamic contrast-enhanced time-resolved near-infrared spectroscopy, can monitor disease activity and treatment response in a rat model of RA. Approach Ankle joint BF was measured every 5 days in eight rats with adjuvant-induced arthritis (AIA) and four healthy controls. Arthritis was allowed to progress for 20 days before rats with AIA were treated with a DMARD once every 5 days until day 40. Results Time and group had separate significant main effects on joint BF; however, there was no significant interaction between time and group despite a notable difference in average joint BF on day 5. Comparison of individual blood flow measures between rats with AIA and control group animals did not reveal a clear response to treatment. Conclusions Joint BF time courses could not distinguish between rats with AIA and study controls. Heterogeneous disease response and low temporal frequency of BF measurements may have been important study limitations.
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Affiliation(s)
- Seva Ioussoufovitch
- Western University, Bone and Joint Institute, School of Biomedical Engineering, Faculty of Engineering, London, Ontario, Canada
| | - Laura B. Morrison
- Lawson Health Research Institute, Imaging Program, London, Ontario, Canada
| | - Lise Desjardins
- Lawson Health Research Institute, Imaging Program, London, Ontario, Canada
| | - Jennifer A. Hadway
- Lawson Health Research Institute, Imaging Program, London, Ontario, Canada
| | - Keith St. Lawrence
- Lawson Health Research Institute, Imaging Program, London, Ontario, Canada
- Western University, Schulich School of Medicine and Dentistry, Department of Medical Biophysics, London, Ontario, Canada
| | - Ting-Yim Lee
- Lawson Health Research Institute, Imaging Program, London, Ontario, Canada
- Western University, Schulich School of Medicine and Dentistry, Department of Medical Biophysics, London, Ontario, Canada
- Robarts Research Institute, Imaging Program, London, Ontario, Canada
| | - Frank Beier
- Western University, Schulich School of Medicine and Dentistry, Department of Physiology and Pharmacology, London, Ontario, Canada
| | - Mamadou Diop
- Western University, Bone and Joint Institute, School of Biomedical Engineering, Faculty of Engineering, London, Ontario, Canada
- Lawson Health Research Institute, Imaging Program, London, Ontario, Canada
- Western University, Schulich School of Medicine and Dentistry, Department of Medical Biophysics, London, Ontario, Canada
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28
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Cherkashin MN, Brenner C, Hofmann MR. High-resolution 3D light fluence mapping for heterogeneous scattering media by localized sampling. APPLIED OPTICS 2018; 57:10441-10448. [PMID: 30645387 DOI: 10.1364/ao.57.010441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 11/13/2018] [Indexed: 06/09/2023]
Abstract
We demonstrate an innovative concept for three-dimensional optical fluence mapping in heterogeneous highly scattering media as, e.g., biomedical tissues. We propose to use the relative light extinction analysis principle together with a miniaturized collection fiber in a direct fluence measurement setup as a method to obtain the spatially resolved light intensity distribution under transversally inhomogeneous light propagation conditions and provide local characterization of the transport medium. System performance is validated in two extreme conditions: an optically thin scattering medium and an absorption-dominated light transport. Both extremes demonstrate good agreement to theoretical expectations. Finally, we successfully prove the ability of the system to deliver high-resolution fluence maps through a model study of the light distribution induced in a scattering medium by a vertical diode laser stack with individual bars pitched only 500 μm apart.
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APPLICATION OF DEVICES FOR SPACE-RESOLVED SPECTROSCOPY ON THE EXAMPLE OF TWO-LAYER PHANTOMS CONTAINING METALLIC NANOPARTICLES. BIOMEDICAL PHOTONICS 2018. [DOI: 10.24931/2413-9432-2018-7-2-4-12] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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30
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Miao Y, Koomson VJ. A CMOS-Based Bidirectional Brain Machine Interface System With Integrated fdNIRS and tDCS for Closed-Loop Brain Stimulation. IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS 2018; 12:554-563. [PMID: 29877819 DOI: 10.1109/tbcas.2018.2798924] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
A CMOS-based bidirectional brain machine interface system with on-chip frequency-domain near infrared spectroscopy (fdNIRS) and transcranial direct-current stimulation (tDCS) is designed to enable noninvasive closed-loop brain stimulation for neural disorders treatment and cognitive performance enhancement. The dual channel fdNIRS can continuously monitor absolute cerebral oxygenation during the entire tDCS process by measuring NIR light's attenuation and phase shift across brain tissue. Each fdNIRS channel provides 120 dBΩ transimpedance gain at 80 MHz with a power consumption of 30 mW while tolerating up to 8 pF input capacitance. A photocurrent between 10 and 450 nA can be detected with a phase resolution down to 0.2°. A lensless system with subnanowatt sensitivity is realized by using an avalanche photodiode. The on-chip programmable voltage-controlled resistor stimulator can support a stimulation current from 0.6 to 2.2 mA with less than 1% variation, which covers the required current range of tDCS. The chip is fabricated in a standard 130-nm CMOS process and occupies an area of 2.25 mm2.
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31
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Larsson J, Liao P, Lundin P, Krite Svanberg E, Swartling J, Lewander Xu M, Bood J, Andersson-Engels S. Development of a 3-dimensional tissue lung phantom of a preterm infant for optical measurements of oxygen-Laser-detector position considerations. JOURNAL OF BIOPHOTONICS 2018; 11:e201700097. [PMID: 28816029 DOI: 10.1002/jbio.201700097] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 08/11/2017] [Accepted: 08/11/2017] [Indexed: 05/24/2023]
Abstract
There is a need to further improve the clinical care of our most vulnerable patients-preterm infants. Novel diagnostic and treatment tools facilitate such advances. Here, we evaluate a potential percutaneous optical monitoring tool to assess the oxygen and water vapor content in the lungs of preterm babies. The aim is to prepare for further clinical studies by gaining a detailed understanding of how the measured light intensity and gas absorption signal behave for different possible geometries of light delivery and receiver. Such an experimental evaluation is conducted for the first time utilizing a specially developed 3-dimensional-printed optical phantom based on a geometry model obtained from computer tomography images of the thorax (chest) of a 1700-g premature infant. The measurements yield reliable signals for source-detector distances up to about 50 mm, with stronger gas absorption signals at long separations and positions related to the lower part of the lung, consistent with a larger relative volume of this. The limitations of this study include the omission of scattering tissue within the lungs and that similar optical properties are used for the wavelengths employed for the 2 gases, yielding no indication on the optimal wavelength pair to use.
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Affiliation(s)
- Jim Larsson
- Division of Combustion Physics, Department of Physics, Lund University, Lund, Sweden
| | - Peilang Liao
- Department of Physics, Lund University, Lund, Sweden
- GASPOROX AB (publ), Lund, Sweden
| | - Patrik Lundin
- Department of Physics, Lund University, Lund, Sweden
- GASPOROX AB (publ), Lund, Sweden
| | - Emilie Krite Svanberg
- Department of Clinical Sciences, Anesthesiology and Intensive Care Medicine, Skåne University Hospital, Lund University, Lund, Sweden
- Lund Laser Centre, Lund University, Lund, Sweden
| | | | | | - Joakim Bood
- Division of Combustion Physics, Department of Physics, Lund University, Lund, Sweden
| | - Stefan Andersson-Engels
- Department of Physics, Lund University, Lund, Sweden
- IPIC, Tyndall National Institute, Lee Maltings, Cork, Ireland
- Department of Physics, University College Cork, Cork, Ireland
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32
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Shahin A, Bachir W. Broadband spectroscopy for characterization of tissue-like phantom optical properties. POLISH JOURNAL OF MEDICAL PHYSICS AND ENGINEERING 2017. [DOI: 10.1515/pjmpe-2017-0020] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Abstract
Optical phantoms are widely used for evaluating the performance of biomedical optical modalities, and hence, absorbing and scattering materials are required for the construction of optical phantoms. Towards that aim, new readily available and inexpensive black Ink (Parker) as a simulating absorber as well as Intralipid 20% as a simulating scatterer are thoroughly investigated. Broadband Transmittance and Diffuse reflectance spectroscopic measurements were performed in the visible range 400 – 700 nm. Optical properties of the phantom materials are determined. Analytical expressions for absorption and scattering coefficient related to the concentrations and wavelength of the Parker ink and Intralipid are also presented and discussed. The results show nonlinear trend in the absorption coefficient of Parker ink over the examined visible spectral range. Furthermore, Intralipid scattering coefficient variation across the mentioned spectral range shows a tissue-like scattering trend. The findings demonstrate the capability of the broadband transmission and diffuse reflectance for characterizing tissue-like phantom materials in the examined spectral range.
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Affiliation(s)
- Ali Shahin
- Biomedical Photonics Laboratory , Higher Institute for Laser Research and Applications , Damascus University , Damascus airport freeway, 11-111 Damascus , Syria
| | - Wesam Bachir
- Biomedical Photonics Laboratory , Higher Institute for Laser Research and Applications , Damascus University , Damascus airport freeway, 11-111 Damascus , Syria
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33
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Xu J, Zhou J, Zhong Y, Zhang Y, Liu J, Chen Y, Deng L, Sheng D, Wang Z, Ran H, Guo D. Phase Transition Nanoparticles as Multimodality Contrast Agents for the Detection of Thrombi and for Targeting Thrombolysis: in Vitro and in Vivo Experiments. ACS APPLIED MATERIALS & INTERFACES 2017; 9:42525-42535. [PMID: 29160060 DOI: 10.1021/acsami.7b12689] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Thrombotic disease is extremely harmful to human health, and early detection and treatment can improve the prognosis and reduce mortality. Multimodal molecular imaging can provide abundant information about thrombi, but to date, few studies have used multimodal and multifunctional nanoparticles (NPs) for thrombus detection and for targeting thrombolysis. In this study, phase transition multimodal and multifunctional NPs (EWVDV-Fe-Ink-PFH NPs) were constructed for the first time using a three-step emulsification and carbodiimide method, and the physical and chemical properties of the NPs were investigated. The targeting abilities of the NPs and multimodal imaging, that is, photoacoustic, magnetic resonance, and ultrasound imaging, were successfully achieved in vitro and in vivo. The ability of the EWVDV peptide on the NPs to effectively target the P-selectin of thrombi was confirmed by multimodal imaging and pathology, and the penetration depths of the NPs into the thrombi were far deeper than the previously reported depths. Moreover, a perfluorohexane (PFH) phase transition induced by low-intensity focused ultrasound irradiation enabled the EWVDV-Fe-Ink-PFH NPs to cause thrombolysis in vitro. In summary, EWVDV-Fe-Ink-PFH NPs are a theranostic contrast agent that will provide a simple, effective, and noninvasive approach for the diagnosis and treatment of thrombosis.
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Affiliation(s)
- Jie Xu
- Department of Radiology and ‡Institute of Ultrasound Imaging, Department of Ultrasound, The Second Affiliated Hospital of Chongqing Medical University , No. 74 Linjiang Rd, Yuzhong District, Chongqing 400010, P. R. China
| | - Jun Zhou
- Department of Radiology and ‡Institute of Ultrasound Imaging, Department of Ultrasound, The Second Affiliated Hospital of Chongqing Medical University , No. 74 Linjiang Rd, Yuzhong District, Chongqing 400010, P. R. China
| | - Yixin Zhong
- Department of Radiology and ‡Institute of Ultrasound Imaging, Department of Ultrasound, The Second Affiliated Hospital of Chongqing Medical University , No. 74 Linjiang Rd, Yuzhong District, Chongqing 400010, P. R. China
| | - Yu Zhang
- Department of Radiology and ‡Institute of Ultrasound Imaging, Department of Ultrasound, The Second Affiliated Hospital of Chongqing Medical University , No. 74 Linjiang Rd, Yuzhong District, Chongqing 400010, P. R. China
| | - Jia Liu
- Department of Radiology and ‡Institute of Ultrasound Imaging, Department of Ultrasound, The Second Affiliated Hospital of Chongqing Medical University , No. 74 Linjiang Rd, Yuzhong District, Chongqing 400010, P. R. China
| | - Yuli Chen
- Department of Radiology and ‡Institute of Ultrasound Imaging, Department of Ultrasound, The Second Affiliated Hospital of Chongqing Medical University , No. 74 Linjiang Rd, Yuzhong District, Chongqing 400010, P. R. China
| | - Liming Deng
- Department of Radiology and ‡Institute of Ultrasound Imaging, Department of Ultrasound, The Second Affiliated Hospital of Chongqing Medical University , No. 74 Linjiang Rd, Yuzhong District, Chongqing 400010, P. R. China
| | - Danli Sheng
- Department of Radiology and ‡Institute of Ultrasound Imaging, Department of Ultrasound, The Second Affiliated Hospital of Chongqing Medical University , No. 74 Linjiang Rd, Yuzhong District, Chongqing 400010, P. R. China
| | - Zhigang Wang
- Department of Radiology and ‡Institute of Ultrasound Imaging, Department of Ultrasound, The Second Affiliated Hospital of Chongqing Medical University , No. 74 Linjiang Rd, Yuzhong District, Chongqing 400010, P. R. China
| | - Haitao Ran
- Department of Radiology and ‡Institute of Ultrasound Imaging, Department of Ultrasound, The Second Affiliated Hospital of Chongqing Medical University , No. 74 Linjiang Rd, Yuzhong District, Chongqing 400010, P. R. China
| | - Dajing Guo
- Department of Radiology and ‡Institute of Ultrasound Imaging, Department of Ultrasound, The Second Affiliated Hospital of Chongqing Medical University , No. 74 Linjiang Rd, Yuzhong District, Chongqing 400010, P. R. China
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Dolet A, Varray F, Roméo E, Dehoux T, Vray D. Spectrophotometry and Photoacoustic Imaging: A Comparative Study. Ing Rech Biomed 2017. [DOI: 10.1016/j.irbm.2017.10.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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35
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Levine ZH, Streater RH, Lieberson AMR, Pintar AL, Cooksey CC, Lemaillet P. Algorithm for rapid determination of optical scattering parameters. OPTICS EXPRESS 2017; 25:26728-26746. [PMID: 29092156 PMCID: PMC5894000 DOI: 10.1364/oe.25.026728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 10/11/2017] [Indexed: 05/16/2023]
Abstract
Preliminary experiments at the NIST Spectral Tri-function Automated Reference Reflectometer (STARR) facility have been conducted with the goal of providing the diffuse optical properties of a solid reference standard with optical properties similar to human skin. Here, we describe an algorithm for determining the best-fit parameters and the statistical uncertainty associated with the measurement. The objective function is determined from the profile log likelihood, including both experimental and Monte Carlo uncertainties. Initially, the log likelihood is determined over a large parameter search box using a relatively small number of Monte Carlo samples such as 2·104. The search area is iteratively reduced to include the 99.9999% confidence region, while doubling the number of samples at each iteration until the experimental uncertainty dominates over the Monte Carlo uncertainty. Typically this occurs by 1.28·106 samples. The log likelihood is then fit to determine a 95% confidence ellipse. The inverse problem requires the values of the log likelihood on many points. Our implementation uses importance sampling to calculate these points on a grid in an efficient manner. Ultimately, the time-to-solution is approximately six times the cost of a Monte Carlo simulation of the radiation transport problem for a single set of parameters with the largest number of photons required. The results are found to be 64 times faster than our implementation of Particle Swarm Optimization.
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Affiliation(s)
- Zachary H. Levine
- National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Richelle H. Streater
- National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
- Colorado School of Mines, Golden, Colorado 80401, USA
| | - Anne-Michelle R. Lieberson
- National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
- Sherwood High School, Sandy Spring, Maryland 20860, USA
| | - Adam L. Pintar
- National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Catherine C. Cooksey
- National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Paul Lemaillet
- National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
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36
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Liu J, Zhang H, Lu J, Ni X, Shen Z. Simultaneously extracting multiple parameters via multi-distance and multi-exposure diffuse speckle contrast analysis. BIOMEDICAL OPTICS EXPRESS 2017; 8:4537-4550. [PMID: 29082083 PMCID: PMC5654798 DOI: 10.1364/boe.8.004537] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 09/03/2017] [Accepted: 09/14/2017] [Indexed: 05/25/2023]
Abstract
Recent advancements in diffuse speckle contrast analysis (DSCA) have opened the path for noninvasive acquisition of deep tissue microvasculature blood flow. In fact, in addition to blood flow index αDB , the variations of tissue optical absorption μa , reduced scattering coefficients [Formula: see text], as well as coherence factor β can modulate temporal fluctuations of speckle patterns. In this study, we use multi-distance and multi-exposure DSCA (MDME-DSCA) to simultaneously extract multiple parameters such as μa , [Formula: see text], αDB , and β. The validity of MDME-DSCA has been validated by the simulated data and phantoms experiments. Moreover, as a comparison, the results also show that it is impractical to simultaneously obtain multiple parameters by multi-exposure DSCA (ME-DSCA).
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37
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Bentz BZ, Wu TC, Gaind V, Webb KJ. Diffuse optical localization of blood vessels and 3D printing for guiding oral surgery. APPLIED OPTICS 2017; 56:6649-6654. [PMID: 29047957 PMCID: PMC5652004 DOI: 10.1364/ao.56.006649] [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] [Indexed: 05/08/2023]
Abstract
Diffuse optical imaging through centimeters of tissue has emerged as a powerful tool in biomedical research. However, applications in the operating theater have been limited in part due to data set requirements and computational burden. We present an approach that uses a small number of optical source-detector pairs that allows for the fast localization of arteries in the roof of the mouth and has the potential to reduce complications during oral surgery. The arteries are modeled as multiple-point absorbers, allowing localization of their complex shapes. The method is demonstrated using a printed tissue-simulating mouth phantom. Furthermore, we use the extracted position information to fabricate a custom surgical guide using 3D printing that could protect the arteries during surgery.
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Affiliation(s)
- Brian Z. Bentz
- School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, USA
| | - Timothy C. Wu
- Private Practice in Periodontology, Mountain View, California 94040, USA
| | | | - Kevin J. Webb
- School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, USA
- Corresponding author:
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38
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Liu J, Zhang H, Lu J, Ni X, Shen Z. Quantitative model of diffuse speckle contrast analysis for flow measurement. JOURNAL OF BIOMEDICAL OPTICS 2017; 22:76016. [PMID: 28742921 DOI: 10.1117/1.jbo.22.7.076016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 06/30/2017] [Indexed: 05/22/2023]
Abstract
Diffuse speckle contrast analysis (DSCA) is a noninvasive optical technique capable of monitoring deep tissue blood flow. However, a detailed study of the speckle contrast model for DSCA has yet to be presented. We deduced the theoretical relationship between speckle contrast and exposure time and further simplified it to a linear approximation model. The feasibility of this linear model was validated by the liquid phantoms which demonstrated that the slope of this linear approximation was able to rapidly determine the Brownian diffusion coefficient of the turbid media at multiple distances using multiexposure speckle imaging. Furthermore, we have theoretically quantified the influence of optical property on the measurements of the Brownian diffusion coefficient which was a consequence of the fact that the slope of this linear approximation was demonstrated to be equal to the inverse of correlation time of the speckle.
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Affiliation(s)
- Jialin Liu
- Nanjing University of Science and Technology, School of Science, Nanjing, China
| | - Hongchao Zhang
- Nanjing University of Science and Technology, School of Science, Nanjing, China
| | - Jian Lu
- Nanjing University of Science and Technology, School of Science, Nanjing, China
| | - Xiaowu Ni
- Nanjing University of Science and Technology, School of Science, Nanjing, China
| | - Zhonghua Shen
- Nanjing University of Science and Technology, School of Science, Nanjing, China
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39
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Chen AI, Balter ML, Chen MI, Gross D, Alam SK, Maguire TJ, Yarmush ML. Multilayered tissue mimicking skin and vessel phantoms with tunable mechanical, optical, and acoustic properties. Med Phys 2017; 43:3117-3131. [PMID: 27277058 DOI: 10.1118/1.4951729] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
PURPOSE This paper describes the design, fabrication, and characterization of multilayered tissue mimicking skin and vessel phantoms with tunable mechanical, optical, and acoustic properties. The phantoms comprise epidermis, dermis, and hypodermis skin layers, blood vessels, and blood mimicking fluid. Each tissue component may be individually tailored to a range of physiological and demographic conditions. METHODS The skin layers were constructed from varying concentrations of gelatin and agar. Synthetic melanin, India ink, absorbing dyes, and Intralipid were added to provide optical absorption and scattering in the skin layers. Bovine serum albumin was used to increase acoustic attenuation, and 40 μm diameter silica microspheres were used to induce acoustic backscatter. Phantom vessels consisting of thin-walled polydimethylsiloxane tubing were embedded at depths of 2-6 mm beneath the skin, and blood mimicking fluid was passed through the vessels. The phantoms were characterized through uniaxial compression and tension experiments, rheological frequency sweep studies, diffuse reflectance spectroscopy, and ultrasonic pulse-echo measurements. Results were then compared to in vivo and ex vivo literature data. RESULTS The elastic and dynamic shear behavior of the phantom skin layers and vessel wall closely approximated the behavior of porcine skin tissues and human vessels. Similarly, the optical properties of the phantom tissue components in the wavelength range of 400-1100 nm, as well as the acoustic properties in the frequency range of 2-9 MHz, were comparable to human tissue data. Normalized root mean square percent errors between the phantom results and the literature reference values ranged from 1.06% to 9.82%, which for many measurements were less than the sample variability. Finally, the mechanical and imaging characteristics of the phantoms were found to remain stable after 30 days of storage at 21 °C. CONCLUSIONS The phantoms described in this work simulate the mechanical, optical, and acoustic properties of human skin tissues, vessel tissue, and blood. In this way, the phantoms are uniquely suited to serve as test models for multimodal imaging techniques and image-guided interventions.
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Affiliation(s)
- Alvin I Chen
- Department of Biomedical Engineering, Rutgers University, Piscataway, New Jersey 08854
| | - Max L Balter
- Department of Biomedical Engineering, Rutgers University, Piscataway, New Jersey 08854
| | - Melanie I Chen
- Ernest Mario School of Pharmacy, Rutgers University, Piscataway, New Jersey 08854
| | - Daniel Gross
- Riverside Research Institute, Piscataway, New York, New York 10038
| | - Sheikh K Alam
- Center for Computational Biomedicine Imaging and Modeling, Rutgers University, Piscataway, New Jersey 08854
| | | | - Martin L Yarmush
- Department of Biomedical Engineering, Rutgers University, Piscataway, New Jersey 08854
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Farraro R, Fathi O, Choi B. Handheld, point-of-care laser speckle imaging. JOURNAL OF BIOMEDICAL OPTICS 2016; 21:94001. [PMID: 27579578 PMCID: PMC5005973 DOI: 10.1117/1.jbo.21.9.094001] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 08/12/2016] [Indexed: 05/15/2023]
Abstract
Laser speckle imaging (LSI) enables measurement of relative changes in blood flow in biological tissues. We postulate that a point-of-care form factor will lower barriers to routine clinical use of LSI. Here, we describe a first-generation handheld LSI device based on a tablet computer. The coefficient of variation of speckle contrast was < 2% after averaging imaging data collected over an acquisition period of 5.3 s. With a single, experienced user, handheld motion artifacts had a negligible effect on data collection. With operation by multiple users, we did not identify any significant difference (p > 0.05) between the measured speckle contrast values using either a handheld or mounted configuration. In vivo data collected during occlusion experiments demonstrate that a handheld LSI is capable of both quantitative and qualitative assessment of changes in blood flow. Finally, as a practical application of handheld LSI, we collected data from a 53-day-old neonate with confirmed compromised blood flow in the hand. We readily identified with LSI a region of diminished blood flow in the thumb of the affected hand. Our data collectively suggest that handheld LSI is a promising technique to enable clinicians to obtain point-of-care measurements of blood flow.
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Affiliation(s)
- Ryan Farraro
- University of California-Irvine, Beckman Laser Institute and Medical Clinic, 1002 Health Sciences Road East, Irvine, California 92612, United States
- University of California-Irvine, Department of Biomedical Engineering, 3120 Natural Sciences II, Irvine, California 92697, United States
| | - Omid Fathi
- University of California-Irvine, Department of Pediatrics, 505 South Main Street, Irvine, Orange, California 92868, United States
| | - Bernard Choi
- University of California-Irvine, Beckman Laser Institute and Medical Clinic, 1002 Health Sciences Road East, Irvine, California 92612, United States
- University of California-Irvine, Department of Biomedical Engineering, 3120 Natural Sciences II, Irvine, California 92697, United States
- University of California-Irvine, Department of Surgery, 333 City Boulevard West, Suite 1600, Orange, California 92868, United States
- University of California-Irvine, Edwards Lifesciences Center for Advanced Cardiovascular Technology, 2400 Engineering Hall, Irvine, California 92697, United States
- CHOC Children’s Hospital, 1201 West La Veta Avenue, Orange, California 92868, United States
- Address all correspondence to: Bernard Choi, E-mail:
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Ley S, Stadthalter M, Link D, Laqua D, Husar P. Phantom materials mimicking the optical properties in the near infrared range for non-invasive fetal pulse oximetry. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2016; 2014:1432-5. [PMID: 25570237 DOI: 10.1109/embc.2014.6943869] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
An optical phantom of the maternal abdomen during pregnancy is an appropriate test environment to evaluate a non-invasive system for fetal pulse oximetry. To recreate the optical properties of maternal tissue, fetal tissue and blood suitable substitutes are required. For this purpose, phantom materials are used, which consist of transparent silicone or water as host material. Cosmetic powder and India ink are investigated as absorbing materials, whereas titanium dioxide particles are examined as scattering medium. Transmittance and reflectance measurements of the samples were performed in the spectral range from 600 nm to 900 nm using integrating sphere technique. The scattering and absorption coefficients and the anisotropy factor were determined using Kubelka-Munk theory. The results were used to compute the required mixture ratios of the respective components to replicate the optical properties of maternal tissue, fetal tissue and blood, and corresponding samples were produced. Their optical properties were investigated in the same manner as mentioned above. The results conform to the values of various types of tissues and blood given in the scientific literature.
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Park J, Ha M, Yu S, Jung B. Fabrication of various optical tissue phantoms by the spin-coating method. JOURNAL OF BIOMEDICAL OPTICS 2016; 21:65008. [PMID: 27367252 DOI: 10.1117/1.jbo.21.6.065008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2015] [Accepted: 06/13/2016] [Indexed: 06/06/2023]
Abstract
Although numerous studies have been performed to fabricate various optical tissue phantom (OTP) models, the fabrication of OTPs that simulate skin layers is laborious and time-consuming owing to the intricate characteristics of skin tissue. This study presents various OTP models that optically and structurally simulate the epidermis–dermis skin layer. The spin-coating method was employed to reproduce a uniform thin layer that mimics the epidermis layer, and the fabrication parameters were optimized for epoxy and silicone reference materials. Various OTP models simulating blood vessels and hyperpigmentation lesions were fabricated using the two reference materials to determine their feasibility. The suitability of each of the two reference materials for OTP fabrication was qualitatively evaluated by comparing the quality of the OTP models.
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Vardaki MZ, Matousek P, Stone N. Characterisation of signal enhancements achieved when utilizing a photon diode in deep Raman spectroscopy of tissue. BIOMEDICAL OPTICS EXPRESS 2016; 7:2130-2141. [PMID: 27375932 PMCID: PMC4918570 DOI: 10.1364/boe.7.002130] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 04/05/2016] [Accepted: 04/05/2016] [Indexed: 06/06/2023]
Abstract
We characterise the performance of a beam enhancing element ('photon diode') for use in deep Raman spectroscopy (DRS) of biological tissues. The optical component enhances the number of laser photons coupled into a tissue sample by returning escaping photons back into it at the illumination zone. The method is compatible with transmission Raman spectroscopy, a deep Raman spectroscopy concept, and its implementation leads to considerable enhancement of detected Raman photon rates. In the past, the enhancement concept was demonstrated with a variety of samples (pharmaceutical tablets, tissue, etc) but it was not systematically characterized with biological tissues. In this study, we investigate the enhancing properties of the photon diode in the transmission Raman geometry as a function of: a) the depth and b) the optical properties of tissue samples. Liquid tissue phantoms were employed to facilitate systematic variation of optical properties. These were chosen to mimic optical properties of human tissues, including breast and prostate. The obtained results evidence that a photon diode can enhance Raman signals of tissues by a maximum of × 2.4, although it can also decrease the signals created towards the back of samples that exhibit high scattering or absorption properties.
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Affiliation(s)
- Martha Z Vardaki
- School of Physics and Astronomy, College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter EX4 4QL, UK
| | - Pavel Matousek
- Central Laser Facility, Research Complex at Harwell, STFC Rutherford Appleton Laboratory, Harwell Oxford, OX11 0QX, UK;
| | - Nicholas Stone
- School of Physics and Astronomy, College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter EX4 4QL, UK;
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Towards monitoring dysplastic progression in the oral cavity using a hybrid fiber-bundle imaging and spectroscopy probe. Sci Rep 2016; 6:26734. [PMID: 27220821 PMCID: PMC4879668 DOI: 10.1038/srep26734] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Accepted: 05/06/2016] [Indexed: 02/06/2023] Open
Abstract
Intraepithelial dysplasia of the oral mucosa typically originates in the proliferative cell layer at the basement membrane and extends to the upper epithelial layers as the disease progresses. Detection of malignancies typically occurs upon visual inspection by non-specialists at a late-stage. In this manuscript, we validate a quantitative hybrid imaging and spectroscopy microendoscope to monitor dysplastic progression within the oral cavity microenvironment in a phantom and pre-clinical study. We use an empirical model to quantify optical properties and sampling depth from sub-diffuse reflectance spectra (450–750 nm) at two source-detector separations (374 and 730 μm). Average errors in recovering reduced scattering (5–26 cm−1) and absorption coefficients (0–10 cm−1) in hemoglobin-based phantoms were approximately 2% and 6%, respectively. Next, a 300 μm-thick phantom tumor model was used to validate the probe’s ability to monitor progression of a proliferating optical heterogeneity. Finally, the technique was demonstrated on 13 healthy volunteers and volume-averaged optical coefficients, scattering exponent, hemoglobin concentration, oxygen saturation, and sampling depth are presented alongside a high-resolution microendoscopy image of oral mucosa from one volunteer. This multimodal microendoscopy approach encompasses both structural and spectroscopic reporters of perfusion within the tissue microenvironment and can potentially be used to monitor tumor response to therapy.
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Hong S, Carlson J, Lee H, Weissleder R. Bioorthogonal Radiopaque Hydrogel for Endoscopic Delivery and Universal Tissue Marking. Adv Healthc Mater 2016; 5:421-6. [PMID: 26688173 PMCID: PMC4811597 DOI: 10.1002/adhm.201500780] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Revised: 11/19/2015] [Indexed: 11/07/2022]
Abstract
A novel dual marking hydrogel system is reported for radiological and laparoscopic localization of lesions. Bioorthogonally crosslinked hydrogel containing both tantalum and India ink can be rapidly formed inside the body after injecting precursors, and stably located for several days as a long-term biocompatible carrier for markers.
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Affiliation(s)
- Seonki Hong
- Center for Systems Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, USA
| | - Jonathan Carlson
- Center for Systems Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, USA
| | - Hakho Lee
- Center for Systems Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, USA
| | - Ralph Weissleder
- Center for Systems Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, USA
- Department of Systems Biology, Harvard Medical School, Boston, MA, 02114, USA
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Martelli F, Del Bianco S, Spinelli L, Cavalieri S, Di Ninni P, Binzoni T, Jelzow A, Macdonald R, Wabnitz H. Optimal estimation reconstruction of the optical properties of a two-layered tissue phantom from time-resolved single-distance measurements. JOURNAL OF BIOMEDICAL OPTICS 2015; 20:115001. [PMID: 26524677 DOI: 10.1117/1.jbo.20.11.115001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Accepted: 09/25/2015] [Indexed: 05/02/2023]
Abstract
In this work, we have tested the optimal estimation (OE) algorithm for the reconstruction of the optical properties of a two-layered liquid tissue phantom from time-resolved single-distance measurements. The OE allows a priori information, in particular on the range of variation of fit parameters, to be included. The purpose of the present investigations was to compare the performance of OE with the Levenberg–Marquardt method for a geometry and real experimental conditions typically used to reconstruct the optical properties of biological tissues such as muscle and brain. The absorption coefficient of the layers was varied in a range of values typical for biological tissues. The reconstructions performed demonstrate the substantial improvements achievable with the OE provided a priori information is available. We note the extreme reliability, robustness, and accuracy of the retrieved absorption coefficient of the second layer obtained with the OE that was found for up to six fit parameters, with an error in the retrieved values of less than 10%. A priori information on fit parameters and fixed forward model parameters clearly improves robustness and accuracy of the inversion procedure.
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Affiliation(s)
- Fabrizio Martelli
- Università degli Studi di Firenze, Dipartimento di Fisica e Astronomia, Via G. Sansone 1, Sesto Fiorentino 50019, Firenze, Italy
| | - Samuele Del Bianco
- Istituto di Fisica Applicata Nello Carrara del Consiglio Nazionale delle Ricerche, Via Madonna del Piano 10, Sesto Fiorentino 50019, Italy
| | - Lorenzo Spinelli
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Piazza Leonardo da Vinci 32, Milano 20133, Italy
| | - Stefano Cavalieri
- Università degli Studi di Firenze, Dipartimento di Fisica e Astronomia, Via G. Sansone 1, Sesto Fiorentino 50019, Firenze, Italy
| | - Paola Di Ninni
- Università degli Studi di Firenze, Dipartimento di Fisica e Astronomia, Via G. Sansone 1, Sesto Fiorentino 50019, Firenze, Italy
| | - Tiziano Binzoni
- University of Geneva, Département de Neurosciences Fondamentales, 1, rue Michel-Servet 1211 Genève 4, SwitzerlandeUniversity Hospital, Département de l'Imagerie et des Sciences de l'Information Médicale, 1, 4 rue Gabrielle-Perret-Gentil, 1211 Geneva 14, S
| | - Alexander Jelzow
- Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin, Germany
| | - Rainer Macdonald
- Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin, Germany
| | - Heidrun Wabnitz
- Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin, Germany
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Characterisation of a fibre optic Raman probe within a hypodermic needle. Anal Bioanal Chem 2015; 407:8311-20. [PMID: 26416020 DOI: 10.1007/s00216-015-9021-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Revised: 08/25/2015] [Accepted: 08/31/2015] [Indexed: 12/14/2022]
Abstract
We demonstrate the first use of a multifibre Raman probe that fits inside the bore of a hypodermic needle. A Raman probe containing multiple collection fibres provides improved signal collection efficiency in biological samples compared with a previous two-fibre design. Furthermore, probe performance (signal-to-noise ratios) compared favourably with the performance achieved in previous Raman microscope experiments able to distinguish between benign lymph nodes, primary malignancies in lymph nodes and secondary malignancies in lymph nodes. The experimental measurements presented here give an indication of the sampling volume of the Raman needle probe in lymphoid tissues. Liquid tissue phantoms were used that contained scattering medium encompassing a range of scattering properties similar to those of a variety of tissue types, including lymph node tissues. To validate the appropriateness of the phantoms, the sampling depth of the probe was also measured in excised lymph node tissue. More than 50 % of Raman photons collected were found to originate from between the tip of the needle and a depth of 500 μm into the tissue. The needle probe presented here achieves spectral quality comparable to that in numerous studies previously demonstrating Raman disease discrimination. It is expected that this approach could achieve targeted subcutaneous tissue measurements and be viable for use for the in vivo Raman diagnostics of solid organs located within a few centimetres below the skin's surface. Graphical Abstract Schematic of multi-fibre Raman needle probe with disposible tips and proximal optical filtration.
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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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Huang J, Zhang S, Gnyawali S, Sen CK, Xu RX. Second derivative multispectral algorithm for quantitative assessment of cutaneous tissue oxygenation. JOURNAL OF BIOMEDICAL OPTICS 2015; 20:036001. [PMID: 25734405 PMCID: PMC4347514 DOI: 10.1117/1.jbo.20.3.036001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Accepted: 01/20/2015] [Indexed: 05/12/2023]
Abstract
We report a second derivative multispectral algorithm for quantitative assessment of cutaneous tissue oxygen saturation (StO₂). The algorithm is based on a forward model of light transport in multilayered skin tissue and an inverse algorithm for StO₂ reconstruction. Based on the forward simulation results, a parameter of a second derivative ratio (SDR) is derived as a function of cutaneous tissue StO₂. The SDR function is optimized at a wavelength set of 544, 552, 568, 576, 592, and 600 nm so that cutaneous tissue StO₂ can be derived with minimal artifacts by blood concentration, tissue scattering, and melanin concentration. The proposed multispectral StO₂ imaging algorithm is verified in both benchtop and in vivo experiments. The experimental results show that the proposed multispectral imaging algorithm is able to map cutaneous tissue StO₂ in high temporal resolution with reduced measurement artifacts induced by different skin conditions in comparison with other three commercial tissue oxygen measurement systems. These results indicate that the multispectral StO₂ imaging technique has the potential for noninvasive and quantitative assessment of skin tissue oxygenation with a high temporal resolution.
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Affiliation(s)
- Jiwei Huang
- The Ohio State University, Department of Biomedical Engineering, Columbus, Ohio 43210, United States
| | - Shiwu Zhang
- University of Science and Technology of China, Department of Precision Machinery and Precision Instrumentation, Hefei, Anhui 230027, China
| | - Surya Gnyawali
- The Ohio State University, Department of Surgery, Columbus, Ohio 43210, United States
| | - Chandan K. Sen
- The Ohio State University, Department of Surgery, Columbus, Ohio 43210, United States
| | - Ronald X. Xu
- The Ohio State University, Department of Biomedical Engineering, Columbus, Ohio 43210, United States
- University of Science and Technology of China, Department of Precision Machinery and Precision Instrumentation, Hefei, Anhui 230027, China
- Address all correspondence to: Ronald X. Xu, E-mail:
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Vardaki MZ, Gardner B, Stone N, Matousek P. Studying the distribution of deep Raman spectroscopy signals using liquid tissue phantoms with varying optical properties. Analyst 2015; 140:5112-9. [DOI: 10.1039/c5an01118c] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We studied experimentally the magnitude and origin of Raman signals in a transmission Raman geometry as a function of optical properties of the medium and the location of Raman scatterer within the phantom.
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Affiliation(s)
| | | | | | - Pavel Matousek
- Central Laser Facility
- Research Complex at Harwell
- STFC Rutherford Appleton Laboratory
- Oxford
- UK
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