1
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Burhan S, Detrez N, Rewerts K, Strenge P, Buschschlüter S, Kren J, Hagel C, Bonsanto MM, Brinkmann R, Huber R. Phase unwrapping for MHz optical coherence elastography and application to brain tumor tissue. BIOMEDICAL OPTICS EXPRESS 2024; 15:1038-1058. [PMID: 38404346 PMCID: PMC10890849 DOI: 10.1364/boe.510020] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 12/15/2023] [Accepted: 12/17/2023] [Indexed: 02/27/2024]
Abstract
During neuro-oncologic surgery, phase-sensitive optical coherence elastography (OCE) can be valuable for distinguishing between healthy and diseased tissue. However, the phase unwrapping process required to retrieve the original phase signal is a challenging and critical task. To address this issue, we demonstrate a one-dimensional unwrapping algorithm that recovers the phase signal from a 3.2 MHz OCE system. With a processing time of approximately 0.11 s per frame on the GPU, multiple 2π wraps are detected and corrected. By utilizing this approach, exact and reproducible information on tissue deformation can be obtained with pixel accuracy over the entire acquisition time. Measurements of brain tumor-mimicking phantoms and human ex vivo brain tumor samples verified the algorithm's reliability. The tissue samples were subjected to a 200 ms short air pulse. A correlation with histological findings confirmed the algorithm's dependability.
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Affiliation(s)
- Sazgar Burhan
- Institut für Biomedizinische Optik, Universität zu Lübeck, Peter-Monnik-Weg 4, 23562 Lübeck, Germany
| | - Nicolas Detrez
- Medizinisches Laserzentrum Lübeck GmbH, Peter-Monnik-Weg 4, 23562 Lübeck, Germany
| | - Katharina Rewerts
- Institut für Biomedizinische Optik, Universität zu Lübeck, Peter-Monnik-Weg 4, 23562 Lübeck, Germany
| | - Paul Strenge
- Medizinisches Laserzentrum Lübeck GmbH, Peter-Monnik-Weg 4, 23562 Lübeck, Germany
| | | | - Jessica Kren
- Klinik für Neurochirurgie, Universitätsklinikum Schleswig-Holstein, Campus Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Christian Hagel
- Institut für Neuropathologie, Universitätsklinikum Hamburg-Eppendorf, Martinistrasse 52, 20251 Hamburg, Germany
| | - Matteo Mario Bonsanto
- Institut für Neuropathologie, Universitätsklinikum Hamburg-Eppendorf, Martinistrasse 52, 20251 Hamburg, Germany
| | - Ralf Brinkmann
- Institut für Biomedizinische Optik, Universität zu Lübeck, Peter-Monnik-Weg 4, 23562 Lübeck, Germany
- Medizinisches Laserzentrum Lübeck GmbH, Peter-Monnik-Weg 4, 23562 Lübeck, Germany
| | - Robert Huber
- Institut für Biomedizinische Optik, Universität zu Lübeck, Peter-Monnik-Weg 4, 23562 Lübeck, Germany
- Medizinisches Laserzentrum Lübeck GmbH, Peter-Monnik-Weg 4, 23562 Lübeck, Germany
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2
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Li YH, Lee YW, Huang SL. Broadband wavelength-swept Cr 4+:YAG crystal fiber laser. OPTICS EXPRESS 2023; 31:32772-32782. [PMID: 37859072 DOI: 10.1364/oe.497798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 09/10/2023] [Indexed: 10/21/2023]
Abstract
We present a broadband wavelength-swept laser using a 16-µm-core-diameter Cr4+:YAG crystal fiber as the gain medium. The laser-diode-pumped crystal fiber laser has a threshold of only 102 mW due to the low propagation loss and high heat dissipation efficiency. The laser achieves a sweeping wavelength range of 134 nm, centered around 1425 nm, with a scanning speed of 163 k nm/s. Notably, the cross-polarization-coupled excited state absorption of the signal wavelength constrained the long-wavelength lasing limit. This laser has the potential for swept source optical coherence tomography applications, providing an axial resolution of 11.4 µm.
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3
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Afsharan H, Silva D, Joo C, Cense B. Non-Invasive Retinal Blood Vessel Wall Measurements with Polarization-Sensitive Optical Coherence Tomography for Diabetes Assessment: A Quantitative Study. Biomolecules 2023; 13:1230. [PMID: 37627295 PMCID: PMC10452597 DOI: 10.3390/biom13081230] [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: 06/14/2023] [Revised: 07/31/2023] [Accepted: 08/07/2023] [Indexed: 08/27/2023] Open
Abstract
Diabetes affects the structure of the blood vessel walls. Since the blood vessel walls are made of birefringent organized tissue, any change or damage to this organization can be evaluated using polarization-sensitive optical coherence tomography (PS-OCT). In this paper, we used PS-OCT along with the blood vessel wall birefringence index (BBI = thickness/birefringence2) to non-invasively assess the structural integrity of the human retinal blood vessel walls in patients with diabetes and compared the results to those of healthy subjects. PS-OCT measurements revealed that blood vessel walls of diabetic patients exhibit a much higher birefringence while having the same wall thickness and therefore lower BBI values. Applying BBI to diagnose diabetes demonstrated high accuracy (93%), sensitivity (93%) and specificity (93%). PS-OCT measurements can quantify small changes in the polarization properties of retinal vessel walls associated with diabetes, which provides researchers with a new imaging tool to determine the effects of exercise, medication, and alternative diets on the development of diabetes.
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Affiliation(s)
- Hadi Afsharan
- Optical+Biomedical Engineering Laboratory, Department of Electrical, Electronic and Computer Engineering, The University of Western Australia, Perth, WA 6009, Australia;
| | - Dilusha Silva
- Microelectronics Research Group, Department of Electrical, Electronic and Computer Engineering, The University of Western Australia, Perth, WA 6009, Australia;
| | - Chulmin Joo
- Department of Mechanical Engineering, Yonsei University, Seodaemun-gu, Seoul 03722, Republic of Korea;
| | - Barry Cense
- Optical+Biomedical Engineering Laboratory, Department of Electrical, Electronic and Computer Engineering, The University of Western Australia, Perth, WA 6009, Australia;
- Department of Mechanical Engineering, Yonsei University, Seodaemun-gu, Seoul 03722, Republic of Korea;
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4
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Plekhanov AA, Gubarkova EV, Sirotkina MA, Sovetsky AA, Vorontsov DA, Matveev LA, Kuznetsov SS, Bogomolova AY, Vorontsov AY, Matveyev AL, Gamayunov SV, Zagaynova EV, Zaitsev VY, Gladkova ND. Compression OCT-elastography combined with speckle-contrast analysis as an approach to the morphological assessment of breast cancer tissue. BIOMEDICAL OPTICS EXPRESS 2023; 14:3037-3056. [PMID: 37342703 PMCID: PMC10278614 DOI: 10.1364/boe.489021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 05/15/2023] [Accepted: 05/18/2023] [Indexed: 06/23/2023]
Abstract
Currently, optical biopsy technologies are being developed for rapid and label-free visualization of biological tissue with micrometer-level resolution. They can play an important role in breast-conserving surgery guidance, detection of residual cancer cells, and targeted histological analysis. For solving these problems, compression optical coherence elastography (C-OCE) demonstrated impressive results based on differences in the elasticity of different tissue constituents. However, sometimes straightforward C-OCE-based differentiation is insufficient because of the similar stiffness of certain tissue components. We present a new automated approach to the rapid morphological assessment of human breast cancer based on the combined usage of C-OCE and speckle-contrast (SC) analysis. Using the SC analysis of structural OCT images, the threshold value of the SC coefficient was established to enable the separation of areas of adipose cells from necrotic cancer cells, even if they are highly similar in elastic properties. Consequently, the boundaries of the tumor bed can be reliably identified. The joint analysis of structural and elastographic images enables automated morphological segmentation based on the characteristic ranges of stiffness (Young's modulus) and SC coefficient established for four morphological structures of breast-cancer samples from patients post neoadjuvant chemotherapy (residual cancer cells, cancer stroma, necrotic cancer cells, and mammary adipose cells). This enabled precise automated detection of residual cancer-cell zones within the tumor bed for grading cancer response to chemotherapy. The results of C-OCE/SC morphometry highly correlated with the histology-based results (r =0.96-0.98). The combined C-OCE/SC approach has the potential to be used intraoperatively for achieving clean resection margins in breast cancer surgery and for performing targeted histological analysis of samples, including the evaluation of the efficacy of cancer chemotherapy.
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Affiliation(s)
- Anton A. Plekhanov
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, Minin and Pozharsky sq. 10/1, 603950 Nizhny Novgorod, Russia
| | - Ekaterina V. Gubarkova
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, Minin and Pozharsky sq. 10/1, 603950 Nizhny Novgorod, Russia
| | - Marina A. Sirotkina
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, Minin and Pozharsky sq. 10/1, 603950 Nizhny Novgorod, Russia
| | - Alexander A. Sovetsky
- Institute of Applied Physics of the Russian Academy of Sciences, Ulyanova st. 46, 603950 Nizhny Novgorod, Russia
| | - Dmitry A. Vorontsov
- Nizhny Novgorod Regional Oncologic Hospital, Delovaya st. 11/1, 603093 Nizhny Novgorod, Russia
| | - Lev A. Matveev
- Institute of Applied Physics of the Russian Academy of Sciences, Ulyanova st. 46, 603950 Nizhny Novgorod, Russia
| | - Sergey S. Kuznetsov
- Nizhny Novgorod Regional Oncologic Hospital, Delovaya st. 11/1, 603093 Nizhny Novgorod, Russia
| | - Alexandra Y. Bogomolova
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, Minin and Pozharsky sq. 10/1, 603950 Nizhny Novgorod, Russia
- Lobachevsky State University, Gagarin Avenue 23, 603950 Nizhny Novgorod, Russia
| | - Alexey Y. Vorontsov
- Nizhny Novgorod Regional Oncologic Hospital, Delovaya st. 11/1, 603093 Nizhny Novgorod, Russia
| | - Alexander L. Matveyev
- Institute of Applied Physics of the Russian Academy of Sciences, Ulyanova st. 46, 603950 Nizhny Novgorod, Russia
| | - Sergey V. Gamayunov
- Nizhny Novgorod Regional Oncologic Hospital, Delovaya st. 11/1, 603093 Nizhny Novgorod, Russia
| | - Elena V. Zagaynova
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, Minin and Pozharsky sq. 10/1, 603950 Nizhny Novgorod, Russia
- Lobachevsky State University, Gagarin Avenue 23, 603950 Nizhny Novgorod, Russia
| | - Vladimir Y. Zaitsev
- Institute of Applied Physics of the Russian Academy of Sciences, Ulyanova st. 46, 603950 Nizhny Novgorod, Russia
| | - Natalia D. Gladkova
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, Minin and Pozharsky sq. 10/1, 603950 Nizhny Novgorod, Russia
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5
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Mason JH, Luo L, Reinwald Y, Taffetani M, Hallas-Potts A, Herrington CS, Srsen V, Lin CJ, Barroso IA, Zhang Z, Zhang Z, Ghag AK, Yang Y, Waters S, El Haj AJ, Bagnaninchi PO. Debiased ambient vibrations optical coherence elastography to profile cell, organoid and tissue mechanical properties. Commun Biol 2023; 6:543. [PMID: 37202417 DOI: 10.1038/s42003-023-04788-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 03/31/2023] [Indexed: 05/20/2023] Open
Abstract
The role of the mechanical environment in defining tissue function, development and growth has been shown to be fundamental. Assessment of the changes in stiffness of tissue matrices at multiple scales has relied mostly on invasive and often specialist equipment such as AFM or mechanical testing devices poorly suited to the cell culture workflow.In this paper, we have developed a unbiased passive optical coherence elastography method, exploiting ambient vibrations in the sample that enables real-time noninvasive quantitative profiling of cells and tissues. We demonstrate a robust method that decouples optical scattering and mechanical properties by actively compensating for scattering associated noise bias and reducing variance. The efficiency for the method to retrieve ground truth is validated in silico and in vitro, and exemplified for key applications such as time course mechanical profiling of bone and cartilage spheroids, tissue engineering cancer models, tissue repair models and single cell. Our method is readily implementable with any commercial optical coherence tomography system without any hardware modifications, and thus offers a breakthrough in on-line tissue mechanical assessment of spatial mechanical properties for organoids, soft tissues and tissue engineering.
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Affiliation(s)
- Jonathan H Mason
- MRC Centre for Regenerative Medicine, The University of Edinburgh, Edinburgh, UK
| | - Lu Luo
- Healthcare Technology Institute, University of Birmingham, Birmingham, UK
| | - Yvonne Reinwald
- Department of Engineering, Nottingham Trent University, Nottingham, UK
| | | | - Amelia Hallas-Potts
- MRC Centre for Regenerative Medicine, The University of Edinburgh, Edinburgh, UK
- Cancer Research UK Edinburgh Centre, The University of Edinburgh, Edinburgh, UK
| | - C Simon Herrington
- Cancer Research UK Edinburgh Centre, The University of Edinburgh, Edinburgh, UK
| | - Vlastimil Srsen
- MRC Centre for Regenerative Medicine, The University of Edinburgh, Edinburgh, UK
| | - Chih-Jen Lin
- MRC Centre for Reproductive Health, The Univeristy of Edinburgh, Edinburgh, UK
| | - Inês A Barroso
- School of Chemical Engineering, University of Birmingham, Birmingham, UK
| | - Zhihua Zhang
- School of Chemical Engineering, University of Birmingham, Birmingham, UK
| | - Zhibing Zhang
- School of Chemical Engineering, University of Birmingham, Birmingham, UK
| | - Anita K Ghag
- School of Chemical Engineering, University of Birmingham, Birmingham, UK
| | - Ying Yang
- Institute of Science and Technology in Medicine, Keele University, Stoke-on-Trent, UK
| | - Sarah Waters
- Mathematical Institute, University of Oxford, Oxford, UK
| | - Alicia J El Haj
- Healthcare Technology Institute, University of Birmingham, Birmingham, UK.
| | - Pierre O Bagnaninchi
- MRC Centre for Regenerative Medicine, The University of Edinburgh, Edinburgh, UK.
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6
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Lan G, Twa MD, Song C, Feng J, Huang Y, Xu J, Qin J, An L, Wei X. In vivo corneal elastography: A topical review of challenges and opportunities. Comput Struct Biotechnol J 2023; 21:2664-2687. [PMID: 37181662 PMCID: PMC10173410 DOI: 10.1016/j.csbj.2023.04.009] [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: 02/14/2023] [Revised: 04/07/2023] [Accepted: 04/12/2023] [Indexed: 05/16/2023] Open
Abstract
Clinical measurement of corneal biomechanics can aid in the early diagnosis, progression tracking, and treatment evaluation of ocular diseases. Over the past two decades, interdisciplinary collaborations between investigators in optical engineering, analytical biomechanical modeling, and clinical research has expanded our knowledge of corneal biomechanics. These advances have led to innovations in testing methods (ex vivo, and recently, in vivo) across multiple spatial and strain scales. However, in vivo measurement of corneal biomechanics remains a long-standing challenge and is currently an active area of research. Here, we review the existing and emerging approaches for in vivo corneal biomechanics evaluation, which include corneal applanation methods, such as ocular response analyzer (ORA) and corneal visualization Scheimpflug technology (Corvis ST), Brillouin microscopy, and elastography methods, and the emerging field of optical coherence elastography (OCE). We describe the fundamental concepts, analytical methods, and current clinical status for each of these methods. Finally, we discuss open questions for the current state of in vivo biomechanics assessment techniques and requirements for wider use that will further broaden our understanding of corneal biomechanics for the detection and management of ocular diseases, and improve the safety and efficacy of future clinical practice.
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Affiliation(s)
- Gongpu Lan
- Guangdong-Hong Kong-Macao Intelligent Micro-Nano Optoelectronic Technology Joint Laboratory, School of Physics and Optoelectronic Engineering, Foshan University, Foshan, Guangdong 528000, China
- Weiren Meditech Co., Ltd., Foshan, Guangdong 528000, China
| | - Michael D Twa
- College of Optometry, University of Houston, Houston, TX 77204, United States
| | - Chengjin Song
- Guangdong-Hong Kong-Macao Intelligent Micro-Nano Optoelectronic Technology Joint Laboratory, School of Physics and Optoelectronic Engineering, Foshan University, Foshan, Guangdong 528000, China
| | - JinPing Feng
- Institute of Engineering and Technology, Hubei University of Science and Technology, Xianning, Hubei 437100, China
| | - Yanping Huang
- Guangdong-Hong Kong-Macao Intelligent Micro-Nano Optoelectronic Technology Joint Laboratory, School of Physics and Optoelectronic Engineering, Foshan University, Foshan, Guangdong 528000, China
- Weiren Meditech Co., Ltd., Foshan, Guangdong 528000, China
| | - Jingjiang Xu
- Guangdong-Hong Kong-Macao Intelligent Micro-Nano Optoelectronic Technology Joint Laboratory, School of Physics and Optoelectronic Engineering, Foshan University, Foshan, Guangdong 528000, China
- Weiren Meditech Co., Ltd., Foshan, Guangdong 528000, China
| | - Jia Qin
- Weiren Meditech Co., Ltd., Foshan, Guangdong 528000, China
| | - Lin An
- Weiren Meditech Co., Ltd., Foshan, Guangdong 528000, China
| | - Xunbin Wei
- Biomedical Engineering Department, Peking University, Beijing 100081, China
- International Cancer Institute, Peking University, Beijing 100191, China
- Institute of Medical Technology, Peking University Health Science Center, Beijing 100191, China
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7
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Lee B, Jeong S, Lee J, Kim TS, Braaf B, Vakoc BJ, Oh WY. Wide-Field Three-Dimensional Depth-Invariant Cellular-Resolution Imaging of the Human Retina. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2203357. [PMID: 36642824 PMCID: PMC10023497 DOI: 10.1002/smll.202203357] [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: 05/31/2022] [Revised: 12/02/2022] [Indexed: 06/17/2023]
Abstract
Three-dimensional (3D) cellular-resolution imaging of the living human retina over a large field of view will bring a great impact in clinical ophthalmology, potentially finding new biomarkers for early diagnosis and improving the pathophysiological understanding of ocular diseases. While hardware-based and computational adaptive optics (AO) optical coherence tomography (OCT) have been developed to achieve cellular-resolution retinal imaging, these approaches support limited 3D imaging fields, and their high cost and intrinsic hardware complexity limit their practical utility. Here, this work demonstrates 3D depth-invariant cellular-resolution imaging of the living human retina over a 3 × 3 mm field of view using the first intrinsically phase-stable multi-MHz retinal swept-source OCT and novel computational defocus and aberration correction methods. Single-acquisition imaging of photoreceptor cells, retinal nerve fiber layer, and retinal capillaries is presented across unprecedented imaging fields. By providing wide-field 3D cellular-resolution imaging in the human retina using a standard point-scan architecture routinely used in the clinic, this platform proposes a strategy for expanded utilization of high-resolution retinal imaging in both research and clinical settings.
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Affiliation(s)
- ByungKun Lee
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
- KI for Health Science and Technology, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
| | - Sunhong Jeong
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
- KI for Health Science and Technology, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
| | - Joosung Lee
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
- KI for Health Science and Technology, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
| | - Tae Shik Kim
- Wellman Center for Photomedicine, Massachusetts General Hospital and Harvard Medical School, Boston 02140, USA
| | - Boy Braaf
- Wellman Center for Photomedicine, Massachusetts General Hospital and Harvard Medical School, Boston 02140, USA
| | - Benjamin J. Vakoc
- Wellman Center for Photomedicine, Massachusetts General Hospital and Harvard Medical School, Boston 02140, USA
| | - Wang-Yuhl Oh
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
- KI for Health Science and Technology, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
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8
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Wu T, Zou J, Liu Y, Lu Y, Wang J, Shi Y, Shen H, Gu X, He C. Local polarization properties extraction using single incident state, single-mode-fiber-based spectral domain polarization-sensitive optical coherence tomography. APPLIED OPTICS 2023; 62:989-996. [PMID: 36821157 DOI: 10.1364/ao.476231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 01/01/2023] [Indexed: 06/18/2023]
Abstract
We showed the local polarization properties extraction method for the single incident state, all-single-mode-fiber-based spectral domain polarization-sensitive optical coherence tomography (SD-PS-OCT) system that uses the single linear-in-wavenumber spectral camera. Polarization controllers are used in the single-mode-fiber-based SD-PS-OCT system to provide a compact structure with polarization state stability. The local polarization properties of the birefringent sample are extracted from the cumulative polarization properties iteratively. The reconstructed polarization images demonstrate the local polarization properties extraction ability of the system.
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9
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Koutsiaris AG, Batis V, Liakopoulou G, Tachmitzi SV, Detorakis ET, Tsironi EE. Optical Coherence Tomography Angiography (OCTA) of the eye: A review on basic principles, advantages, disadvantages and device specifications. Clin Hemorheol Microcirc 2022; 83:247-271. [PMID: 36502308 DOI: 10.3233/ch-221634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Optical Coherence Tomography Angiography (OCTA) is a relatively new imaging technique in ophthalmology for the visualization of the retinal microcirculation and other tissues of the human eye. This review paper aims to describe the basic definitions and principles of OCT and OCTA in the most straightforward possible language without complex mathematical and engineering analysis. This is done to help health professionals of various disciplines improve their understanding of OCTA and design further clinical research more efficiently. First, the basic technical principles of OCT and OCTA and related terminology are described. Then, a list of OCTA advantages and disadvantages, with a special reference to blood flow quantification limitations. Finally, an updated list of the basic hardware and software specifications of some of the commercially available OCTA devices is presented.
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Affiliation(s)
- Aristotle G. Koutsiaris
- Medical Informatics Laboratory, Faculty of Medicine, School of Health Sciences, University of Thessaly, Biopolis, Larissa, Greece
| | - Vasilios Batis
- Jules Gonin Eye Hospital Lausanne, Switzerland
- Department of Ophthalmology, University Hospital of Heraklion, Crete, Greece
| | - Georgia Liakopoulou
- Medical Informatics Laboratory, Faculty of Medicine, School of Health Sciences, University of Thessaly, Biopolis, Larissa, Greece
| | | | | | - Evangelia E. Tsironi
- Department of Ophthalmology, University Hospital of Larissa, Faculty of Medicine, School of Health Sciences, University of Thessaly, Larissa, Greece
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10
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Miao Y, Song J, Ju MJ. Image-based cross-calibration method for multiple spectrometer-based OCT. OPTICS LETTERS 2022; 47:5096-5099. [PMID: 36181195 DOI: 10.1364/ol.468707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Accepted: 08/31/2022] [Indexed: 06/16/2023]
Abstract
A fast and practical computational cross-calibration of multiple spectrometers is described. A signal correlation matrix (CM) can be constructed from paired B-scans in a multiple-spectrometer optical coherence tomography (OCT), where the wavelength-corresponding pixels are indicated by high cross correlation. The CM can be used to either guide the physical alignment of spectrometers or to numerically match the spectra in the post-process. The performance is comparable to the previously reported optimization approach, as demonstrated by the mirror tests, qualitative comparison of OCT and optical coherence tomography angiography (OCTA) images, and quantitative comparison of image metrics.
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11
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Li J, Pijewska E, Fang Q, Szkulmowski M, Kennedy BF. Analysis of strain estimation methods in phase-sensitive compression optical coherence elastography. BIOMEDICAL OPTICS EXPRESS 2022; 13:2224-2246. [PMID: 35519281 PMCID: PMC9045929 DOI: 10.1364/boe.447340] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 12/20/2021] [Accepted: 12/23/2021] [Indexed: 05/11/2023]
Abstract
In compression optical coherence elastography (OCE), deformation is quantified as the local strain at each pixel in the OCT field-of-view. A range of strain estimation methods have been demonstrated, yet it is unclear which method provides the best performance. Here, we analyze the two most prevalent strain estimation methods used in phase-sensitive compression OCE, i.e., weighted least squares (WLS) and the vector method. We introduce a framework to compare strain imaging metrics, incorporating strain sensitivity, strain signal-to-noise ratio (SNR), strain resolution, and strain accuracy. In addition, we propose a new phase unwrapping algorithm in OCE, fast phase unwrapping (FPU), and combine it with WLS, termed WLSFPU. Using the framework, we compare this new strain estimation method with both a current implementation of WLS that incorporates weighted phase unwrapping (WPU), termed WLSWPU, and the vector method. Our analysis reveals that the three methods provide similar strain sensitivity, strain SNR, and strain resolution, but that WLSFPU extends the dynamic range of accurate, measurable local strain, e.g., measuring a strain of 2.5 mɛ with ∼4% error, that is ×11 and ×15 smaller than the error measured using WLSWPU and the vector method, respectively. We also demonstrate, for the first time, the capability to detect sub-resolution contrast in compression OCE, i.e., changes in strain occurring within the strain axial resolution, and how this contrast varies between the different strain estimation methods. Lastly, we compare the performance of the three strain estimation methods on mouse skeletal muscle and human breast tissue and demonstrate that WLSFPU avoids strain imaging artifacts resulting from phase unwrapping errors in WLSWPU and provides improved contrast over the other two methods.
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Affiliation(s)
- Jiayue Li
- BRITElab, Harry Perkins Institute of Medical Research, QEII Medical Centre Nedlands and Centre for Medical Research, The University of Western Australia, Crawley, Western Australia 6009, Australia
- Department of Electrical, Electronic & Computer Engineering, School of Engineering, The University of Western Australia, Crawley 6009, Australia
- Australian Research Council Centre for Personalized Therapeutics Technologies, Australia
- These authors contributed equally to this work
| | - Ewelina Pijewska
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, Grudziądzka 5, 87-100 Torun, Poland
- These authors contributed equally to this work
| | - Qi Fang
- BRITElab, Harry Perkins Institute of Medical Research, QEII Medical Centre Nedlands and Centre for Medical Research, The University of Western Australia, Crawley, Western Australia 6009, Australia
- Department of Electrical, Electronic & Computer Engineering, School of Engineering, The University of Western Australia, Crawley 6009, Australia
| | - Maciej Szkulmowski
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, Grudziądzka 5, 87-100 Torun, Poland
| | - Brendan F. Kennedy
- BRITElab, Harry Perkins Institute of Medical Research, QEII Medical Centre Nedlands and Centre for Medical Research, The University of Western Australia, Crawley, Western Australia 6009, Australia
- Department of Electrical, Electronic & Computer Engineering, School of Engineering, The University of Western Australia, Crawley 6009, Australia
- Australian Research Council Centre for Personalized Therapeutics Technologies, Australia
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12
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Tomczewski S, Węgrzyn P, Borycki D, Auksorius E, Wojtkowski M, Curatolo A. Light-adapted flicker optoretinograms captured with a spatio-temporal optical coherence-tomography (STOC-T) system. BIOMEDICAL OPTICS EXPRESS 2022; 13:2186-2201. [PMID: 35519256 PMCID: PMC9045926 DOI: 10.1364/boe.444567] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 02/20/2022] [Accepted: 02/23/2022] [Indexed: 06/14/2023]
Abstract
For many years electroretinography (ERG) has been used for obtaining information about the retinal physiological function. More recently, a new technique called optoretinography (ORG) has been developed. In one form of this technique, the physiological response of retinal photoreceptors to visible light, resulting in a nanometric photoreceptor optical path length change, is measured by phase-sensitive optical coherence tomography (OCT). To date, a limited number of studies with phase-based ORG measured the retinal response to a flickering light stimulation. In this work, we use a spatio-temporal optical coherence tomography (STOC-T) system to capture optoretinograms with a flickering stimulus over a 1.7 × 0.85 mm2 area of a light-adapted retina located between the fovea and the optic nerve. We show that we can detect statistically-significant differences in the photoreceptor optical path length (OPL) modulation amplitudes in response to different flicker frequencies and with better signal to noise ratios (SNRs) than for a dark-adapted eye. We also demonstrate the ability to spatially map such response to a patterned stimulus with light stripes flickering at different frequencies, highlighting the prospect of characterizing the spatially-resolved temporal-frequency response of the retina with ORG.
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Affiliation(s)
- Sławomir Tomczewski
- International Centre for Translational Eye Research, Skierniewicka 10A, 01-230, Warszawa, Poland
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warszawa, Poland
- Equal contributors
| | - Piotr Węgrzyn
- International Centre for Translational Eye Research, Skierniewicka 10A, 01-230, Warszawa, Poland
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warszawa, Poland
- Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warszawa, Poland
- Equal contributors
| | - Dawid Borycki
- International Centre for Translational Eye Research, Skierniewicka 10A, 01-230, Warszawa, Poland
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warszawa, Poland
| | - Egidijus Auksorius
- International Centre for Translational Eye Research, Skierniewicka 10A, 01-230, Warszawa, Poland
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warszawa, Poland
- Center for Physical Sciences and Technology (FTMC), Saulėtekio al. 3, LT-10257 Vilnius, Lithuania
| | - Maciej Wojtkowski
- International Centre for Translational Eye Research, Skierniewicka 10A, 01-230, Warszawa, Poland
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warszawa, Poland
| | - Andrea Curatolo
- International Centre for Translational Eye Research, Skierniewicka 10A, 01-230, Warszawa, Poland
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warszawa, Poland
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13
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Li Q, Yu Y, Ding Z, Zhu F, Li Y, Tao K, Hua P, Lai T, Kuang H, Liu T. Analysis and reduction of noise-induced depolarization in catheter based polarization sensitive optical coherence tomography. OPTICS EXPRESS 2022; 30:11130-11149. [PMID: 35473063 DOI: 10.1364/oe.453116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 03/08/2022] [Indexed: 06/14/2023]
Abstract
In catheter based polarization sensitive optical coherence tomography (PS-OCT), a optical fiber with a rapid rotation in the catheter can cause low signal-to-noise ratio (SNR), polarization state instability, phase change of PS-OCT signals and then heavy noise-induced depolarization, which has a strong impact on the phase retardation measurement of the sample. In this paper, we analyze the noise-induced depolarization and find that the effect of depolarization can be reduced by polar decomposition after incoherent averaging in the Mueller matrix averaging (MMA) method. Namely, MMA can reduce impact of noise on phase retardation mapping. We present a Monte Carlo method based on PS-OCT to numerically describe noise-induced depolarization effect and contrast phase retardation imaging results by MMA and Jones matrix averaging (JMA) methods. The peak signal to noise ratio (PSNR) of simulated images processed by MMA is higher than about 8.9 dB than that processed by JMA. We also implement experiments of multiple biological tissues using the catheter based PS-OCT system. From the simulation and experimental results, we find the polarization contrasts processed by the MMA are better than those by JMA, especially at areas with high depolarization, because the MMA can reduce effect of noise-induced depolarization on the phase retardation measurement.
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14
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Singh M, Zvietcovich F, Larin KV. Introduction to optical coherence elastography: tutorial. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2022; 39:418-430. [PMID: 35297425 PMCID: PMC10052825 DOI: 10.1364/josaa.444808] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 01/25/2022] [Indexed: 06/03/2023]
Abstract
Optical coherence elastography (OCE) has seen rapid growth since its introduction in 1998. The past few decades have seen tremendous advancements in the development of OCE technology and a wide range of applications, including the first clinical applications. This tutorial introduces the basics of solid mechanics, which form the foundation of all elastography methods. We then describe how OCE measurements of tissue motion can be used to quantify tissue biomechanical parameters. We also detail various types of excitation methods, imaging systems, acquisition schemes, and data processing algorithms and how various parameters associated with each step of OCE imaging can affect the final quantitation of biomechanical properties. Finally, we discuss the future of OCE, its potential, and the next steps required for OCE to become an established medical imaging technology.
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Affiliation(s)
- Manmohan Singh
- Biomedical Engineering, University of Houston, Houston, Texas 77204, USA
| | - Fernando Zvietcovich
- Biomedical Engineering, University of Houston, Houston, Texas 77204, USA
- Department of Engineering, Pontificia Universidad Catolica del Peru, San Miguel, Lima 15088, Peru
| | - Kirill V. Larin
- Biomedical Engineering, University of Houston, Houston, Texas 77204, USA
- Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas 77030, USA
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15
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Baumann B, Merkle CW, Augustin M, Glösmann M, Garhöfer G. Pulsatile tissue deformation dynamics of the murine retina and choroid mapped by 4D optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2022; 13:647-661. [PMID: 35284183 PMCID: PMC8884196 DOI: 10.1364/boe.445093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 12/20/2021] [Accepted: 12/28/2021] [Indexed: 05/11/2023]
Abstract
Irregular ocular pulsatility and altered mechanical tissue properties are associated with some of the most sight-threatening eye diseases. Here we present 4D optical coherence tomography (OCT) for the quantitative assessment and depth-resolved mapping of pulsatile dynamics in the murine retina and choroid. Through a pixel-wise analysis of phase changes of the complex OCT signal, we reveal spatiotemporal displacement characteristics across repeated frame acquisitions. We demonstrate in vivo fundus elastography (FUEL) imaging in wildtype mouse retinas and in a mouse model of retinal neovascularization and uncover subtle structural deformations related to ocular pulsation. Our data in mouse eyes hold promise for a powerful retinal elastography technique that may enable a new paradigm of OCT-based measurements and image contrast.
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Affiliation(s)
- Bernhard Baumann
- Center for Medical Physics and Biomedical
Engineering, Medical University of Vienna,
Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Conrad W. Merkle
- Center for Medical Physics and Biomedical
Engineering, Medical University of Vienna,
Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Marco Augustin
- Center for Medical Physics and Biomedical
Engineering, Medical University of Vienna,
Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Martin Glösmann
- Core Facility for Research and Technology,
University of Veterinary Medicine Vienna,
Veterinärplatz 1, 1210 Vienna, Austria
| | - Gerhard Garhöfer
- Department of Clinical Pharmacology,
Medical University of Vienna, Währinger
Gürtel 18-20, 1090 Vienna, Austria
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16
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Veysset D, Ling T, Zhuo Y, Pandiyan VP, Sabesan R, Palanker D. Interferometric imaging of thermal expansion for temperature control in retinal laser therapy. BIOMEDICAL OPTICS EXPRESS 2022; 13:728-743. [PMID: 35284191 PMCID: PMC8884207 DOI: 10.1364/boe.448803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 12/27/2021] [Accepted: 12/28/2021] [Indexed: 06/14/2023]
Abstract
Precise control of the temperature rise is a prerequisite for proper photothermal therapy. In retinal laser therapy, the heat deposition is primarily governed by the melanin concentration, which can significantly vary across the retina and from patient to patient. In this work, we present a method for determining the optical and thermal properties of layered materials, directly applicable to the retina, using low-energy laser heating and phase-resolved optical coherence tomography (pOCT). The method is demonstrated on a polymer-based tissue phantom heated with a laser pulse focused onto an absorbing layer buried below the phantom's surface. Using a line-scan spectral-domain pOCT, optical path length changes induced by the thermal expansion were extracted from sequential B-scans. The material properties were then determined by matching the optical path length changes to a thermo-mechanical model developed for fast computation. This method determined the absorption coefficient with a precision of 2.5% and the temperature rise with a precision of about 0.2°C from a single laser exposure, while the peak did not exceed 8°C during 1 ms pulse, which is well within the tissue safety range and significantly more precise than other methods.
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Affiliation(s)
- David Veysset
- Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305, USA
- Department of Ophthalmology, Stanford University, Stanford, CA 94305, USA
| | - Tong Ling
- Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305, USA
- Department of Ophthalmology, Stanford University, Stanford, CA 94305, USA
- Present address: School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637457, Singapore
| | - Yueming Zhuo
- Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305, USA
- Department of Electrical Engineering, Stanford University, Stanford, CA 94305, USA
| | | | - Ramkumar Sabesan
- Department of Ophthalmology, University of Washington, Seattle, WA 98109, USA
| | - Daniel Palanker
- Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305, USA
- Department of Ophthalmology, Stanford University, Stanford, CA 94305, USA
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17
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Wan M, Liang S, Li X, Duan Z, Zou J, Chen J, Yuan J, Zhang J. Balanced detection spectral-domain optical coherence tomography with a single line-scan camera. OPTICS EXPRESS 2022; 30:2578-2584. [PMID: 35209394 DOI: 10.1364/oe.446941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 01/05/2022] [Indexed: 06/14/2023]
Abstract
This paper describes a balanced detection spectral-domain optical coherence tomography (BD-SD-OCT) system for suppressing autocorrelation (AC) artifacts and increasing the signal-to-noise ratio (SNR). The system employed three optical fiber couplers to generate two phase-opposed interference spectra that were acquired by a single line-scan camera simultaneously. When compared with conventional unbalanced detection SD-OCT systems, the developed BD-SD-OCT system improved the SNR by 5.4-6 dB and suppressed the AC term by 5-10 dB. The imaging quality of the BD-SD-OCT system was evaluated by in vivo imaging of human nail folds and retinas.
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18
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Bouma B, de Boer J, Huang D, Jang I, Yonetsu T, Leggett C, Leitgeb R, Sampson D, Suter M, Vakoc B, Villiger M, Wojtkowski M. Optical coherence tomography. NATURE REVIEWS. METHODS PRIMERS 2022; 2:79. [PMID: 36751306 PMCID: PMC9901537 DOI: 10.1038/s43586-022-00162-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Optical coherence tomography (OCT) is a non-contact method for imaging the topological and internal microstructure of samples in three dimensions. OCT can be configured as a conventional microscope, as an ophthalmic scanner, or using endoscopes and small diameter catheters for accessing internal biological organs. In this Primer, we describe the principles underpinning the different instrument configurations that are tailored to distinct imaging applications and explain the origin of signal, based on light scattering and propagation. Although OCT has been used for imaging inanimate objects, we focus our discussion on biological and medical imaging. We examine the signal processing methods and algorithms that make OCT exquisitely sensitive to reflections as weak as just a few photons and that reveal functional information in addition to structure. Image processing, display and interpretation, which are all critical for effective biomedical imaging, are discussed in the context of specific applications. Finally, we consider image artifacts and limitations that commonly arise and reflect on future advances and opportunities.
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Affiliation(s)
- B.E. Bouma
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, USA,Institute for Medical Engineering and Physics, Massachusetts Institute of Technology, Cambridge, MA, USA,Harvard Medical School, Boston, MA, USA,Corresponding author:
| | - J.F. de Boer
- Department of Physics and Astronomy, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - D. Huang
- Casey Eye Institute, Oregon Health and Science University, Portland, OR, USA
| | - I.K. Jang
- Harvard Medical School, Boston, MA, USA,Cardiology Division, Massachusetts General Hospital, Boston, MA, USA
| | - T. Yonetsu
- Department of Cardiovascular Medicine, Tokyo Medical and Dental University
| | - C.L. Leggett
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN, USA
| | - R. Leitgeb
- Institute of Medical Physics, University of Vienna, Wien, Austria
| | - D.D. Sampson
- School of Physics and School of Biosciences and Medicine, University of Surrey, Guildford, United Kingdom
| | - M. Suter
- Harvard Medical School, Boston, MA, USA,Division of Pulmonary and Critical Care Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - B. Vakoc
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, USA,Harvard Medical School, Boston, MA, USA
| | - M. Villiger
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, USA,Harvard Medical School, Boston, MA, USA
| | - M. Wojtkowski
- Institute of Physical Chemistry and International Center for Translational Eye Research, Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland,Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Torun, Poland
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19
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Pijewska E, Zhang P, Meina M, Meleppat RK, Szkulmowski M, Zawadzki RJ. Extraction of phase-based optoretinograms (ORG) from serial B-scans acquired over tens of seconds by mouse retinal raster scanning OCT system. BIOMEDICAL OPTICS EXPRESS 2021; 12:7849-7871. [PMID: 35003871 PMCID: PMC8713677 DOI: 10.1364/boe.439900] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 11/01/2021] [Accepted: 11/08/2021] [Indexed: 06/14/2023]
Abstract
Several specialized retinal optical coherence tomography (OCT) acquisition and processing methods have been recently developed to allow in vivo probing of light-evoked photoreceptors function, focusing on measurements in individual photoreceptors (rods and cones). Recent OCT investigations in humans and experimental animals have shown that the outer segments in dark-adapted rods and cones elongate in response to the visible optical stimuli that bleach fractions of their visual photopigment. We have previously successfully contributed to these developments by implementing OCT intensity-based "optoretinograms" (ORG), the paradigm of using near-infrared OCT (NIR OCT) to measure bleaching-induced back-scattering and/or elongation changes of photoreceptors in the eye in vivo. In parallel, several groups have successfully implemented phase-based ORGs, mainly in human studies, exploiting changes in the phases of back-scattered light. This allowed more sensitive observations of tiny alterations of photoreceptors structures. Applications of the phase-based ORG have been implemented primarily in high speed and cellular resolution AO-OCT systems that can visualize photoreceptor mosaic, allowing phase measurements of path length changes in outer segments of individual photoreceptors. The phase-based ORG in standard resolution OCT systems is much more demanding to implement and has not been explored extensively. This manuscript describes our efforts to implement a phase analysis framework to retinal images acquired with a standard resolution and raster scanning OCT system, which offers much lower phase stability than line-field or full-field OCT detection schemes due to the relatively slower acquisition speed. Our initial results showcase the successful extraction of phase-based ORG signal from the B-scans acquired at ∼100 Hz rate and its favorable comparison with intensity-based ORG signal extracted from the same data sets. We implemented the calculation of phase-based ORG signals using Knox-Thompson paths and modified signal recovery by adding decorrelation weights. The phase-sensitive ORG signal analysis developed here for mouse retinal raster scanning OCT systems could be in principle extended to clinical retinal raster scanning OCT systems, potentially opening doors for clinically friendly ORG probing.
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Affiliation(s)
- Ewelina Pijewska
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, Grudziądzka 5, 87-100 Torun, Poland
| | - Pengfei Zhang
- UC Davis Eyepod Imaging Laboratory, Dept. of Cell Biology and Human Anatomy, University of California Davis, 4320 Tupper Hall, Davis, CA 95616, USA
- School of Optoelectronic Engineering and Instrumentation Science, Dalian University of Technology, No. 2 Linggong Road, Ganjingzi District, Dalian City, Liaoning Province 116024, China
| | - Michał Meina
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, Grudziądzka 5, 87-100 Torun, Poland
| | - Ratheesh K. Meleppat
- UC Davis Eyepod Imaging Laboratory, Dept. of Cell Biology and Human Anatomy, University of California Davis, 4320 Tupper Hall, Davis, CA 95616, USA
| | - Maciej Szkulmowski
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, Grudziądzka 5, 87-100 Torun, Poland
| | - Robert J. Zawadzki
- UC Davis Eyepod Imaging Laboratory, Dept. of Cell Biology and Human Anatomy, University of California Davis, 4320 Tupper Hall, Davis, CA 95616, USA
- Department of Ophthalmology & Vision Science, University of California Davis, 4860 Y Street Suite 2400 Sacramento, CA 95817, USA
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20
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Leartprapun N, Adie SG. Resolution-enhanced OCT and expanded framework of information capacity and resolution in coherent imaging. Sci Rep 2021; 11:20541. [PMID: 34654877 PMCID: PMC8521598 DOI: 10.1038/s41598-021-99889-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 09/17/2021] [Indexed: 11/09/2022] Open
Abstract
Spatial resolution in conventional optical microscopy has traditionally been treated as a fixed parameter of the optical system. Here, we present an approach to enhance transverse resolution in beam-scanned optical coherence tomography (OCT) beyond its aberration-free resolution limit, without any modification to the optical system. Based on the theorem of invariance of information capacity, resolution-enhanced (RE)-OCT navigates the exchange of information between resolution and signal-to-noise ratio (SNR) by exploiting efficient noise suppression via coherent averaging and a simple computational bandwidth expansion procedure. We demonstrate a resolution enhancement of 1.5 × relative to the aberration-free limit while maintaining comparable SNR in silicone phantom. We show that RE-OCT can significantly enhance the visualization of fine microstructural features in collagen gel and ex vivo mouse brain. Beyond RE-OCT, our analysis in the spatial-frequency domain leads to an expanded framework of information capacity and resolution in coherent imaging that contributes new implications to the theory of coherent imaging. RE-OCT can be readily implemented on most OCT systems worldwide, immediately unlocking information that is beyond their current imaging capabilities, and so has the potential for widespread impact in the numerous areas in which OCT is utilized, including the basic sciences and translational medicine.
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Affiliation(s)
- Nichaluk Leartprapun
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, 14853, USA
| | - Steven G Adie
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, 14853, USA.
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21
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Zhou Y, Liu E, Müller H, Cui B. Optical Electrophysiology: Toward the Goal of Label-Free Voltage Imaging. J Am Chem Soc 2021; 143:10482-10499. [PMID: 34191488 PMCID: PMC8514153 DOI: 10.1021/jacs.1c02960] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Measuring and monitoring the electrical signals transmitted between neurons is key to understanding the communication between neurons that underlies human perception, information processing, and decision-making. While electrode-based electrophysiology has been the gold standard, optical electrophysiology has opened up a new area in the past decade. Voltage-dependent fluorescent reporters enable voltage imaging with high spatial resolution and flexibility to choose recording locations. However, they exhibit photobleaching as well as phototoxicity and may perturb the physiology of the cell. Label-free optical electrophysiology seeks to overcome these hurdles by detecting electrical activities optically, without the incorporation of exogenous fluorophores in cells. For example, electrochromic optical recording detects neuroelectrical signals via a voltage-dependent color change of extracellular materials, and interferometric optical recording monitors membrane deformations that accompany electrical activities. Label-free optical electrophysiology, however, is in an early stage, and often has limited sensitivity and temporal resolution. In this Perspective, we review the recent progress to overcome these hurdles. We hope this Perspective will inspire developments of label-free optical electrophysiology techniques with high recording sensitivity and temporal resolution in the near future.
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Affiliation(s)
- Yuecheng Zhou
- Department of Chemistry, Stanford University, S285 ChEM-H/Wu Tsai Neuroscience Research Complex, Stanford, California 94305, United States
| | - Erica Liu
- Department of Chemistry, Stanford University, S285 ChEM-H/Wu Tsai Neuroscience Research Complex, Stanford, California 94305, United States
| | - Holger Müller
- Department of Physics, University of California, 366 LeConte Hall, Berkeley, California 94720, United States
- Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Bianxiao Cui
- Department of Chemistry, Stanford University, S285 ChEM-H/Wu Tsai Neuroscience Research Complex, Stanford, California 94305, United States
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22
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Afsharan H, Hackmann MJ, Wang Q, Navaeipour F, Jayasree SVK, Zawadzki RJ, Silva D, Joo C, Cense B. Polarization properties of retinal blood vessel walls measured with polarization sensitive optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2021; 12:4340-4362. [PMID: 34457418 PMCID: PMC8367251 DOI: 10.1364/boe.426079] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 05/23/2021] [Accepted: 05/27/2021] [Indexed: 05/08/2023]
Abstract
A new method based on polarization-sensitive optical coherence tomography (PS-OCT) is introduced to determine the polarization properties of human retinal vessel walls, in vivo. Measurements were obtained near the optic nerve head of three healthy human subjects. The double pass phase retardation per unit depth (DPPR/UD), which is proportional to the birefringence, is higher in artery walls, presumably because of the presence of muscle tissue. Measurements in surrounding retinal nerve fiber layer tissue yielded lower DPPR/UD values, suggesting that the retinal vessel wall tissue near the optic nerve is not covered by retinal nerve fiber layer tissue (0.43°/µm vs. 0.77°/µm, respectively). Measurements were obtained from multiple artery-vein pairs, to quantify the different polarization properties. Measurements were taken along a section of the vessel wall, with changes in DPPR/UD up to 15%, while the vessel wall thickness remained relatively constant. A stationary scan pattern was applied to determine the influence of involuntary eye motion on the measurement, which was significant. Measurements were also analyzed by two examiners, with high inter-observer agreement. The measurement repeatability was determined with measurements that were acquired during multiple visits. An improvement in accuracy can be achieved with an ultra-broad-bandwidth PS-OCT system since it will provide more data points in-depth, which reduces the influence of discretization and helps to facilitate better fitting of the birefringence data.
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Affiliation(s)
- Hadi Afsharan
- Optical+Biomedical Engineering Laboratory, Department of Electrical, Electronic and Computer Engineering, The University of Western Australia, Perth WA 6009, Australia
| | - Michael J. Hackmann
- Optical+Biomedical Engineering Laboratory, Department of Electrical, Electronic and Computer Engineering, The University of Western Australia, Perth WA 6009, Australia
- School of Human Sciences, The University of Western Australia, Crawley 6009, WA, Australia
| | - Qiang Wang
- Optical+Biomedical Engineering Laboratory, Department of Electrical, Electronic and Computer Engineering, The University of Western Australia, Perth WA 6009, Australia
| | - Farzaneh Navaeipour
- Department of Physics, Engineering Physics and Astronomy, Queen’s University, Kingston, Ontario K7L 3N6, Canada
| | - Stephy Vijaya Kumar Jayasree
- Department of Physics, School of Physics, Mathematics and Computing, The University of Western Australia, Perth WA 6009, Australia
| | - Robert J. Zawadzki
- Department of Ophthalmology and Vision Science, University of California Davis, Sacramento, CA 95817, USA
| | - Dilusha Silva
- Microelectronics Research Group, Department of Electrical, Electronic and Computer Engineering, The University of Western Australia, Perth WA 6009, Australia
| | - Chulmin Joo
- Department of Mechanical Engineering, Yonsei University, Seodaemun-gu, Seoul 03722, Republic of Korea
| | - Barry Cense
- Optical+Biomedical Engineering Laboratory, Department of Electrical, Electronic and Computer Engineering, The University of Western Australia, Perth WA 6009, Australia
- Department of Mechanical Engineering, Yonsei University, Seodaemun-gu, Seoul 03722, Republic of Korea
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23
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Hepburn MS, Foo KY, Wijesinghe P, Munro PRT, Chin L, Kennedy BF. Speckle-dependent accuracy in phase-sensitive optical coherence tomography. OPTICS EXPRESS 2021; 29:16950-16968. [PMID: 34154247 DOI: 10.1364/oe.417954] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 03/26/2021] [Indexed: 05/25/2023]
Abstract
Phase-sensitive optical coherence tomography (OCT) is used to measure motion in a range of techniques, such as Doppler OCT and optical coherence elastography (OCE). In phase-sensitive OCT, motion is typically estimated using a model of the OCT signal derived from a single reflector. However, this approach is not representative of turbid samples, such as tissue, which exhibit speckle. In this study, for the first time, we demonstrate, through theory and experiment that speckle significantly lowers the accuracy of phase-sensitive OCT in a manner not accounted for by the OCT signal-to-noise ratio (SNR). We describe how the inaccuracy in speckle reduces phase difference sensitivity and introduce a new metric, speckle brightness, to quantify the amount of constructive interference at a given location in an OCT image. Experimental measurements show an almost three-fold degradation in sensitivity between regions of high and low speckle brightness at a constant OCT SNR. Finally, we apply these new results in compression OCE to demonstrate a ten-fold improvement in strain sensitivity, and a five-fold improvement in contrast-to-noise by incorporating independent speckle realizations. Our results show that speckle introduces a limit to the accuracy of phase-sensitive OCT and that speckle brightness should be considered to avoid erroneous interpretation of experimental data.
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24
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Pospíšil J, Wiebusch G, Fliegel K, Klíma M, Huser T. Highly compact and cost-effective 2-beam super-resolution structured illumination microscope based on all-fiber optic components. OPTICS EXPRESS 2021; 29:11833-11844. [PMID: 33984956 DOI: 10.1364/oe.420592] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Current super-resolution structured illumination microscopes (SR-SIM) utilize relatively expensive electro-optic components and free-space optics, resulting in large setups. Moreover, high power laser sources are required to compensate for the losses associated with generating the illumination pattern by diffractive optics. Here, we present a highly compact and flexible 2D SR-SIM microscope based on all-fiber optic components (fiberSIM). Fiber-splitters deliver the laser light to the sample resulting in the interference illumination pattern. A microelectromechanical systems (MEMS) based fiber switch performs rapid pattern rotation. The pattern phase shift is achieved by the spatial displacement of one arm of the fiber interferometer using a piezoelectric crystal. Compared with existing methods, fiberSIM is highly compact and significantly reduces the SR-SIM component cost while achieving comparable results, thus providing a route to making SR-SIM technology accessible to even more laboratories in the life sciences.
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Li J, Hepburn MS, Chin L, Mowla A, Kennedy BF. Analysis of sensitivity in quantitative micro-elastography. BIOMEDICAL OPTICS EXPRESS 2021; 12:1725-1745. [PMID: 33796383 PMCID: PMC7984799 DOI: 10.1364/boe.417829] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 01/20/2021] [Accepted: 01/22/2021] [Indexed: 05/11/2023]
Abstract
Quantitative micro-elastography (QME), a variant of compression optical coherence elastography (OCE), is a technique to image tissue elasticity on the microscale. QME has been proposed for a range of applications, most notably tumor margin assessment in breast-conserving surgery. However, QME sensitivity, a key imaging metric, has yet to be systematically analyzed. Consequently, it is difficult to optimize imaging performance and to assess the potential of QME in new application areas. To address this, we present a framework for analyzing sensitivity that incorporates the three main steps in QME image formation: mechanical deformation, its detection using optical coherence tomography (OCT), and signal processing used to estimate elasticity. Firstly, we present an analytical model of QME sensitivity, validated by experimental data, and demonstrate that sub-kPa elasticity sensitivity can be achieved in QME. Using silicone phantoms, we demonstrate that sensitivity is dependent on friction, OCT focus depth, and averaging methods in signal processing. For the first time, we show that whilst lubrication of layer improves accuracy by reducing surface friction, it reduces sensitivity due to the time-dependent effect of lubricant exudation from the layer boundaries resulting in increased friction. Furthermore, we demonstrate how signal processing in QME provides a trade-off between sensitivity and resolution that can be used to optimize imaging performance. We believe that our framework to analyze sensitivity can help to sustain the development of QME and, also, that it can be readily adapted to other OCE techniques.
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Affiliation(s)
- Jiayue Li
- BRITElab, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, Western Australia, 6009, Australia and Centre for Medical Research, The University of Western Australia, Crawley, Western Australia, 6009, Australia
- Department of Electrical, Electronic and Computer Engineering, School of Engineering, The University of Western Australia, 35, Stirling Highway, Perth, Western Australia, 6009, Australia
- Australian Research Council Centre for Personalized Therapeutics Technologies, Australia
| | - Matt S. Hepburn
- BRITElab, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, Western Australia, 6009, Australia and Centre for Medical Research, The University of Western Australia, Crawley, Western Australia, 6009, Australia
- Department of Electrical, Electronic and Computer Engineering, School of Engineering, The University of Western Australia, 35, Stirling Highway, Perth, Western Australia, 6009, Australia
| | - Lixin Chin
- BRITElab, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, Western Australia, 6009, Australia and Centre for Medical Research, The University of Western Australia, Crawley, Western Australia, 6009, Australia
- Department of Electrical, Electronic and Computer Engineering, School of Engineering, The University of Western Australia, 35, Stirling Highway, Perth, Western Australia, 6009, Australia
| | - Alireza Mowla
- BRITElab, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, Western Australia, 6009, Australia and Centre for Medical Research, The University of Western Australia, Crawley, Western Australia, 6009, Australia
- Department of Electrical, Electronic and Computer Engineering, School of Engineering, The University of Western Australia, 35, Stirling Highway, Perth, Western Australia, 6009, Australia
| | - Brendan F. Kennedy
- BRITElab, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, Western Australia, 6009, Australia and Centre for Medical Research, The University of Western Australia, Crawley, Western Australia, 6009, Australia
- Department of Electrical, Electronic and Computer Engineering, School of Engineering, The University of Western Australia, 35, Stirling Highway, Perth, Western Australia, 6009, Australia
- Australian Research Council Centre for Personalized Therapeutics Technologies, Australia
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26
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Raghunathan R, Liu CH, Kouka A, Singh M, Miranda RC, Larin KV. Dose-response analysis of microvasculature changes in the murine fetal brain and the maternal extremities due to prenatal ethanol exposure. JOURNAL OF BIOMEDICAL OPTICS 2020; 25:JBO-200176RR. [PMID: 33244919 PMCID: PMC7689263 DOI: 10.1117/1.jbo.25.12.126001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Accepted: 11/06/2020] [Indexed: 05/29/2023]
Abstract
SIGNIFICANCE Prenatal exposure to ethanol causes several morphological and neurobehavioral deficits. While there are some studies on the effects of ethanol exposure on blood flow, research focusing on acute changes in the microvasculature is limited. AIM The first aim of this study was to assess the dose-dependent changes in murine fetal brain microvasculature of developing fetuses in response to maternal alcohol consumption. The second aim was to quantify changes in vasculature occurring concurrently in the mother's hindlimb and the fetus's brain after maternal exposure to alcohol. APPROACH Correlation mapping optical coherence angiography was used to evaluate the effects of prenatal exposure to different doses of ethanol (3, 1.5, and 0.75 g / kg) on murine fetal brain vasculature in utero. Additionally, simultaneous imaging of maternal peripheral vessels and the fetal brain vasculature was performed to assess changes of the vasculature occurring concurrently in response to ethanol consumption. RESULTS The fetal brain vessel diameters (VDs) decreased by ∼47 % , 30%, and 14% in response to ethanol doses of 3, 1.5, and 0.75 g / kg, respectively. However, the mother's hindlimb VD increased by 63% in response to ethanol at a dose of 3 g / kg. CONCLUSIONS Results showed a dose-dependent reduction in vascular blood flow in fetal brain vessels when the mother was exposed to ethanol, whereas vessels in the maternal hindlimb exhibited concurrent vasodilation.
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Affiliation(s)
- Raksha Raghunathan
- University of Houston, Department of Biomedical Engineering, Houston, Texas, United States
| | - Chih-Hao Liu
- University of Houston, Department of Biomedical Engineering, Houston, Texas, United States
| | - Amur Kouka
- University of Houston, Department of Biomedical Engineering, Houston, Texas, United States
| | - Manmohan Singh
- University of Houston, Department of Biomedical Engineering, Houston, Texas, United States
| | - Rajesh C. Miranda
- Texas A&M University Health Science Center College of Medicine, Department of Neuroscience and Experimental Therapeutics, Bryan, Texas, United States
| | - Kirill V. Larin
- University of Houston, Department of Biomedical Engineering, Houston, Texas, United States
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27
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Kho AM, Zhang T, Zhu J, Merkle CW, Srinivasan VJ. Incoherent excess noise spectrally encodes broadband light sources. LIGHT, SCIENCE & APPLICATIONS 2020; 9:172. [PMID: 33082941 PMCID: PMC7538909 DOI: 10.1038/s41377-020-00404-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 08/26/2020] [Accepted: 09/09/2020] [Indexed: 05/09/2023]
Abstract
Across optics and photonics, excess intensity noise is often considered a liability. Here, we show that excess noise in broadband supercontinuum and superluminescent diode light sources encodes each spectral channel with unique intensity fluctuations, which actually serve a useful purpose. Specifically, we report that excess noise correlations can both characterize the spectral resolution of spectrometers and enable cross-calibration of their wavelengths across a broad bandwidth. Relative to previous methods that use broadband interferometry and narrow linewidth lasers to characterize and calibrate spectrometers, our approach is simple, comprehensive, and rapid enough to be deployed during spectrometer alignment. First, we employ this approach to aid alignment and reduce the depth-dependent degradation of the sensitivity and axial resolution in a spectrometer-based optical coherence tomography (OCT) system, revealing a new outer retinal band. Second, we achieve a pixel-to-pixel correspondence between two otherwise disparate spectrometers, enabling a robust comparison of their respective measurements. Thus, excess intensity noise has useful applications in optics and photonics.
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Affiliation(s)
- Aaron M. Kho
- Department of Biomedical Engineering, University of California Davis, Davis, CA 95616 USA
| | - Tingwei Zhang
- Department of Biomedical Engineering, University of California Davis, Davis, CA 95616 USA
| | - Jun Zhu
- Department of Biomedical Engineering, University of California Davis, Davis, CA 95616 USA
| | - Conrad W. Merkle
- 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 School of Medicine, Sacramento, CA 95817 USA
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28
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Li A, Du C, Volkow ND, Pan Y. A deep-learning-based approach for noise reduction in high-speed optical coherence Doppler tomography. JOURNAL OF BIOPHOTONICS 2020; 13:e202000084. [PMID: 32649059 PMCID: PMC7722172 DOI: 10.1002/jbio.202000084] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 06/20/2020] [Accepted: 06/30/2020] [Indexed: 05/30/2023]
Abstract
Optical coherence Doppler tomography (ODT) increasingly attracts attention because of its unprecedented advantages with respect to high contrast, capillary-level resolution and flow speed quantification. However, the trade-off between the signal-to-noise ratio of ODT images and A-scan sampling density significantly slows down the imaging speed, constraining its clinical applications. To accelerate ODT imaging, a deep-learning-based approach is proposed to suppress the overwhelming phase noise from low-sampling density. To handle the issue of limited paired training datasets, a generative adversarial network is performed to implicitly learn the distribution underlying Doppler phase noise and to generate the synthetic data. Then a 3D based convolutional neural network is trained and applied for the image denoising. We demonstrate this approach outperforms traditional denoise methods in noise reduction and image details preservation, enabling high speed ODT imaging with low A-scan sampling density.
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Affiliation(s)
- Ang Li
- Biomedical Engineering, Stony Brook University, Stony Brook, New York
| | - Congwu Du
- Biomedical Engineering, Stony Brook University, Stony Brook, New York
| | - Nora D Volkow
- National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, USA
| | - Yingtian Pan
- Biomedical Engineering, Stony Brook University, Stony Brook, New York
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29
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Pandiyan VP, Jiang X, Maloney-Bertelli A, Kuchenbecker JA, Sharma U, Sabesan R. High-speed adaptive optics line-scan OCT for cellular-resolution optoretinography. BIOMEDICAL OPTICS EXPRESS 2020; 11:5274-5296. [PMID: 33014614 PMCID: PMC7510866 DOI: 10.1364/boe.399034] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 08/05/2020] [Accepted: 08/19/2020] [Indexed: 05/15/2023]
Abstract
Optoretinography-the non-invasive, optical imaging of light-induced functional activity in the retina-stands to provide a critical biomarker for testing the safety and efficacy of new therapies as well as their rapid translation to the clinic. Optical phase change in response to light, as readily accessible in phase-resolved OCT, offers a path towards all-optical imaging of retinal function. However, typical human eye motion adversely affects phase stability. In addition, recording fast light-induced retinal events necessitates high-speed acquisition. Here, we introduce a high-speed line-scan spectral domain OCT with adaptive optics (AO), aimed at volumetric imaging and phase-resolved acquisition of retinal responses to light. By virtue of parallel acquisition of an entire retinal cross-section (B-scan) in a single high-speed camera frame, depth-resolved tomograms at speeds up to 16 kHz were achieved with high sensitivity and phase stability. To optimize spectral and spatial resolution, an anamorphic detection paradigm was introduced, enabling improved light collection efficiency and signal roll-off compared to traditional methods. The benefits in speed, resolution and sensitivity were exemplified in imaging nanometer-millisecond scale light-induced optical path length changes in cone photoreceptor outer segments. With 660 nm stimuli, individual cone responses readily segregated into three clusters, corresponding to long, middle, and short-wavelength cones. Recording such optoretinograms on spatial scales ranging from individual cones, to 100 µm-wide retinal patches offers a robust and sensitive biomarker for cone function in health and disease.
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Affiliation(s)
- Vimal Prabhu Pandiyan
- Department of Ophthalmology, University of Washington School of Medicine, Seattle, WA 98109, USA
| | - Xiaoyun Jiang
- Department of Ophthalmology, University of Washington School of Medicine, Seattle, WA 98109, USA
| | - Aiden Maloney-Bertelli
- Department of Ophthalmology, University of Washington School of Medicine, Seattle, WA 98109, USA
| | - James A Kuchenbecker
- Department of Ophthalmology, University of Washington School of Medicine, Seattle, WA 98109, USA
| | - Utkarsh Sharma
- Catapult Sky LLC, 34116 Blue Heron Dr, Solon, OH 44139, USA
| | - Ramkumar Sabesan
- Department of Ophthalmology, University of Washington School of Medicine, Seattle, WA 98109, USA
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30
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Halaney DL, Jonak CR, Liu J, Davoodzadeh N, Cano-Velázquez MS, Ehtiyatkar P, Park H, Binder DK, Aguilar G. Chronic Brain Imaging Across a Transparent Nanocrystalline Yttria-Stabilized-Zirconia Cranial Implant. Front Bioeng Biotechnol 2020; 8:659. [PMID: 32695757 PMCID: PMC7339873 DOI: 10.3389/fbioe.2020.00659] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Accepted: 05/28/2020] [Indexed: 12/28/2022] Open
Abstract
Repeated non-diffuse optical imaging of the brain is difficult. This is due to the fact that the cranial bone is highly scattering and thus a strong optical barrier. Repeated craniotomies increase the risk of complications and may disrupt the biological systems being imaged. We previously introduced a potential solution in the form of a transparent ceramic cranial implant called the Window to the Brain (WttB) implant. This implant is made of nanocrystalline Yttria-Stabilized Zirconia (nc-YSZ), which possesses the requisite mechanical strength to serve as a permanent optical access window in human patients. In this present study, we demonstrate repeated brain imaging of n = 5 mice using both OCT and LSI across the WttB implant over 4 weeks. The main objectives are to determine if the WttB implant allows for chronic OCT imaging, and to shed further light on the question of whether optical access provided by the WttB implant remains stable over this duration in the body. The Window to the Brain implant allowed for stable repeated imaging of the mouse brain with Optical Coherence Tomography over 28 days, without loss of signal intensity. Repeated Laser Speckle Imaging was also possible over this timeframe, but signal to noise ratio and the sharpness of vessels in the images decreased with time. This can be partially explained by elevated blood flow during the first imaging session in response to trauma from the surgery, which was also detected by OCT flow imaging. These results are promising for long-term optical access through the WttB implant, making feasible chronic in vivo studies in multiple neurological models of brain disease.
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Affiliation(s)
- David L Halaney
- Laboratory of Guillermo Aguilar, Department of Mechanical Engineering, University of California, Riverside, Riverside, CA, United States
| | - Carrie R Jonak
- Laboratory of Devin Binder, Division of Biomedical Sciences, University of California, Riverside, Riverside, CA, United States
| | - Junze Liu
- Laboratory of Hyle Park, Department of Bioengineering, University of California, Riverside, Riverside, CA, United States
| | - Nami Davoodzadeh
- Laboratory of Guillermo Aguilar, Department of Mechanical Engineering, University of California, Riverside, Riverside, CA, United States
| | - Mildred S Cano-Velázquez
- Laboratory of Juan Hernandez-Cordero, Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Pasha Ehtiyatkar
- Laboratory of Guillermo Aguilar, Department of Mechanical Engineering, University of California, Riverside, Riverside, CA, United States.,Department of Neuroscience, University of California, Riverside, Riverside, CA, United States
| | - Hyle Park
- Laboratory of Hyle Park, Department of Bioengineering, University of California, Riverside, Riverside, CA, United States
| | - Devin K Binder
- Laboratory of Devin Binder, Division of Biomedical Sciences, University of California, Riverside, Riverside, CA, United States
| | - Guillermo Aguilar
- Laboratory of Guillermo Aguilar, Department of Mechanical Engineering, University of California, Riverside, Riverside, CA, United States
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31
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Kim S, Cense B, Joo C. Single-pixel, single-input-state polarization-sensitive wavefront imaging. OPTICS LETTERS 2020; 45:3965-3968. [PMID: 32667329 DOI: 10.1364/ol.396442] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 06/17/2020] [Indexed: 06/11/2023]
Abstract
In this Letter, we describe a single-pixel polarization-sensitive imaging technique, capable of generating the birefringence map of a thin specimen by using single-pixel detectors. Spatially modulated light is circularly polarized to illuminate the specimen. The transmitted light through the specimen is then focused via a lens and measured by position-sensitive detectors in two orthogonal polarization channels. The measurement of the irradiance and centroid position of the optical focus and subsequent computations enable the production of polarization-dependent wavefront maps, which can then be utilized to reconstruct sample birefringence information. We demonstrate the feasibility of our method by measuring distribution of optic-axis orientation and phase retardation of various birefringent samples.
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32
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Raghunathan R, Liu CH, Ambekar YS, Singh M, Miranda RC, Larin KV. Optical coherence tomography angiography to evaluate murine fetal brain vasculature changes caused by prenatal exposure to nicotine. BIOMEDICAL OPTICS EXPRESS 2020; 11:3618-3632. [PMID: 33014555 PMCID: PMC7510910 DOI: 10.1364/boe.394905] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 06/01/2020] [Accepted: 06/02/2020] [Indexed: 05/03/2023]
Abstract
Maternal smoking causes several defects ranging from intrauterine growth restriction to sudden infant death syndrome and spontaneous abortion. While several studies have documented the effects of prenatal nicotine exposure in development and behavior, acute vasculature changes in the fetal brain due to prenatal nicotine exposure have not been evaluated yet. This study uses correlation mapping optical coherence angiography to evaluate changes in fetal brain vasculature flow caused by maternal exposure to nicotine during the second trimester-equivalent of gestation in a mouse model. The effects of two different doses of nicotine were evaluated. Results showed a decrease in the vasculature for both doses of nicotine, which was not seen in the case of the sham group.
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Affiliation(s)
- Raksha Raghunathan
- Department of Biomedical Engineering, University of Houston, 3517 Cullen Blvd., Houston, TX 77204, USA
| | - Chih-Hao Liu
- Department of Biomedical Engineering, University of Houston, 3517 Cullen Blvd., Houston, TX 77204, USA
| | - Yogeshwari S Ambekar
- Department of Biomedical Engineering, University of Houston, 3517 Cullen Blvd., Houston, TX 77204, USA
| | - Manmohan Singh
- Department of Biomedical Engineering, University of Houston, 3517 Cullen Blvd., Houston, TX 77204, USA
| | - Rajesh C Miranda
- Department of Neuroscience and Experimental Therapeutics, TAMHSC College of Medicine, 8441 Riverside Parkway, Bryan, TX 77807, USA
| | - Kirill V Larin
- Department of Biomedical Engineering, University of Houston, 3517 Cullen Blvd., Houston, TX 77204, USA
- Molecular Physiology and Biophysics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77206, USA
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33
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Ling T, Boyle KC, Zuckerman V, Flores T, Ramakrishnan C, Deisseroth K, Palanker D. High-speed interferometric imaging reveals dynamics of neuronal deformation during the action potential. Proc Natl Acad Sci U S A 2020; 117:10278-10285. [PMID: 32341158 PMCID: PMC7229674 DOI: 10.1073/pnas.1920039117] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Neurons undergo nanometer-scale deformations during action potentials, and the underlying mechanism has been actively debated for decades. Previous observations were limited to a single spot or the cell boundary, while movement across the entire neuron during the action potential remained unclear. Here we report full-field imaging of cellular deformations accompanying the action potential in mammalian neuron somas (-1.8 to 1.4 nm) and neurites (-0.7 to 0.9 nm), using high-speed quantitative phase imaging with a temporal resolution of 0.1 ms and an optical path length sensitivity of <4 pm per pixel. The spike-triggered average, synchronized to electrical recording, demonstrates that the time course of the optical phase changes closely matches the dynamics of the electrical signal. Utilizing the spatial and temporal correlations of the phase signals across the cell, we enhance the detection and segmentation of spiking cells compared to the shot-noise-limited performance of single pixels. Using three-dimensional (3D) cellular morphology extracted via confocal microscopy, we demonstrate that the voltage-dependent changes in the membrane tension induced by ionic repulsion can explain the magnitude, time course, and spatial features of the phase imaging. Our full-field observations of the spike-induced deformations shed light upon the electromechanical coupling mechanism in electrogenic cells and open the door to noninvasive label-free imaging of neural signaling.
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Affiliation(s)
- Tong Ling
- Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305;
- Department of Ophthalmology, Stanford University, Stanford, CA 94305
| | - Kevin C Boyle
- Department of Electrical Engineering, Stanford University, Stanford, CA 94305;
| | - Valentina Zuckerman
- Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305
| | - Thomas Flores
- Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305
| | | | - Karl Deisseroth
- Department of Bioengineering, Stanford University, Stanford, CA 94305
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA 94305
- Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305
| | - Daniel Palanker
- Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305;
- Department of Ophthalmology, Stanford University, Stanford, CA 94305
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34
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Gräfe MGO, van de Kreeke JA, Willemse J, Braaf B, de Jong Y, Tan HS, Verbraak FD, de Boer JF. Subretinal Fibrosis Detection Using Polarization Sensitive Optical Coherence Tomography. Transl Vis Sci Technol 2020; 9:13. [PMID: 32818100 PMCID: PMC7396173 DOI: 10.1167/tvst.9.4.13] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 12/16/2019] [Indexed: 12/22/2022] Open
Abstract
Purpose Subretinal fibrosis (SRFib) is an important cause of permanent loss-of-vision diseases with submacular neovascularization, but a reliable diagnostic method is currently missing. This study uses polarization-sensitive optical coherence tomography (PS-OCT) to detect SRFib within retinal lesions by measurement of its birefringent collagen fibers. Methods Twenty-five patients were enrolled with retinal pathology in one or both eyes containing (1) suspected SRFib, (2) lesions suspected not to be fibrotic, or (3) lesions with doubtful presence of SRFib. All eyes were evaluated for SRFIb using conventional diagnostics by three retinal specialists. PS-OCT images were visually evaluated for SRFib based on cumulative phase retardation, local birefringence, and optic axis uniformity. Results Twenty-nine eyes from 22 patients were scanned successfully. In 13 eyes, SRFib was diagnosed by all retinal specialists; of these, 12 were confirmed by PS-OCT and one was inconclusive. In nine eyes, the retinal specialists expected no SRFib, which was confirmed by PS-OCT in all cases. In seven eyes, the retinal specialists’ evaluations were inconsistent with regard to the presence of SRFib. PS-OCT confirmed the presence of SRFib in four of these eyes and the absence of SRFib in two eyes and was inconclusive in one eye. Conclusions In 21 out of 22 eyes, PS-OCT confirmed the evaluation of retinal specialists regarding the presence of SRFib. PS-OCT provided additional information to distinguish SRFib from other tissues within subretinal neovascular lesions in 6 out of 7 eyes. Translational Relevance PS-OCT can identify and quantify SRFib in doubtful cases for which a reliable diagnosis is currently lacking.
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Affiliation(s)
- Maximilian G O Gräfe
- LaserLaB Amsterdam, Department of Physics and Astronomy, Vrije Universiteit, Amsterdam, The Netherlands
| | | | - Joy Willemse
- LaserLaB Amsterdam, Department of Physics and Astronomy, Vrije Universiteit, Amsterdam, The Netherlands
| | - Boy Braaf
- LaserLaB Amsterdam, Department of Physics and Astronomy, Vrije Universiteit, Amsterdam, The Netherlands
| | - Yvonne de Jong
- Department of Ophthalmology, Amsterdam UMC, Amsterdam, The Netherlands
| | - H Stevie Tan
- Department of Ophthalmology, Amsterdam UMC, Amsterdam, The Netherlands
| | - Frank D Verbraak
- Department of Ophthalmology, Amsterdam UMC, Amsterdam, The Netherlands
| | - Johannes F de Boer
- LaserLaB Amsterdam, Department of Physics and Astronomy, Vrije Universiteit, Amsterdam, The Netherlands.,Department of Ophthalmology, Amsterdam UMC, Amsterdam, The Netherlands
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35
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Jiao S. Biomedical optical imaging technology and applications: From basic research toward clinical diagnosis. Exp Biol Med (Maywood) 2020; 245:269-272. [PMID: 32141780 DOI: 10.1177/1535370220909543] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Affiliation(s)
- Shuliang Jiao
- Department of Biomedical Engineering, Florida International University, Miami, FL 33174, USA
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36
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Yao X, Li D, Park HC, Chen D, Guan H, Mahendroo M, Li X. Ultra-sensitive optical coherence elastography using a high-dynamic-range force loading scheme for cervical rigidity assessment. BIOMEDICAL OPTICS EXPRESS 2020; 11:688-698. [PMID: 32133219 PMCID: PMC7041475 DOI: 10.1364/boe.383720] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 12/16/2019] [Accepted: 12/22/2019] [Indexed: 05/29/2023]
Abstract
An ultra-sensitive, wide-range force loading scheme is proposed for compression optical coherence elastography (OCE) that allows for the quantitative analysis of cervical tissue elasticity ex vivo. We designed a force loading apparatus featuring a water sink for minuscule incremental loading through a volume-controlled water droplet, from which the Young's modulus can be calculated by fitting the stress-strain curve. We validated the performance of the proposed OCE system on homogenous agar phantoms, showing the Young's modulus can be accurately estimated using this scheme. We then measured the Young's modulus of rodent cervical tissues acquired at different gestational ages, showing that the cervical rigidity of rodents was significantly dropped when entering the third trimester of pregnancy.
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Affiliation(s)
- Xinwen Yao
- Department of Biomedical Engineering, 720 Rutland Ave, Baltimore, MD 21205, USA
- SERI-NTU Advanced Ocular Engineering (STANCE), 50 Nanyang Drive #04-13, Singapore 637553, Singapore
- These authors contribute equally to this work
| | - Dawei Li
- Department of Biomedical Engineering, 720 Rutland Ave, Baltimore, MD 21205, USA
- These authors contribute equally to this work
| | - Hyeon-Cheol Park
- Department of Biomedical Engineering, 720 Rutland Ave, Baltimore, MD 21205, USA
| | - Defu Chen
- Department of Biomedical Engineering, 720 Rutland Ave, Baltimore, MD 21205, USA
| | - Honghua Guan
- Department of Biomedical Engineering, 720 Rutland Ave, Baltimore, MD 21205, USA
| | - Mala Mahendroo
- Department of Obstetrics and Gynecology, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Xingde Li
- Department of Biomedical Engineering, 720 Rutland Ave, Baltimore, MD 21205, USA
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Kurokawa K, Crowell JA, Zhang F, Miller DT. Suite of methods for assessing inner retinal temporal dynamics across spatial and temporal scales in the living human eye. NEUROPHOTONICS 2020; 7:015013. [PMID: 32206680 PMCID: PMC7070771 DOI: 10.1117/1.nph.7.1.015013] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 02/17/2020] [Indexed: 05/08/2023]
Abstract
Significance: There are no label-free imaging descriptors related to physiological activity of inner retinal cells in the living human eye. A major reason is that inner retinal neurons are highly transparent and reflect little light, making them extremely difficult to visualize and quantify. Aim: To measure physiologically-induced optical changes of inner retinal cells despite their challenging optical properties. Approach: We developed an imaging method based on adaptive optics and optical coherence tomography (AO-OCT) and a suite of postprocessing algorithms, most notably a new temporal correlation method. Results: We captured the temporal dynamics of entire inner retinal layers, of specific tissue types, and of individual cells across three different timescales from fast (seconds) to extremely slow (one year). Time correlation analysis revealed significant differences in time constant (up to 0.4 s) between the principal layers of the inner retina with the ganglion cell layer (GCL) being the most dynamic. At the cellular level, significant differences were found between individual GCL somas. The mean time constant of the GCL somas ( 0.69 ± 0.17 s ) was ∼ 30 % smaller than that of nerve fiber bundles and inner plexiform layer synapses and processes. Across longer durations, temporal speckle contrast and time-lapse imaging revealed motion of macrophage-like cells (over minutes) and GCL neuron loss and remodeling (over one year). Conclusions: Physiological activity of inner retinal cells is now measurable in the living human eye.
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Affiliation(s)
- Kazuhiro Kurokawa
- Indiana University, School of Optometry, Bloomington, Indiana, United States
| | - James A. Crowell
- Indiana University, School of Optometry, Bloomington, Indiana, United States
| | - Furu Zhang
- Indiana University, School of Optometry, Bloomington, Indiana, United States
| | - Donald T. Miller
- Indiana University, School of Optometry, Bloomington, Indiana, United States
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38
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Park KS, Shin JG, Eom TJ. Buffered polarization diverse detection for single-camera polarization-sensitive optical coherence tomography. OPTICS LETTERS 2019; 44:5739-5742. [PMID: 31774767 DOI: 10.1364/ol.44.005739] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Accepted: 10/08/2019] [Indexed: 06/10/2023]
Abstract
Herein we propose a method to mitigate a position mismatch problem for a spectral-domain polarization-sensitive optical coherence tomography (SD-PS-OCT) system that uses a single line-scan detection scheme. A single detector-based PS-OCT detects two orthogonal polarization components as two adjacent A-scan signals in turns. Thus, two adjacent A-scan signals are not scattered at a fixed point in time (position mismatch problem), resulting in uncorrelated signals between them. To achieve sequential detection of simultaneously scattered light, a buffering single-mode fiber was connected to one of the two ports coming out of the optical switch, provided a proper time delay. A single-mode optical fiber of 2.69 km in length was used to buffer, and its length was determined by a frame rate of the spectrometer used as a detector. With the proposed SD-PS-OCT scheme, the PS-OCT system with a simple configuration, and the minimized position mismatch problem between two polarization components can be set.
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39
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Li Y, Chen J, Chen Z. Advances in Doppler optical coherence tomography and angiography. TRANSLATIONAL BIOPHOTONICS 2019; 1:e201900005. [PMID: 33005888 PMCID: PMC7523705 DOI: 10.1002/tbio.201900005] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Accepted: 11/14/2019] [Indexed: 12/22/2022] Open
Abstract
Since the first demonstration of Doppler optical coherence tomography (OCT) in 1997, several functional extensions of Doppler OCT have been developed, including velocimetry, angiogram, and optical coherence elastography. These functional techniques have been widely used in research and clinical applications, particularly in ophthalmology. Here, we review the principles, representative methods, and applications of different Doppler OCT techniques, followed by discussion on the innovations, limitations, and future directions of each of these techniques.
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Affiliation(s)
- Yan Li
- Beckman Laser Institute, University of California, Irvine, California
- Department of Biomedical Engineering, University of California, Irvine, California
| | - Jason Chen
- Beckman Laser Institute, University of California, Irvine, California
- Department of Biomedical Engineering, University of California, Irvine, California
| | - Zhongping Chen
- Beckman Laser Institute, University of California, Irvine, California
- Department of Biomedical Engineering, University of California, Irvine, California
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40
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Gräfe MGO, Nadiarnykh O, De Boer JF. Optical coherence tomography velocimetry based on decorrelation estimation of phasor pair ratios (DEPPAIR). BIOMEDICAL OPTICS EXPRESS 2019; 10:5470-5485. [PMID: 31799025 PMCID: PMC6865093 DOI: 10.1364/boe.10.005470] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 09/17/2019] [Accepted: 09/20/2019] [Indexed: 05/13/2023]
Abstract
Quantitative velocity estimations in optical coherence tomography requires the estimation of the axial and lateral flow components. Optical coherence tomography measures the depth resolved complex field reflected from a sample. While the axial velocity component can be determined from the Doppler shift or phase shift between a pair of consecutive measurements at the same location, the estimation of the lateral component for in vivo applications is still challenging. One approach to determine lateral velocity is multiple simultaneous measurements at different angles. In another approach the lateral component can be retrieved through repeated measurements at (nearly) the same location by an analysis of the decorrelation over time. In this paper we follow the latter approach. We describe a model for the complex field changes between consecutive measurements and use it to predict the uncertainties for amplitude-based, phase-based and complex algorithms. The uncertainty of the flow estimations follows from a statistical analysis and is determined by the number of available measurements and the applied analysis method. The model is verified in phantom measurements and the dynamic range of velocity estimations is investigated. We demonstrate that phase-based and complex (phasor) based lateral flow estimation methods are superior to amplitude-based algorithms.
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41
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Leartprapun N, Iyer RR, Mackey CD, Adie SG. Spatial localization of mechanical excitation affects spatial resolution, contrast, and contrast-to-noise ratio in acoustic radiation force optical coherence elastography. BIOMEDICAL OPTICS EXPRESS 2019; 10:5877-5904. [PMID: 31799053 PMCID: PMC6865116 DOI: 10.1364/boe.10.005877] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 09/30/2019] [Accepted: 10/06/2019] [Indexed: 05/05/2023]
Abstract
The notion that a spatially confined mechanical excitation would produce an elastogram with high spatial resolution has motivated the development of various elastography techniques with localized mechanical excitation. However, a quantitative investigation of the effects of spatial localization of mechanical excitation on the spatial resolution of elastograms is still lacking in optical coherence elastography (OCE). Here, we experimentally investigated the effect of spatial localization of acoustic radiation force (ARF) excitation on spatial resolution, contrast, and contrast-to-noise ratio (CNR) of dynamic uniaxial strain elastograms in dynamic ARF-OCE, based on a framework for analyzing the factors that influence the quality of the elastogram at different stages of the elastography workflow. Our results show that localized ARF excitation with a smaller acoustic focal spot size produced a strain elastogram with superior spatial resolution, contrast, and CNR. Our results also suggest that the spatial extent spanned by the displacement response in the sample may connect between the spatial localization of the mechanical excitation and the resulting elastogram quality. The elastography framework and experimental approach presented here may provide a basis for the quantitative analysis of elastogram quality in OCE that can be adapted and applied to different OCE systems and applications.
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Affiliation(s)
- Nichaluk Leartprapun
- Cornell University, Meinig School of Biomedical Engineering, Weill Hall, Ithaca, New York 14853, USA
| | - Rishyashring R. Iyer
- Cornell University, Meinig School of Biomedical Engineering, Weill Hall, Ithaca, New York 14853, USA
- Present address: University of Illinois at Urbana-Champaign, Beckman Institute for Advanced Science and Technology, Urbana, Illinois 61801, USA
| | - Colin D. Mackey
- Cornell University, Meinig School of Biomedical Engineering, Weill Hall, Ithaca, New York 14853, USA
| | - Steven G. Adie
- Cornell University, Meinig School of Biomedical Engineering, Weill Hall, Ithaca, New York 14853, USA
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42
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Leartprapun N, Lin Y, Adie SG. Microrheological quantification of viscoelastic properties with photonic force optical coherence elastography. OPTICS EXPRESS 2019; 27:22615-22630. [PMID: 31510549 PMCID: PMC6825604 DOI: 10.1364/oe.27.022615] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Photonic force optical coherence elastography (PF-OCE) is a new approach for volumetric characterization of microscopic mechanical properties of three-dimensional viscoelastic medium. It is based on measurements of the complex mechanical response of embedded micro-beads to harmonically modulated radiation-pressure force from a weakly-focused beam. Here, we utilize the Generalized Stokes-Einstein relation to reconstruct local complex shear modulus in polyacrylamide gels by combining PF-OCE measurements of bead mechanical responses and experimentally measured depth-resolved radiation-pressure force profile of our forcing beam. Data exclusion criteria for quantitative PF-OCE based on three noise-related parameters were identified from the analysis of measurement noise at key processing steps. Shear storage modulus measured by quantitative PF-OCE was found to be in good agreement with standard shear rheometry, whereas shear loss modulus was in agreement with previously published atomic force microscopy results. The analysis and results presented here may serve to inform practical, application-specific implementations of PF-OCE, and establish the technique as a viable tool for quantitative mechanical microscopy.
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43
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Raghunathan R, Liu CH, Kouka A, Singh M, Miranda RC, Larin KV. Assessing the acute effects of prenatal synthetic cannabinoid exposure on murine fetal brain vasculature using optical coherence tomography. JOURNAL OF BIOPHOTONICS 2019; 12:e201900050. [PMID: 30887665 PMCID: PMC10039318 DOI: 10.1002/jbio.201900050] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 03/15/2019] [Accepted: 03/17/2019] [Indexed: 05/02/2023]
Abstract
Marijuana is one of the most commonly abused substances during pregnancy. Synthetic cannabinoids (SCBs) are a group of heterogeneous compounds that are 40- to 600-fold more potent than Δ9 -tetrahydrocannabinol, the major psychoactive component of marijuana. With SCBs being legally available for purchase and the prevalence of unplanned pregnancies, the possibility of prenatal exposure to SCBs is high. However, the effects of prenatal SCB exposure on embryonic brain development are not well understood. In this study, we use complex correlation mapping optical coherence angiography to evaluate changes in murine fetal brain vasculature in utero, minutes after maternal exposure to an SCB, CP-55940. Results showed a significant decrease (P < 0.05) in fetal brain vessel diameter, length fraction and area density when compared to the sham group. This preliminary study shows that acute prenatal exposure to an SCB resulted in significant fetal brain vasoconstriction during the peak period for brain development.
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Affiliation(s)
- Raksha Raghunathan
- Department of Biomedical Engineering, University of Houston, Houston, Texas
| | - Chih-Hao Liu
- Department of Biomedical Engineering, University of Houston, Houston, Texas
| | - Amur Kouka
- Department of Biomedical Engineering, University of Houston, Houston, Texas
| | - Manmohan Singh
- Department of Biomedical Engineering, University of Houston, Houston, Texas
| | - Rajesh C. Miranda
- Department of Neuroscience and Experimental Therapeutics, TAMHSC College of Medicine, Bryan, Texas
| | - Kirill V. Larin
- Department of Biomedical Engineering, University of Houston, Houston, Texas
- Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas
- Correspondence: Kirill V. Larin, Department of Biomedical Engineering, University of Houston, 3517 Cullen Blvd., Houston, TX 77204.
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44
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Shi W, Chen C, Pasarikovski CR, Gao W, Yang VXD. Differential phase standard-deviation-based optical coherence tomographic angiography for human retinal imaging in vivo. APPLIED OPTICS 2019; 58:3401-3409. [PMID: 31044835 DOI: 10.1364/ao.58.003401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 03/25/2019] [Indexed: 06/09/2023]
Abstract
We present a differential phase standard-deviation (DPSD)-based optical coherence tomographic (OCT) angiography (OCTA) technique to calculate the angiography images of the human retina. The standard deviation was calculated along the depth direction on the differential phase image of two B-scans (from the same position, at different times) to contrast dynamic vascular signals. The performance of a DPSD was verified by both phantom and in vivo experiments. When compared to other OCTA algorithms such as phase variance OCT, speckle variance OCT, and optical microangiography, we showed that a DPSD achieved improved image contrast and higher sensitivity. Furthermore, we also found the improved signal-to-noise ratio and contrast-to-noise ratio of 1.6 dB and 0.5, respectively, in large scanning range images.
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45
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Nadiarnykh O, Davidoiu V, Gräfe MGO, Bosscha M, Moll AC, de Boer JF. Phase-based OCT angiography in diagnostic imaging of pediatric retinoblastoma patients: abnormal blood vessels in post-treatment regression patterns. BIOMEDICAL OPTICS EXPRESS 2019; 10:2213-2226. [PMID: 31143490 PMCID: PMC6524593 DOI: 10.1364/boe.10.002213] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 03/18/2019] [Accepted: 03/19/2019] [Indexed: 05/26/2023]
Abstract
Phase-based OCT angiography of retinoblastoma regression patterns with a novel handheld 1050 nm clinical imaging system is demonstrated for the first time in children between 0 and 4 years old under general anesthesia. Angiography is mapped at OCT resolution by flow detection at every pixel with en-face projection from the volume between nerve fiber layer and retinal pigment epithelium. We show a striking difference between blood vasculature of healthy retina, and retinoblastoma regression patterns after chemotherapy, as well as varying complexity of abnormal vasculature in regression patterns types 2, 3, and 4. We demonstrate abnormal, tortuous and prominent vasculature in type 3 regression patterns having the highest risk of tumor recurrences and a lower probability to reduction into flat scars. The ability to visualize 3-D angiography might offer new insights in understanding of retinoblastoma development and its response to therapy.
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Affiliation(s)
- Oleg Nadiarnykh
- Department of Physics and Astronomy, VU University, De Boelelaan 1081, Amsterdam, 1081 HV, The Netherlands
| | - Valentina Davidoiu
- Department of Physics and Astronomy, VU University, De Boelelaan 1081, Amsterdam, 1081 HV, The Netherlands
| | - Maximilian G. O. Gräfe
- Department of Physics and Astronomy, VU University, De Boelelaan 1081, Amsterdam, 1081 HV, The Netherlands
| | - Machteld Bosscha
- Amsterdam UMC, VU University, Department of Ophthalmology, De Boelelaan 1117, Amsterdam, 1081 HV, The Netherlands
| | - Annette C. Moll
- Amsterdam UMC, VU University, Department of Ophthalmology, De Boelelaan 1117, Amsterdam, 1081 HV, The Netherlands
| | - Johannes F. de Boer
- Department of Physics and Astronomy, VU University, De Boelelaan 1081, Amsterdam, 1081 HV, The Netherlands
- Amsterdam UMC, VU University, Department of Ophthalmology, De Boelelaan 1117, Amsterdam, 1081 HV, The Netherlands
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46
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Yamanari M, Uematsu S, Ishihara K, Ikuno Y. Parallel detection of Jones-matrix elements in polarization-sensitive optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2019; 10:2318-2336. [PMID: 31149375 PMCID: PMC6524579 DOI: 10.1364/boe.10.002318] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 03/16/2019] [Accepted: 03/18/2019] [Indexed: 06/09/2023]
Abstract
The polarization properties of a sample can be characterized using a Jones matrix. To measure the Jones matrix without assumptions of the sample, two different incident states of polarization are usually used. This requirement often causes certain drawbacks in polarization-sensitive optical coherence tomography (PS-OCT), e.g., a decrease in the effective A-scan rate or axial depth range, if a multiplexing scheme is used. Because both the A-scan rate and axial depth range are important for clinical applications, including the imaging of an anterior eye segment, a new PS-OCT method that does not have these drawbacks is desired. Here, we present a parallel-detection approach that maintains the same A-scan rate and axial measurement range as conventional OCT. The interferometer consists of fiber-optic components, most of which are polarization-maintaining components with fast-axis blocking free from polarization management. When a parallel detection is implemented using swept-source OCT (SS-OCT), synchronization between the A-scans and synchronization between the detection channels have critical effects on the Jones-matrix measurement. Because it is difficult to achieve perfect synchronization using only hardware, we developed a solution using a numerical correction with signals from a static mirror. Using the developed system, we demonstrate the imaging of an anterior eye segment from the cornea to the back surface of the crystalline lens.
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Affiliation(s)
- Masahiro Yamanari
- Engineering Department, Tomey Corporation, 2-11-33 Noritakeshinmachi, Nishiku, Nagoya, Aichi, 451-0051, Japan
| | - Sato Uematsu
- Department of Ophthalmology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Kenji Ishihara
- Engineering Department, Tomey Corporation, 2-11-33 Noritakeshinmachi, Nishiku, Nagoya, Aichi, 451-0051, Japan
| | - Yasushi Ikuno
- Ikuno Eye Center, 2-9-10 3F Juso-Higashi, Yodogawaku, Osaka, Osaka, 532-0023, Japan
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47
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Biosensors for Epilepsy Management: State-of-Art and Future Aspects. SENSORS 2019; 19:s19071525. [PMID: 30925837 PMCID: PMC6480455 DOI: 10.3390/s19071525] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 03/24/2019] [Accepted: 03/25/2019] [Indexed: 12/16/2022]
Abstract
Epilepsy is a serious neurological disorder which affects every aspect of patients’ life, including added socio-economic burden. Unfortunately, only a few suppressive medicines are available, and a complete cure for the disease has not been found yet. Excluding the effectiveness of available therapies, the timely detection and monitoring of epilepsy are of utmost priority for early remediation and prevention. Inability to detect underlying epileptic signatures at early stage causes serious damage to the central nervous system (CNS) and irreversible detrimental variations in the organ system. Therefore, development of a multi-task solving novel smart biosensing systems is urgently required. The present review highlights advancements in state-of-art biosensing technology investigated for epilepsy diseases diagnostics and progression monitoring or both together. State of art epilepsy biosensors are composed of nano-enabled smart sensing platform integrated with micro/electronics and display. These diagnostics systems provide bio-information needed to understand disease progression and therapy optimization timely. The associated challenges related to the development of an efficient epilepsy biosensor and vision considering future prospects are also discussed in this report. This review will serve as a guide platform to scholars for understanding and planning of future research aiming to develop a smart bio-sensing system to detect and monitor epilepsy for point-of-care (PoC) applications.
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48
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Gräfe MGO, Gondre M, de Boer JF. Precision analysis and optimization in phase decorrelation OCT velocimetry. BIOMEDICAL OPTICS EXPRESS 2019; 10:1297-1314. [PMID: 30891347 PMCID: PMC6420279 DOI: 10.1364/boe.10.001297] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 01/11/2019] [Accepted: 02/12/2019] [Indexed: 05/13/2023]
Abstract
Quantitative flow velocimetry in Optical Coherence Tomography is used to determine both the axial and lateral flow component at the level of individual voxels. The lateral flow is determined by analyzing the statistical properties of reflected electro-magnetic fields for repeated measurements at (nearly) the same location. The precision or statistical fluctuation of the quantitative velocity estimation depends on the number of repeated measurements and the method to determine quantitative flow velocity. In this paper, both a method to determine quantitative flow velocity and a model for the prediction of the statistical fluctuations of velocity estimations are developed to analyze and optimize the estimation precision for phase-based velocimetry methods. The method and model are validated by phantom measurements in a bulk scattering medium as well as in intralipid solution in a capillary. Based on the model, the number of repeated measurements to achieve a certain velocimetry precision is predicted.
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Affiliation(s)
- Maximilian G. O. Gräfe
- LaserLaB, Department of Physics and Astronomy, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Maude Gondre
- LaserLaB, Department of Physics and Astronomy, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
- Université de Genève, GAP-Biophotonics, Chemin de Pinchat 22, CH-1211 Geneva 4, Switzerland
| | - Johannes F. de Boer
- LaserLaB, Department of Physics and Astronomy, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
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49
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Pijewska E, Gorczynska I, Szkulmowski M. Computationally effective 2D and 3D fast phase unwrapping algorithms and their applications to Doppler optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2019; 10:1365-1382. [PMID: 30891352 PMCID: PMC6420292 DOI: 10.1364/boe.10.001365] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 01/20/2019] [Accepted: 01/22/2019] [Indexed: 05/07/2023]
Abstract
We propose a simplification for a robust and easy to implement fast phase unwrapping (FPU) algorithm that is used to solve the phase wrapping problem encountered in various fields of optical imaging and metrology. We show that the number of necessary computations using the algorithm can be reduced compared to its original version. FPU can be easily extended from two to three spatial dimensions. We demonstrate the applicability of the two- and three-dimensional FPU algorithm for Doppler optical coherence tomography (DOCT) in numerical simulations, and in the imaging of a flow phantom and blood flow in the human retina in vivo. We introduce an FPU applicability plot for use as a guide in the selection of the most suitable version of the algorithm depending on the phase noise in the acquired data. This plot uses the circular standard deviation of the wrapped phase distribution as a measure of noise and relates it to the root-mean-square error of the recovered, unwrapped phase.
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50
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Coote JM, Alles EJ, Noimark S, Mosse CA, Little CD, Loder CD, David AL, Rakhit RD, Finlay MC, Desjardins AE. Dynamic physiological temperature and pressure sensing with phase-resolved low-coherence interferometry. OPTICS EXPRESS 2019; 27:5641-5654. [PMID: 30876162 PMCID: PMC6410922 DOI: 10.1364/oe.27.005641] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
We report the development and characterisation of highly miniaturised fibre-optic sensors for simultaneous pressure and temperature measurement, and a compact interrogation system with a high sampling rate. The sensors, which have a maximum diameter of 250 µm, are based on multiple low-finesse optical cavities formed from polydimethylsiloxane (PDMS), positioned at the distal ends of optical fibres, and interrogated using phase-resolved low-coherence interferometry. At acquisition rates of 250 Hz, temperature and pressure changes of 0.0021 °C and 0.22 mmHg are detectable. An in vivo experiment demonstrated that the sensors had sufficient speed and sensitivity for monitoring dynamic physiological pressure waveforms. These sensors are ideally suited to various applications in minimally invasive surgery, where diminutive lateral dimensions, high sensitivity and low manufacturing complexities are particularly valuable.
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Affiliation(s)
- J. M. Coote
- Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London WC1E 6BT, United Kingdom
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences, University College London, Charles Bell House, 43-45 Foley Street, London W1W 7TS, United Kingdom
| | - E. J. Alles
- Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London WC1E 6BT, United Kingdom
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences, University College London, Charles Bell House, 43-45 Foley Street, London W1W 7TS, United Kingdom
| | - S. Noimark
- Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London WC1E 6BT, United Kingdom
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences, University College London, Charles Bell House, 43-45 Foley Street, London W1W 7TS, United Kingdom
- Materials Chemistry Research Centre, Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
| | - C. A. Mosse
- Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London WC1E 6BT, United Kingdom
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences, University College London, Charles Bell House, 43-45 Foley Street, London W1W 7TS, United Kingdom
| | - C. D. Little
- Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London WC1E 6BT, United Kingdom
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences, University College London, Charles Bell House, 43-45 Foley Street, London W1W 7TS, United Kingdom
- The Royal Free Hospital, Pond Street, London NW3 2QG, United Kingdom
| | - C. D. Loder
- The Royal Free Hospital, Pond Street, London NW3 2QG, United Kingdom
| | - A. L. David
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences, University College London, Charles Bell House, 43-45 Foley Street, London W1W 7TS, United Kingdom
- Institute for Women’s Health, University College London, 86-96 Chenies Mews, London WC1E 6HX, United Kingdom
| | - R. D. Rakhit
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences, University College London, Charles Bell House, 43-45 Foley Street, London W1W 7TS, United Kingdom
- The Royal Free Hospital, Pond Street, London NW3 2QG, United Kingdom
| | - M. C. Finlay
- Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London WC1E 6BT, United Kingdom
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences, University College London, Charles Bell House, 43-45 Foley Street, London W1W 7TS, United Kingdom
- Barts Heart Centre, St Bartholomew’s Hospital and Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, United Kingdom
| | - A. E. Desjardins
- Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London WC1E 6BT, United Kingdom
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences, University College London, Charles Bell House, 43-45 Foley Street, London W1W 7TS, United Kingdom
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