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Chen W, Du C, Pan Y. Cerebral capillary flow imaging by wavelength-division-multiplexing swept-source optical Doppler tomography. JOURNAL OF BIOPHOTONICS 2018; 11:e201800004. [PMID: 29603668 DOI: 10.1002/jbio.201800004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Revised: 02/27/2018] [Accepted: 03/13/2018] [Indexed: 05/09/2023]
Abstract
Swept-source-based optical coherence tomography (SS-OCT) has demonstrated the unique advantages for fast imaging rate and long imaging distance; however, limited axial resolution and complex phase noises restrict swept-source optical Doppler tomography (SS-ODT) for quantitative capillary blood flow imaging in the deep cortices. Here, the wavelength-dividing-multiplexing optical Doppler tomography (WDM-ODT) method that divides a single interferogram into multiple phase-correlated interferograms is proposed to effectively enhance the sensitivity for cerebral capillary flow imaging. Both flow phantom and in vivo mouse brain imaging studies show that WDM-ODT is able to significantly suppress background phase noise and image cerebral capillary flow down to the vessel size of 5.6 μm. Comparison between the wavelength-division-multiplexing SS-ODT and the spectral-domain ultrahigh-resolution ODT (uODT) reveals that SS-ODT outpaces uODT by extending the capillary flow imaging depth to 1.6 mm in mouse cortex. Thus, for the first time, quantitative capillary flow imaging is demonstrated using SS-ODT in the deep cortex.
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Affiliation(s)
- Wei Chen
- Biomedical Engineering, Stony Brook University, Stony Brook, New York
| | - Congwu Du
- Biomedical Engineering, Stony Brook University, Stony Brook, New York
| | - Yingtian Pan
- Biomedical Engineering, Stony Brook University, Stony Brook, New York
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2
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Leedumrongwatthanakun S, Thavarungkul P, Kanatharana P, Buranachai C. Wavelet analysis on time-frequency plane of optical coherence tomography: simultaneous signal quality improvement in structural and velocity images. OPTICS LETTERS 2018; 43:3730-3733. [PMID: 30067666 DOI: 10.1364/ol.43.003730] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 07/09/2018] [Indexed: 06/08/2023]
Abstract
In this Letter, we utilize one-dimensional wavelet analysis to improve the quality of morphology images and velocity profiles of optical coherence tomography simultaneously, by performing analysis on the complex time-frequency plane of raw interferograms, prior to image construction. The results indicate a robust signal improvement that also preserves accuracy for both morphology and velocity information and has been demonstrated on a variety of samples with diverse flow speeds and morphologies.
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3
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de Boer JF, Leitgeb R, Wojtkowski M. Twenty-five years of optical coherence tomography: the paradigm shift in sensitivity and speed provided by Fourier domain OCT [Invited]. BIOMEDICAL OPTICS EXPRESS 2017; 8:3248-3280. [PMID: 28717565 PMCID: PMC5508826 DOI: 10.1364/boe.8.003248] [Citation(s) in RCA: 104] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Revised: 04/26/2017] [Accepted: 05/22/2017] [Indexed: 05/19/2023]
Abstract
Optical coherence tomography (OCT) has become one of the most successful optical technologies implemented in medicine and clinical practice mostly due to the possibility of non-invasive and non-contact imaging by detecting back-scattered light. OCT has gone through a tremendous development over the past 25 years. From its initial inception in 1991 [Science254, 1178 (1991)] it has become an indispensable medical imaging technology in ophthalmology. Also in fields like cardiology and gastro-enterology the technology is envisioned to become a standard of care. A key contributor to the success of OCT has been the sensitivity and speed advantage offered by Fourier domain OCT. In this review paper the development of FD-OCT will be revisited, providing a single comprehensive framework to derive the sensitivity advantage of both SD- and SS-OCT. We point out the key aspects of the physics and the technology that has enabled a more than 2 orders of magnitude increase in sensitivity, and as a consequence an increase in the imaging speed without loss of image quality. This speed increase provided a paradigm shift from point sampling to comprehensive 3D in vivo imaging, whose clinical impact is still actively explored by a large number of researchers worldwide.
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Affiliation(s)
- Johannes F. de Boer
- Department of Physics and Astronomy and LaserLaB Amsterdam, VU University, De Boelelaan 1105, 1081 HV Amsterdam, Department of Ophthalmology, VU Medical Center, Amsterdam, The Netherlands
- Authors are listed in alphabetical order and contributed equally
| | - Rainer Leitgeb
- Christian Doppler Laboratory OPTRAMED, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
- Authors are listed in alphabetical order and contributed equally
| | - Maciej Wojtkowski
- Physical Optics and Biophotonics Group, Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52 01-224 Warsaw, Poland
- Authors are listed in alphabetical order and contributed equally
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4
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Gao W. Quantitative depth-resolved microcirculation imaging with optical coherence tomography angiography (Part Ι): Blood flow velocity imaging. Microcirculation 2017; 25:e12375. [PMID: 28419622 DOI: 10.1111/micc.12375] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 04/11/2017] [Indexed: 12/20/2022]
Abstract
The research goal of the microvascular network imaging with OCT angiography is to achieve depth-resolved blood flow and vessel imaging in vivo in the clinical management of patents. In this review, we review the main phenomena that have been explored in OCT to image the blood flow velocity vector and the vessels of the microcirculation within living tissues. Parameters that limit the accurate measurements of blood flow velocity are then considered. Finally, initial clinical diagnosis applications and future developments of OCT flow images are discussed.
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Affiliation(s)
- Wanrong Gao
- Department of Optical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu, China.,MIIT Key Laboratory of Advanced soIid Laser, Nanjing University of science and Technology, Nanjing, Jiangsu, China
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5
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Leitgeb RA, Werkmeister RM, Blatter C, Schmetterer L. Doppler optical coherence tomography. Prog Retin Eye Res 2014; 41:26-43. [PMID: 24704352 PMCID: PMC4073226 DOI: 10.1016/j.preteyeres.2014.03.004] [Citation(s) in RCA: 227] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Revised: 03/21/2014] [Accepted: 03/26/2014] [Indexed: 11/19/2022]
Abstract
Optical Coherence Tomography (OCT) has revolutionized ophthalmology. Since its introduction in the early 1990s it has continuously improved in terms of speed, resolution and sensitivity. The technique has also seen a variety of extensions aiming to assess functional aspects of the tissue in addition to morphology. One of these approaches is Doppler OCT (DOCT), which aims to visualize and quantify blood flow. Such extensions were already implemented in time domain systems, but have gained importance with the introduction of Fourier domain OCT. Nowadays phase-sensitive detection techniques are most widely used to extract blood velocity and blood flow from tissues. A common problem with the technique is that the Doppler angle is not known and several approaches have been realized to obtain absolute velocity and flow data from the retina. Additional studies are required to elucidate which of these techniques is most promising. In the recent years, however, several groups have shown that data can be obtained with high validity and reproducibility. In addition, several groups have published values for total retinal blood flow. Another promising application relates to non-invasive angiography. As compared to standard techniques such as fluorescein and indocyanine-green angiography the technique offers two major advantages: no dye is required and depth resolution is required is provided. As such Doppler OCT has the potential to improve our abilities to diagnose and monitor ocular vascular diseases.
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Affiliation(s)
- Rainer A Leitgeb
- Center for Medical Physics and Biomedical Engineering, Medical University Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
| | - René M Werkmeister
- Center for Medical Physics and Biomedical Engineering, Medical University Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
| | - Cedric Blatter
- Center for Medical Physics and Biomedical Engineering, Medical University Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
| | - Leopold Schmetterer
- Center for Medical Physics and Biomedical Engineering, Medical University Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria; Department of Clinical Pharmacology, Medical University Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria.
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6
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Weiss N, van Leeuwen TG, Kalkman J. Localized measurement of longitudinal and transverse flow velocities in colloidal suspensions using optical coherence tomography. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2013; 88:042312. [PMID: 24229177 DOI: 10.1103/physreve.88.042312] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Indexed: 05/05/2023]
Abstract
We report on localized measurement of the longitudinal and transverse flow velocities in a colloidal suspension using optical coherence tomography. We present a model for the path-length resolved autocorrelation function including diffusion and flow, which we experimentally verify. For flow that is not perpendicular to the incident beam, the longitudinal velocity gradient over the coherence gate causes additional decorrelation, which is described by our model. We demonstrate simultaneous imaging of sample morphology and longitudinal and transverse flow at micrometer scale in a single measurement.
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Affiliation(s)
- Nicolás Weiss
- Biomedical Engineering and Physics, Academic Medical Center, University of Amsterdam, P.O. Box 22700, 1100 DE Amsterdam, the Netherlands
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7
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Daly SM, Leahy MJ. 'Go with the flow ': a review of methods and advancements in blood flow imaging. JOURNAL OF BIOPHOTONICS 2013; 6:217-55. [PMID: 22711377 DOI: 10.1002/jbio.201200071] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Revised: 05/22/2012] [Accepted: 05/23/2012] [Indexed: 05/25/2023]
Abstract
Physics has delivered extraordinary developments in almost every facet of modern life. From the humble thermometer and stethoscope to X-Ray, CT, MRI, ultrasound, PET and radiotherapy, our health has been transformed by these advances yielding both morphological and functional metrics. Recently high resolution label-free imaging of the microcirculation at clinically relevant depths has become available in the research domain. In this paper, we present a comprehensive review on current imaging techniques, state-of-the-art advancements and applications, and general perspectives on the prospects for these modalities in the clinical realm.
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Affiliation(s)
- Susan M Daly
- Biophotonics Research Facility, Department of Physics & Energy, University of Limerick, Ireland.
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8
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Wojtkowski M. High-speed optical coherence tomography: basics and applications. APPLIED OPTICS 2010; 49:D30-61. [PMID: 20517358 DOI: 10.1364/ao.49.000d30] [Citation(s) in RCA: 141] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
In the past decade we have observed a rapid development of ultrahigh-speed optical coherence tomography (OCT) instruments, which currently enable performing cross-sectional in vivo imaging of biological samples with speeds of more than 100,000 A-scans/s. This progress in OCT technology has been achieved by the development of Fourier-domain detection techniques. Introduction of high-speed imaging capabilities lifts the primary limitation of early OCT technology by giving access to in vivo three-dimensional volumetric reconstructions on large scales within reasonable time constraints. As result, novel tools can be created that add new perspective for existing OCT applications and open new fields of research in biomedical imaging. Especially promising is the capability of performing functional imaging, which shows a potential to enable the differentiation of tissue pathologies via metabolic properties or functional responses. In this contribution the fundamental limitations and advantages of time-domain and Fourier-domain interferometric detection methods are discussed. Additionally the progress of high-speed OCT instruments and their impact on imaging applications is reviewed. Finally new perspectives on functional imaging with the use of state-of-the-art high-speed OCT technology are demonstrated.
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Affiliation(s)
- Maciej Wojtkowski
- Institute of Physics, Nicolaus Copernicus University, ul. Grudziadzka 5, 87-100, Torun, Poland.
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9
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Yu L, Chen Z. Doppler variance imaging for three-dimensional retina and choroid angiography. JOURNAL OF BIOMEDICAL OPTICS 2010; 15:016029. [PMID: 20210473 PMCID: PMC2839803 DOI: 10.1117/1.3302806] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2009] [Revised: 11/25/2009] [Accepted: 12/28/2009] [Indexed: 05/17/2023]
Abstract
We demonstrate the use of Doppler variance (standard deviation) imaging for 3-D in vivo angiography in the human eye. In addition to the regular optical Doppler tomography velocity and structural images, we use the variance of blood flow velocity to map the retina and choroid vessels. Variance imaging is subject to bulk motion artifacts as in phase-resolved Doppler imaging, and a histogram-based method is proposed for bulk-motion correction in variance imaging. Experiments were performed to demonstrate the effectiveness of the proposed method for 3-D vasculature imaging of human retina and choroid.
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Affiliation(s)
- Lingfeng Yu
- University of California, Irvine, Irvine Beckman Laser Institute, Department of Biomedical Engineering, Irvine, California 92612, USA.
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10
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Werkmeister RM, Dragostinoff N, Pircher M, Götzinger E, Hitzenberger CK, Leitgeb RA, Schmetterer L. Bidirectional Doppler Fourier-domain optical coherence tomography for measurement of absolute flow velocities in human retinal vessels. OPTICS LETTERS 2008; 33:2967-9. [PMID: 19079508 DOI: 10.1364/ol.33.002967] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
We describe a bidirectional color Doppler Fourier-domain optical coherence tomography system capable of measuring absolute velocities of moving scatterers by illuminating the sample with two linearly and orthogonally polarized beams, incident at a known angle on the sample. The velocity calculation is independent of the exact orientation of the velocity vector in the detection plane. First measurements were performed on a rotating disk driven at well-defined velocities and tilted by various small angles. Our results indicate a high correlation between preset and calculated velocities (correlation coefficient 0.999) and the independency of these velocities from the tilting angle of the disk. We demonstrate that bidirectional color Doppler optical coherence tomography allows for the measurement of absolute blood flow values in vivo in human retinal vessels.
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Affiliation(s)
- René M Werkmeister
- Center for Biomedical Engineering and Physics, Medical University of Vienna, Vienna, Austria
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11
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Chen Y, Willett P, Zhu Q. Frequency tracking in optical Doppler tomography using an adaptive notch filter. JOURNAL OF BIOMEDICAL OPTICS 2007; 12:014018. [PMID: 17343493 PMCID: PMC1993810 DOI: 10.1117/1.2710240] [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] [Indexed: 05/14/2023]
Abstract
Optical Doppler tomography is a valuable functional extension of optical coherence tomography (OCT) that can be used to study subsurface blood flows of biological tissues. We propose a novel frequency estimation technique that uses an adaptive notch filter (ANF) to track the depth-resolved Doppler frequency. This new technique is a minimal-parameter filter and works in the time domain without the need of Fourier transformation. Therefore, the algorithm has a computationally efficient structure that may be well suited for implementation in real-time ODT systems. Our simulations and imaging results also demonstrate that this filter has good performance in terms of noise robustness and estimation accuracy compared with existing estimation algorithms.
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Affiliation(s)
- Yueli Chen
- University of Connecticut, Electrical and Computer Engineering Department, Storrs, Connecticut 06269, E-mail:
| | - Peter Willett
- University of Connecticut, Electrical and Computer Engineering Department, Storrs, Connecticut 06269, E-mail:
| | - Quing Zhu
- University of Connecticut, Electrical and Computer Engineering Department, Storrs, Connecticut 06269, E-mail:
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12
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Xi C, Marks D, Schlachter S, Luo W, Boppart SA. High-resolution three-dimensional imaging of biofilm development using optical coherence tomography. JOURNAL OF BIOMEDICAL OPTICS 2006; 11:34001. [PMID: 16822051 DOI: 10.1117/1.2209962] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
We describe the use of optical coherence tomography (OCT) for high-resolution, real-time imaging of three-dimensional structure and development of a Pseudomonas aeruginosa biofilm in a standard capillary flow-cell model. As the penetration depth of OCT can reach several millimeters in scattering samples, we are able to observe complete biofilm development on all surfaces of a 1 mm x 1 mm flow-cell. We find that biofilm growing at the bottom of the tube has more structural features including voids, outward projections, and microcolonies while the biofilm growing on the top of the tube is relatively flat and contains less structural features. Volume-rendered reconstructions of cross-sectional OCT images also reveal three-dimensional structural information. These three-dimensional OCT images are visually similar to biofilm images obtained with confocal laser scanning microscopy, but are obtained at greater depths. Based on the imaging capabilities of OCT and the biofilm imaging data obtained, OCT has potential to be used as a non-invasive, label-free, real-time, in-situ and/or in-vivo imaging modality for biofilm characterization.
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Affiliation(s)
- Chuanwu Xi
- University of Illinois at Urbana-Champaign, Department of Civil and Environmental Engineering, Biophotonics Imaging Laboratory, Beckman Institute for Advanced Science and Technology, 61801, USA
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13
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Choma MA, Ellerbee AK, Yazdanfar S, Izatt JA. Doppler flow imaging of cytoplasmic streaming using spectral domain phase microscopy. JOURNAL OF BIOMEDICAL OPTICS 2006; 11:024014. [PMID: 16674204 DOI: 10.1117/1.2193167] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Spectral domain phase microscopy (SDPM) is a function extension of spectral domain optical coherence tomography. SDPM achieves exquisite levels of phase stability by employing common-path interferometry. We discuss the theory and limitations of Doppler flow imaging using SDPM, demonstrate monitoring the thermal contraction of a glass sample with nanometer per second velocity sensitivity, and apply this technique to measurement of cytoplasmic streaming in an Amoeba proteus pseudopod. We observe reversal of cytoplasmic flow induced by extracellular CaCl2, and report results that suggest parabolic flow of cytoplasm in the A. proteus pseudopod.
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Affiliation(s)
- Michael A Choma
- Duke University, Department of Biomedical Engineering, Durham, North Carolina 27708, USA.
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14
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Wu FI, Glucksberg MR. Choroidal perfusion measurements made with optical coherence tomography. APPLIED OPTICS 2005; 44:1426-1433. [PMID: 15796241 DOI: 10.1364/ao.44.001426] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Choroidal perfusion measurements are complicated by the choroid's location posterior to the retina and its associated retinal blood vessels. Optical coherence tomography is a relatively new imaging technique with sufficient spatial resolution to isolate choroidal backscattering events from the posterior eye. We modified a speckle imaging algorithm to analyze sequential axial depth scans obtained from posterior rat eye to obtain an indicator of choroidal perfusion. This indicator is correlated with known changes in choroidal blood flow in response to increased intraocular pressure.
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Affiliation(s)
- Frank I Wu
- Department of Biomedical Engineering, Northwestern University, Tech Building E310, 2145 Sheridan Road, Evanston, Illinois 60201, USA
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15
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Xi C, Marks DL, Parikh DS, Raskin L, Boppart SA. Structural and functional imaging of 3D microfluidic mixers using optical coherence tomography. Proc Natl Acad Sci U S A 2004; 101:7516-21. [PMID: 15136742 PMCID: PMC419637 DOI: 10.1073/pnas.0402433101] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
To achieve high mixing efficiency in microfluidic devices, complex designs are often required. Microfluidic devices have been evaluated with light and confocal microscopy, but fluid-flow characteristics at different depths are difficult to separate from the en face images produced. By using optical coherence tomography (OCT), an imaging modality capable of imaging 3D microstructures at micrometer-scale resolutions over millimeter-size scales, we obtained 3D dynamic functional and structural data for three representative microfluidic mixers: a Y channel mixer, a 3D serpentine mixer, and a vortex mixer. In the serpentine mixer, OCT image analysis revealed that the mixing efficiency was linearly dependent on the Reynolds number, whereas it appeared to have exponential dependence when imaged with light microscopy. The visual overlap of fluid flows in light-microscopy images leads to an overestimation of the mixing efficiency, an effect that was eliminated with OCT imaging. Doppler OCT measurements determined velocity profiles at various points in the serpentine mixer. Mixing patterns in the vortex mixer were compared with light-microscopy and OCT image analysis. These results demonstrate that OCT can significantly improve the characterization of 3D microfluidic device structure and function.
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Affiliation(s)
- Chuanwu Xi
- Department of Civil and Environmental Engineering, Beckman Institute for Advanced Science and Technology, College of Medicine, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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16
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Yan S, Piao D, Chen Y, Zhu Q. Digital signal processor-based real-time optical Doppler tomography system. JOURNAL OF BIOMEDICAL OPTICS 2004; 9:454-463. [PMID: 15189082 DOI: 10.1117/1.1695409] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We present a real-time data-processing and display unit based on a custom-designed digital signal processor (DSP) module for imaging tissue structure and Doppler blood flow. The DSP module is incorporated into a conventional optical coherence tomography system. We also demonstrate the flexibility of embedding advanced Doppler processing algorithms in the DSP module. Two advanced velocity estimation algorithms previously introduced by us are incorporated in this DSP module. Experiments on Intralipid flow demonstrate that a pulsatile flow of several hundred pulses per minute can be faithfully captured in M-scan mode by this DSP system. In vivo imaging of a rat's abdominal blood flow is also presented.
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Affiliation(s)
- Shikui Yan
- Electrical & Computer Engineering Department, University of Connecticut, 371 Fairfield Road U11257, Storrs, CT 06269-2157, USA
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17
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Piao D, Zhu Q. Quantifying Doppler angle and mapping flow velocity by a combination of Doppler-shift and Doppler-bandwidth measurements in optical Doppler tomography. APPLIED OPTICS 2003; 42:5158-5166. [PMID: 12962396 DOI: 10.1364/ao.42.005158] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Recently we introduced a novel procedure that estimates Doppler angle and flow velocity simultaneously by combining Doppler-shift and Doppler-bandwidth measurements with a conventional single-beam optical Doppler tomography device. Here we validate this method experimentally with two Intralipid flow setups that correspond to fixed Doppler angle and fixed flow speed. One set of data has a fixed flow speed of 53.6 mm/s with a Doppler angle that changes from 56 degrees to 90 degrees; the other has a fixed Doppler angle of 80 degrees with flow speed that changes from 18.5 to 141.9 mm/s. As obtained with the method introduced here, the Doppler-angle estimation accuracies of the two sets are 97.6% and 98.2%, respectively, and the estimation accuracies of flow speeds of the two sets are 94.3% and 90.4%, respectively.
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Affiliation(s)
- Daqing Piao
- Department of Electrical and Computer Engineering, University of Connecticut, 260 Glenbrook Road, U157, Storrs, Connecticut 06269-1157, USA
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18
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Proskurin SG, He Y, Wang RK. Determination of flow velocity vector based on Doppler shift and spectrum broadening with optical coherence tomography. OPTICS LETTERS 2003; 28:1227-9. [PMID: 12885029 DOI: 10.1364/ol.28.001227] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
We describe a technique that uses Doppler optical coherence tomography to estimate accurately the scattering fluid-flow velocity without a priori knowledge of the Doppler angle. Our technique is based on the combined use of the Doppler shift on the interference signal and the Doppler spectrum broadening caused by the particles moving across the probe beam. It is shown that the estimated values of the Doppler angle and average fluid velocity from the experiments agree well with the preset values.
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Affiliation(s)
- Sergey G Proskurin
- Cranfield Biomedical Centre, Institute of Bioscience and Technology, Cranfield University at Silsoe, Bedfordshire, MK45 4DT, UK
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19
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Hauger C, Wörz M, Hellmuth T. Interferometer for optical coherence tomography. APPLIED OPTICS 2003; 42:3896-902. [PMID: 12868828 DOI: 10.1364/ao.42.003896] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
We describe a new interferometer setup for optical coherence tomography (OCT). The interferometer is based on a fiber arrangement similar to Young's two-pinhole interference experiment with spatial coherent and temporal incoherent light. Depth gating is achieved detection of the interference signal on a linear CCD array. Therefore no reference optical delay scanning is needed. The interference signal, the modulation of the signal, the axial resolution, and the depth range are derived theoretically and compared with experiments. The dynamic range of the setup is compared with OCT sensors in the time domain. To our knowledge, the first images of porcine brain and heart tissue and human skin are presented.
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Affiliation(s)
- J.G. Fujimoto
- Department of Electrical Engineering and Computer Science and Research Laboratory of Electronics Massachusetts Institute of Technology
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21
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Yazdanfar S, Izatt JA. Self-referenced Doppler optical coherence tomography. OPTICS LETTERS 2002; 27:2085-7. [PMID: 18033449 DOI: 10.1364/ol.27.002085] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Doppler optical coherence tomography (DOCT) allows simultaneous micrometer-scale resolution cross-sectional imaging of tissue structure and blood flow. We demonstrate a fiber-optic polarization-diversity-based differential phase contrast DOCT system as a method to perform self-referenced velocimetry in highly scattering media. Using this strategy, we reduced common-mode interferometer noise to <1 Hz and improved Doppler estimates in a scattering flow phantom by a factor of 5.
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22
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Piao D, Otis LL, Dutta NK, Zhu Q. Quantitative assessment of flow velocity-estimation algorithms for optical Doppler tomography imaging. APPLIED OPTICS 2002; 41:6118-6127. [PMID: 12389980 DOI: 10.1364/ao.41.006118] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We present a quantitative comparison of three categories of velocity estimation algorithms, including centroid techniques (the adaptive centroid technique and the weighted centroid technique), the sliding-window filtering technique, and correlation techniques (autocorrelation and cross correlation). We introduce, among these five algorithms, two new algorithms: weighted centroid and sliding-window filtering. Simulations and in vivo blood flow data are used to assess the velocity estimation accuracies of these algorithms. These comparisons demonstrate that the sliding-window filtering technique is superior to the other techniques in terms of velocity estimation accuracy and robustness to noise.
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Affiliation(s)
- Daqing Piao
- Department of Electrical and Computer Engineering, University of Connecticut, Storrs 06269-2157, USA.
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Ren H, Brecke KM, Ding Z, Zhao Y, Nelson JS, Chen Z. Imaging and quantifying transverse flow velocity with the Doppler bandwidth in a phase-resolved functional optical coherence tomography. OPTICS LETTERS 2002; 27:409-11. [PMID: 18007817 DOI: 10.1364/ol.27.000409] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
The Doppler bandwidth extracted from the standard deviation of the frequency shift in phase-resolved functional optical coherence tomography (F-OCT) was used to image the velocity component that is transverse to the optical probing beam. It was found that above a certain threshold level the Doppler bandwidth is a linear function of flow velocity and that the effective numerical aperture of the optical objective in the sample arm determines the slope of this dependence. The Doppler bandwidth permits accurate measurement of flow velocity without the need for precise determination of flow direction when the Doppler flow angle is within +/-15 degrees perpendicular to the probing beam. Such an approach extends the dynamic range of flow velocity measurements obtained with the phase-resolved F-OCT.
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24
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Wong RCK, Yazdanfar S, Izatt JA, Kulkarni MD, Barton JK, Welch AJ, Willis J, Sivak MV. Visualization of subsurface blood vessels by color Doppler optical coherence tomography in rats: before and after hemostatic therapy. Gastrointest Endosc 2002; 55:88-95. [PMID: 11756926 DOI: 10.1067/mge.2002.120104] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
BACKGROUND The ability to visualize subsurface blood vessels and measure flow may be useful in certain experimental and clinical settings. METHODS Color Doppler optical coherence tomography was used to visualize and measure blood flow in subsurface vessels in vivo in a rat skin flap model. Local "hemostatic" interventions (epinephrine or sclerosant injection, heat probe, and laser) were then applied and imaging was repeated. The skin flap was evaluated histologically. RESULTS Subsurface blood vessels were easily visualized in cross-section, and vessel diameter and bidirectional blood flow velocity were readily measured. Color Doppler optical coherence tomography demonstrated that flow was significantly reduced after epinephrine injection and became undetectable after the other interventions. This correlated with pathologic evidence of vessel damage in all interventions, except for epinephrine injection. Although vessel response was as predicted to most interventions, the response to epinephrine was only temporary, and limited application of heat alone from the heat probe halted flow without visually apparent surface injury. CONCLUSIONS Color Doppler optical coherence tomography provides high-resolution, cross-sectional flow imaging in subsurface blood vessels. Color Doppler optical coherence tomography is potentially a better technique for the study of existing and new hemostatic intervention in the laboratory. Potential future clinical applications include monitoring of the response to hemostatic modalities.
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Affiliation(s)
- Richard C K Wong
- Division of Gastroenterology, Department of Medicine, University Hospitals of Cleveland, Cleveland, Ohio 44106-5066, USA
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25
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Li X, Ko TH, Fujimoto JG. Intraluminal fiber-optic Doppler imaging catheter for structural and functional optical coherence tomography. OPTICS LETTERS 2001; 26:1906-8. [PMID: 18059733 DOI: 10.1364/ol.26.001906] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
We describe a miniature fiber-optic Doppler imaging catheter for integrated functional and structural optical coherence tomography (OCT) imaging. The Doppler catheter can map blood flow within a vessel as well as image vessel wall structures. A prototype Doppler catheter has been developed and demonstrated for measuring the intraluminal velocity profile in a vessel phantom (conduit). A simple mathematical model is demonstrated to estimate the total flow rate. This estimation technique also enables the spatial range of flow measurements to be extended by approximately two times the normal OCT image-penetration depth. The Doppler OCT catheter could be a powerful device for cardiovascular imaging.
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26
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Piao D, Zhu Q, Dutta NK, Yan S, Otis LL. Cancellation of coherent artifacts in optical coherence tomography imaging. APPLIED OPTICS 2001; 40:5124-31. [PMID: 18364794 PMCID: PMC3571715 DOI: 10.1364/ao.40.005124] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Coherent artifacts in optical coherence tomography (OCT) images can severely degrade image quality by introducing false targets if no targets are present at the artifact locations. Coherent artifacts can also add constructively or destructively to the targets that are present at the artifact locations. This constructive or destructive interference will result in cancellation of the true targets or in display of incorrect echo amplitudes of the targets. We introduce the use of a nonlinear deconvolution algorithm, CLEAN, to cancel coherent artifacts in OCT images of extracted human teeth. The results show that CLEAN can reduce the coherent artifacts to the noise background, sharpen the air-enamel and enamel-dentin interfaces, and improve the image contrast.
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Affiliation(s)
- Daqing Piao
- Department of Electrical and Computer Engineering, University of Connecticut, Storrs, Connecticut 06269-2157
| | - Quing Zhu
- Department of Electrical and Computer Engineering, University of Connecticut, Storrs, Connecticut 06269-2157
| | - Niloy K. Dutta
- Department of Physics, University of Connecticut, Storrs, Connecticut 06269-3046
| | - Shikui Yan
- Department of Electrical and Computer Engineering, University of Connecticut, Storrs, Connecticut 06269-2157
| | - Linda L. Otis
- University of Pennsylvania School of Dental Medicine, Philadelphia, Pennsylvania, 19104-6003
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27
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Zvyagin AV, Fitzgerald JB, Silva KK, Sampson DD. Real-time detection technique for Doppler optical coherence tomography. OPTICS LETTERS 2000; 25:1645-1647. [PMID: 18066302 DOI: 10.1364/ol.25.001645] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We propose and demonstrate a novel detection technique, based on a modified electronic phase-locked loop, for Doppler optical coherence tomography. The technique permits real-time simultaneous reflectivity and continuous, bidirectional velocity mapping in turbid media over a wide velocity range with minimal sensitivity penalty compared with conventional optical coherence tomography, which is a major advance over current postprocessing and discrete parallel detection techniques.
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28
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Davé DP, Milner TE. Doppler-angle measurement in highly scattering media. OPTICS LETTERS 2000; 25:1523-5. [PMID: 18066266 DOI: 10.1364/ol.25.001523] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We describe a dual-channel optical low-coherence reflectometer for accurate measurement of Doppler angles in highly scattering media. Accurate fluid-flow velocity estimation requires measurement of the Doppler shift and angle. Estimated values of the Doppler angle and average fluid-flow velocity from experimental data are in good agreement with preset values.
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Affiliation(s)
- D P Davé
- Department of Electrical and Computer Engineering, University of Texas at Austin, Austin, Texas 78712, USA
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29
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Yazdanfar S, Rollins AM, Izatt JA. Imaging and velocimetry of the human retinal circulation with color Doppler optical coherence tomography. OPTICS LETTERS 2000; 25:1448-50. [PMID: 18066244 DOI: 10.1364/ol.25.001448] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Noninvasive monitoring of blood flow in retinal microcirculation may elucidate the progression and treatment of ocular disorders, including diabetic retinopathy, age-related macular degeneration, and glaucoma. Color Doppler optical coherence tomography (CDOCT) is a technique that allows simultaneous micrometer-scale resolution cross-sectional imaging of tissue microstructure and blood flow in living tissues. CDOCT is demonstrated for the first time in living human subjects for bidirectional blood-flow mapping of retinal vasculature.
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30
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Zhao Y, Chen Z, Saxer C, Shen Q, Xiang S, de Boer JF, Nelson JS. Doppler standard deviation imaging for clinical monitoring of in vivo human skin blood flow. OPTICS LETTERS 2000; 25:1358-60. [PMID: 18066216 DOI: 10.1364/ol.25.001358] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
We used a novel phase-resolved optical Doppler tomographic (ODT) technique with very high flow-velocity sensitivity (10microm/s) and high spatial resolution (10microm) to image blood flow in port-wine stain (PWS) birthmarks in human skin. In addition to the regular ODT velocity and structural images, we use the variance of blood flow velocity to map the PWS vessels. Our device combines ODT and therapeutic systems such that PWS blood flow can be monitored in situ before and after laser treatment. To the authors' knowledge this is the first clinical application of ODT to provide a fast semiquantitative evaluation of the efficacy of PWS laser therapy in situ and in real time.
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31
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Zhao Y, Chen Z, Saxer C, Xiang S, de Boer JF, Nelson JS. Phase-resolved optical coherence tomography and optical Doppler tomography for imaging blood flow in human skin with fast scanning speed and high velocity sensitivity. OPTICS LETTERS 2000; 25:114-6. [PMID: 18059800 DOI: 10.1364/ol.25.000114] [Citation(s) in RCA: 329] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
We have developed a novel phase-resolved optical coherence tomography (OCT) and optical Doppler tomography (ODT) system that uses phase information derived from a Hilbert transformation to image blood flow in human skin with fast scanning speed and high velocity sensitivity. Using the phase change between sequential scans to construct flow-velocity imaging, this technique decouples spatial resolution and velocity sensitivity in flow images and increases imaging speed by more than 2 orders of magnitude without compromising spatial resolution or velocity sensitivity. The minimum flow velocity that can be detected with an axial-line scanning speed of 400 Hz and an average phase change over eight sequential scans is as low as 10 microm/s, while a spatial resolution of 10 microm is maintained. Using this technique, we present what are to our knowledge the first phase-resolved OCT/ODT images of blood flow in human skin.
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van Leeuwen TG, Kulkarni MD, Yazdanfar S, Rollins AM, Izatt JA. High-flow-velocity and shear-rate imaging by use of color Doppler optical coherence tomography. OPTICS LETTERS 1999; 24:1584-6. [PMID: 18079871 DOI: 10.1364/ol.24.001584] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Color Doppler optical coherence tomography (CDOCT) is capable of precise velocity mapping in turbid media. Previous CDOCT systems based on the short-time Fourier transform have been limited to maximum flow velocities of the order of tens of millimeters per second. We describe a technique, based on interference signal demodulation at multiple frequencies, to extend the physiological relevance of CDOCT by increasing the dynamic range of measurable velocities to hundreds of millimeters per second. The physiologically important parameter of shear rate is also derived from CDOCT measurements. The measured flow-velocity profiles and shear-rate distributions correlate very well with theoretical predictions. The multiple demodulation technique, therefore, may be useful to monitor blood flow in vivo and to identify regions with high and low shear rates.
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Affiliation(s)
- T G van Leeuwen
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio 44106-5066, USA
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33
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de Boer JF, Srinivas SM, Park BH, Pham TH, Chen Z, Milner TE, Nelson JS. Polarization Effects in Optical Coherence Tomography of Various Biological Tissues. IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS : A PUBLICATION OF THE IEEE LASERS AND ELECTRO-OPTICS SOCIETY 1999; 5:1200-1204. [PMID: 25774083 DOI: 10.1109/2944.796348] [Citation(s) in RCA: 358] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Polarization sensitive optical coherence tomography (PS-OCT) was used to obtain spatially resolved ex vivo images of polarization changes in skeletal muscle, bone, skin and brain. Through coherent detection of two orthogonal polarization states of the signal formed by interference of light reflected from the biological sample and a mirror in the reference arm of a Michelson interferometer, the depth resolved change in polarization was measured. Inasmuch as any fibrous structure will influence the polarization of light, PS-OCT is a potentially powerful technique investigating tissue structural properties. In addition, the effects of single polarization state detection on OCT image formation is demonstrated.
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Affiliation(s)
- Johannes F de Boer
- Beckman Laser Institute and Medical Clinic, University of California, Irvine, CA 92612 USA
| | - Shyam M Srinivas
- Beckman Laser Institute and Medical Clinic, University of California, Irvine, CA 92612 USA
| | - B Hyle Park
- Beckman Laser Institute and Medical Clinic, University of California, Irvine, CA 92612 USA
| | - Tuan H Pham
- Beckman Laser Institute and Medical Clinic, University of California, Irvine, CA 92612 USA
| | - Zhongping Chen
- Beckman Laser Institute and Medical Clinic, University of California, Irvine, CA 92612 USA
| | - Thomas E Milner
- Biomedical Engineering Program, University of Texas at Austin, Austin, TX 78712 USA
| | - J Stuart Nelson
- Beckman Laser Institute and Medical Clinic, University of California, Irvine, CA 92612 USA
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Rollins A, Yazdanfar S, Kulkarni M, Ung-Arunyawee R, Izatt J. In vivo video rate optical coherence tomography. OPTICS EXPRESS 1998; 3:219-29. [PMID: 19384364 DOI: 10.1364/oe.3.000219] [Citation(s) in RCA: 166] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
An optical coherence tomography system is described which can image up to video rate. The system utilizes a high power broadband source and real time image acquisition hardware and features a high speed scanning delay line in the reference arm based on Fourier-transform pulse shaping technology. The theory of low coherence interferometry with a dispersive delay line, and the operation of the delay line are detailed and the design equations of the system are presented. Real time imaging is demonstrated in vivo in tissues relevant to early human disease diagnosis (skin, eye) and in an important model in developmental biology (Xenopus laevis).
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