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Monroy GL, Erfanzadeh M, Tao M, DePaoli DT, Saytashev I, Nam SA, Rafi H, Kwong KC, Shea K, Vakoc BJ, Vasudevan S, Hammer DX. Development of polarization-sensitive optical coherence tomography imaging platform and metrics to quantify electrostimulation-induced peripheral nerve injury in vivo in a small animal model. NEUROPHOTONICS 2023; 10:025004. [PMID: 37077218 PMCID: PMC10109528 DOI: 10.1117/1.nph.10.2.025004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 03/28/2023] [Indexed: 05/03/2023]
Abstract
Significance Neuromodulation devices are rapidly evolving for the treatment of neurological diseases and conditions. Injury from implantation or long-term use without obvious functional losses is often only detectable through terminal histology. New technologies are needed that assess the peripheral nervous system (PNS) under normal and diseased or injured conditions. Aim We aim to demonstrate an imaging and stimulation platform that can elucidate the biological mechanisms and impacts of neurostimulation in the PNS and apply it to the sciatic nerve to extract imaging metrics indicating electrical overstimulation. Approach A sciatic nerve injury model in a 15-rat cohort was observed using a newly developed imaging and stimulation platform that can detect electrical overstimulation effects with polarization-sensitive optical coherence tomography. The sciatic nerve was electrically stimulated using a custom-developed nerve holder with embedded electrodes for 1 h, followed by a 1-h recovery period, delivered at above-threshold Shannon model k -values in experimental groups: sham control (SC, n = 5 , 0.0 mA / 0 Hz ), stimulation level 1 (SL1, n = 5 , 3.4 mA / 50 Hz , and k = 2.57 ), and stimulation level 2 (SL2, n = 5 , 6.8 mA / 100 Hz , and k = 3.17 ). Results The stimulation and imaging system successfully captured study data across the cohort. When compared to a SC after a 1-week recovery, the fascicle closest to the stimulation lead showed an average change of + 4 % / - 309 % (SL1/SL2) in phase retardation and - 79 % / - 148 % in optical attenuation relative to SC. Analysis of immunohistochemistry (IHC) shows a + 1 % / - 36 % difference in myelin pixel counts and - 13 % / + 29 % difference in axon pixel counts, and an overall increase in cell nuclei pixel count of + 20 % / + 35 % . These metrics were consistent with IHC and hematoxylin/eosin tissue section analysis. Conclusions The poststimulation changes observed in our study are manifestations of nerve injury and repair, specifically degeneration and angiogenesis. Optical imaging metrics quantify these processes and may help evaluate the safety and efficacy of neuromodulation devices.
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Affiliation(s)
- Guillermo L. Monroy
- U. S. Food and Drug Administration, Center for Devices and Radiological Health, Office of Science and Engineering Laboratories, Division of Biomedical Physics, Silver Spring, Maryland, United States
| | - Mohsen Erfanzadeh
- Massachusetts General Hospital, Harvard Medical School, Wellman Center for Photomedicine, Boston, Massachusetts, United States
- Harvard Medical School, Boston, Massachusetts, United States
| | - Michael Tao
- U. S. Food and Drug Administration, Center for Devices and Radiological Health, Office of Science and Engineering Laboratories, Division of Biomedical Physics, Silver Spring, Maryland, United States
| | - Damon T. DePaoli
- Massachusetts General Hospital, Harvard Medical School, Wellman Center for Photomedicine, Boston, Massachusetts, United States
- Harvard Medical School, Boston, Massachusetts, United States
| | - Ilyas Saytashev
- U. S. Food and Drug Administration, Center for Devices and Radiological Health, Office of Science and Engineering Laboratories, Division of Biomedical Physics, Silver Spring, Maryland, United States
| | - Stephanie A. Nam
- Massachusetts General Hospital, Harvard Medical School, Wellman Center for Photomedicine, Boston, Massachusetts, United States
- Harvard Medical School, Boston, Massachusetts, United States
| | - Harmain Rafi
- U. S. Food and Drug Administration, Center for Devices and Radiological Health, Office of Science and Engineering Laboratories, Division of Biomedical Physics, Silver Spring, Maryland, United States
| | - Kasey C. Kwong
- Massachusetts General Hospital, Harvard Medical School, Wellman Center for Photomedicine, Boston, Massachusetts, United States
- Harvard Medical School, Boston, Massachusetts, United States
| | - Katherine Shea
- U. S. Food and Drug Administration, Center for Drug Evaluation and Research, Office of Clinical Pharmacology, Office of Translational Science, Division of Applied Regulatory Science, Silver Spring, Maryland, United States
| | - Benjamin J. Vakoc
- Massachusetts General Hospital, Harvard Medical School, Wellman Center for Photomedicine, Boston, Massachusetts, United States
- Harvard Medical School, Boston, Massachusetts, United States
- Massachusetts Institute of Technology, Division of Health Science and Technology, Cambridge, Massachusetts, United States
| | - Srikanth Vasudevan
- U. S. Food and Drug Administration, Center for Devices and Radiological Health, Office of Science and Engineering Laboratories, Division of Biomedical Physics, Silver Spring, Maryland, United States
- Address all correspondence to Srikanth Vasudevan, ; Daniel X. Hammer,
| | - Daniel X. Hammer
- U. S. Food and Drug Administration, Center for Devices and Radiological Health, Office of Science and Engineering Laboratories, Division of Biomedical Physics, Silver Spring, Maryland, United States
- Address all correspondence to Srikanth Vasudevan, ; Daniel X. Hammer,
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Yamanari M, Mase M, Obata R, Matsuzaki M, Minami T, Takagi S, Yamamoto M, Miyamoto N, Ueda K, Koide N, Maeda T, Totani K, Aoki N, Hirami Y, Sugiyama S, Mandai M, Aihara M, Takahashi M, Kato S, Kurimoto Y. Melanin concentration and depolarization metrics measurement by polarization-sensitive optical coherence tomography. Sci Rep 2020; 10:19513. [PMID: 33177585 PMCID: PMC7658243 DOI: 10.1038/s41598-020-76397-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 10/23/2020] [Indexed: 11/16/2022] Open
Abstract
Imaging of melanin in the eye is important as the melanin is structurally associated with some ocular diseases, such as age-related macular degeneration. Although optical coherence tomography (OCT) cannot distinguish tissues containing the melanin from other tissues intrinsically, polarization-sensitive OCT (PS-OCT) can detect the melanin through spatial depolarization of the backscattered light from the melanin granules. Entropy is one of the depolarization metrics that can be used to detect malanin granules in PS-OCT and valuable quantitative information on ocular tissue abnormalities can be retrived by correlating entropy with the melanin concentration. In this study, we investigate a relationship between the melanin concentration and some depolarization metrics including the entropy, and show that the entropy is linearly proportional to the melanin concentration in double logarithmic scale when noise bias is corrected for the entropy. In addition, we also confirm that the entropy does not depend on the incident state of polarization using the experimental data, which is one of important attributes that depolarization metrics should have. The dependence on the incident state of polarization is also analyzed for other depolarization metrics.
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Affiliation(s)
| | - Mutsuki Mase
- Engineering Department, Tomey Corporation, Nagoya, Aichi, Japan
| | - Ryo Obata
- Department of Ophthalmology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, Tokyo, Japan
| | - Mitsuhiro Matsuzaki
- Department of Ophthalmology, Kobe City Eye Hospital, Kobe, Hyogo, Japan.,Department of Ophthalmology, Kobe City Medical Centre General Hospital, Kobe, Hyogo, Japan
| | - Takahiro Minami
- Department of Ophthalmology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, Tokyo, Japan
| | - Seiji Takagi
- Department of Ophthalmology, Kobe City Eye Hospital, Kobe, Hyogo, Japan.,Department of Ophthalmology, Kobe City Medical Centre General Hospital, Kobe, Hyogo, Japan
| | - Motoshi Yamamoto
- Department of Ophthalmology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, Tokyo, Japan
| | - Noriko Miyamoto
- Department of Ophthalmology, Kobe City Eye Hospital, Kobe, Hyogo, Japan.,Department of Ophthalmology, Kobe City Medical Centre General Hospital, Kobe, Hyogo, Japan
| | - Koji Ueda
- Department of Ophthalmology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, Tokyo, Japan
| | - Naoshi Koide
- Laboratory for Retinal Regeneration, Riken Centre for Biosystems Dynamics Research, Kobe, Hyogo, Japan
| | - Tadao Maeda
- Department of Ophthalmology, Kobe City Eye Hospital, Kobe, Hyogo, Japan.,Department of Ophthalmology, Kobe City Medical Centre General Hospital, Kobe, Hyogo, Japan.,Laboratory for Retinal Regeneration, Riken Centre for Biosystems Dynamics Research, Kobe, Hyogo, Japan
| | - Kota Totani
- Engineering Department, Tomey Corporation, Nagoya, Aichi, Japan
| | - Nobuyori Aoki
- Engineering Department, Tomey Corporation, Nagoya, Aichi, Japan
| | - Yasuhiko Hirami
- Department of Ophthalmology, Kobe City Eye Hospital, Kobe, Hyogo, Japan.,Department of Ophthalmology, Kobe City Medical Centre General Hospital, Kobe, Hyogo, Japan.,Laboratory for Retinal Regeneration, Riken Centre for Biosystems Dynamics Research, Kobe, Hyogo, Japan
| | | | - Michiko Mandai
- Department of Ophthalmology, Kobe City Eye Hospital, Kobe, Hyogo, Japan.,Laboratory for Retinal Regeneration, Riken Centre for Biosystems Dynamics Research, Kobe, Hyogo, Japan
| | - Makoto Aihara
- Department of Ophthalmology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, Tokyo, Japan
| | - Masayo Takahashi
- Department of Ophthalmology, Kobe City Eye Hospital, Kobe, Hyogo, Japan.,Laboratory for Retinal Regeneration, Riken Centre for Biosystems Dynamics Research, Kobe, Hyogo, Japan.,Vision Care Inc., Kobe, Hyogo, Japan
| | - Satoshi Kato
- Department of Ophthalmology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, Tokyo, Japan
| | - Yasuo Kurimoto
- Department of Ophthalmology, Kobe City Eye Hospital, Kobe, Hyogo, Japan.,Department of Ophthalmology, Kobe City Medical Centre General Hospital, Kobe, Hyogo, Japan.,Laboratory for Retinal Regeneration, Riken Centre for Biosystems Dynamics Research, Kobe, Hyogo, Japan
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Lippok N, Braaf B, Villiger M, Oh WY, Vakoc BJ, Bouma BE. Quantitative depolarization measurements for fiber-based polarization-sensitive optical frequency domain imaging of the retinal pigment epithelium. JOURNAL OF BIOPHOTONICS 2019; 12:e201800156. [PMID: 30009506 PMCID: PMC6526942 DOI: 10.1002/jbio.201800156] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 07/07/2018] [Indexed: 05/05/2023]
Abstract
A full quantitative evaluation of the depolarization of light may serve to assess concentrations of depolarizing particles in the retinal pigment epithelium and to investigate their role in retinal diseases in the human eye. Optical coherence tomography and optical frequency domain imaging use spatial incoherent averaging to compute depolarization. Depolarization depends on accurate measurements of the polarization states at the receiver but also on the polarization state incident upon and within the tissue. Neglecting this dependence can result in artifacts and renders depolarization measurements vulnerable to birefringence in the system and in the sample. In this work, we discuss the challenges associated with using a single input polarization state and traditional depolarization metrics such as the degree-of-polarization and depolarization power. We demonstrate quantitative depolarization measurements based on Jones vector synthesis and polar decomposition using fiber-based polarization-sensitive optical frequency domain imaging of the retinal pigment epithelium in a human eye.
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Affiliation(s)
- Norman Lippok
- Harvard Medical School, Boston, Massachusetts
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts
| | - Boy Braaf
- Harvard Medical School, Boston, Massachusetts
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts
| | - Martin Villiger
- Harvard Medical School, Boston, Massachusetts
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts
| | - Wang-Yuhl Oh
- Department of Mechanical Engineering, KAIST, Daejeon, South Korea
- KI for Health Science and Technology, KAIST, Daejeon, South Korea
| | - Benjamin J. Vakoc
- Harvard Medical School, Boston, Massachusetts
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Brett E. Bouma
- Harvard Medical School, Boston, Massachusetts
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, Massachusetts
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Miyazawa A, Hong YJ, Makita S, Kasaragod D, Yasuno Y. Generation and optimization of superpixels as image processing kernels for Jones matrix optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2017; 8:4396-4418. [PMID: 29082073 PMCID: PMC5654788 DOI: 10.1364/boe.8.004396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 08/31/2017] [Accepted: 09/01/2017] [Indexed: 05/05/2023]
Abstract
Jones matrix-based polarization sensitive optical coherence tomography (JM-OCT) simultaneously measures optical intensity, birefringence, degree of polarization uniformity, and OCT angiography. The statistics of the optical features in a local region, such as the local mean of the OCT intensity, are frequently used for image processing and the quantitative analysis of JM-OCT. Conventionally, local statistics have been computed with fixed-size rectangular kernels. However, this results in a trade-off between image sharpness and statistical accuracy. We introduce a superpixel method to JM-OCT for generating the flexible kernels of local statistics. A superpixel is a cluster of image pixels that is formed by the pixels' spatial and signal value proximities. An algorithm for superpixel generation specialized for JM-OCT and its optimization methods are presented in this paper. The spatial proximity is in two-dimensional cross-sectional space and the signal values are the four optical features. Hence, the superpixel method is a six-dimensional clustering technique for JM-OCT pixels. The performance of the JM-OCT superpixels and its optimization methods are evaluated in detail using JM-OCT datasets of posterior eyes. The superpixels were found to well preserve tissue structures, such as layer structures, sclera, vessels, and retinal pigment epithelium. And hence, they are more suitable for local statistics kernels than conventional uniform rectangular kernels.
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