1
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Wang Q, Pan M, Kreiss L, Samaei S, Carp SA, Johansson JD, Zhang Y, Wu M, Horstmeyer R, Diop M, Li DDU. A comprehensive overview of diffuse correlation spectroscopy: Theoretical framework, recent advances in hardware, analysis, and applications. Neuroimage 2024; 298:120793. [PMID: 39153520 DOI: 10.1016/j.neuroimage.2024.120793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2024] [Revised: 07/23/2024] [Accepted: 08/14/2024] [Indexed: 08/19/2024] Open
Abstract
Diffuse correlation spectroscopy (DCS) is a powerful tool for assessing microvascular hemodynamic in deep tissues. Recent advances in sensors, lasers, and deep learning have further boosted the development of new DCS methods. However, newcomers might feel overwhelmed, not only by the already-complex DCS theoretical framework but also by the broad range of component options and system architectures. To facilitate new entry to this exciting field, we present a comprehensive review of DCS hardware architectures (continuous-wave, frequency-domain, and time-domain) and summarize corresponding theoretical models. Further, we discuss new applications of highly integrated silicon single-photon avalanche diode (SPAD) sensors in DCS, compare SPADs with existing sensors, and review other components (lasers, sensors, and correlators), as well as data analysis tools, including deep learning. Potential applications in medical diagnosis are discussed and an outlook for the future directions is provided, to offer effective guidance to embark on DCS research.
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Affiliation(s)
- Quan Wang
- Department of Biomedical Engineering, Faculty of Engineering, University of Strathclyde, Glasgow, United Kingdom
| | - Mingliang Pan
- Department of Biomedical Engineering, Faculty of Engineering, University of Strathclyde, Glasgow, United Kingdom
| | - Lucas Kreiss
- Department of Biomedical Engineering, Duke University, Durham, NC, United States
| | - Saeed Samaei
- Department of Medical and Biophysics, Schulich School of Medical & Dentistry, Western University, London, Ontario, Canada; Lawson Health Research Institute, Imaging Program, London, Ontario, Canada
| | - Stefan A Carp
- Massachusetts General Hospital, Optics at Athinoula A. Martinos Center for Biomedical Imaging, Harvard Medical School, Charlestown, MA, United States
| | | | - Yuanzhe Zhang
- Department of Biomedical Engineering, Faculty of Engineering, University of Strathclyde, Glasgow, United Kingdom
| | - Melissa Wu
- Department of Biomedical Engineering, Duke University, Durham, NC, United States
| | - Roarke Horstmeyer
- Department of Biomedical Engineering, Duke University, Durham, NC, United States
| | - Mamadou Diop
- Department of Medical and Biophysics, Schulich School of Medical & Dentistry, Western University, London, Ontario, Canada; Lawson Health Research Institute, Imaging Program, London, Ontario, Canada
| | - David Day-Uei Li
- Department of Biomedical Engineering, Faculty of Engineering, University of Strathclyde, Glasgow, United Kingdom.
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2
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Kobayashi Frisk L, Verma M, Bešlija F, Lin CHP, Patil N, Chetia S, Trobaugh JW, Culver JP, Durduran T. Comprehensive workflow and its validation for simulating diffuse speckle statistics for optical blood flow measurements. BIOMEDICAL OPTICS EXPRESS 2024; 15:875-899. [PMID: 38404339 PMCID: PMC10890893 DOI: 10.1364/boe.502421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 12/19/2023] [Accepted: 12/20/2023] [Indexed: 02/27/2024]
Abstract
Diffuse optical methods including speckle contrast optical spectroscopy and tomography (SCOS and SCOT), use speckle contrast (κ) to measure deep blood flow. In order to design practical systems, parameters such as signal-to-noise ratio (SNR) and the effects of limited sampling of statistical quantities, should be considered. To that end, we have developed a method for simulating speckle contrast signals including effects of detector noise. The method was validated experimentally, and the simulations were used to study the effects of physical and experimental parameters on the accuracy and precision of κ. These results revealed that systematic detector effects resulted in decreased accuracy and precision of κ in the regime of low detected signals. The method can provide guidelines for the design and usage of SCOS and/or SCOT instruments.
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Affiliation(s)
- Lisa Kobayashi Frisk
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona), Spain
| | - Manish Verma
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona), Spain
| | - Faruk Bešlija
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona), Spain
| | - Chen-Hao P. Lin
- Department of Physics, Washington University in St. Louis, St. Louis, Missouri 63110, USA
- Department of Radiology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
| | - Nishighanda Patil
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona), Spain
| | - Sumana Chetia
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona), Spain
| | - Jason W. Trobaugh
- Department of Electrical and Systems Engineering, Washington University School of Medicine, St. Louis, Missouri 63110, USA
| | - Joseph P. Culver
- Department of Physics, Washington University in St. Louis, St. Louis, Missouri 63110, USA
- Department of Radiology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
| | - Turgut Durduran
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona), Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
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3
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Mohtasebi M, Singh D, Liu X, Fathi F, Haratbar SR, Saatman KE, Chen L, Yu G. Depth-sensitive diffuse speckle contrast topography for high-density mapping of cerebral blood flow in rodents. NEUROPHOTONICS 2023; 10:045007. [PMID: 38076725 PMCID: PMC10704187 DOI: 10.1117/1.nph.10.4.045007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 10/26/2023] [Accepted: 10/27/2023] [Indexed: 02/12/2024]
Abstract
Significance Frequent assessment of cerebral blood flow (CBF) is crucial for the diagnosis and management of cerebral vascular diseases. In contrast to large and expensive imaging modalities, such as nuclear medicine and magnetic resonance imaging, optical imaging techniques are portable and inexpensive tools for continuous measurements of cerebral hemodynamics. The recent development of an innovative noncontact speckle contrast diffuse correlation tomography (scDCT) enables three-dimensional (3D) imaging of CBF distributions. However, scDCT requires complex and time-consuming 3D reconstruction, which limits its ability to achieve high spatial resolution without sacrificing temporal resolution and computational efficiency. Aim We investigate a new diffuse speckle contrast topography (DSCT) method with parallel computation for analyzing scDCT data to achieve fast and high-density two-dimensional (2D) mapping of CBF distributions at different depths without the need for 3D reconstruction. Approach A new moving window method was adapted to improve the sampling rate of DSCT. A fast computation method utilizing MATLAB functions in the Image Processing Toolbox™ and Parallel Computing Toolbox™ was developed to rapidly generate high-density CBF maps. The new DSCT method was tested for spatial resolution and depth sensitivity in head-simulating layered phantoms and in-vivo rodent models. Results DSCT enables 2D mapping of the particle flow in the phantom at different depths through the top layer with varied thicknesses. Both DSCT and scDCT enable the detection of global and regional CBF changes in deep brains of adult rats. However, DSCT achieves fast and high-density 2D mapping of CBF distributions at different depths without the need for complex and time-consuming 3D reconstruction. Conclusions The depth-sensitive DSCT method has the potential to be used as a noninvasive, noncontact, fast, high resolution, portable, and inexpensive brain imager for basic neuroscience research in small animal models and for translational studies in human neonates.
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Affiliation(s)
- Mehrana Mohtasebi
- University of Kentucky, Department of Biomedical Engineering, Lexington, Kentucky, United States
| | - Dara Singh
- University of Kentucky, Department of Biomedical Engineering, Lexington, Kentucky, United States
| | - Xuhui Liu
- University of Kentucky, Department of Biomedical Engineering, Lexington, Kentucky, United States
| | - Faraneh Fathi
- University of Kentucky, Department of Biomedical Engineering, Lexington, Kentucky, United States
| | | | - Kathryn E. Saatman
- University of Kentucky, Spinal Cord and Brain Injury Research Center, Department of Physiology, Lexington, Kentucky, United States
| | - Lei Chen
- University of Kentucky, Spinal Cord and Brain Injury Research Center, Department of Physiology, Lexington, Kentucky, United States
| | - Guoqiang Yu
- University of Kentucky, Department of Biomedical Engineering, Lexington, Kentucky, United States
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4
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Cao J, Grover P, Kainerstorfer JM. A model of neurovascular coupling and its application to cortical spreading depolarization. J Theor Biol 2023; 572:111580. [PMID: 37459953 DOI: 10.1016/j.jtbi.2023.111580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 06/09/2023] [Accepted: 07/10/2023] [Indexed: 08/01/2023]
Abstract
Cortical spreading depolarization (CSD) is a neuropathological condition involving propagating waves of neuronal silence, and is related to multiple diseases, such as migraine aura, traumatic brain injury (TBI), stroke, and cardiac arrest, as well as poor outcome of patients. While CSDs of different severity share similar roots on the ion exchange level, they can lead to different vascular responses (namely spreading hyperemia and spreading ischemia). In this paper, we propose a mathematical model relating neuronal activities to predict vascular changes as measured with near-infrared spectroscopy (NIRS) and fMRI recordings, and apply it to the extreme case of CSD, where sustained near-complete neuronal depolarization is seen. We utilize three serially connected models (namely, ion exchange, neurovascular coupling, and hemodynamic model) which are described by differential equations. Propagating waves of ion concentrations, as well as the associated vasodynamics and hemodynamics, are simulated by solving these equations. Our proposed model predicts vasodynamics and hemodynamics that agree both qualitatively and quantitatively with experimental literature. Mathematical modeling and simulation offer a powerful tool to help understand the underlying mechanisms of CSD and help interpret the data. In addition, it helps develop novel monitoring techniques prior to data collection. Our simulated results strongly suggest that fMRI is unable to reliably distinguish between spreading hyperemia and spreading ischemia, while NIRS signals are substantially distinct in the two cases.
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Affiliation(s)
- Jiaming Cao
- Department of Biomedical Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, 15213, PA, United States
| | - Pulkit Grover
- Department of Biomedical Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, 15213, PA, United States; Department of Electrical and Computer Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, 15213, PA, United States; Neuroscience Institute, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, 15213, PA, United States
| | - Jana M Kainerstorfer
- Department of Biomedical Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, 15213, PA, United States; Department of Electrical and Computer Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, 15213, PA, United States; Neuroscience Institute, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, 15213, PA, United States.
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5
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Frisk LK, Verma M, Bešlija F, Lin CHP, Patil N, Chetia S, Trobaugh J, Culver JP, Durduran T. A comprehensive workflow and its validation for simulating diffuse speckle statistics for optical blood flow measurements. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.03.551830. [PMID: 37577491 PMCID: PMC10418286 DOI: 10.1101/2023.08.03.551830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Diffuse optical methods including speckle contrast optical spectroscopy and tomography (SCOS and SCOT), use speckle contrast (κ ) to measure deep blood flow. In order to design practical systems, parameters such as signal-to-noise ratio (SNR) and the effects of limited sampling of statistical quantities, should be considered. To that end, we have developed a method for simulating speckle contrast signals including effects of detector noise. The method was validated experimentally, and the simulations were used to study the effects of physical and experimental parameters on the accuracy and precision of κ . These results revealed that systematic detector effects resulted in decreased accuracy and precision of κ in the regime of low detected signals. The method can provide guidelines for the design and usage of SCOS and/or SCOT instruments.
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Affiliation(s)
- Lisa Kobayashi Frisk
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona), Spain
| | - Manish Verma
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona), Spain
| | - Faruk Bešlija
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona), Spain
| | - Chen-Hao P. Lin
- Department of Physics, Washington University in St. Louis, St. Louis, Missouri 63110, USA
- Department of Radiology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
| | - Nishighanda Patil
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona), Spain
| | - Sumana Chetia
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona), Spain
| | - Jason Trobaugh
- Department of Electrical and Systems Engineering, Washington University School of Medicine, St. Louis, Missouri 63110, USA
| | - Joseph P. Culver
- Department of Physics, Washington University in St. Louis, St. Louis, Missouri 63110, USA
- Department of Radiology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
| | - Turgut Durduran
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona), Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
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6
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Sanford EL, Akorede R, Miller I, Morriss MC, Nandy K, Raman L, Busch DR. Association Between Disrupted Cerebral Autoregulation and Radiographic Neurologic Injury for Children on Extracorporeal Membrane Oxygenation: A Prospective Pilot Study. ASAIO J 2023; 69:e315-e321. [PMID: 37172001 DOI: 10.1097/mat.0000000000001970] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/14/2023] Open
Abstract
Validation of a real-time monitoring device to evaluate the risk or occurrence of neurologic injury while on extracorporeal membrane oxygenation (ECMO) may aid clinicians in prevention and treatment. Therefore, we performed a pilot prospective cohort study of children under 18 years old on ECMO to analyze the association between cerebral blood pressure autoregulation as measured by diffuse correlation spectroscopy (DCS) and radiographic neurologic injury. DCS measurements of regional cerebral blood flow were collected on enrolled patients and correlated with mean arterial blood pressure to determine the cerebral autoregulation metric termed DCSx. The primary outcome of interest was radiographic neurologic injury on eligible computed tomography (CT) or magnetic resonance imaging (MRI) scored by a blinded pediatric neuroradiologist utilizing a previously validated scale. Higher DCSx scores, which indicate disruption of cerebral autoregulation, were associated with higher radiographic neurologic injury score (slope, 11.0; 95% confidence interval [CI], 0.29-22). Patients with clinically significant neurologic injury scores of 10 or more had higher median DCSx measures than patients with lower neurologic injury scores (0.48 vs . 0.13; p = 0.01). Our study indicates that obtaining noninvasive DCS measures for children on ECMO is feasible and disruption of cerebral autoregulation determined from DCS is associated with higher radiographic neurologic injury score.
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Affiliation(s)
- Ethan L Sanford
- From the Department of Anesthesiology and Pain Management, UT Southwestern Medical Center/Children's Medical Center, Dallas, Texas
- Division of Pediatric Critical Care Medicine, UT Southwestern Medical Center/Children's Medical Center, Dallas, Texas
| | - Rufai Akorede
- From the Department of Anesthesiology and Pain Management, UT Southwestern Medical Center/Children's Medical Center, Dallas, Texas
| | - Isabel Miller
- UT Southwestern Medical Center Medical School, Dallas, Texas
| | - Michael Craig Morriss
- Department of Radiology, UT Southwestern Medical Center/Children's Medical Center, Dallas, Texas
| | - Karabi Nandy
- Peter O'Donnell Jr. School of Public Health, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Lakshmi Raman
- Division of Pediatric Critical Care Medicine, UT Southwestern Medical Center/Children's Medical Center, Dallas, Texas
| | - David R Busch
- From the Department of Anesthesiology and Pain Management, UT Southwestern Medical Center/Children's Medical Center, Dallas, Texas
- Department of Neurology, UT Southwestern Medical Center, Dallas, Texas
- Department of Biomedical Engineering, UT Southwestern Medical Center, Dallas, Texas
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7
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Wayne MA, Sie EJ, Ulku AC, Mos P, Ardelean A, Marsili F, Bruschini C, Charbon E. Massively parallel, real-time multispeckle diffuse correlation spectroscopy using a 500 × 500 SPAD camera. BIOMEDICAL OPTICS EXPRESS 2023; 14:703-713. [PMID: 36874503 PMCID: PMC9979680 DOI: 10.1364/boe.473992] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 12/01/2022] [Accepted: 12/24/2022] [Indexed: 06/02/2023]
Abstract
Diffuse correlation spectroscopy (DCS) is a promising noninvasive technique for monitoring cerebral blood flow and measuring cortex functional activation tasks. Taking multiple parallel measurements has been shown to increase sensitivity, but is not easily scalable with discrete optical detectors. Here we show that with a large 500 × 500 SPAD array and an advanced FPGA design, we achieve an SNR gain of almost 500 over single-pixel mDCS performance. The system can also be reconfigured to sacrifice SNR to decrease correlation bin width, with 400 ns resolution being demonstrated over 8000 pixels.
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Affiliation(s)
- Michael A. Wayne
- Advanced Quantum Architecture Laboratory, École polytechnique fédérale de Lausanne, Rue de la Maladière 71B, Neuchatel, NE 2000, Switzerland
| | - Edbert J. Sie
- Reality Labs Research, Meta Platforms Inc., Menlo Park, CA 94025, USA
| | - Arin C. Ulku
- Advanced Quantum Architecture Laboratory, École polytechnique fédérale de Lausanne, Rue de la Maladière 71B, Neuchatel, NE 2000, Switzerland
| | - Paul Mos
- Advanced Quantum Architecture Laboratory, École polytechnique fédérale de Lausanne, Rue de la Maladière 71B, Neuchatel, NE 2000, Switzerland
| | - Andrei Ardelean
- Advanced Quantum Architecture Laboratory, École polytechnique fédérale de Lausanne, Rue de la Maladière 71B, Neuchatel, NE 2000, Switzerland
| | - Francesco Marsili
- Reality Labs Research, Meta Platforms Inc., Menlo Park, CA 94025, USA
| | - Claudio Bruschini
- Advanced Quantum Architecture Laboratory, École polytechnique fédérale de Lausanne, Rue de la Maladière 71B, Neuchatel, NE 2000, Switzerland
| | - Edoardo Charbon
- Advanced Quantum Architecture Laboratory, École polytechnique fédérale de Lausanne, Rue de la Maladière 71B, Neuchatel, NE 2000, Switzerland
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8
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Helton M, Rajasekhar S, Zerafa S, Vishwanath K, Mycek MA. Numerical approach to quantify depth-dependent blood flow changes in real-time using the diffusion equation with continuous-wave and time-domain diffuse correlation spectroscopy. BIOMEDICAL OPTICS EXPRESS 2023; 14:367-384. [PMID: 36698680 PMCID: PMC9841990 DOI: 10.1364/boe.469419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 11/09/2022] [Accepted: 11/10/2022] [Indexed: 05/11/2023]
Abstract
Diffuse correlation spectroscopy (DCS) is a non-invasive optical technique that can measure brain perfusion by quantifying temporal intensity fluctuations of multiply scattered light. A primary limitation for accurate quantitation of cerebral blood flow (CBF) is the fact that experimental measurements contain information about both extracerebral scalp blood flow (SBF) as well as CBF. Separating CBF from SBF is typically achieved using multiple source-detector channels when using continuous-wave (CW) light sources, or more recently with use of time-domain (TD) techniques. Analysis methods that account for these partial volume effects are often employed to increase CBF contrast. However, a robust, real-time analysis procedure that can separate and quantify SBF and CBF with both traditional CW and TD-DCS measurements is still needed. Here, we validate a data analysis procedure based on the diffusion equation in layered media capable of quantifying both extra- and cerebral blood flow in the CW and TD. We find that the model can quantify SBF and CBF coefficients with less than 5% error compared to Monte Carlo simulations using a 3-layered brain model in both the CW and TD. The model can accurately fit data at a rate of <10 ms for CW data and <250 ms for TD data when using a least-squares optimizer.
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Affiliation(s)
- Michael Helton
- Applied Physics Program, University of Michigan, Ann Arbor, USA
| | - Suraj Rajasekhar
- Cell, Molecular and Structural Biology Program, Miami University, Oxford, OH, USA
| | - Samantha Zerafa
- Biomedical Engineering Department, University of Michigan, Ann Arbor, USA
| | - Karthik Vishwanath
- Cell, Molecular and Structural Biology Program, Miami University, Oxford, OH, USA
- Department of Physics, Miami University, Oxford, OH, USA
| | - Mary-Ann Mycek
- Applied Physics Program, University of Michigan, Ann Arbor, USA
- Biomedical Engineering Department, University of Michigan, Ann Arbor, USA
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9
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Biswas A, Parthasarathy AB. Lossless Compressed Sensing of Photon Counts for Fast Diffuse Correlation Spectroscopy. IEEE ACCESS : PRACTICAL INNOVATIONS, OPEN SOLUTIONS 2022; 10:129754-129762. [PMID: 36644002 PMCID: PMC9835098 DOI: 10.1109/access.2022.3228439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Diffuse Correlation Spectroscopy (DCS), a noninvasive optical technique, measures deep tissue blood flow using avalanche photon counting modules and data acquisition devices such as FPGAs or correlator boards. Conventional DCS instruments use in-processor counter modules that consume 32 bits/channel which is inefficient for low-photon budget situations prevalent in diffuse optics. Scaling these photon counters for large-scale imaging applications is difficult due to bandwidth and processing time considerations. Here, we introduce a new, lossless compressed sensing approach for fast and efficient detection of photon counts. The compressed DCS method uses an array of binary-coded-decimal counters to record photon counts from 8 channels simultaneously as a single 32-bit number. We validate the compressed DCS approach by comparisons with conventional DCS in experiments on tissue simulating phantoms and in-vivo arm cuff occlusion. Lossless compressed DCS was implemented with 87.5% compression efficiency. In tissue simulating phantoms, it was able to accurately estimate a tissue blood flow index, with no statistically significant difference compared to conventional DCS. Compressed DCS also recorded blood flow in vivo, in human forearm, with signal-to-noise ratio and dynamic range comparable to conventional DCS. Lossless 87.5% efficient compressed sensing counting of photon counts meets and exceeds benchmarks set by conventional DCS systems, offering a low-cost alternative for fast (~100 Hz) deep tissue blood flow measurement with optics.
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Affiliation(s)
- Arindam Biswas
- Department of Electrical Engineering, University of South Florida, Tampa, FL 33620, USA
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10
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K M, Varma HM. Laser speckle simulation tool based on stochastic differential equations for bio imaging applications. BIOMEDICAL OPTICS EXPRESS 2022; 13:6745-6762. [PMID: 36589556 PMCID: PMC9774864 DOI: 10.1364/boe.470926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 10/24/2022] [Accepted: 10/25/2022] [Indexed: 06/17/2023]
Abstract
Laser speckle-based blood flow imaging is a well-accepted and widely used method for pre-clinical and clinical applications. Although it was introduced as a method to measure only superficial blood flow (< 1mm depth), several recently introduced variants resulted in measuring deep tissue blood flow (a few cm) as well. A means of simulating laser speckles is often necessary for the analysis and development of these imaging modalities, as evident from many such attempts towards developing simulation tools in the past. Such methods often employ Fourier transforms or statistical tools to simulate speckles with desired statistical properties. We present the first method to use a stochastic differential equation to generate laser speckles with a pre-determined probability density function and a temporal auto-correlation. The method allows the choice of apriori gamma distribution along with simple exponential or more complex temporal auto-correlation statistics for simulated speckles, making it suitable for different blood flow profiles. In contrast to the existing methods that often generate speckles associated with superficial flow, we simulate both superficial and diffuse speckles leading to applications in deep tissue blood flow imaging. In addition, we have also incorporated appropriate models for noise associated with the detectors to simulate realistic speckles. We have validated our model by comparing the simulated speckles with those obtained from in-vivo studies in mice and healthy human subject.
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Affiliation(s)
- Murali K
- Department of Biosciences and Bioengineering,
Indian Institute of Technology –
Bombay, 400076, India
| | - Hari M. Varma
- Department of Biosciences and Bioengineering,
Indian Institute of Technology –
Bombay, 400076, India
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11
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Zilpelwar S, Sie EJ, Postnov D, Chen AI, Zimmermann B, Marsili F, Boas DA, Cheng X. Model of dynamic speckle evolution for evaluating laser speckle contrast measurements of tissue dynamics. BIOMEDICAL OPTICS EXPRESS 2022; 13:6533-6549. [PMID: 36589566 PMCID: PMC9774840 DOI: 10.1364/boe.472263] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 10/17/2022] [Accepted: 11/09/2022] [Indexed: 05/02/2023]
Abstract
We introduce a dynamic speckle model (DSM) to simulate the temporal evolution of fully developed speckle patterns arising from the interference of scattered light reemitted from dynamic tissue. Using this numerical tool, the performance of laser speckle contrast imaging (LSCI) or speckle contrast optical spectroscopy (SCOS) systems which quantify tissue dynamics using the spatial contrast of the speckle patterns with a certain camera exposure time is evaluated. We have investigated noise sources arising from the fundamental speckle statistics due to the finite sampling of the speckle patterns as well as those induced by experimental measurement conditions including shot noise, camera dark and read noise, and calibrated the parameters of an analytical noise model initially developed in the fundamental or shot noise regime that quantifies the performance of SCOS systems using the number of independent observables (NIO). Our analysis is particularly focused on the low photon flux regime relevant for human brain measurements, where the impact of shot noise and camera read noise can become significant. Our numerical model is also validated experimentally using a novel fiber based SCOS (fb-SCOS) system for a dynamic sample. We have found that the signal-to-noise ratio (SNR) of fb-SCOS measurements plateaus at a camera exposure time, which marks the regime where shot and fundamental noise dominates over camera read noise. For a fixed total measurement time, there exists an optimized camera exposure time if temporal averaging is utilized to improve SNR. For a certain camera exposure time, photon flux value, and camera noise properties, there exists an optimized speckle-to-pixel size ratio (s/p) at which SNR is maximized. Our work provides the design principles for any LSCI or SCOS systems given the detected photon flux and properties of the instruments, which will guide the experimental development of a high-quality, low-cost fb-SCOS system that monitors human brain blood flow and functions.
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Affiliation(s)
- Sharvari Zilpelwar
- Department of Electrical and Computer Engineering, Boston University, MA 02215, USA
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, MA 02215, USA
| | - Edbert J Sie
- Reality Labs Research, Meta Platforms Inc., Menlo Park, CA 94025, USA
| | - Dmitry Postnov
- Department of Clinical Medicine, Aarhus University, Aarhus 8000, Denmark
| | - Anderson Ichun Chen
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, MA 02215, USA
| | - Bernhard Zimmermann
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, MA 02215, USA
| | - Francesco Marsili
- Reality Labs Research, Meta Platforms Inc., Menlo Park, CA 94025, USA
| | - David A Boas
- Department of Electrical and Computer Engineering, Boston University, MA 02215, USA
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, MA 02215, USA
| | - Xiaojun Cheng
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, MA 02215, USA
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12
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Paul R, Murali K, Varma HM. High-density diffuse correlation tomography with enhanced depth localization and minimal surface artefacts. BIOMEDICAL OPTICS EXPRESS 2022; 13:6081-6099. [PMID: 36733746 PMCID: PMC9872877 DOI: 10.1364/boe.469405] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 09/14/2022] [Accepted: 09/21/2022] [Indexed: 05/08/2023]
Abstract
A spatially weighted filter applied to both the measurement and the Jacobian is proposed for high-density diffuse correlation tomography (DCT) to remove unwanted extracerebral interferences and artefacts along with better depth localization in the reconstructed blood flow images. High-density DCT is implemented by appropriate modification of recently introduced Multi-speckle Diffuse Correlation Spectroscopy (M-DCS) system. Additionally, we have used autocorrelation measurements at multiple delay-times in an iterative manner to improve the reconstruction results. The proposed scheme has been validated by simulations, phantom experiments and in-vivo human experiments.
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13
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Xu S, Yang X, Liu W, Jönsson J, Qian R, Konda PC, Zhou KC, Kreiß L, Wang H, Dai Q, Berrocal E, Horstmeyer R. Imaging Dynamics Beneath Turbid Media via Parallelized Single-Photon Detection. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2201885. [PMID: 35748188 PMCID: PMC9404405 DOI: 10.1002/advs.202201885] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 05/16/2022] [Indexed: 05/05/2023]
Abstract
Noninvasive optical imaging through dynamic scattering media has numerous important biomedical applications but still remains a challenging task. While standard diffuse imaging methods measure optical absorption or fluorescent emission, it is also well-established that the temporal correlation of scattered coherent light diffuses through tissue much like optical intensity. Few works to date, however, have aimed to experimentally measure and process such temporal correlation data to demonstrate deep-tissue video reconstruction of decorrelation dynamics. In this work, a single-photon avalanche diode array camera is utilized to simultaneously monitor the temporal dynamics of speckle fluctuations at the single-photon level from 12 different phantom tissue surface locations delivered via a customized fiber bundle array. Then a deep neural network is applied to convert the acquired single-photon measurements into video of scattering dynamics beneath rapidly decorrelating tissue phantoms. The ability to reconstruct images of transient (0.1-0.4 s) dynamic events occurring up to 8 mm beneath a decorrelating tissue phantom with millimeter-scale resolution is demonstrated, and it is highlighted how the model can flexibly extend to monitor flow speed within buried phantom vessels.
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Affiliation(s)
- Shiqi Xu
- Department of Biomedical EngineeringDuke UniversityDurhamNC27708USA
| | - Xi Yang
- Department of Biomedical EngineeringDuke UniversityDurhamNC27708USA
| | - Wenhui Liu
- Department of Biomedical EngineeringDuke UniversityDurhamNC27708USA
- Department of AutomationTsinghua UniversityBeijing100084China
| | - Joakim Jönsson
- Division of Combustion PhysicsDepartment of PhysicsLund UniversityLund22100Sweden
| | - Ruobing Qian
- Department of Biomedical EngineeringDuke UniversityDurhamNC27708USA
| | | | - Kevin C. Zhou
- Department of Biomedical EngineeringDuke UniversityDurhamNC27708USA
| | - Lucas Kreiß
- Department of Biomedical EngineeringDuke UniversityDurhamNC27708USA
- Institute of Medical BiotechnologyFriedrich‐Alexander‐University Erlangen‐Nürnberg (FAU)Erlangen91054Germany
| | - Haoqian Wang
- Tsinghua Shenzhen International Graduate SchoolTsinghua UniversityShenzhen518055China
| | - Qionghai Dai
- Department of AutomationTsinghua UniversityBeijing100084China
| | - Edouard Berrocal
- Division of Combustion PhysicsDepartment of PhysicsLund UniversityLund22100Sweden
| | - Roarke Horstmeyer
- Department of Biomedical EngineeringDuke UniversityDurhamNC27708USA
- Department of Electrical and Computer EngineeringDuke UniversityDurhamNC27708USA
- Department of PhysicsDuke UniversityDurhamNC27708USA
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14
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Xu S, Liu W, Yang X, Jönsson J, Qian R, McKee P, Kim K, Konda PC, Zhou KC, Kreiß L, Wang H, Berrocal E, Huettel SA, Horstmeyer R. Transient Motion Classification Through Turbid Volumes via Parallelized Single-Photon Detection and Deep Contrastive Embedding. Front Neurosci 2022; 16:908770. [PMID: 35873809 PMCID: PMC9304989 DOI: 10.3389/fnins.2022.908770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 07/13/2022] [Indexed: 12/03/2022] Open
Abstract
Fast noninvasive probing of spatially varying decorrelating events, such as cerebral blood flow beneath the human skull, is an essential task in various scientific and clinical settings. One of the primary optical techniques used is diffuse correlation spectroscopy (DCS), whose classical implementation uses a single or few single-photon detectors, resulting in poor spatial localization accuracy and relatively low temporal resolution. Here, we propose a technique termed ClassifyingRapid decorrelationEvents viaParallelized single photon dEtection (CREPE), a new form of DCS that can probe and classify different decorrelating movements hidden underneath turbid volume with high sensitivity using parallelized speckle detection from a 32 × 32 pixel SPAD array. We evaluate our setup by classifying different spatiotemporal-decorrelating patterns hidden beneath a 5 mm tissue-like phantom made with rapidly decorrelating dynamic scattering media. Twelve multi-mode fibers are used to collect scattered light from different positions on the surface of the tissue phantom. To validate our setup, we generate perturbed decorrelation patterns by both a digital micromirror device (DMD) modulated at multi-kilo-hertz rates, as well as a vessel phantom containing flowing fluid. Along with a deep contrastive learning algorithm that outperforms classic unsupervised learning methods, we demonstrate our approach can accurately detect and classify different transient decorrelation events (happening in 0.1–0.4 s) underneath turbid scattering media, without any data labeling. This has the potential to be applied to non-invasively monitor deep tissue motion patterns, for example identifying normal or abnormal cerebral blood flow events, at multi-Hertz rates within a compact and static detection probe.
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Affiliation(s)
- Shiqi Xu
- Department of Biomedical Engineering, Duke University, Durham, NC, United States
| | - Wenhui Liu
- Department of Biomedical Engineering, Duke University, Durham, NC, United States
- Department of Automation, Tsinghua University, Beijing, China
| | - Xi Yang
- Department of Biomedical Engineering, Duke University, Durham, NC, United States
| | - Joakim Jönsson
- Division of Combustion Physics, Department of Physics, Lund University, Lund, Sweden
| | - Ruobing Qian
- Department of Biomedical Engineering, Duke University, Durham, NC, United States
| | - Paul McKee
- Department of Psychology and Neuroscience, Duke University, Durham, NC, United States
| | - Kanghyun Kim
- Department of Biomedical Engineering, Duke University, Durham, NC, United States
| | - Pavan Chandra Konda
- Department of Biomedical Engineering, Duke University, Durham, NC, United States
| | - Kevin C. Zhou
- Department of Biomedical Engineering, Duke University, Durham, NC, United States
| | - Lucas Kreiß
- Department of Biomedical Engineering, Duke University, Durham, NC, United States
- Institute of Medical Biotechnology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Haoqian Wang
- Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, China
| | - Edouard Berrocal
- Division of Combustion Physics, Department of Physics, Lund University, Lund, Sweden
| | - Scott A. Huettel
- Department of Psychology and Neuroscience, Duke University, Durham, NC, United States
| | - Roarke Horstmeyer
- Department of Biomedical Engineering, Duke University, Durham, NC, United States
- Department of Electrical Engineering, Duke University, Durham, NC, United States
- *Correspondence: Roarke Horstmeyer
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15
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Zhao H, Buckley EM. Influence of source-detector separation on diffuse correlation spectroscopy measurements of cerebral blood flow with a multilayered analytical model. NEUROPHOTONICS 2022; 9:035002. [PMID: 35874143 PMCID: PMC9299346 DOI: 10.1117/1.nph.9.3.035002] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 06/22/2022] [Indexed: 05/24/2023]
Abstract
Significance: Diffuse correlation spectroscopy (DCS) is an emerging noninvasive optical technology for bedside monitoring of cerebral blood flow. However, extracerebral hemodynamics can significantly influence DCS estimations of cerebral perfusion. Advanced analytical models can be used to remove the contribution of extracerebral hemodynamics; however, these models are highly sensitive to measurement noise. There is a need for an empirical determination of the optimal source-detector separation(s) (SDS) that improves the accuracy and reduces sensitivity to noise in the estimation of cerebral blood flow with these models. Aim: To determine the influence of SDS on solution uniqueness, measurement accuracy, and sensitivity to inaccuracies in model parameters when using the three-layer model to estimate cerebral blood flow with DCS. Approach: We performed a series of in silico simulations on samples spanning a wide range of physiologically-relevant layer optical properties, thicknesses, and flow. Data were simulated at SDS ranging from 0.5 to 3.0 cm using the three-layer solution to the correlation diffusion equation (with and without noise added) and using three-layer slab Monte Carlo simulations. We quantified the influence of SDS on uniqueness, accuracy, and sensitivity to inaccuracies in model parameters using the three-layer inverse model. Results: Two SDS are required to ensure a unique solution of cerebral blood flow index (CBFi). Combinations of 0.5/1.0/1.5 and 2.5 cm provide the optimal choice for balancing the depth penetration with signal-to-noise ratio to minimize the error in CBFi across a wide range of samples with varying optical properties, thicknesses, and dynamics. Conclusions: These results suggest that the choice of SDS is critical for minimizing the estimated error of cerebral blood flow when using the three-layer model to analyze DCS data.
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Affiliation(s)
- Hongting Zhao
- Wallace H. Coulter Department of Biomedical Engineering at Georgia Institute of Technology and Emory University, Atlanta, Georgia, United States
| | - Erin M. Buckley
- Wallace H. Coulter Department of Biomedical Engineering at Georgia Institute of Technology and Emory University, Atlanta, Georgia, United States
- Emory University School of Medicine, Department of Pediatrics, Atlanta, Georgia, United States
- Children’s Healthcare of Atlanta, Children’s Research Scholar, Atlanta, Georgia, United States
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16
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James E, Powell S, Munro P. Performance optimisation of a holographic Fourier domain diffuse correlation spectroscopy instrument. BIOMEDICAL OPTICS EXPRESS 2022; 13:3836-3853. [PMID: 35991914 PMCID: PMC9352302 DOI: 10.1364/boe.454346] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 04/05/2022] [Accepted: 04/22/2022] [Indexed: 06/02/2023]
Abstract
We have previously demonstrated a novel interferometric multispeckle Fourier domain diffuse correlation spectroscopy system that makes use of holographic camera-based detection, and which is capable of making in vivo pulsatile flow measurements. In this work, we report on a systematic characterisation of the signal-to-noise ratio performance of our system. This includes demonstration and elimination of laser mode hopping, and correction for the instrument's modulation transfer function to ensure faithful reconstruction of measured intensity profiles. We also demonstrate a singular value decomposition approach to ensure that spatiotemporally correlated experimental noise sources do not limit optimal signal-to-noise ratio performance. Finally, we present a novel multispeckle denoising algorithm that allows our instrument to achieve a signal-to-noise ratio gain that is equal to the square root of the number of detected speckles, whilst detecting up to ∼1290 speckles in parallel. The signal-to-noise ratio gain of 36 that we report is a significant step toward mitigating the trade-off that exists between signal-to-noise ratio and imaging depth in diffuse correlation spectroscopy.
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Affiliation(s)
- Edward James
- Department of Medical Physics & Biomedical Engineering, University College London, London, WC1E 6BT, UK
| | - Samuel Powell
- Department of Medical Physics & Biomedical Engineering, University College London, London, WC1E 6BT, UK
- Faculty of Engineering, The University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Peter Munro
- Department of Medical Physics & Biomedical Engineering, University College London, London, WC1E 6BT, UK
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17
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Zeng C, Chen Z, Yang H, Fan Y, Fei L, Chen X, Zhang M. Advanced high resolution three-dimensional imaging to visualize the cerebral neurovascular network in stroke. Int J Biol Sci 2022; 18:552-571. [PMID: 35002509 PMCID: PMC8741851 DOI: 10.7150/ijbs.64373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 10/28/2021] [Indexed: 11/05/2022] Open
Abstract
As an important method to accurately and timely diagnose stroke and study physiological characteristics and pathological mechanism in it, imaging technology has gone through more than a century of iteration. The interaction of cells densely packed in the brain is three-dimensional (3D), but the flat images brought by traditional visualization methods show only a few cells and ignore connections outside the slices. The increased resolution allows for a more microscopic and underlying view. Today's intuitive 3D imagings of micron or even nanometer scale are showing its essentiality in stroke. In recent years, 3D imaging technology has gained rapid development. With the overhaul of imaging mediums and the innovation of imaging mode, the resolution has been significantly improved, endowing researchers with the capability of holistic observation of a large volume, real-time monitoring of tiny voxels, and quantitative measurement of spatial parameters. In this review, we will summarize the current methods of high-resolution 3D imaging applied in stroke.
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Affiliation(s)
- Chudai Zeng
- Department of Neurology, Xiangya Hospital of Central South University, Changsha, Hunan, China, 410008.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China, 410008
| | - Zhuohui Chen
- Department of Neurology, Xiangya Hospital of Central South University, Changsha, Hunan, China, 410008.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China, 410008
| | - Haojun Yang
- Department of Neurology, Xiangya Hospital of Central South University, Changsha, Hunan, China, 410008.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China, 410008
| | - Yishu Fan
- Department of Neurology, Xiangya Hospital of Central South University, Changsha, Hunan, China, 410008.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China, 410008
| | - Lujing Fei
- Department of Neurology, Xiangya Hospital of Central South University, Changsha, Hunan, China, 410008.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China, 410008
| | - Xinghang Chen
- Department of Neurology, Xiangya Hospital of Central South University, Changsha, Hunan, China, 410008.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China, 410008
| | - Mengqi Zhang
- Department of Neurology, Xiangya Hospital of Central South University, Changsha, Hunan, China, 410008.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China, 410008
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18
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Cheng X, Chen H, Sie EJ, Marsili F, Boas DA. Development of a Monte Carlo-wave model to simulate time domain diffuse correlation spectroscopy measurements from first principles. JOURNAL OF BIOMEDICAL OPTICS 2022; 27:JBO-210362SSR. [PMID: 35199501 PMCID: PMC8866418 DOI: 10.1117/1.jbo.27.8.083009] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 02/07/2022] [Indexed: 05/18/2023]
Abstract
SIGNIFICANCE Diffuse correlation spectroscopy (DCS) is an optical technique that measures blood flow non-invasively and continuously. The time-domain (TD) variant of DCS, namely, TD-DCS has demonstrated a potential to improve brain depth sensitivity and to distinguish superficial from deeper blood flow by utilizing pulsed laser sources and a gating strategy to select photons with different pathlengths within the scattering tissue using a single source-detector separation. A quantitative tool to predict the performance of TD-DCS that can be compared with traditional continuous wave DCS (CW-DCS) currently does not exist but is crucial to provide guidance for the continued development and application of these DCS systems. AIMS We aim to establish a model to simulate TD-DCS measurements from first principles, which enables analysis of the impact of measurement noise that can be utilized to quantify the performance for any particular TD-DCS system and measurement geometry. APPROACH We have integrated the Monte Carlo simulation describing photon scattering in biological tissue with the wave model that calculates the speckle intensity fluctuations due to tissue dynamics to simulate TD-DCS measurements from first principles. RESULTS Our model is capable of simulating photon counts received at the detector as a function of time for both CW-DCS and TD-DCS measurements. The effects of the laser coherence, instrument response function, detector gate delay, gate width, intrinsic noise arising from speckle statistics, and shot noise are incorporated in the model. We have demonstrated the ability of our model to simulate TD-DCS measurements under different conditions, and the use of our model to compare the performance of TD-DCS and CW-DCS under a few typical measurement conditions. CONCLUSION We have established a Monte Carlo-Wave model that is capable of simulating CW-DCS and TD-DCS measurements from first principles. In our exploration of the parameter space, we could not find realistic measurement conditions under which TD-DCS outperformed CW-DCS. However, the parameter space for the optimization of the contrast to noise ratio of TD-DCS is large and complex, so our results do not imply that TD-DCS cannot indeed outperform CW-DCS under different conditions. We made our code available publicly for others in the field to find use cases favorable to TD-DCS. TD-DCS also provides a promising way to measure deep brain tissue dynamics using a short source-detector separation, which will benefit the development of technologies including high density DCS systems and image reconstruction using a limited number of source-detector pairs.
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Affiliation(s)
- Xiaojun Cheng
- Boston University, Neurophotonics Center, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Hui Chen
- Meta Platforms Inc., Reality Labs Research, Menlo Park, California, United States
| | - Edbert J. Sie
- Meta Platforms Inc., Reality Labs Research, Menlo Park, California, United States
| | - Francesco Marsili
- Meta Platforms Inc., Reality Labs Research, Menlo Park, California, United States
| | - David A. Boas
- Boston University, Neurophotonics Center, Department of Biomedical Engineering, Boston, Massachusetts, United States
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19
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Biswas A, Moka S, Muller A, Parthasarathy AB. Fast diffuse correlation spectroscopy with a low-cost, fiber-less embedded diode laser. BIOMEDICAL OPTICS EXPRESS 2021; 12:6686-6700. [PMID: 34858674 PMCID: PMC8606156 DOI: 10.1364/boe.435136] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 09/20/2021] [Accepted: 09/21/2021] [Indexed: 06/02/2023]
Abstract
Diffuse correlation spectroscopy (DCS), a popular optical technique for fast noninvasive measurement of blood flow, is commonly implemented using expensive fiber-coupled long coherence length laser systems. Here, we report the development of a portable and fiber-less approach that can be used as a low-cost alternative to illuminate tissue in DCS instruments. We validate the accuracy and noise characteristics of the fiber-less DCS laser source, by comparisons against traditional DCS light sources, with experiments on controlled tissue-simulating phantoms and in humans.
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Affiliation(s)
- Arindam Biswas
- Department of Electrical Engineering, University of South Florida, 4202 E. Fowler Avenue, ENG030, Tampa, FL 33620, USA
| | - Sadhu Moka
- Department of Electrical Engineering, University of South Florida, 4202 E. Fowler Avenue, ENG030, Tampa, FL 33620, USA
| | - Andreas Muller
- Department of Physics, University of South Florida, 4202 E. Fowler Avenue, ISA2019, Tampa, FL 33620, USA
| | - Ashwin B. Parthasarathy
- Department of Electrical Engineering, University of South Florida, 4202 E. Fowler Avenue, ENG030, Tampa, FL 33620, USA
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20
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Zhao H, Sathialingam E, Buckley EM. Accuracy of diffuse correlation spectroscopy measurements of cerebral blood flow when using a three-layer analytical model. BIOMEDICAL OPTICS EXPRESS 2021; 12:7149-7161. [PMID: 34858706 PMCID: PMC8606134 DOI: 10.1364/boe.438303] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 10/15/2021] [Accepted: 10/15/2021] [Indexed: 05/06/2023]
Abstract
Diffuse correlation spectroscopy (DCS) is a non-invasive optical technology for the assessment of an index of cerebral blood flow (CBFi). Analytical methods that model the head as a three-layered medium (i.e., scalp, skull, brain) are becoming more commonly used to minimize the contribution of extracerebral layers to the measured DCS signal in adult cerebral blood flow studies. However, these models rely on a priori knowledge of layer optical properties and thicknesses. Errors in these values can lead to errors in the estimation of CBFi, although the magnitude of this influence has not been rigorously characterized. Herein, we investigate the accuracy of measuring cerebral blood flow with a three-layer model when errors in layer optical properties or thicknesses are present. Through a series of in silico experiments, we demonstrate that CBFi is highly sensitive to errors in brain optical properties and skull and scalp thicknesses. Relative changes in CBFi are less sensitive to optical properties but are influenced by errors in layer thickness. Thus, when using the three-layer model, accurate estimation of scalp and skull thickness are required for reliable results.
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Affiliation(s)
- Hongting Zhao
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 1760 Haygood Dr. NE, Atlanta, GA 30322, USA
| | - Eashani Sathialingam
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 1760 Haygood Dr. NE, Atlanta, GA 30322, USA
| | - Erin M. Buckley
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 1760 Haygood Dr. NE, Atlanta, GA 30322, USA
- Department of Pediatrics, Emory University School of Medicine, 2015 Uppergate Dr., Atlanta, GA 30322, USA
- Children’s Research Scholar, Children’s Healthcare of Atlanta, 2015 Uppergate Dr., Atlanta, GA 30322, USA
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21
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Samaei S, Colombo L, Borycki D, Pagliazzi M, Durduran T, Sawosz P, Wojtkiewicz S, Contini D, Torricelli A, Pifferi A, Liebert A. Performance assessment of laser sources for time-domain diffuse correlation spectroscopy. BIOMEDICAL OPTICS EXPRESS 2021; 12:5351-5367. [PMID: 34692187 PMCID: PMC8515963 DOI: 10.1364/boe.432363] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 07/26/2021] [Accepted: 07/27/2021] [Indexed: 05/02/2023]
Abstract
Time-domain diffuse correlation spectroscopy (TD-DCS) is an emerging optical technique that enables noninvasive measurement of microvascular blood flow with photon path-length resolution. In TD-DCS, a picosecond pulsed laser with a long coherence length, adequate illumination power, and narrow instrument response function (IRF) is required, and satisfying all these features is challenging. To this purpose, in this study we characterized the performance of three different laser sources for TD-DCS. First, the sources were evaluated based on their emission spectrum and IRF. Then, we compared the signal-to-noise ratio and the sensitivity to velocity changes of scattering particles in a series of phantom measurements. We also compared the results for in vivo measurements, performing an arterial occlusion protocol on the forearm of three adult subjects. Overall, each laser has the potential to be successfully used both for laboratory and clinical applications. However, we found that the effects caused by the IRF are more significant than the effect of a limited temporal coherence.
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Affiliation(s)
- Saeed Samaei
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Ks. Trojdena 4, 02-109, Warsaw, Poland
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Lorenzo Colombo
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Dawid Borycki
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
- International Centre for Translational Eye Research, Skierniewicka 10A, 01-230 Warsaw, Poland
| | - Marco Pagliazzi
- ICFO—Institut de Ciències Fotòniques, Mediterranean Technology Park, Avinguda Carl Friedrich Gauss 3, 08860 Castelldefels, Barcelona, Spain
| | - Turgut Durduran
- ICFO—Institut de Ciències Fotòniques, Mediterranean Technology Park, Avinguda Carl Friedrich Gauss 3, 08860 Castelldefels, Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Passeig de Lluís Companys 23, 08010 Barcelona, Spain
| | - Piotr Sawosz
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Ks. Trojdena 4, 02-109, Warsaw, Poland
| | - Stanislaw Wojtkiewicz
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Ks. Trojdena 4, 02-109, Warsaw, Poland
| | - Davide Contini
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Alessandro Torricelli
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Antonio Pifferi
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Adam Liebert
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Ks. Trojdena 4, 02-109, Warsaw, Poland
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22
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Cheng X, Sie EJ, Naufel S, Boas DA, Marsili F. Measuring neuronal activity with diffuse correlation spectroscopy: a theoretical investigation. NEUROPHOTONICS 2021; 8:035004. [PMID: 34368390 PMCID: PMC8339443 DOI: 10.1117/1.nph.8.3.035004] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 07/16/2021] [Indexed: 05/18/2023]
Abstract
Significance: Diffuse correlation spectroscopy (DCS) measures cerebral blood flow non-invasively. Variations in blood flow can be used to detect neuronal activities, but its peak has a latency of a few seconds, which is slow for real-time monitoring. Neuronal cells also deform during activation, which, in principle, can be utilized to detect neuronal activity on fast timescales (within 100 ms) using DCS. Aims: We aim to characterize DCS signal variation quantified as the change of the decay time of the speckle intensity autocorrelation function during neuronal activation on both fast (within 100 ms) and slow (100 ms to seconds) timescales. Approach: We extensively modeled the variations in the DCS signal that are expected to arise from neuronal activation using Monte Carlo simulations, including the impacts of neuronal cell motion, vessel wall dilation, and blood flow changes. Results: We found that neuronal cell motion induces a DCS signal variation of ∼ 10 - 5 . We also estimated the contrast and number of channels required to detect hemodynamic signals at different time delays. Conclusions: From this extensive analysis, we do not expect to detect neuronal cell motion using DCS in the near future based on current technology trends. However, multi-channel DCS will be able to detect hemodynamic response with sub-second latency, which is interesting for brain-computer interfaces.
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Affiliation(s)
- Xiaojun Cheng
- Boston University, Neurophotonics Center, Department of Biomedical Engineering, Massachusetts, United States
- Address all correspondence to Xiaojun Cheng,
| | - Edbert J. Sie
- Facebook Reality Labs Research, Menlo Park, California, United States
| | - Stephanie Naufel
- Facebook Reality Labs Research, Menlo Park, California, United States
| | - David A. Boas
- Boston University, Neurophotonics Center, Department of Biomedical Engineering, Massachusetts, United States
| | - Francesco Marsili
- Facebook Reality Labs Research, Menlo Park, California, United States
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23
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Li Z, Ge Q, Feng J, Jia K, Zhao J. Quantification of blood flow index in diffuse correlation spectroscopy using long short-term memory architecture. BIOMEDICAL OPTICS EXPRESS 2021; 12:4131-4146. [PMID: 34457404 PMCID: PMC8367234 DOI: 10.1364/boe.423777] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 06/08/2021] [Accepted: 06/08/2021] [Indexed: 05/30/2023]
Abstract
Diffuse correlation spectroscopy (DCS) is a noninvasive technique that derives blood flow information from measurements of the temporal intensity fluctuations of multiply scattered light. Blood flow index (BFI) and especially its variation was demonstrated to be approximately proportional to absolute blood flow. We investigated and assessed the utility of a long short-term memory (LSTM) architecture for quantification of BFI in DCS. Phantom and in vivo experiments were established to measure normalized intensity autocorrelation function data. Improved accuracy and faster computational time were gained by the proposed LSTM architecture. The results support the notion of using proposed LSTM architecture for quantification of BFI in DCS. This approach would be especially useful for continuous real-time monitoring of blood flow.
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Affiliation(s)
- Zhe Li
- Faculty of Information Technology, Beijing University of Technology, Beijing 100124, China
- Beijing Laboratory of Advanced Information Networks, Beijing 100124, China
- Beijing Key Laboratory of Computational Intelligence and Intelligent System, Beijing University of Technology, Beijing 100124, China
- Zhe Li and Qisi Ge contributed equally to this work
| | - Qisi Ge
- Faculty of Information Technology, Beijing University of Technology, Beijing 100124, China
- Beijing Laboratory of Advanced Information Networks, Beijing 100124, China
- Beijing Key Laboratory of Computational Intelligence and Intelligent System, Beijing University of Technology, Beijing 100124, China
- Zhe Li and Qisi Ge contributed equally to this work
| | - Jinchao Feng
- Faculty of Information Technology, Beijing University of Technology, Beijing 100124, China
- Beijing Laboratory of Advanced Information Networks, Beijing 100124, China
- Beijing Key Laboratory of Computational Intelligence and Intelligent System, Beijing University of Technology, Beijing 100124, China
| | - Kebin Jia
- Faculty of Information Technology, Beijing University of Technology, Beijing 100124, China
- Beijing Laboratory of Advanced Information Networks, Beijing 100124, China
- Beijing Key Laboratory of Computational Intelligence and Intelligent System, Beijing University of Technology, Beijing 100124, China
| | - Jing Zhao
- College of Pharmaceutical Engineering of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China
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24
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Cortese L, Lo Presti G, Pagliazzi M, Contini D, Dalla Mora A, Dehghani H, Ferri F, Fischer JB, Giovannella M, Martelli F, Weigel UM, Wojtkiewicz S, Zanoletti M, Durduran T. Recipes for diffuse correlation spectroscopy instrument design using commonly utilized hardware based on targets for signal-to-noise ratio and precision. BIOMEDICAL OPTICS EXPRESS 2021; 12:3265-3281. [PMID: 34221659 PMCID: PMC8221932 DOI: 10.1364/boe.423071] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 04/18/2021] [Accepted: 05/04/2021] [Indexed: 05/09/2023]
Abstract
Over the recent years, a typical implementation of diffuse correlation spectroscopy (DCS) instrumentation has been adapted widely. However, there are no detailed and accepted recipes for designing such instrumentation to meet pre-defined signal-to-noise ratio (SNR) and precision targets. These require specific attention due to the subtleties of the DCS signals. Here, DCS experiments have been performed using liquid tissue simulating phantoms to study the effect of the detected photon count-rate, the number of parallel detection channels and the measurement duration on the precision and SNR to suggest scaling relations to be utilized for device design.
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Affiliation(s)
- Lorenzo Cortese
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
- These authors equally contributed to this work. Authors are listed in alphabetical order except for the first three and the last
| | - Giuseppe Lo Presti
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
- These authors equally contributed to this work. Authors are listed in alphabetical order except for the first three and the last
| | - Marco Pagliazzi
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
| | - Davide Contini
- Politecnico di Milano, Dipartimento di Fisica, 20133 Milano, Italy
| | | | - Hamid Dehghani
- University of Birmingham, School of Computer Science, Edgbaston, Birmingham, B15 2TT, UK
| | - Fabio Ferri
- Università degli Studi dell’Insubria, Dipartimento di Scienza e Alta Tecnologia and To. Sca. Lab., 22100 Como, Italy
| | - Jonas B. Fischer
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
- HemoPhotonics S.L., 08860 Castelldefels (Barcelona), Spain
| | - Martina Giovannella
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
| | - Fabrizio Martelli
- Università degli Studi di Firenze, Dipartimento di Fisica, 50100 Firenze, Italy
| | - Udo M. Weigel
- HemoPhotonics S.L., 08860 Castelldefels (Barcelona), Spain
| | - Stanislaw Wojtkiewicz
- University of Birmingham, School of Computer Science, Edgbaston, Birmingham, B15 2TT, UK
| | - Marta Zanoletti
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
- Politecnico di Milano, Dipartimento di Fisica, 20133 Milano, Italy
| | - Turgut Durduran
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), 08015 Barcelona, Spain
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25
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Pagliazzi M, Colombo L, Vidal-Rosas EE, Dragojević T, Parfentyeva V, Culver JP, Konugolu Venkata Sekar S, Di Sieno L, Contini D, Torricelli A, Pifferi A, Dalla Mora A, Durduran T. Time resolved speckle contrast optical spectroscopy at quasi-null source-detector separation for non-invasive measurement of microvascular blood flow. BIOMEDICAL OPTICS EXPRESS 2021; 12:1499-1511. [PMID: 33796368 PMCID: PMC7984782 DOI: 10.1364/boe.418882] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 02/10/2021] [Accepted: 02/10/2021] [Indexed: 05/03/2023]
Abstract
Time (or path length) resolved speckle contrast optical spectroscopy (TD-SCOS) at quasi-null (2.85 mm) source-detector separation was developed and demonstrated. The method was illustrated by in vivo studies on the forearm muscle of an adult subject. The results have shown that selecting longer photon path lengths results in higher hyperemic blood flow change and a faster return to baseline by a factor of two after arterial cuff occlusion when compared to SCOS without time resolution. This indicates higher sensitivity to the deeper muscle tissue. In the long run, this approach may allow the use of simpler and cheaper detector arrays compared to time resolved diffuse correlation spectroscopy that are based on readily available technologies. Hence, TD-SCOS may increase the performance and decrease cost of devices for continuous non-invasive, deep tissue blood flow monitoring.
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Affiliation(s)
- Marco Pagliazzi
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | - Lorenzo Colombo
- Politecnico di Milano, Dipartimento di Fisica, 20133 Milano, Italy
| | - Ernesto E. Vidal-Rosas
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | - Tanja Dragojević
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | - Veronika Parfentyeva
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | - Joseph P. Culver
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
| | | | - Laura Di Sieno
- Politecnico di Milano, Dipartimento di Fisica, 20133 Milano, Italy
| | - Davide Contini
- Politecnico di Milano, Dipartimento di Fisica, 20133 Milano, Italy
| | - Alessandro Torricelli
- Politecnico di Milano, Dipartimento di Fisica, 20133 Milano, Italy
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, 20133 Milano, Italy
| | - Antonio Pifferi
- Politecnico di Milano, Dipartimento di Fisica, 20133 Milano, Italy
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, 20133 Milano, Italy
| | | | - Turgut Durduran
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), 08015 Barcelona, Spain
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26
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Feng S, Gui Z, Zhang X, Shang Y. Collimating micro-lens fiber array for noncontact near-infrared diffuse correlation tomography. BIOMEDICAL OPTICS EXPRESS 2021; 12:1467-1481. [PMID: 33796366 PMCID: PMC7984780 DOI: 10.1364/boe.413734] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 02/06/2021] [Accepted: 02/06/2021] [Indexed: 06/01/2023]
Abstract
Near-infrared diffuse correlation spectroscopy/tomography (DCS/DCT) has recently emerged as a noninvasive measurement/imaging technology for tissue blood flow. In DCT studies, the high-dense collection of light temporal autocorrelation curves (g 2(τ)) via fiber array are critical for image reconstruction of blood flow. Previously, the camera-based fiber array limits the field of view (FOV), precluding its applications on large-size human tissues. The line-shape fiber probe based on lens combination, which is predominantly used in current DCT studies, requires rotated-scanning over the surface of target tissue, substantially prolonging the measurement time and increasing the system instability. In this study, we design a noncontact optical probe for DCT based on collimating micro-lens fiber array, termed as FA-nc-DCT system. For each source/detector fiber, a single optical path was collimated by coupling with one micro-lens in the fiber array that is integrated in a square-shape base. Additionally, an 8×8 optical switch is used to share the hardware laser and detectors without spatial scanning. The FA-nc approach for the precise collection of g 2(τ) curves was validated through a speed-varied phantom experiment and the human experiments of cuff occlusion, from which the expected value of the blood flow index (BFI) was obtained. Furthermore, the flow anomaly in the phantom and the ischemic muscle in human were accurately reconstructed from the FA-nc-DCT system, which is combined with the imaging framework based on the Nth-order linear algorithm that we recently created. Those outcomes demonstrated the great potential of FA-nc-DCT technology for fast and robust imaging of various diseases such as human breast cancers.
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27
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Mo W, Patel NJ, Chen Y, Pandey R, Sunar U. Mapping fluorescence resonance energy transfer parameters of a bifunctional agent using time-domain fluorescence diffuse optical tomography. JOURNAL OF BIOPHOTONICS 2021; 14:e202000291. [PMID: 33025728 DOI: 10.1002/jbio.202000291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 09/22/2020] [Accepted: 09/25/2020] [Indexed: 06/11/2023]
Abstract
We present a method to map fluorescence resonance energy transfer (FRET) parameters of a bifunctional photodynamic therapy agent, (2-[1-hexyloxyethyl]-2-devinyl pyropheophorbide-a)-cyanine dye (HPPH-CD) conjugate, which consists of a photosensitizer (HPPH) and a fluorescent agent CD. We utilized time-domain fluorescence diffuse optical tomography, the normalized Born ratio model in the Fourier-domain, and an iterative algorithm to map depth-resolved spatial heterogeneities of FRET parameters. Our results exhibited depth-resolved changes of fluorophore's lifetime and the distance maps due to FRET between HPPH and CD. Our model suggests a potential approach of using FRET parameters to monitor efficacies of multifunctional photodynamic therapy agents in deep tissue.
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Affiliation(s)
- Weirong Mo
- Topcon Healthcare Solutions, San Jose, California, USA
| | - Nayan J Patel
- Department of Cell Stress Biology and PDT Center, Roswell Park Cancer Institute, Buffalo, New York, USA
| | - Yihui Chen
- Department of Cell Stress Biology and PDT Center, Roswell Park Cancer Institute, Buffalo, New York, USA
| | - Ravindra Pandey
- Department of Cell Stress Biology and PDT Center, Roswell Park Cancer Institute, Buffalo, New York, USA
| | - Ulas Sunar
- Department of Biomedical Engineering, Wright State University, Dayton, Ohio, USA
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28
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Colombo L, Pagliazzi M, Konugolu Venkata Sekar S, Contini D, Durduran T, Pifferi A. In vivo time-domain diffuse correlation spectroscopy above the water absorption peak. OPTICS LETTERS 2020; 45:3377-3380. [PMID: 32630849 DOI: 10.1364/ol.392355] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 05/09/2020] [Indexed: 05/18/2023]
Abstract
Time-domain diffuse correlation spectroscopy (TD-DCS) is a newly emerging optical technique that exploits pulsed, yet coherent light to non-invasively resolve the blood flow in depth. In this work, we have explored TD-DCS at longer wavelengths compared to those previously used in literature (i.e., 750-850 nm). The measurements were performed using a custom-made titanium-sapphire mode-locked laser, operating at 1000 nm, and an InGaAs photomultiplier as a detector. Tissue-mimicking phantoms and in vivo measurements during arterial arm cuff occlusion in n=4 adult volunteers were performed to demonstrate the proof of concept. We obtained a good signal-to-noise ratio, following the hemodynamics continuously with a relatively fast (1 Hz) sampling rate. In all the experiments, the auto-correlation functions show a decay rate approximately five-fold slower compared to shorter wavelengths. This work demonstrates the feasibility of in vivo TD-DCS in this spectral region and its potentiality for biomedical applications.
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29
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Sie EJ, Chen H, Saung EF, Catoen R, Tiecke T, Chevillet MA, Marsili F. High-sensitivity multispeckle diffuse correlation spectroscopy. NEUROPHOTONICS 2020; 7:035010. [PMID: 32995362 PMCID: PMC7519351 DOI: 10.1117/1.nph.7.3.035010] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 09/04/2020] [Indexed: 05/04/2023]
Abstract
Significance: Cerebral blood flow is an important biomarker of brain health and function as it regulates the delivery of oxygen and substrates to tissue and the removal of metabolic waste products. Moreover, blood flow changes in specific areas of the brain are correlated with neuronal activity in those areas. Diffuse correlation spectroscopy (DCS) is a promising noninvasive optical technique for monitoring cerebral blood flow and for measuring cortex functional activation tasks. However, the current state-of-the-art DCS adoption is hindered by a trade-off between sensitivity to the cortex and signal-to-noise ratio (SNR). Aim: We aim to develop a scalable method that increases the sensitivity of DCS instruments. Approach: We report on a multispeckle DCS (mDCS) approach that is based on a 1024-pixel single-photon avalanche diode (SPAD) camera. Our approach is scalable to > 100,000 independent speckle measurements since large-pixel-count SPAD cameras are becoming available, owing to the investments in LiDAR technology for automotive and augmented reality applications. Results: We demonstrated a 32-fold increase in SNR with respect to traditional single-speckle DCS. Conclusion: A mDCS system that is based on a SPAD camera serves as a scalable method toward high-sensitivity DCS measurements, thus enabling both high sensitivity to the cortex and high SNR.
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Affiliation(s)
- Edbert J. Sie
- Facebook Reality Labs Research, Menlo Park, California, United States
- Address all correspondence to Edbert J. Sie, ; Francesco Marsili,
| | - Hui Chen
- Facebook Reality Labs Research, Menlo Park, California, United States
| | - E-Fann Saung
- Facebook Reality Labs Research, Menlo Park, California, United States
| | - Ryan Catoen
- Facebook Reality Labs Research, Menlo Park, California, United States
| | - Tobias Tiecke
- Facebook Reality Labs Research, Menlo Park, California, United States
| | - Mark A. Chevillet
- Facebook Reality Labs Research, Menlo Park, California, United States
| | - Francesco Marsili
- Facebook Reality Labs Research, Menlo Park, California, United States
- Address all correspondence to Edbert J. Sie, ; Francesco Marsili,
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30
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Bi R, Du Y, Singh G, Ho CJH, Zhang S, Attia ABE, Li X, Olivo M. Fast pulsatile blood flow measurement in deep tissue through a multimode detection fiber. JOURNAL OF BIOMEDICAL OPTICS 2020; 25:1-10. [PMID: 32406214 PMCID: PMC7219964 DOI: 10.1117/1.jbo.25.5.055003] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 04/27/2020] [Indexed: 05/05/2023]
Abstract
SIGNIFICANCE Noninvasive in vivo fast pulsatile blood flow measurement in deep tissue is important because the blood flow waveform is correlated with physiological parameters, such as blood pressure and elasticity of blood vessels. Compromised blood flow may cause diseases, such as stroke, foot ulcer, and myocardial ischemia. There is great clinical demand for a portable and cost-effective device for noninvasive pulsatile blood flow measurement. AIM A diffuse-optics-based method, diffuse speckle pulsatile flowmetry (DSPF), was developed for fast measurement (∼300 Hz) of deep tissue blood flow noninvasively. To validate its performance, both a phantom experiment and in vivo demonstration were conducted. APPROACH Over the past two decades, single-mode fibers have been used as detection fibers in most diffuse-optics-based deep tissue blood flow measurement modalities. We used a multimode (MM) detection fiber with a core size of 200 μm for diffused speckle pattern detection. A background intensity correction algorithm was implemented for speckle contrast calculation. The MM detection fiber helped to achieve a level of deep tissue blood flow measurement similar to that of conventional modalities, such as diffuse correlation spectroscopy and diffuse speckle contrast analysis, but it increases the measurement rate of blood flow to 300 Hz. RESULTS The design and implementation of the DSPF system were introduced. The theory of the background intensity correction for the diffused speckle pattern detected by the MM fiber was explained. A flow phantom was built for validation of the performance of the DSPF system. An in vivo cuff-induced occlusion experiment was performed to demonstrate the capability of the proposed DSPF system. CONCLUSIONS An MM detection fiber can help to achieve fast (∼300 Hz) pulsatile blood flow measurement in the proposed DSPF method. The cost-effective device and the fiber-based flexible probe increase the usability of the DSPF system significantly.
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Affiliation(s)
- Renzhe Bi
- Singapore Bioimaging Consortium, Singapore
| | - Yao Du
- Singapore Bioimaging Consortium, Singapore
| | | | | | | | | | - Xiuting Li
- Singapore Bioimaging Consortium, Singapore
| | - Malini Olivo
- Singapore Bioimaging Consortium, Singapore
- Address all correspondence to Malini Olivo, E-mail:
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31
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Du Le VN, Srinivasan VJ. Beyond diffuse correlations: deciphering random flow in time-of-flight resolved light dynamics. OPTICS EXPRESS 2020; 28:11191-11214. [PMID: 32403635 PMCID: PMC7340374 DOI: 10.1364/oe.385202] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Diffusing wave spectroscopy (DWS) and diffuse correlation spectroscopy (DCS) can assess blood flow index (BFI) of biological tissue with multiply scattered light. Though the main biological function of red blood cells (RBCs) is advection, in DWS/DCS, RBCs are assumed to undergo Brownian motion. To explain this discrepancy, we critically examine the cumulant approximation, a major assumption in DWS/DCS. We present a precise criterion for validity of the cumulant approximation, and in realistic tissue models, identify conditions that invalidate it. We show that, in physiologically relevant scenarios, the first cumulant term for random flow and second cumulant term for Brownian motion alone can cancel each other. In such circumstances, assuming pure Brownian motion of RBCs and the first cumulant approximation, a routine practice in DWS/DCS of BFI, can yield good agreement with data, but only because errors due to two incorrect assumptions cancel out. We conclude that correctly assessing random flow from scattered light dynamics requires going beyond the cumulant approximation and propose a more accurate model to do so.
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Affiliation(s)
- V. N. Du Le
- Department of Biomedical Engineering, University of California Davis, Davis, CA 95616, USA
| | - Vivek J. Srinivasan
- Department of Biomedical Engineering, University of California Davis, Davis, CA 95616, USA
- Department of Ophthalmology and Vision Science, University of California Davis, Davis School of Medicine, Sacramento, CA 96817, USA
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32
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Ren J, Han S, Proctor AR, Desa DE, Ramirez GA, Ching-Roa VRD, Majeski JB, Dar IA, Barber NE, Forti AM, Benoit DSW, Choe R. Longitudinal 3D Blood Flow Distribution Provided by Diffuse Correlation Tomography during Bone Healing in a Murine Fracture Model. Photochem Photobiol 2020; 96:380-387. [PMID: 31883385 DOI: 10.1111/php.13201] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 11/20/2019] [Indexed: 12/19/2022]
Abstract
Noninvasive monitoring of vascularization can potentially diagnose impaired bone healing earlier than current radiographic methods. In this study, a noncontact diffuse correlation tomography (DCT) technique was employed to measure longitudinal blood flow changes during bone healing in a murine femoral fracture model. The three-dimensional distribution of the relative blood flow was quantified from one day pre-fracture to 48 days post-fracture. For three mice, frequent DCT measurements were performed every other day for one week after fracture, and then weekly thereafter. A decrease in blood flow was observed in the bone fracture region at one day post-fracture, followed by a monotonic increase in blood flow beyond the pre-injury baseline until five to seven days post-fracture. For the remaining 12 mice, only weekly DCT measurements were performed. Data collected on a weekly basis show the blood flow for most mice was elevated above baseline during the first two post-fracture weeks, followed by a subsequent decrease. Torsional strength of the excised femurs was measured for all 15 mice after 7 weeks of healing. A metric based on the early blood flow changes shows a statistically significant difference between the high strength group and the low strength group.
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Affiliation(s)
- Jingxuan Ren
- Department of Biomedical Engineering, University of Rochester, Rochester, NY
| | - Songfeng Han
- Institute of Optics, University of Rochester, Rochester, NY
| | - Ashley R Proctor
- Department of Biomedical Engineering, University of Rochester, Rochester, NY
| | - Danielle E Desa
- Department of Biomedical Engineering, University of Rochester, Rochester, NY
| | - Gabriel A Ramirez
- Department of Biomedical Engineering, University of Rochester, Rochester, NY
| | | | - Joseph B Majeski
- Department of Biomedical Engineering, University of Rochester, Rochester, NY
| | - Irfaan A Dar
- Department of Biomedical Engineering, University of Rochester, Rochester, NY
| | - Nathaniel E Barber
- Department of Biomedical Engineering, University of Rochester, Rochester, NY
| | - Amanda M Forti
- Department of Biomedical Engineering, University of Rochester, Rochester, NY
| | - Danielle S W Benoit
- Department of Biomedical Engineering, University of Rochester, Rochester, NY.,Department of Orthopaedics and Center for Musculoskeletal Research, University of Rochester, Rochester, NY.,Department of Chemical Engineering, University of Rochester, Rochester, NY.,Department of Biomedical Genetics and Center for Oral Biology, University of Rochester, Rochester, NY.,Materials Science Program, University of Rochester, Rochester, NY
| | - Regine Choe
- Department of Biomedical Engineering, University of Rochester, Rochester, NY.,Department of Electrical and Computer Engineering, University of Rochester, Rochester, NY
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33
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Johansson JD, Portaluppi D, Buttafava M, Villa F. A multipixel diffuse correlation spectroscopy system based on a single photon avalanche diode array. JOURNAL OF BIOPHOTONICS 2019; 12:e201900091. [PMID: 31339649 DOI: 10.1002/jbio.201900091] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 07/19/2019] [Accepted: 07/21/2019] [Indexed: 05/21/2023]
Abstract
The autocorrelation of laser speckles from coherent near infrared light is used for noninvasive estimates of relative changes in blood perfusion in techniques such as laser Doppler flowmetry (LDF) and diffuse correlation spectroscopy (DCS). In this study, a 2D array of single photon avalanche diodes (SPADs) was used to combine the strengths of multiple detectors in LDF with high light sensitivity in DCS. The system was tested on milk phantoms with varying detector fiber diameter (200 and 600 μm), source-detector fiber separation (4.6-10.2 mm), fiber-SPAD distance (2.5-36.5 mm), contiguous measurement time per repetition for the autocorrelation (1-33 ms) and temperature (15.6-46.7°C). An in vivo blood occlusion test was also performed. The multipixel approach improved signal-to-noise ratio (SNR) and, in our setup, the use of a multimode detector fiber was beneficial for SNR. In conclusion, the multipixel system works, but improvements and further studies regarding, for example, the data acquisition and optimal settings are still needed.
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Affiliation(s)
| | - Davide Portaluppi
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy
| | - Mauro Buttafava
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy
| | - Federica Villa
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy
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34
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Murali K, Nandakumaran AK, Durduran T, Varma HM. Recovery of the diffuse correlation spectroscopy data-type from speckle contrast measurements: towards low-cost, deep-tissue blood flow measurements. BIOMEDICAL OPTICS EXPRESS 2019; 10:5395-5413. [PMID: 31646054 PMCID: PMC6788603 DOI: 10.1364/boe.10.005395] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 08/28/2019] [Accepted: 08/28/2019] [Indexed: 05/23/2023]
Abstract
A multi-step Volterra integral equation-based algorithm was developed to measure the electric field auto-correlation function from multi-exposure speckle contrast data. This enabled us to derive an estimate of the full diffuse correlation spectroscopy data-type from a low-cost, camera-based system. This method is equally applicable for both single and multiple scattering field auto-correlation models. The feasibility of the system and method was verified using simulation studies, tissue mimicking phantoms and subsequently in in vivo experiments.
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Affiliation(s)
- K. Murali
- Department of Biosciences and Bioengineering, Indian Institute of Technology - Bombay (IITB), India
| | - A. K. Nandakumaran
- Department of Mathematics, Indian Institute of Science, Bangalore, India
| | - Turgut Durduran
- ICFO-Institut de Ciéncies Fotóniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
| | - Hari M. Varma
- Department of Biosciences and Bioengineering, Indian Institute of Technology - Bombay (IITB), India
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35
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Dragojević T, Vidal Rosas EE, Hollmann JL, Culver JP, Justicia C, Durduran T. High-density speckle contrast optical tomography of cerebral blood flow response to functional stimuli in the rodent brain. NEUROPHOTONICS 2019; 6:045001. [PMID: 31620545 PMCID: PMC6782685 DOI: 10.1117/1.nph.6.4.045001] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 09/12/2019] [Indexed: 05/20/2023]
Abstract
Noninvasive, three-dimensional, and longitudinal imaging of cerebral blood flow (CBF) in small animal models and ultimately in humans has implications for fundamental research and clinical applications. It enables the study of phenomena such as brain development and learning and the effects of pathologies, with a clear vision for translation to humans. Speckle contrast optical tomography (SCOT) is an emerging optical method that aims to achieve this goal by directly measuring three-dimensional blood flow maps in deep tissue with a relatively inexpensive and simple system. High-density SCOT is developed to follow CBF changes in response to somatosensory cortex stimulation. Measurements are carried out through the intact skull on the rat brain. SCOT is able to follow individual trials in each brain hemisphere, where signal averaging resulted in comparable, cortical images to those of functional magnetic resonance images in spatial extent, location, and depth. Sham stimuli are utilized to demonstrate that the observed response is indeed due to local changes in the brain induced by forepaw stimulation. In developing and demonstrating the method, algorithms and analysis methods are developed. The results pave the way for longitudinal, nondestructive imaging in preclinical rodent models that can readily be translated to the human brain.
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Affiliation(s)
- Tanja Dragojević
- Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Barcelona, Spain
- Address all correspondence to Tanja Dragojević, E-mail:
| | - Ernesto E. Vidal Rosas
- Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Joseph L. Hollmann
- Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Joseph P. Culver
- Washington University, School of Medicine, Department of Radiology, St. Louis, Missouri, United States
- Washington University, Department of Physics, St. Louis, Missouri, United States
| | - Carles Justicia
- Institut d’Investigacions Biomèdiques de Barcelona, Consejo Superior de Investigaciones Científicas, Department of Brain Ischemia and Neurodegeneration, Barcelona, Spain
- Institut d’Investigacions Biomèdiques August Pi i Sunyer, Àrea de Neurociències, Barcelona, Spain
| | - Turgut Durduran
- Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats, Barcelona, Spain
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Huang C, Mazdeyasna S, Chen L, Abu Jawdeh EG, Bada HS, Saatman KE, Chen L, Yu G. Noninvasive noncontact speckle contrast diffuse correlation tomography of cerebral blood flow in rats. Neuroimage 2019; 198:160-169. [DOI: 10.1016/j.neuroimage.2019.05.047] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 05/16/2019] [Accepted: 05/17/2019] [Indexed: 01/05/2023] Open
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Yamato H, Jin T, Nomura Y. Near infrared imaging of intrinsic signals in cortical spreading depression observed through the intact scalp in hairless mice. Neurosci Lett 2019; 701:213-217. [PMID: 30797869 DOI: 10.1016/j.neulet.2019.02.034] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2018] [Revised: 02/19/2019] [Accepted: 02/20/2019] [Indexed: 01/15/2023]
Abstract
Brain cooling was inevitable in both thinned and intact skull windows in neuroimaging in vivo of mice. Thus we proposed the novel imaging method leaving intact scalp on the skull using the light at 670, 785, and 975 nm. In this study, we used hairless mice (Hos:HR-1) since the deterioration of image quality was resulted from the hair. Cortical spreading depression was induced by KCl application through small incision and burr hole on the frontal bone. Intrinsic optical signals through the intact scalp in the observation area were detected. Time course of the signal showed a triphasic feature which was consistent with the intrinsic optical signals through the intact skull. In three pairs of signal amplitudes at the different wavelengths, no significant differences were observed. Although the intact scalp weakened the amplitudes significantly, e.g., 4.0 from 6.9 at 975 nm, the signals during cortical spreading depression were sufficient to be detected.
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Affiliation(s)
- Hiro Yamato
- Department of Systems Life Engineering, Maebashi Institute of Technology, 460-1, Kamisadori, Maebashi, Gunma 371-0816, Japan
| | - Takashi Jin
- Laboratory for Nano-Bio Probes, RIKEN Quantitative Biology Center, Furuedai 6-2-3, Suita, Osaka 565-0874, Japan
| | - Yasutomo Nomura
- Department of Systems Life Engineering, Maebashi Institute of Technology, 460-1, Kamisadori, Maebashi, Gunma 371-0816, Japan; Laboratory for Nano-Bio Probes, RIKEN Quantitative Biology Center, Furuedai 6-2-3, Suita, Osaka 565-0874, Japan.
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38
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Giovannella M, Spinelli L, Pagliazzi M, Contini D, Greisen G, Weigel UM, Torricelli A, Durduran T. Accuracy and precision of tissue optical properties and hemodynamic parameters estimated by the BabyLux device: a hybrid time-resolved near-infrared and diffuse correlation spectroscopy neuro-monitor. BIOMEDICAL OPTICS EXPRESS 2019; 10:2556-2579. [PMID: 31149383 PMCID: PMC6524603 DOI: 10.1364/boe.10.002556] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 03/29/2019] [Accepted: 04/17/2019] [Indexed: 05/20/2023]
Abstract
We have investigated the accuracy and precision of "the BabyLux device", a hybrid time-resolved near-infrared (TRS) and diffuse correlation spectroscopy (DCS) neuro-monitor for the pre-term infant. Numerical data with realistic noise were simulated and analyzed using the BabyLux device as a reference system and different experimental and analysis parameters. The results describe the limits for the precision and the accuracy to be expected. The dependence of these limits on different experimental conditions and choices of the analysis method is also described. Experiments demonstrate comparable values for precision with respect to the simulation results.
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Affiliation(s)
- Martina Giovannella
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona),
Spain
| | - Lorenzo Spinelli
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Milan,
Italy
| | - Marco Pagliazzi
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona),
Spain
| | - Davide Contini
- Politecnico di Milano-Dipartimento di Fisica, Milan,
Italy
| | - Gorm Greisen
- Department of Neonatology, Rigshopitalet, Copenhagen,
Denmark
| | - Udo M. Weigel
- HemoPhotonics S.L., Castelldefels (Barcelona),
Spain
| | - Alessandro Torricelli
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Milan,
Italy
- Politecnico di Milano-Dipartimento di Fisica, Milan,
Italy
| | - Turgut Durduran
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona),
Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona,
Spain
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39
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Zhang P, Gui Z, Guo G, Shang Y. Approaches to denoise the diffuse optical signals for tissue blood flow measurement. BIOMEDICAL OPTICS EXPRESS 2018; 9:6170-6185. [PMID: 31065421 PMCID: PMC6490982 DOI: 10.1364/boe.9.006170] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 10/21/2018] [Accepted: 10/26/2018] [Indexed: 05/03/2023]
Abstract
Various diseases are relevant to the abnormal blood flow in tissue. Diffuse correlation spectroscopy (DCS) is an emerging technology to extract the blood flow index (BFI) from light electric field temporal autocorrelation data. To account for tissue heterogeneity and irregular geometry, we developed an innovative DCS algorithm (i.e., the Nth order linear algorithm, or simply the NL algorithm) previously, in which the DCS signals are fully utilized through iterative linear regressions. Under the framework of NL algorithm, the BFI to be extracted is significantly influenced by the linear regression approach adopted. In this study, three approaches were proposed and evaluated for performing the iterative linear regressions, in order to understand what are the appropriate regression methods for BFI estimation. The three methods are least-squared minimization (L2 norm), least-absolute minimization (L1 norm) and support vector regression (SVR), where L2 norm is a conventional approach to perform linear regression. L1 norm and SVR are the approaches newly introduced here to process the DCS data. Computer simulations and the autocorrelation data collected from liquid phantom and human tissues are utilized to evaluate the three approaches. The results show that the best performance is achieved by the SVR approach in extracting the BFI values, with an error rate of 2.23% at 3.0 cm source-detector separation. The L1 norm method gives a medium error of 2.81%. In contrast, the L2 norm method leads to the largest error (3.93%) in extracting the BFI values. The outcomes derived from this study will be very helpful for the tissue blood flow measurements, which is critical for translating the DCS technology to the clinic.
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Affiliation(s)
- Peng Zhang
- Shanxi Provincial Key Laboratory for Biomedical Imaging and Big Data, North University of China, No. 3 Xueyuan Road, Taiyuan 030051, China
| | - Zhiguo Gui
- Shanxi Provincial Key Laboratory for Biomedical Imaging and Big Data, North University of China, No. 3 Xueyuan Road, Taiyuan 030051, China
| | - GuoDong Guo
- Shanxi Provincial Key Laboratory for Biomedical Imaging and Big Data, North University of China, No. 3 Xueyuan Road, Taiyuan 030051, China
- Department of Computer Science and Electrical Engineering, West Virginia University, Morgantown, WV26506, USA
| | - Yu Shang
- Shanxi Provincial Key Laboratory for Biomedical Imaging and Big Data, North University of China, No. 3 Xueyuan Road, Taiyuan 030051, China
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Sathialingam E, Lee SY, Sanders B, Park J, McCracken CE, Bryan L, Buckley EM. Small separation diffuse correlation spectroscopy for measurement of cerebral blood flow in rodents. BIOMEDICAL OPTICS EXPRESS 2018; 9:5719-5734. [PMID: 30460158 PMCID: PMC6238900 DOI: 10.1364/boe.9.005719] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 10/15/2018] [Accepted: 10/16/2018] [Indexed: 05/11/2023]
Abstract
Diffuse correlation spectroscopy (DCS) has shown promise as a means to non-invasively measure cerebral blood flow in small animal models. Here, we characterize the validity of DCS at small source-detector reflectance separations needed for small animal measurements. Through Monte Carlo simulations and liquid phantom experiments, we show that DCS error increases as separation decreases, although error remains below 12% for separations > 0.2 cm. In mice, DCS measures of cerebral blood flow have excellent intra-user repeatability and strongly correlate with MRI measures of blood flow (R = 0.74, p<0.01). These results are generalizable to other DCS applications wherein short-separation reflectance geometries are desired.
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Affiliation(s)
- Eashani Sathialingam
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 1760 Haygood Dr. NE, Atlanta, GA 30322, USA
- co-first authorship
| | - Seung Yup Lee
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 1760 Haygood Dr. NE, Atlanta, GA 30322, USA
- co-first authorship
| | - Bharat Sanders
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 1760 Haygood Dr. NE, Atlanta, GA 30322, USA
| | - Jaekeun Park
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 1760 Haygood Dr. NE, Atlanta, GA 30322, USA
| | - Courtney E. McCracken
- Department of Pediatrics, School of Medicine, Emory University, 2015 Uppergate Dr., Atlanta, GA 30322, USA
| | - Leah Bryan
- Department of Pediatrics, School of Medicine, Emory University, 2015 Uppergate Dr., Atlanta, GA 30322, USA
| | - Erin M. Buckley
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 1760 Haygood Dr. NE, Atlanta, GA 30322, USA
- Department of Pediatrics, School of Medicine, Emory University, 2015 Uppergate Dr., Atlanta, GA 30322, USA
- Children’s Research Scholar, Children’s Healthcare of Atlanta, 2015 Uppergate Dr., Atlanta, GA 30322, USA
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41
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Berezhnoi A, Schwarz M, Buehler A, Ovsepian SV, Aguirre J, Ntziachristos V. Assessing hyperthermia-induced vasodilation in human skin in vivo using optoacoustic mesoscopy. JOURNAL OF BIOPHOTONICS 2018; 11:e201700359. [PMID: 29573174 DOI: 10.1002/jbio.201700359] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 02/14/2018] [Accepted: 03/18/2018] [Indexed: 06/08/2023]
Abstract
The aim of this study was to explore the unique imaging abilities of optoacoustic mesoscopy to visualize skin structures and microvasculature with the view of establishing a robust approach for monitoring heat-induced hyperemia in human skin in vivo. Using raster-scan optoacoustic mesoscopy (RSOM), we investigated whether optoacoustic (photoacoustic) mesoscopy can identify changes in skin response to local heating at microvasculature resolution in a cross-sectional fashion through skin in the human forearm. We visualized the heat-induced hyperemia for the first time with single-vessel resolution throughout the whole skin depth. We quantified changes in total blood volume in the skin and their correlation with local heating. In response to local heating, total blood volume increased 1.83- and 1.76-fold, respectively, in the volar and dorsal aspects of forearm skin. We demonstrate RSOM imaging of the dilation of individual vessels in the skin microvasculature, consistent with hyperemic response to heating at the skin surface. Our results demonstrate great potential of RSOM for elucidating the morphology, functional state and reactivity of dermal microvasculature, with implications for diagnostics and disease monitoring. Image: Cross-sectional view of skin microvasculature dilated in response to hyperthermia.
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Affiliation(s)
- Andrei Berezhnoi
- Chair of Biological Imaging, Technische Universität München, Munich, Germany
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
| | - Mathias Schwarz
- Chair of Biological Imaging, Technische Universität München, Munich, Germany
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
- iThera Medical GmbH, Munich, Germany
| | - Andreas Buehler
- Chair of Biological Imaging, Technische Universität München, Munich, Germany
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
| | - Saak V Ovsepian
- Chair of Biological Imaging, Technische Universität München, Munich, Germany
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
| | - Juan Aguirre
- Chair of Biological Imaging, Technische Universität München, Munich, Germany
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
| | - Vasilis Ntziachristos
- Chair of Biological Imaging, Technische Universität München, Munich, Germany
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
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42
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Biganzoli D, Ferri F. Statistical analysis of dynamic light scattering data: revisiting and beyond the Schätzel formulas. OPTICS EXPRESS 2018; 26:29375-29392. [PMID: 30470102 DOI: 10.1364/oe.26.029375] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 09/11/2018] [Indexed: 05/24/2023]
Abstract
We revisited the classical Schätzel formulas (K. Schätzel, Quantum Optics2, 2871990) of the variance and covariance matrix associated to the normalized auto-correlation function in a Dynamic Light Scattering experiment when the sample is characterized by a single exponential decay function. Although thoroughly discussed by Schätzel who also outlined a correcting procedure, such formulas do not include explicitly the effects of triangular averaging that arise when the sampling time Δt is comparable or larger than the correlation time τc. If these effects are not taken into account, such formulas might be highly inaccurate. In this work we have solved this problem and worked out two exact analytical expressions that generalize the Schätzel formulas for any value of the ratio Δt/τc. By the use of extensive computer simulations we tested the correctness of the new formulas and showed that the variance formula can be exploited also in the case of fairly broad bell-shaped polydisperse samples (polydispersities up to ∼ 50 - 100%) and in connection with single exponential decay cross-correlation functions, provided that the average count rate is computed as the geometrical mean of the average count rates of the two channels. Finally, when tested on calibrated polystyrene particles, the new variance formula is able to reproduce quite accurately the error bars obtained by averaging the experimental data.
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Mazdeyasna S, Huang C, Zhao M, Agochukwu NB, Bahrani AA, Wong L, Yu G. Noncontact speckle contrast diffuse correlation tomography of blood flow distributions in tissues with arbitrary geometries. JOURNAL OF BIOMEDICAL OPTICS 2018; 23:1-9. [PMID: 30251483 PMCID: PMC6183314 DOI: 10.1117/1.jbo.23.9.096005] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 09/04/2018] [Indexed: 05/25/2023]
Abstract
A noncontact electron multiplying charge-coupled-device (EMCCD)-based speckle contrast diffuse correlation tomography (scDCT) technology has been recently developed in our laboratory, allowing for noninvasive three-dimensional measurement of tissue blood flow distributions. One major remaining constraint in the scDCT is the assumption of a semi-infinite tissue volume with a flat surface, which affects the image reconstruction accuracy for tissues with irregular geometries. An advanced photometric stereo technique (PST) was integrated into the scDCT system to obtain the surface geometry in real time for image reconstruction. Computer simulations demonstrated that a priori knowledge of tissue surface geometry is crucial for precisely reconstructing the anomaly with blood flow contrast. Importantly, the innovative integration design with one single-EMCCD camera for both PST and scDCT data collection obviates the need for offline alignment of sources and detectors on the tissue boundary. The in vivo imaging capability of the updated scDCT is demonstrated by imaging dynamic changes in forearm blood flow distribution during a cuff-occlusion procedure. The feasibility and safety in clinical use are evidenced by intraoperative imaging of mastectomy skin flaps and comparison with fluorescence angiography.
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Affiliation(s)
- Siavash Mazdeyasna
- University of Kentucky, F. Joseph Halcomb III, M.D. Department of Biomedical Engineering, Lexington, Kentucky, United States
| | - Chong Huang
- University of Kentucky, F. Joseph Halcomb III, M.D. Department of Biomedical Engineering, Lexington, Kentucky, United States
| | - Mingjun Zhao
- University of Kentucky, F. Joseph Halcomb III, M.D. Department of Biomedical Engineering, Lexington, Kentucky, United States
| | - Nneamaka B. Agochukwu
- University of Kentucky, Division of Plastic Surgery, Lexington, Kentucky, United States
| | - Ahmed A. Bahrani
- University of Kentucky, F. Joseph Halcomb III, M.D. Department of Biomedical Engineering, Lexington, Kentucky, United States
- University of Baghdad, Al-Khwarizmi College of Engineering, Biomedical Engineering Department, Aljadriya, Baghdad, Iraq
| | - Lesley Wong
- University of Kentucky, Division of Plastic Surgery, Lexington, Kentucky, United States
| | - Guoqiang Yu
- University of Kentucky, F. Joseph Halcomb III, M.D. Department of Biomedical Engineering, Lexington, Kentucky, United States
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Han S, Proctor AR, Ren J, Benoit DSW, Choe R. Temporal blood flow changes measured by diffuse correlation tomography predict murine femoral graft healing. PLoS One 2018; 13:e0197031. [PMID: 29813078 PMCID: PMC5973582 DOI: 10.1371/journal.pone.0197031] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 04/25/2018] [Indexed: 12/18/2022] Open
Abstract
Blood flow changes during bone graft healing have the potential to provide important information about graft success, as the nutrients, oxygen, circulating cells and growth factors essential for integration are delivered by blood. However, longitudinal monitoring of blood flow changes during graft healing has been a challenge due to limitations in current techniques. To this end, non-invasive diffuse correlation tomography (DCT) was investigated to enable longitudinal monitoring of three-dimensional blood flow changes in deep tissue. Specific to this study, longitudinal blood flow changes were utilized to predict healing outcomes of common interventions for massive bone defects using a common mouse femoral defect model. Weekly blood flow changes were non-invasively measured using a diffuse correlation tomography system for 9 weeks in three types of grafts: autografts (N = 7), allografts (N = 6) and tissue-engineered allografts (N = 6). Healing outcomes were quantified using an established torsion testing method 9 weeks after transplantation. Analysis of the spatial and temporal blood flow reveals that major differences among the three groups were captured in weeks 1-5 after graft transplantation. A multivariate model to predict maximum torque by relative blood flow changes over 5 weeks after graft transplantation was built using partial least squares regression. The results reveal lower bone strength correlates with greater cumulative blood flow over an extended period of time (i.e., 1-5 weeks). The current research demonstrates that DCT-measured blood flow changes after graft transplantation can be utilized to predict long-term healing outcomes in a mouse femoral graft model.
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Affiliation(s)
- Songfeng Han
- Institute of Optics, University of Rochester, Rochester, NY, United States of America
| | - Ashley R. Proctor
- Department of Biomedical Engineering, University of Rochester, Rochester, NY, United States of America
| | - Jingxuan Ren
- Department of Biomedical Engineering, University of Rochester, Rochester, NY, United States of America
| | - Danielle S. W. Benoit
- Department of Biomedical Engineering, University of Rochester, Rochester, NY, United States of America
- Department of Orthopaedics and Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY, United States of America
- Department of Chemical Engineering, University of Rochester, Rochester, NY, United States of America
- Department of Biomedical Genetics, University of Rochester Medical Center, Rochester, NY, United States of America
| | - Regine Choe
- Department of Biomedical Engineering, University of Rochester, Rochester, NY, United States of America
- Department of Electrical and Computer Engineering, University of Rochester, Rochester, NY, United States of America
- * E-mail:
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45
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Zhang X, Gui Z, Qiao Z, Liu Y, Shang Y. Nth-order linear algorithm for diffuse correlation tomography. BIOMEDICAL OPTICS EXPRESS 2018; 9:2365-2382. [PMID: 29760994 PMCID: PMC5946795 DOI: 10.1364/boe.9.002365] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 04/06/2018] [Accepted: 04/17/2018] [Indexed: 05/08/2023]
Abstract
The current approaches to imaging the tissue blood flow index (BFI) from diffuse correlation tomography (DCT) data are either an analytical solution or a finite element method, both of which are unable to simultaneously account for the tissue heterogeneity and fully utilize the DCT data. In this study, a new imaging concept for DCT, namely NL-DCT, was created by us in which the medical images are combined with light Monte Carlo simulation to provide geometrical and heterogeneous information in tissue. Moreover, the DCT data at multiple delay time are fully utilized via iterative linear regression. The unique merit of NL-DCT in utilizing the medical images as prior information, when combined with a split Bregman algorithm for total variation minimization (Bregman-TV), was validated on a realistic human head model. Computer simulation outcomes demonstrate the accuracy and robustness of NL-DCT in localizing and separating the flow anomalies as well as the capability to preserve edges of anomalies.
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Affiliation(s)
- Xiaojuan Zhang
- Shanxi Provincial Key Laboratory for Biomedical Imaging and Big Data, North University of China, No. 3 Xueyuan Road, Taiyuan 030051, China
- Department of Electrical Engineering, Taiyuan Institute of Technology, No. 31 Xinlan Road, Taiyuan, Shanxi 030008, China
| | - Zhiguo Gui
- Shanxi Provincial Key Laboratory for Biomedical Imaging and Big Data, North University of China, No. 3 Xueyuan Road, Taiyuan 030051, China
| | - Zhiwei Qiao
- School of Computer and Information Technology, Shanxi University, No. 92 Wucheng Road, Taiyuan, Shanxi 030006, China
| | - Yi Liu
- Shanxi Provincial Key Laboratory for Biomedical Imaging and Big Data, North University of China, No. 3 Xueyuan Road, Taiyuan 030051, China
| | - Yu Shang
- Shanxi Provincial Key Laboratory for Biomedical Imaging and Big Data, North University of China, No. 3 Xueyuan Road, Taiyuan 030051, China
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Tricoli U, Macdonald CM, Durduran T, Da Silva A, Markel VA. Diffuse correlation tomography in the transport regime: A theoretical study of the sensitivity to Brownian motion. Phys Rev E 2018; 97:022408. [PMID: 29548080 DOI: 10.1103/physreve.97.022408] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Indexed: 11/07/2022]
Abstract
Diffuse correlation tomography (DCT) uses the electric-field temporal autocorrelation function to measure the mean-square displacement of light-scattering particles in a turbid medium over a given exposure time. The movement of blood particles is here estimated through a Brownian-motion-like model in contrast to ordered motion as in blood flow. The sensitivity kernel relating the measurable field correlation function to the mean-square displacement of the particles can be derived by applying a perturbative analysis to the correlation transport equation (CTE). We derive an analytical expression for the CTE sensitivity kernel in terms of the Green's function of the radiative transport equation, which describes the propagation of the intensity. We then evaluate the kernel numerically. The simulations demonstrate that, in the transport regime, the sensitivity kernel provides sharper spatial information about the medium as compared with the correlation diffusion approximation. Also, the use of the CTE allows one to explore some additional degrees of freedom in the data such as the collimation direction of sources and detectors. Our results can be used to improve the spatial resolution of DCT, in particular, with applications to blood flow imaging in regions where the Brownian motion is dominant.
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Affiliation(s)
- Ugo Tricoli
- Aix Marseille Univ, CNRS, Centrale Marseille, Institut Fresnel, Marseille 13013, France
| | - Callum M Macdonald
- Aix Marseille Univ, CNRS, Centrale Marseille, Institut Fresnel, Marseille 13013, France
| | - Turgut Durduran
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain.,Institució Catalana de Recerca i Estudis Avançats (ICREA), 08015 Barcelona, Spain
| | - Anabela Da Silva
- Aix Marseille Univ, CNRS, Centrale Marseille, Institut Fresnel, Marseille 13013, France
| | - Vadim A Markel
- Aix Marseille Univ, CNRS, Centrale Marseille, Institut Fresnel, Marseille 13013, France
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47
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Mustari A, Nakamura N, Kawauchi S, Sato S, Sato M, Nishidate I. RGB camera-based imaging of cerebral tissue oxygen saturation, hemoglobin concentration, and hemodynamic spontaneous low-frequency oscillations in rat brain following induction of cortical spreading depression. BIOMEDICAL OPTICS EXPRESS 2018; 9:933-951. [PMID: 29541495 PMCID: PMC5846540 DOI: 10.1364/boe.9.000933] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 01/20/2018] [Accepted: 01/23/2018] [Indexed: 05/24/2023]
Abstract
To evaluate cerebral hemodynamics and spontaneous low-frequency oscillations (SLFOs) of cerebral blood flow in rat brain, we investigated an imaging method using a digital RGB camera. In this method, the RGB values were converted into tristimulus values in the CIE (Commission Internationale de l'Eclairage) XYZ color space, which is compatible with the common RGB working spaces. Monte Carlo simulation for light transport in tissue was then used to specify the relationship among the tristimulus XYZ values and the concentrations of oxygenated hemoglobin (CHbO), deoxygenated hemoglobin (CHbR), and total hemoglobin (CHbT) and cerebral tissue oxygen saturation (StO2). Applying the fast Fourier transform to each pixel of the sequential images of CHbT along the timeline, SLFOs of cerebral blood volume were visualized as a spatial map of power spectral density (PSD) at specific frequencies related to vasomotion. To confirm the feasibility of this method, we performed in vivo experiments using exposed rat brain during a cortical spreading depression (CSD) evoked by topical application of KCl. Cerebral hemodynamic responses to CSD such as initial hypoperfusion, profound hyperemia, and post-CSD oligemia and hypoxemia were successfully visualized with this method. At the transition to the hyperemia phase from hypoperfusion, CHbO and StO2 were significantly increased, which implied vasodilatation in arterioles and increased cerebral blood volume in response to CSD. In the wake of the hyperemic phase, CHbO and CHbT were significantly reduced to 25 ± 12% and 3.5 ± 1% of baseline, respectively, suggesting long-lasting vasoconstriction after CSD. In this persistent oligemia, StO2 significantly dropped to at most 23 ± 12% of the level before CSD, indicating long-lasting hypoxemia. The PSD value of SLFOs in CHbT for arteriole regions during CSD was significantly reduced to 28 ± 20% of baseline with respect to the pre-CSD level, which was correlated with the reduction in StO2. The results showed the possibility of RGB camera-based diffuse reflectance spectroscopy imaging for evaluating cerebral hemodynamics and SLFOs under normal and pathologic conditions.
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Affiliation(s)
- Afrina Mustari
- Graduate School of Bio-Applications & Systems Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan
| | - Naoki Nakamura
- Graduate School of Bio-Applications & Systems Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan
| | - Satoko Kawauchi
- Division of Bioinformation and Therapeutic Systems, National Defense Medical College Research Institute, 3-2 Namiki, Tokorozawa, Saitama 359-8513, Japan
| | - Shunichi Sato
- Division of Bioinformation and Therapeutic Systems, National Defense Medical College Research Institute, 3-2 Namiki, Tokorozawa, Saitama 359-8513, Japan
| | - Manabu Sato
- Graduate School of Science and Engineering, Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata 992-8510, Japan
| | - Izumi Nishidate
- Graduate School of Bio-Applications & Systems Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan
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48
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Tamborini D, Farzam P, Zimmermann B, Wu KC, Boas DA, Franceschini MA. Development and characterization of a multidistance and multiwavelength diffuse correlation spectroscopy system. NEUROPHOTONICS 2018; 5:011015. [PMID: 28948194 PMCID: PMC5607257 DOI: 10.1117/1.nph.5.1.011015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 09/01/2017] [Indexed: 05/03/2023]
Abstract
This paper presents a multidistance and multiwavelength diffuse correlation spectroscopy (DCS) approach and its implementation to simultaneously measure the optical proprieties of deep tissue as well as the blood flow. The system consists of three long coherence length lasers at different wavelengths in the near-infrared, eight single-photon detectors, and a correlator board. With this approach, we collect both light intensity and DCS data at multiple distances and multiple wavelengths, which provide unique information to fit for all the parameters of interest: scattering, blood flow, and hemoglobin concentration. We present the characterization of the system and its validation with phantom measurements.
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Affiliation(s)
- Davide Tamborini
- Harvard Medical School, MGH/HST Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts, United States
- Address all correspondence to: Davide Tamborini, E-mail:
| | - Parisa Farzam
- Harvard Medical School, MGH/HST Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts, United States
| | - Bernhard Zimmermann
- Harvard Medical School, MGH/HST Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts, United States
| | - Kuan-Cheng Wu
- Harvard Medical School, MGH/HST Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts, United States
| | - David A. Boas
- Boston University, Boston University Neurophotonics Center, Boston, Massachusetts, United States
| | - Maria Angela Franceschini
- Harvard Medical School, MGH/HST Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts, United States
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Blanco I, Zirak P, Dragojević T, Castellvi C, Durduran T, Justicia C. Longitudinal, transcranial measurement of functional activation in the rat brain by diffuse correlation spectroscopy. NEUROPHOTONICS 2017; 4:045006. [PMID: 29226175 PMCID: PMC5715584 DOI: 10.1117/1.nph.4.4.045006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 11/09/2017] [Indexed: 05/16/2023]
Abstract
Neural activity is an important biomarker for the presence of neurodegenerative diseases, cerebrovascular alterations, and brain trauma; furthermore, it is a surrogate marker for treatment effects. These pathologies may occur and evolve in a long time-period, thus, noninvasive, transcutaneous techniques are necessary to allow a longitudinal follow-up. In the present work, we have customized noninvasive, transcutaneous, diffuse correlation spectroscopy (DCS) to localize changes in cerebral blood flow (CBF) induced by neural activity. We were able to detect changes in CBF in the somatosensory cortex by using a model of electrical forepaw stimulation in rats. The suitability of DCS measurements for longitudinal monitoring was demonstrated by performing multiple sessions with the same animals at different ages (from 6 to 18 months). In addition, functional DCS has been cross-validated by comparison with functional magnetic resonance imaging (fMRI) in the same animals in a subset of the time-points. The overall results obtained with transcutaneous DCS demonstrates that it can be utilized in longitudinal studies safely and reproducibly to locate changes in CBF induced by neural activity in the small animal brain.
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Affiliation(s)
- Igor Blanco
- ICFO-Institut de Ciències Fotòniques, Barcelona Institute of Science and Technology, Castelldefels, Barcelona, Spain
- Address all correspondence to: Igor Blanco, E-mail:
| | - Peyman Zirak
- ICFO-Institut de Ciències Fotòniques, Barcelona Institute of Science and Technology, Castelldefels, Barcelona, Spain
| | - Tanja Dragojević
- ICFO-Institut de Ciències Fotòniques, Barcelona Institute of Science and Technology, Castelldefels, Barcelona, Spain
| | - Clara Castellvi
- Insitut d’Investigacions Biomèdiques de Barcelona (IIBB), Consejo Superior de Investigaciones Científicas (CSIC), Department of Brain Ischemia and Neurodegeneration, Barcelona, Spain
- Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Àrea de Neurociències, Barcelona, Spain
| | - Turgut Durduran
- ICFO-Institut de Ciències Fotòniques, Barcelona Institute of Science and Technology, Castelldefels, Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
| | - Carles Justicia
- Insitut d’Investigacions Biomèdiques de Barcelona (IIBB), Consejo Superior de Investigaciones Científicas (CSIC), Department of Brain Ischemia and Neurodegeneration, Barcelona, Spain
- Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Àrea de Neurociències, Barcelona, Spain
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Huang C, Irwin D, Zhao M, Shang Y, Agochukwu N, Wong L, Yu G. Noncontact 3-D Speckle Contrast Diffuse Correlation Tomography of Tissue Blood Flow Distribution. IEEE TRANSACTIONS ON MEDICAL IMAGING 2017; 36:2068-2076. [PMID: 28574345 PMCID: PMC5645791 DOI: 10.1109/tmi.2017.2708661] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Recent advancements in near-infrared diffuse correlation techniques and instrumentation have opened the path for versatile deep tissue microvasculature blood flow imaging systems. Despite this progress there remains a need for a completely noncontact, noninvasive device with high translatability from small/testing (animal) to large/target (human) subjects with trivial application on both. Accordingly, we discuss our newly developed setup which meets this demand, termed noncontact speckle contrast diffuse correlation tomography (nc_scDCT). The nc_scDCT provides fast, continuous, portable, noninvasive, and inexpensive acquisition of 3-D tomographic deep (up to 10 mm) tissue blood flow distributions with straightforward design and customization. The features presented include a finite-element-method implementation for incorporating complex tissue boundaries, fully noncontact hardware for avoiding tissue compression and interactions, rapid data collection with a diffuse speckle contrast method, reflectance-based design promoting experimental translation, extensibility to related techniques, and robust adjustable source and detector patterns and density for high resolution measurement with flexible regions of interest enabling unique application-specific setups. Validation is shown in the detection and characterization of both high and low contrasts in flow relative to the background using tissue phantoms with a pump-connected tube (high) and phantom spheres (low). Furthermore, in vivo validation of extracting spatiotemporal 3-D blood flow distributions and hyperemic response during forearm cuff occlusion is demonstrated. Finally, the success of instrument feasibility in clinical use is examined through the intraoperative imaging of mastectomy skin flap.
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