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Meleppat RK, Valente D, Lee S, Jonnal RS, Doble N, Zawadzki RJ. On-axis full-field swept-source optical coherence tomography for murine retinal imaging. OPTICS LETTERS 2024; 49:4630-4633. [PMID: 39146121 DOI: 10.1364/ol.531116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2024] [Accepted: 07/19/2024] [Indexed: 08/17/2024]
Abstract
A full-field swept-source optical coherence tomography (FF-SS-OCT) for in vivo murine retinal imaging is demonstrated. The on-axis FF-SS-OCT system was built in a Mach-Zehnder interferometer configuration employing a tunable laser source with an adjustable sweep rate and sweep range in conjunction with a fast 2D-CMOS camera. A large field retinal (coherent) illumination was accomplished using an imaging interface comprised of a short-focal length imaging lens and a contact lens. The magnification between the camera and retina (spatial sampling) was appropriately chosen to record the microscopic structural features of the retina in the image. A pupil stop was employed in the detection path to reject unwanted backscattering from the mouse eye and other sources and limit aberrations distorting the retinal images. In vivo mouse retinal imaging was performed at a sweep rate of 150 Hz to acquire volumes unaffected by the system vibrations, which predominated at lower frequencies. Operating the FF-SS-OCT at this speed yielded an effective axial scan rate of 20 million A-scans/s and a field of view of 820 × 410 µm (24.12° × 12.06°). High-quality retinal B-scans and enface images of the retina were obtained with the SS-FF-OCT, revealing all major retinal layers and vascular plexuses.
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Frigelli M, Büchler P, Kling S. Dynamic evaluation of corneal cross-linking and osmotic diffusion effects using optical coherence elastography. Sci Rep 2024; 14:16614. [PMID: 39025900 PMCID: PMC11258322 DOI: 10.1038/s41598-024-67278-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Accepted: 07/09/2024] [Indexed: 07/20/2024] Open
Abstract
Dynamic deformation events induced by osmosis or photochemical stiffening substantially influence geometrical and mechanical assessments in post-mortem corneas, therefore need to be carefully monitored in experimental settings. In this study, we employed optical coherence elastography (OCE) to quantify dynamic deformation processes at high resolution in freshly enucleated porcine corneas. Osmotic effects were studied by immerging n = 9 eyes in preservation media of three different tonicities. Dynamic processes underlying corneal cross-linking (CXL) were studied by subjecting n = 6 eyes to standard Dresden treatment, while three control groups were used. The entire procedures were performed under an OCE setup during up to 80 min, acquiring a volumetric scan every 20 s. Changes in OCE-derived axial deformations were incrementally calculated between consecutive scans. Preservation conditions had a strong influence on the observed strain patterns, which were consistent with the tonicity of the medium (swelling in hypotonic, deswelling in hypertonic environment). In the CXL group, we observed deswelling of the anterior stroma 10 min after starting the UV irradiation, which was not observed in any control group (p = 0.007). The presented results proved OCE to be a valuable technique to quantify subtle dynamic biomechanical alterations in the cornea resulting from CXL and preservation solutions.
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Affiliation(s)
- Matteo Frigelli
- ARTORG Center for Biomedical Engineering Research, University of Bern, Bern, Switzerland
| | - Philippe Büchler
- ARTORG Center for Biomedical Engineering Research, University of Bern, Bern, Switzerland
| | - Sabine Kling
- ARTORG Center for Biomedical Engineering Research, University of Bern, Bern, Switzerland.
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3
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Shi Y, Liu J, Wang RK. High-speed, long-range and wide-field OCT for in vivo 3D imaging of the oral cavity achieved by a 600 kHz swept source laser. BIOMEDICAL OPTICS EXPRESS 2024; 15:4365-4380. [PMID: 39022551 PMCID: PMC11249692 DOI: 10.1364/boe.528287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/23/2024] [Revised: 06/03/2024] [Accepted: 06/08/2024] [Indexed: 07/20/2024]
Abstract
We report a high-speed, long-range, and wide-field swept-source optical coherence tomography (SS-OCT) system aimed for imaging microstructures and microcirculations in the oral cavity. This system operates at a scan speed of 600 kHz, delivering a wide imaging field of view at 42 × 42 mm2 and a ranging distance of 36 mm. To simultaneously meet the requirements of high speed and long range, it is necessary for the k-clock trigger signal to be generated at its maximum speed, which may induce non-linear phase response in electronic devices due to the excessive k-clock frequency bandwidth, leading to phase errors. To address this challenge, we introduced a concept of electrical dispersion and a global k-clock compensation approach to improve overall performance of the imaging system. Additionally, image distortion in the wide-field imaging mode is also corrected using a method based on distortion vector maps. With this system, we demonstrate comprehensive structural and blood flow imaging of the anterior oral cavity in healthy individuals. The high-speed, long-range, and wide-field SS-OCT system opens new opportunities for comprehensive oral cavity examinations and holds promise as a reliable tool for assessing oral health conditions.
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Affiliation(s)
- Yaping Shi
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Jian Liu
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Ruikang K. Wang
- Department of Bioengineering, University of Washington, Seattle, WA, USA
- Department of Ophthalmology, University of Washington, Seattle, WA, USA
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Ayalon A, Sahel JA, Chhablani J. A journey through the world of vitreous. Surv Ophthalmol 2024:S0039-6257(24)00070-5. [PMID: 38885759 DOI: 10.1016/j.survophthal.2024.06.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2024] [Revised: 06/06/2024] [Accepted: 06/10/2024] [Indexed: 06/20/2024]
Abstract
Vitreous, one of the largest components of the human eye, mostly contains water. Despite decades of studying the vitreous structure, numerous unanswered questions still remain, fueling ongoing active research. We attempt to provide a comprehensive overview of the current understanding of the development, morphology, biochemical composition, and function of the vitreous. We emphasize the impact of the vitreous structure and composition on the distribution of drugs. Fast-developing imaging technologies, such as modern optical coherence tomography, unlocked multiple new approaches, offering the potential for in vivo study of the vitreous structure. They allowed to analyze in vivo a range of vitreous structures, such as posterior precortical vitreous pockets, Cloquet canal, channels that interconnect them, perivascular vitreous fissures, and cisterns. We provide an overview of such imaging techniques and their principles and of some challenges in visualizing vitreous structures. Finally, we explores the potential of combining the latest technologies and machine learning to enhance our understanding of vitreous structures.
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Affiliation(s)
- Anfisa Ayalon
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
| | - José-Alain Sahel
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Jay Chhablani
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
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5
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Valmaggia P, Cattin PC, Sandkühler R, Inglin N, Otto TP, Aumann S, Teussink MM, Spaide RF, Scholl HPN, Maloca PM. Time-Resolved Dynamic Optical Coherence Tomography for Retinal Blood Flow Analysis. Invest Ophthalmol Vis Sci 2024; 65:9. [PMID: 38837167 PMCID: PMC11160951 DOI: 10.1167/iovs.65.6.9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 05/16/2024] [Indexed: 06/06/2024] Open
Abstract
Purpose Optical coherence tomography (OCT) representations in clinical practice are static and do not allow for a dynamic visualization and quantification of blood flow. This study aims to present a method to analyze retinal blood flow dynamics using time-resolved structural OCT. Methods We developed novel imaging protocols to acquire video-rate time-resolved OCT B-scans (1024 × 496 pixels, 10 degrees field of view) at four different sensor integration times (integration time of 44.8 µs at a nominal A-scan rate of 20 kHz, 22.4 µs at 40 kHz, 11.2 µs at 85 kHz, and 7.24 µs at 125 kHz). The vessel centers were manually annotated for each B-scan and surrounding subvolumes were extracted. We used a velocity model based on signal-to-noise ratio (SNR) drops due to fringe washout to calculate blood flow velocity profiles in vessels within five optic disc diameters of the optic disc rim. Results Time-resolved dynamic structural OCT revealed pulsatile SNR changes in the analyzed vessels and allowed the calculation of potential blood flow velocities at all integration times. Fringe washout was stronger in acquisitions with longer integration times; however, the ratio of the average SNR to the peak SNR inside the vessel was similar across all integration times. Conclusions We demonstrated the feasibility of estimating blood flow profiles based on fringe washout analysis, showing pulsatile dynamics in vessels close to the optic nerve head using structural OCT. Time-resolved dynamic OCT has the potential to uncover valuable blood flow information in clinical settings.
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Affiliation(s)
- Philippe Valmaggia
- Department of Biomedical Engineering, University of Basel, Allschwil, Switzerland
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), Basel, Basel, Switzerland
- Department of Ophthalmology, University Hospital Basel, Basel, Switzerland
| | - Philippe C. Cattin
- Department of Biomedical Engineering, University of Basel, Allschwil, Switzerland
| | - Robin Sandkühler
- Department of Biomedical Engineering, University of Basel, Allschwil, Switzerland
| | - Nadja Inglin
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), Basel, Basel, Switzerland
| | | | - Silke Aumann
- Heidelberg Engineering GmbH, Heidelberg, Germany
| | | | - Richard F. Spaide
- Vitreous Retina Macula Consultants of New York, New York, United States
| | - Hendrik P. N. Scholl
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), Basel, Basel, Switzerland
- Department of Ophthalmology, University Hospital Basel, Basel, Switzerland
| | - Peter M. Maloca
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), Basel, Basel, Switzerland
- Department of Ophthalmology, University Hospital Basel, Basel, Switzerland
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Guzman V BM, De La Torre I MH, Frausto-Reyes C. Impact of the preservation media on ex vivo bone samples for full field mechanical testing. APPLIED OPTICS 2024; 63:3745-3752. [PMID: 38856336 DOI: 10.1364/ao.512047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2023] [Accepted: 04/13/2024] [Indexed: 06/11/2024]
Abstract
The preservation method to store bone tissue for posterior analysis is a widespread practice. However, the method's potential influence on the material's mechanical properties is often overlooked during single-point experimentation. Saline and formaldehyde solutions are the most common among the employed preservation media. A full field analysis of the mice femoral bone deformation using non-destructive optical techniques is conducted to assess the influence of the storage media on the viscoelastic properties of the tissue. Three different groups are subjected to a standard three-point bending test. The first group is the control, with fresh post-mortem samples. The second and third groups used saline and formaldehyde solutions, respectively. During the mechanical test, the bone's surface and internal deformation are monitored simultaneously using digital holographic interferometry and Fourier-domain optical coherence tomography. A mechanical comparison among the three groups is presented. The results show that after 48 h of immersion in saline solution, the mice bones keep their viscoelastic behavior similar to fresh bones. Meanwhile, 48 h in formaldehyde modifies the response and affects the marrow structure. The high sensitivity of the optical phase also makes it possible to observe changes in the anisotropy of the samples. As a comparison, Raman spectroscopy analyzes the three bone groups to prove that the preservation media does not affect a single-point inspection.
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Han T, Yang L, Tang Y, Chen C, Ma C, Liu Z, Ding Z. Long range topography by dispersion unmatched spectral-domain interferometry based on virtually imaged phased array modes. OPTICS LETTERS 2024; 49:2281-2284. [PMID: 38691699 DOI: 10.1364/ol.517249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Accepted: 03/24/2024] [Indexed: 05/03/2024]
Abstract
We propose to realize a long range topography by dispersion unmatched spectral-domain interferometry based on virtually imaged phased array (VIPA) modes. By filtering the continuous spectrum of a supercontinuum source through a side-entrance Fabry-Perot etalon configured at two input angles, two groups of VIPA modes are generated. A method based on unmatched dispersion is proposed for non-aliasing reconstruction of the true depth from the interference spectrum under-sampled at two groups of VIPA modes. With the high spectral resolution provided by the VIPA modes instead of the grating-based spectrometer, only a 10 dB falloff in sensitivity over a range of 10 mm was demonstrated. The feasibility of the proposed method was confirmed by topography of a sample of gauge blocks and a model of three-dimensional (3D) printed tooth. The occlusal surface of the tooth model was further quantitatively evaluated, demonstrating its potential application in long range 3D topography.
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Wijesinghe RE, Kahatapitiya NS, Lee C, Han S, Kim S, Saleah SA, Seong D, Silva BN, Wijenayake U, Ravichandran NK, Jeon M, Kim J. Growing Trend to Adopt Speckle Variance Optical Coherence Tomography for Biological Tissue Assessments in Pre-Clinical Applications. MICROMACHINES 2024; 15:564. [PMID: 38793137 PMCID: PMC11122893 DOI: 10.3390/mi15050564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Revised: 04/19/2024] [Accepted: 04/22/2024] [Indexed: 05/26/2024]
Abstract
Speckle patterns are a generic feature in coherent imaging techniques like optical coherence tomography (OCT). Although speckles are granular like noise texture, which degrades the image, they carry information that can be benefited by processing and thereby furnishing crucial information of sample structures, which can serve to provide significant important structural details of samples in in vivo longitudinal pre-clinical monitoring and assessments. Since the motions of tissue molecules are indicated through speckle patterns, speckle variance OCT (SV-OCT) can be well-utilized for quantitative assessments of speckle variance (SV) in biological tissues. SV-OCT has been acknowledged as a promising method for mapping microvasculature in transverse-directional blood vessels with high resolution in micrometers in both the transverse and depth directions. The fundamental scope of this article reviews the state-of-the-art and clinical benefits of SV-OCT to assess biological tissues for pre-clinical applications. In particular, focus on precise quantifications of in vivo vascular response, therapy assessments, and real-time temporal vascular effects of SV-OCT are primarily emphasized. Finally, SV-OCT-incorporating pre-clinical techniques with high potential are presented for future biomedical applications.
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Affiliation(s)
- Ruchire Eranga Wijesinghe
- Department of Electrical and Electronic Engineering, Faculty of Engineering, Sri Lanka Institute of Information Technology, Malabe 10115, Sri Lanka;
- Center for Excellence in Intelligent Informatics, Electronics & Transmission (CIET), Sri Lanka Institute of Information Technology, Malabe 10115, Sri Lanka
| | - Nipun Shantha Kahatapitiya
- Department of Computer Engineering, Faculty of Engineering, University of Sri Jayewardenepura, Nugegoda 10250, Sri Lanka; (N.S.K.); (U.W.)
| | - Changho Lee
- Department of Artificial Intelligence Convergence, Chonnam National University, Gwangju 61186, Republic of Korea
- Department of Nuclear Medicine, Chonnam National University Medical School & Hwasun Hospital, 264, Seoyang-ro, Hwasun 58128, Republic of Korea
| | - Sangyeob Han
- ICT Convergence Research Center, Kyungpook National University, 80, Daehak-ro, Buk-gu, Daegu 41566, Republic of Korea
| | - Shinheon Kim
- ICT Convergence Research Center, Kyungpook National University, 80, Daehak-ro, Buk-gu, Daegu 41566, Republic of Korea
| | - Sm Abu Saleah
- ICT Convergence Research Center, Kyungpook National University, 80, Daehak-ro, Buk-gu, Daegu 41566, Republic of Korea
| | - Daewoon Seong
- School of Electronic and Electrical Engineering, College of IT Engineering, Kyungpook National University, 80, Daehak-ro, Buk-gu, Daegu 41566, Republic of Korea
| | - Bhagya Nathali Silva
- Center for Excellence in Intelligent Informatics, Electronics & Transmission (CIET), Sri Lanka Institute of Information Technology, Malabe 10115, Sri Lanka
- Faculty of Computing, Sri Lanka Institute of Information Technology, Malabe 10115, Sri Lanka
| | - Udaya Wijenayake
- Department of Computer Engineering, Faculty of Engineering, University of Sri Jayewardenepura, Nugegoda 10250, Sri Lanka; (N.S.K.); (U.W.)
| | - Naresh Kumar Ravichandran
- Center for Scientific Instrumentation, Korea Basic Science Institute, 169-148, Gwahak-ro, Yuseong-gu, Daejeon 34133, Republic of Korea
| | - Mansik Jeon
- School of Electronic and Electrical Engineering, College of IT Engineering, Kyungpook National University, 80, Daehak-ro, Buk-gu, Daegu 41566, Republic of Korea
| | - Jeehyun Kim
- School of Electronic and Electrical Engineering, College of IT Engineering, Kyungpook National University, 80, Daehak-ro, Buk-gu, Daegu 41566, Republic of Korea
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9
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Nguyen VP, Hu J, Zhe J, Ramasamy S, Ahmed U, Paulus YM. Advanced nanomaterials for imaging of eye diseases. ADMET AND DMPK 2024; 12:269-298. [PMID: 38720929 PMCID: PMC11075159 DOI: 10.5599/admet.2182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 02/16/2024] [Indexed: 05/12/2024] Open
Abstract
Background and purpose Vision impairment and blindness present significant global challenges, with common causes including age-related macular degeneration, diabetes, retinitis pigmentosa, and glaucoma. Advanced imaging tools, such as optical coherence tomography, fundus photography, photoacoustic microscopy, and fluorescence imaging, play a crucial role in improving therapeutic interventions and diagnostic methods. Contrast agents are often employed with these tools to enhance image clarity and signal detection. This review aims to explore the commonly used contrast agents in ocular disease imaging. Experimental approach The first section of the review delves into advanced ophthalmic imaging techniques, outlining their importance in addressing vision-related issues. The emphasis is on the efficacy of therapeutic interventions and diagnostic methods, establishing a foundation for the subsequent exploration of contrast agents. Key results This review focuses on the role of contrast agents, with a specific emphasis on gold nanoparticles, particularly gold nanorods. The discussion highlights how these contrast agents optimize imaging in ocular disease diagnosis and monitoring, emphasizing their unique properties that enhance signal detection and imaging precision. Conclusion The final section, we explores both organic and inorganic contrast agents and their applications in specific conditions such as choroidal neovascularization, retinal neovascularization, and stem cell tracking. The review concludes by addressing the limitations of current contrast agent usage and discussing potential future clinical applications. This comprehensive exploration contributes to advancing our understanding of contrast agents in ocular disease imaging and sets the stage for further research and development in the field.
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Affiliation(s)
- Van Phuc Nguyen
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA
| | - Justin Hu
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA
| | - Josh Zhe
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA
| | - Sanjay Ramasamy
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA
| | - Umayr Ahmed
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA
| | - Yannis M. Paulus
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48105, USA
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Saleah SA, Kim S, Luna JA, Wijesinghe RE, Seong D, Han S, Kim J, Jeon M. Optical Coherence Tomography as a Non-Invasive Tool for Plant Material Characterization in Agriculture: A Review. SENSORS (BASEL, SWITZERLAND) 2023; 24:219. [PMID: 38203080 PMCID: PMC10781338 DOI: 10.3390/s24010219] [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: 12/03/2023] [Revised: 12/23/2023] [Accepted: 12/27/2023] [Indexed: 01/12/2024]
Abstract
Characterizing plant material is crucial in terms of early disease detection, pest control, physiological assessments, and growth monitoring, which are essential parameters to increase production in agriculture and prevent unnecessary economic losses. The conventional methods employed to assess the aforementioned parameters have several limitations, such as invasive inspection, complexity, high time consumption, and costly features. In recent years, optical coherence tomography (OCT), which is an ultra-high resolution, non-invasive, and real-time unique image-based approach has been widely utilized as a significant and potential tool for assessing plant materials in numerous aspects. The obtained OCT cross-sections and volumetrics, as well as the amplitude signals of plant materials, have the capability to reveal vital information in both axial and lateral directions owing to the high resolution of the imaging system. This review discusses recent technological trends and advanced applications of OCT, which have been potentially adapted for numerous agricultural applications, such as non-invasive disease screening, optical signals-based growth speed detection, the structural analysis of plant materials, and microbiological discoveries. Therefore, this review offers a comprehensive exploration of recent advanced OCT technological approaches for agricultural applications, which provides insights into their potential to incorporate OCT technology into numerous industries.
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Affiliation(s)
- Sm Abu Saleah
- ICT Convergence Research Center, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Shinheon Kim
- Institute of Biomedical Engineering, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Jannat Amrin Luna
- School of Electronic and Electrical Engineering, College of IT Engineering, Kyungpook National University, 80, Daehak-ro, Buk-gu, Daegu 41566, Republic of Korea; (J.A.L.)
| | - Ruchire Eranga Wijesinghe
- Department of Electrical and Electronic Engineering, Faculty of Engineering, Sri Lanka Institute of Information Technology, Malabe 10115, Sri Lanka
| | - Daewoon Seong
- School of Electronic and Electrical Engineering, College of IT Engineering, Kyungpook National University, 80, Daehak-ro, Buk-gu, Daegu 41566, Republic of Korea; (J.A.L.)
| | - Sangyeob Han
- School of Electronic and Electrical Engineering, College of IT Engineering, Kyungpook National University, 80, Daehak-ro, Buk-gu, Daegu 41566, Republic of Korea; (J.A.L.)
| | - Jeehyun Kim
- School of Electronic and Electrical Engineering, College of IT Engineering, Kyungpook National University, 80, Daehak-ro, Buk-gu, Daegu 41566, Republic of Korea; (J.A.L.)
| | - Mansik Jeon
- School of Electronic and Electrical Engineering, College of IT Engineering, Kyungpook National University, 80, Daehak-ro, Buk-gu, Daegu 41566, Republic of Korea; (J.A.L.)
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11
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Zeppieri M, Marsili S, Enaholo ES, Shuaibu AO, Uwagboe N, Salati C, Spadea L, Musa M. Optical Coherence Tomography (OCT): A Brief Look at the Uses and Technological Evolution of Ophthalmology. MEDICINA (KAUNAS, LITHUANIA) 2023; 59:2114. [PMID: 38138217 PMCID: PMC10744394 DOI: 10.3390/medicina59122114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 11/28/2023] [Accepted: 11/30/2023] [Indexed: 12/24/2023]
Abstract
Medical imaging is the mainstay of clinical diagnosis and management. Optical coherence tomography (OCT) is a non-invasive imaging technology that has revolutionized the field of ophthalmology. Since its introduction, OCT has undergone significant improvements in image quality, speed, and resolution, making it an essential diagnostic tool for various ocular pathologies. OCT has not only improved the diagnosis and management of ocular diseases but has also found applications in other fields of medicine. In this manuscript, we provide a brief overview of the history of OCT, its current uses and diagnostic capabilities to assess the posterior segment of the eye, and the evolution of this technology from time-domain (TD) to spectral-domain (SD) and swept-source (SS). This brief review will also discuss the limitations, advantages, disadvantages, and future perspectives of this technology in the field of ophthalmology.
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Affiliation(s)
- Marco Zeppieri
- Department of Ophthalmology, University Hospital of Udine, 33100 Udine, Italy
| | - Stefania Marsili
- Georgia Institute of Technology, School of Biological Sciences, Atlanta, GA 30332, USA
| | - Ehimare Samuel Enaholo
- Centre for Sight Africa, Nkpor, Onitsha 434109, Nigeria
- Africa Eye Laser Centre Ltd., Benin 300102, Nigeria
| | | | - Ngozi Uwagboe
- Department of Optometry, University of Benin, Benin City 300238, Nigeria
| | - Carlo Salati
- Department of Ophthalmology, University Hospital of Udine, 33100 Udine, Italy
| | - Leopoldo Spadea
- Eye Clinic, Policlinico Umberto I, “Sapienza” University of Rome, 00142 Rome, Italy
| | - Mutali Musa
- Department of Optometry, University of Benin, Benin City 300238, Nigeria
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12
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Dolz-Marco R, Muñoz-Solano J, Dechent JF, Gallego-Pinazo R. THE EFFECT OF INCREASING ACQUISITION SPEED ON OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY IMAGES: A Qualitative and Quantitative Analysis. Retina 2023; 43:1653-1661. [PMID: 37721724 DOI: 10.1097/iae.0000000000003867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/19/2023]
Abstract
PURPOSE To evaluate the effect of two different A-scan rates on qualitative and quantitative parameters on optical coherence tomography angiography images in a clinical setting. METHODS Subjects undergoing a comprehensive ophthalmic examination were scheduled for optical coherence tomography angiography imaging using a new SPECTRALIS device allowing for 85 and 125 kHz scan rate. Consecutive registered 20° × 20° optical coherence tomography angiography images using both speeds were acquired using the follow-up tool. The acquisition time and the quality values of each scan were extracted and analyzed. The image quality was also graded in pairs by two independent graders. RESULTS Two-hundred and one eyes of 128 consecutive patients (67 males, 52.3%) were included. Mean acquisition time significantly decreased from 56.92 ± 24.6 seconds on the 85 kHz images to 39.39 ± 15.5 seconds on the 125 kHz images (P < 0.001). The percentage change in acquisition time showed a mean decrease of 28.47%. Mean Q value significantly decreased from 32.97 ± 2.8 dB on the 85 kHz images to 31.43 ± 2.6 dB on the 125 kHz images (P < 0.001). Overall, 92.5% of images were graded as equal or better at 125 kHz A-scan rate. CONCLUSION The use of optical coherence tomography angiography in daily clinical practice may require higher A-scan rates for an optimal workflow. Increased speed may also reduce image sensitivity and thus image quality could be compromised. In this study, 125 kHz scan rate using SPECTRALIS showed significant benefit with reduction on the acquisition time and no clinically significant differences on image quality analysis. Further studies evaluating qualitative and quantitative data in specific retinal conditions and using other devices are required to confirm these results.
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Affiliation(s)
| | - Javier Muñoz-Solano
- Department of Ophthalmology, Galdakao-Usansolo University Hospital, Galdakao, Spain; and
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13
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Miller DA, Kuranov R, Zhang HF. Adaptive balanced detection spectral domain optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2023; 14:5208-5222. [PMID: 37854571 PMCID: PMC10581816 DOI: 10.1364/boe.495622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 08/22/2023] [Accepted: 08/29/2023] [Indexed: 10/20/2023]
Abstract
Balanced detection optical coherence tomography (BD-OCT) enables near-shot noise-limited imaging by suppressing wavelength-dependent relative intensity noise (RIN) originating from the light source. In spectral-domain BD-OCT (SD-BD-OCT), the level of RIN suppression relies on the co-registration accuracy of the spectra simultaneously captured by two independent spectrometers. However, existing matching methods require careful pre-calibration using a RIN-dominated dataset or subjective post-processing using a signal-dominated dataset. We developed an adaptive subpixel matching approach, referred to as adaptive balance, that can be applied to any SD-BD-OCT dataset regardless of RIN or signal level without the need for pre-calibration. We showed that adaptive balance performed comparable to or better than reported methods by imaging phantoms with varying spectrometer camera gain, exposure time, and supercontinuum laser repetition rate. We further demonstrated the benefits of adaptive balance in human retinal imaging.
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Affiliation(s)
- David A. Miller
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA
| | - Roman Kuranov
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA
- Opticent Health, Evanston, IL, USA
| | - Hao F. Zhang
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA
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14
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Lin Q, Choyke PL, Sato N. Visualizing vasculature and its response to therapy in the tumor microenvironment. Theranostics 2023; 13:5223-5246. [PMID: 37908739 PMCID: PMC10614675 DOI: 10.7150/thno.84947] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 07/30/2023] [Indexed: 11/02/2023] Open
Abstract
Tumor vasculature plays a critical role in the progression and metastasis of tumors, antitumor immunity, drug delivery, and resistance to therapies. The morphological and functional changes of tumor vasculature in response to therapy take place in a spatiotemporal-dependent manner, which can be predictive of treatment outcomes. Dynamic monitoring of intratumor vasculature contributes to an improved understanding of the mechanisms of action of specific therapies or reasons for treatment failure, leading to therapy optimization. There is a rich history of methods used to image the vasculature. This review describes recent advances in imaging technologies to visualize the tumor vasculature, with a focus on enhanced intravital imaging techniques and tumor window models. We summarize new insights on spatial-temporal vascular responses to various therapies, including changes in vascular perfusion and permeability and immune-vascular crosstalk, obtained from intravital imaging. Finally, we briefly discuss the clinical applications of intravital imaging techniques.
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Affiliation(s)
| | | | - Noriko Sato
- Molecular Imaging Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland
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15
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Puyo L, Pfäffle C, Spahr H, Franke J, Bublitz D, Hillmann D, Hüttmann G. Diffuse-illumination holographic optical coherence tomography. OPTICS EXPRESS 2023; 31:33500-33517. [PMID: 37859131 DOI: 10.1364/oe.498654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 09/11/2023] [Indexed: 10/21/2023]
Abstract
Holographic optical coherence tomography (OCT) is a powerful imaging technique, but its ability to reveal low-reflectivity features is limited. In this study, we performed holographic OCT by incoherently averaging volumes with changing diffuse illumination of numerical aperture (NA) equal to the detection NA. While the reduction of speckle from singly scattered light is only modest, we discovered that speckle from multiply scattered light can be arbitrarily reduced, resulting in substantial improvements in image quality. This technique also offers the advantage of suppressing noises arising from spatial coherence, and can be implemented with a partially spatially incoherent light source for further mitigation of multiple scattering. Finally, we show that although holographic reconstruction capabilities are increasingly lost with decreasing spatial coherence, they can be retained over an axial range sufficient to standard OCT applications.
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16
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Pattan HF, Liu X, Tankam P. Non-invasive in vivo imaging of human corneal microstructures with optical coherence microscopy. BIOMEDICAL OPTICS EXPRESS 2023; 14:4888-4900. [PMID: 37791273 PMCID: PMC10545177 DOI: 10.1364/boe.495242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 08/06/2023] [Accepted: 08/16/2023] [Indexed: 10/05/2023]
Abstract
Non-invasive imaging systems with cellular-level resolution offer the opportunity to identify biomarkers of the early stage of corneal diseases, enabling early intervention, monitoring of disease progression, and evaluating treatment efficacy. In this study, a non-contact polarization-dependent optical coherence microscope (POCM) was developed to enable non-invasive in vivo imaging of human corneal microstructures. The system integrated quarter-wave plates into the sample and reference arms of the interferometer to enable deeper penetration of light in tissues as well as mitigate the strong specular reflection from the corneal surface. A common-path approach was adopted to enable control over the polarization in a free space configuration, thus alleviating the need for a broadband polarization-maintained fiber. The POCM achieved volumetric imaging of corneal microstructures, including endothelial cells over a field of view 0.5 × 0.5 mm2 with an almost isotropic resolution of ∼2.2 µm and a volume (500 × 500 × 2048 voxels) rate of 1 Hz. A self-interference approach between the corneal surface and underlying layers was also developed to lessen the corneal curvature and axial motion artifacts, thus enabling high-resolution imaging of microstructures in the anterior cornea, including squamous epithelial cells, wing epithelial cells, basal epithelial cells, sub-basal nerve plexus, and stromal keratocytes.
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Affiliation(s)
- Hadiya F. Pattan
- School of Optometry, Indiana University, Bloomington, IN, 47405, USA
| | - Xiao Liu
- School of Optometry, Indiana University, Bloomington, IN, 47405, USA
| | - Patrice Tankam
- School of Optometry, Indiana University, Bloomington, IN, 47405, USA
- Intelligent Systems Engineering, Luddy School of Informatics, Computing, and Engineering, Indiana University, Bloomington, IN, 47405, USA
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17
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Rosenfeld PJ, Cheng Y, Shen M, Gregori G, Wang RK. Unleashing the power of optical attenuation coefficients to facilitate segmentation strategies in OCT imaging of age-related macular degeneration: perspective. BIOMEDICAL OPTICS EXPRESS 2023; 14:4947-4963. [PMID: 37791280 PMCID: PMC10545179 DOI: 10.1364/boe.496080] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 07/22/2023] [Accepted: 07/27/2023] [Indexed: 10/05/2023]
Abstract
The use of optical attenuation coefficients (OAC) in optical coherence tomography (OCT) imaging of the retina has improved the segmentation of anatomic layers compared with traditional intensity-based algorithms. Optical attenuation correction has improved our ability to measure the choroidal thickness and choroidal vascularity index using dense volume scans. Algorithms that combine conventional intensity-based segmentation with depth-resolved OAC OCT imaging have been used to detect elevations of the retinal pigment epithelium (RPE) due to drusen and basal laminar deposits, the location of hyperpigmentation within the retina and along the RPE, the identification of macular atrophy, the thickness of the outer retinal (photoreceptor) layer, and the presence of calcified drusen. OAC OCT algorithms can identify the risk-factors that predict disease progression in age-related macular degeneration.
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Affiliation(s)
- Philip J. Rosenfeld
- Department of Ophthalmology, Bascom Palmer
Eye Institute, University of Miami Miller School of
Medicine, Miami, Florida, USA
| | - Yuxuan Cheng
- Department of Bioengineering,
University of Washington, Seattle,
Washington, USA
| | - Mengxi Shen
- Department of Ophthalmology, Bascom Palmer
Eye Institute, University of Miami Miller School of
Medicine, Miami, Florida, USA
| | - Giovanni Gregori
- Department of Ophthalmology, Bascom Palmer
Eye Institute, University of Miami Miller School of
Medicine, Miami, Florida, USA
| | - Ruikang K. Wang
- Department of Bioengineering,
University of Washington, Seattle,
Washington, USA
- Department of Ophthalmology,
University of Washington, Seattle,
Washington, USA
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18
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Suchand Sandeep CS, Khairyanto A, Aung T, Vadakke Matham M. Bessel Beams in Ophthalmology: A Review. MICROMACHINES 2023; 14:1672. [PMID: 37763835 PMCID: PMC10536271 DOI: 10.3390/mi14091672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 08/22/2023] [Accepted: 08/23/2023] [Indexed: 09/29/2023]
Abstract
The achievable resolution of a conventional imaging system is inevitably limited due to diffraction. Dealing with precise imaging in scattering media, such as in the case of biomedical imaging, is even more difficult owing to the weak signal-to-noise ratios. Recent developments in non-diffractive beams such as Bessel beams, Airy beams, vortex beams, and Mathieu beams have paved the way to tackle some of these challenges. This review specifically focuses on non-diffractive Bessel beams for ophthalmological applications. The theoretical foundation of the non-diffractive Bessel beam is discussed first followed by a review of various ophthalmological applications utilizing Bessel beams. The advantages and disadvantages of these techniques in comparison to those of existing state-of-the-art ophthalmological systems are discussed. The review concludes with an overview of the current developments and the future perspectives of non-diffractive beams in ophthalmology.
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Affiliation(s)
- C. S. Suchand Sandeep
- Centre for Optical and Laser Engineering, School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Ahmad Khairyanto
- Centre for Optical and Laser Engineering, School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Tin Aung
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore 169856, Singapore
- Duke-NUS Medical School, National University of Singapore, Singapore 169857, Singapore
| | - Murukeshan Vadakke Matham
- Centre for Optical and Laser Engineering, School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore 639798, Singapore
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19
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Wolfgang M, Kern A, Deng S, Stranzinger S, Liu M, Drexler W, Leitgeb R, Haindl R. Ultra-high-resolution optical coherence tomography for the investigation of thin multilayered pharmaceutical coatings. Int J Pharm 2023; 643:123096. [PMID: 37268027 DOI: 10.1016/j.ijpharm.2023.123096] [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: 02/20/2023] [Revised: 05/25/2023] [Accepted: 05/26/2023] [Indexed: 06/04/2023]
Abstract
Optical Coherence Tomography (OCT) has recently gained attention as a promising technology for in-line monitoring of pharmaceutical film-coating processes for (single-layered) tablet coatings and end-point detection with commercial systems. An increasing interest in the investigation of multiparticulate dosage forms with mostly multi-layered coatings below 20 µm final film thickness demands advancement in OCT technology for pharmaceutical imaging. We present an ultra-high-resolution (UHR-) OCT and investigate its performance based on three different multiparticulate dosage forms with different layer structures (one single-layered, two multi-layered) with layer thicknesses in a range from 5 to 50 µm. The achieved system resolution of 2.4 µm (axial) and 3.4 µm (lateral, both in air) enables the assessment of defects, film thickness variability and morphological features within the coating, previously unattainable using OCT. Despite the high transverse resolution, the provided depth of field was found sufficient to reach the core region of all dosage forms under test. We further demonstrate an automated segmentation and evaluation of UHR-OCT images for coating thicknesses, where human experts struggle using today's standard OCT systems.
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Affiliation(s)
| | - Alice Kern
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Shiyu Deng
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | | | - Mengyang Liu
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria; Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
| | - Wolfgang Drexler
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Rainer Leitgeb
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria; Christian Doppler Laboratory OPTRAMED, Medical University of Vienna, Vienna, Austria.
| | - Richard Haindl
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria; School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, 62 Nanyang Drive, Singapore, Singapore; Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
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20
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Zhang Z, Yang X, Zhao Z, Zeng F, Ye S, Baldock SJ, Lin H, Hardy JG, Zheng Y, Shen Y. Rapid imaging and product screening with low-cost line-field Fourier domain optical coherence tomography. Sci Rep 2023; 13:10809. [PMID: 37402736 DOI: 10.1038/s41598-023-37646-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 06/25/2023] [Indexed: 07/06/2023] Open
Abstract
Fourier domain optical coherence tomography (FD-OCT) is a well-established imaging technique that provides high-resolution internal structure images of an object at a fast speed. Modern FD-OCT systems typically operate at speeds of 40,000-100,000 A-scans/s, but are priced at least tens of thousands of pounds. In this study, we demonstrate a line-field FD-OCT (LF-FD-OCT) system that achieves an OCT imaging speed of 100,000 A-scan/s at a hardware cost of thousands of pounds. We demonstrate the potential of LF-FD-OCT for biomedical and industrial imaging applications such as corneas, 3D printed electronics, and printed circuit boards.
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Affiliation(s)
- Zijian Zhang
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, L69 3GJ, UK
- Department of Eye and Vision Sciences, University of Liverpool, Liverpool, L7 8TX, UK
| | - Xingyu Yang
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, L69 3GJ, UK
| | - Zhiyi Zhao
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, L69 3GJ, UK
| | - Feng Zeng
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, L69 3GJ, UK
| | - Sicong Ye
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, L69 3GJ, UK
| | - Sara J Baldock
- Department of Chemistry, Lancaster University, Lancaster, LA1 4YB, UK
| | - Hungyen Lin
- School of Engineering, Lancaster University, Lancaster, LA1 4YW, UK
- Materials Science Institute, Lancaster University, Lancaster, LA1 4YB, UK
| | - John G Hardy
- Department of Chemistry, Lancaster University, Lancaster, LA1 4YB, UK
- Materials Science Institute, Lancaster University, Lancaster, LA1 4YB, UK
| | - Yalin Zheng
- Department of Eye and Vision Sciences, University of Liverpool, Liverpool, L7 8TX, UK.
| | - Yaochun Shen
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, L69 3GJ, UK.
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21
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Monfort T, Azzollini S, Ben Yacoub T, Audo I, Reichman S, Grieve K, Thouvenin O. Interface self-referenced dynamic full-field optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2023; 14:3491-3505. [PMID: 37497503 PMCID: PMC10368024 DOI: 10.1364/boe.488663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 06/02/2023] [Accepted: 06/07/2023] [Indexed: 07/28/2023]
Abstract
Dynamic full-field optical coherence tomography (D-FFOCT) has recently emerged as an invaluable live label-free and non-invasive imaging modality able to image subcellular biological structures and their metabolic activity within complex 3D samples. However, D-FFOCT suffers from fringe artefacts when imaging near reflective surfaces and is highly sensitive to vibrations. Here, we present interface Self-Referenced (iSR) D-FFOCT, an alternative configuration to D-FFOCT that takes advantage of the presence of the sample coverslip in between the sample and the objective by using it as a defocused reference arm, thus avoiding the aforementioned artefacts. We demonstrate the ability of iSR D-FFOCT to image 2D fibroblast cell cultures, which are among the flattest mammalian cells.
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Affiliation(s)
- Tual Monfort
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012 Paris, France
- CHNO des Quinze-Vingts, INSERM-DGOS CIC 1423, 28 rue de Charenton, F-75012 Paris, France
| | - Salvatore Azzollini
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012 Paris, France
| | - Tasnim Ben Yacoub
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012 Paris, France
| | - Isabelle Audo
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012 Paris, France
| | - Sacha Reichman
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012 Paris, France
| | - Kate Grieve
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012 Paris, France
- CHNO des Quinze-Vingts, INSERM-DGOS CIC 1423, 28 rue de Charenton, F-75012 Paris, France
| | - Olivier Thouvenin
- Institut Langevin, ESPCI Paris, Université PSL, CNRS, 75005 Paris, France
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22
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Reza SA, Imeri A. Simultaneous thickness and phase index measurements with a motion-free actively tunable Twyman-Green interferometer. APPLIED OPTICS 2023; 62:3948-3958. [PMID: 37706705 DOI: 10.1364/ao.489084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 04/20/2023] [Indexed: 09/15/2023]
Abstract
In this paper, we present a scheme to simultaneously measure the thickness and refractive index of parallel plate samples, involving no bulk mechanical motion, by deploying an electronically tunable Twyman-Green interferometer configuration. The active electronic control with no bulk mechanical motion is realized via the introduction of a tunable focus lens within the classical motion-based Twyman-Green interferometer configuration. The resulting interferometer is repeatable and delivers accurate estimates of the thickness and refractive index of a sample under test. Elimination of bulk motion also promises a potential for miniaturization. We develop a theoretical model for estimating sample thickness and index values using this reconfigurable interferometer setup and present detailed experimental results that demonstrate the working principle of the proposed interferometer.
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23
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Dremin V. Lesion Detection and Analysis Using Optical Imaging. Diagnostics (Basel) 2023; 13:diagnostics13091565. [PMID: 37174956 PMCID: PMC10177594 DOI: 10.3390/diagnostics13091565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 04/25/2023] [Indexed: 05/15/2023] Open
Abstract
The biomedical application of optical spectroscopy and imaging is currently an active, developing area of research, supported by recent technical progress in the development of light sources and detectors [...].
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Affiliation(s)
- Viktor Dremin
- Research & Development Center of Biomedical Photonics, Orel State University, 302026 Orel, Russia
- College of Engineering and Physical Sciences, Aston University, Birmingham B4 7ET, UK
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24
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Lupidi M, Mangoni L, Centini C, Pompucci G, Lanzafame L, Danieli L, Fruttini D, Peiretti E, Chhablani J, Mariotti C. Quantitative and Qualitative Assessments of Retinal Structure with Variable A-Scan Rate Spectralis OCT: Insights into IPL Multilaminarity. J Clin Med 2023; 12:jcm12072637. [PMID: 37048720 PMCID: PMC10094756 DOI: 10.3390/jcm12072637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Revised: 03/20/2023] [Accepted: 03/29/2023] [Indexed: 04/05/2023] Open
Abstract
The aim of this study was to evaluate the qualitative and quantitative differences between 20 and 85 kHz A-scan rate optical coherence tomography (OCT) images acquired by spectral domain OCT. The study included 60 healthy subjects analyzed with horizontal linear scans with a variable A-scan rate (SHIFT technology, Heidelberg Engineering, Heidelberg, Germany). The retinal thickness measurement of each retinal layer was performed in three different positions (subfoveal, nasal, and temporal). The qualitative assessment was performed by two independent observers who rated every image with a score ranging from 1 (“sufficient”) to 3 (“excellent”) on the basis of three parameters: visualization of the vitreo-retinal interface, characterization of the retinal layers, and visualization of the sclero-choroidal interface. No statistically significant differences in terms of retinal layer thickness between the two A-scan rate scans were observed (p > 0.05). The coefficient of variation of the retinal thickness values was lower in the 20 kHz group (25.8% versus 30.1% with the 85 kHz). The 20 kHz images showed a higher quality index for both observers. An inner plexiform layer (IPL) multilaminarity was detected in 78.3% of patients from the 20 kHz group and in 40% of patients from the 85 kHz group (p < 0.05).
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Affiliation(s)
- Marco Lupidi
- Eye Clinic, Department of Experimental and Clinical Medicine, Polytechnic University of Marche, 60126 Ancona, Italy
- Fondazione per la Macula Onlus, Di.N.O.G.Mi., University Eye Clinic, 16132 Genova, Italy
| | - Lorenzo Mangoni
- Eye Clinic, Department of Experimental and Clinical Medicine, Polytechnic University of Marche, 60126 Ancona, Italy
| | - Chiara Centini
- Eye Clinic, Department of Experimental and Clinical Medicine, Polytechnic University of Marche, 60126 Ancona, Italy
| | - Gregorio Pompucci
- Eye Clinic, Department of Experimental and Clinical Medicine, Polytechnic University of Marche, 60126 Ancona, Italy
| | - Luca Lanzafame
- Eye Clinic, Department of Experimental and Clinical Medicine, Polytechnic University of Marche, 60126 Ancona, Italy
| | | | - Daniela Fruttini
- Department of Medicine and Surgery, University of Perugia, S. Maria della Misericordia Hospital, 06123 Perugia, Italy
| | - Enrico Peiretti
- Eye Clinic, Department of Surgical Sciences, University of Cagliari, 09124 Cagliari, Italy
| | - Jay Chhablani
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Cesare Mariotti
- Eye Clinic, Department of Experimental and Clinical Medicine, Polytechnic University of Marche, 60126 Ancona, Italy
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25
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De la Torre I MH, Mauricio Flores M J, Piazza V, Velazquez EDH, Hernandez VH. Concurrent optical inspection to boost characterization of plastic cortical bone under mechanical deformation. APPLIED OPTICS 2023; 62:1483-1491. [PMID: 36821308 DOI: 10.1364/ao.476551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 01/19/2023] [Indexed: 06/18/2023]
Abstract
The simultaneous surface and internal measurements from a chemically modified cortical bovine bone suffering a plastic range deformation are presented. Since the bone is an anisotropic structure, its mechanical response could be modified if its organic or inorganic phases change. The latter could result in high plastic deformations, where the interferometrical signal from an optical analysis is easily de-correlated. In this work, digital holography interferometry (DHI) and Fourier domain optical coherence tomography (FD-OCT) are used to analyze the plastic range deformation of the bone under compression. The simultaneous use of these two optical methods gives information even when one of them de-correlates. The surface results retrieved with DHI show the high anisotropy of the bone as a continuously increasing displacement field map. Meanwhile, the internal information obtained with FD-OCT records larger deformations at different depths. Due to the optical phase, it is possible to complement the measurements of these two methods during the plastic deformation.
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26
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Lou S, Chen X, Wang Y, Cai H, Chen S, Liu L. Multiscale joint segmentation method for retinal optical coherence tomography images using a bidirectional wave algorithm and improved graph theory. OPTICS EXPRESS 2023; 31:6862-6876. [PMID: 36823933 DOI: 10.1364/oe.472154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 12/16/2022] [Indexed: 06/18/2023]
Abstract
Morphology and functional metrics of retinal layers are important biomarkers for many human ophthalmic diseases. Automatic and accurate segmentation of retinal layers is crucial for disease diagnosis and research. To improve the performance of retinal layer segmentation, a multiscale joint segmentation framework for retinal optical coherence tomography (OCT) images based on bidirectional wave algorithm and improved graph theory is proposed. In this framework, the bidirectional wave algorithm was used to segment edge information in multiscale images, and the improved graph theory was used to modify edge information globally, to realize automatic and accurate segmentation of eight retinal layer boundaries. This framework was tested on two public datasets and two OCT imaging systems. The test results show that, compared with other state-of-the-art methods, this framework does not need data pre-training and parameter pre-adjustment on different datasets, and can achieve sub-pixel retinal layer segmentation on a low-configuration computer.
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27
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Britten A, Matten P, Weiss J, Niederleithner M, Roodaki H, Sorg B, Hecker-Denschlag N, Drexler W, Leitgeb RA, Schmoll T. Surgical microscope integrated MHz SS-OCT with live volumetric visualization. BIOMEDICAL OPTICS EXPRESS 2023; 14:846-865. [PMID: 36874504 PMCID: PMC9979659 DOI: 10.1364/boe.477386] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 01/05/2023] [Accepted: 01/07/2023] [Indexed: 06/18/2023]
Abstract
Intraoperative optical coherence tomography is still not overly pervasive in routine ophthalmic surgery, despite evident clinical benefits. That is because today's spectral-domain optical coherence tomography systems lack flexibility, acquisition speed, and imaging depth. We present to the best of our knowledge the most flexible swept-source optical coherence tomography (SS-OCT) engine coupled to an ophthalmic surgical microscope that operates at MHz A-scan rates. We use a MEMS tunable VCSEL to implement application-specific imaging modes, enabling diagnostic and documentary capture scans, live B-scan visualizations, and real-time 4D-OCT renderings. The technical design and implementation of the SS-OCT engine, as well as the reconstruction and rendering platform, are presented. All imaging modes are evaluated in surgical mock maneuvers using ex vivo bovine and porcine eye models. The applicability and limitations of MHz SS-OCT as a visualization tool for ophthalmic surgery are discussed.
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Affiliation(s)
- Anja Britten
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, 4 L, 1090 Vienna, Austria
- These authors contributed equally to this manuscript
| | - Philipp Matten
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, 4 L, 1090 Vienna, Austria
- These authors contributed equally to this manuscript
| | - Jakob Weiss
- Chair for Computer Aided Medical Procedures, Technical University of Munich, Boltzmannstrasse 385748 Munich, Germany
| | - Michael Niederleithner
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, 4 L, 1090 Vienna, Austria
| | - Hessam Roodaki
- Carl Zeiss Meditec AG, Kistlerhofstrasse 75, 81379 Munich, Germany
| | - Benjamin Sorg
- Carl Zeiss Meditec AG, Rudolf-Eber-Strasse 11, 73447 Oberkochen, Germany
| | | | - Wolfgang Drexler
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, 4 L, 1090 Vienna, Austria
| | - Rainer A. Leitgeb
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, 4 L, 1090 Vienna, Austria
| | - Tilman Schmoll
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, 4 L, 1090 Vienna, Austria
- Carl Zeiss Meditec, Inc., 5300 Central Pkwy, Dublin, CA 94568, USA
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28
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Wang S, Larina IV. Dynamics of gametes and embryos in the oviduct: what can in vivo imaging reveal? Reproduction 2023; 165:R25-R37. [PMID: 36318634 PMCID: PMC9827618 DOI: 10.1530/rep-22-0250] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 10/27/2022] [Indexed: 11/07/2022]
Abstract
In brief In vivo imaging of gametes and embryos in the oviduct enables new studies of the native processes that lead to fertilization and pregnancy. This review article discusses recent advancements in the in vivo imaging methods and insights which contribute to understanding the oviductal function. Abstract Understanding the physiological dynamics of gametes and embryos in the fallopian tube (oviduct) has significant implications for managing reproductive disorders and improving assisted reproductive technologies. Recent advancements in imaging of the mouse oviduct in vivo uncovered fascinating dynamics of gametes and embryos in their native states. These new imaging approaches and observations are bringing exciting momentum to uncover the otherwise-hidden processes orchestrating fertilization and pregnancy. For mechanistic investigations, in vivo imaging in genetic mouse models enables dynamic phenotyping of gene functions in the reproductive process. Here, we review these imaging methods, discuss insights recently revealed by in vivo imaging, and comment on emerging directions, aiming to stimulate new in vivo studies of reproductive dynamics.
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Affiliation(s)
- Shang Wang
- Department of Biomedical Engineering, Stevens Institute of Technology, Hoboken, New Jersey 07030, U.S.A
| | - Irina V. Larina
- Department of Integrative Physiology, Baylor College of Medicine, Houston, Texas 77030, U.S.A
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29
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Sen D, Fernández A, Crozier D, Henrich B, Sokolov AV, Scully MO, Rooney WL, Verhoef AJ. Non-Destructive Direct Pericarp Thickness Measurement of Sorghum Kernels Using Extended-Focus Optical Coherence Microscopy. SENSORS (BASEL, SWITZERLAND) 2023; 23:707. [PMID: 36679502 PMCID: PMC9865951 DOI: 10.3390/s23020707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 12/31/2022] [Accepted: 01/05/2023] [Indexed: 06/17/2023]
Abstract
Non-destructive measurements of internal morphological structures in plant materials such as seeds are of high interest in agricultural research. The estimation of pericarp thickness is important to understand the grain quality and storage stability of seeds and can play a crucial role in improving crop yield. In this study, we demonstrate the applicability of fiber-based Bessel beam Fourier domain (FD) optical coherence microscopy (OCM) with a nearly constant high lateral resolution maintained at over ~400 µm for direct non-invasive measurement of the pericarp thickness of two different sorghum genotypes. Whereas measurements based on axial profiles need additional knowledge of the pericarp refractive index, en-face views allow for direct distance measurements. We directly determine pericarp thickness from lateral sections with a 3 µm resolution by taking the width of the signal corresponding to the pericarp at the 1/e threshold. These measurements enable differentiation of the two genotypes with 100% accuracy. We find that trading image resolution for acquisition speed and view size reduces the classification accuracy. Average pericarp thicknesses of 74 µm (thick phenotype) and 43 µm (thin phenotype) are obtained from high-resolution lateral sections, and are in good agreement with previously reported measurements of the same genotypes. Extracting the morphological features of plant seeds using Bessel beam FD-OCM is expected to provide valuable information to the food processing industry and plant breeding programs.
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Affiliation(s)
- Dipankar Sen
- Department of Physics & Astronomy, Texas A&M University, TAMU 4242, College Station, TX 77843, USA
- Institute for Quantum Science & Engineering, Texas A&M University, TAMU 4242, College Station, TX 77843, USA
| | - Alma Fernández
- Institute for Quantum Science & Engineering, Texas A&M University, TAMU 4242, College Station, TX 77843, USA
- Department of Soil and Crop Sciences, Texas A&M University, TAMU 2474, College Station, TX 77843, USA
| | - Daniel Crozier
- Department of Soil and Crop Sciences, Texas A&M University, TAMU 2474, College Station, TX 77843, USA
| | - Brian Henrich
- Department of Soil and Crop Sciences, Texas A&M University, TAMU 2474, College Station, TX 77843, USA
| | - Alexei V. Sokolov
- Department of Physics & Astronomy, Texas A&M University, TAMU 4242, College Station, TX 77843, USA
- Institute for Quantum Science & Engineering, Texas A&M University, TAMU 4242, College Station, TX 77843, USA
| | - Marlan O. Scully
- Institute for Quantum Science & Engineering, Texas A&M University, TAMU 4242, College Station, TX 77843, USA
- Department of Soil and Crop Sciences, Texas A&M University, TAMU 2474, College Station, TX 77843, USA
| | - William L. Rooney
- Department of Soil and Crop Sciences, Texas A&M University, TAMU 2474, College Station, TX 77843, USA
| | - Aart J. Verhoef
- Institute for Quantum Science & Engineering, Texas A&M University, TAMU 4242, College Station, TX 77843, USA
- Department of Soil and Crop Sciences, Texas A&M University, TAMU 2474, College Station, TX 77843, USA
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30
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Advances in Medical Imaging for Wound Repair and Regenerative Medicine. Regen Med 2023. [DOI: 10.1007/978-981-19-6008-6_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
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31
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Pan H, Yang Z, Hou F, Zhao J, Yu Y, Liang Y. Classification of neck tissues in OCT images by using convolutional neural network. Lasers Med Sci 2022; 38:21. [PMID: 36564643 DOI: 10.1007/s10103-022-03665-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Accepted: 11/12/2022] [Indexed: 12/25/2022]
Abstract
Identification and classification of surrounding neck tissues are very important in thyroid surgery. The advantages of optical coherence tomography (OCT), high resolution, non-invasion, and non-destruction make it have great potential in identifying different neck tissues during thyroidectomy. We studied the automatic classification for neck tissues in OCT images based on convolutional neural network in this paper. OCT images of five kinds of neck tissues were collected firstly by our home-made swept source (SS-OCT) system, and a dataset was built for neural network training. Three image classification neural networks: LeNet, VGGNet, and ResNet, were used to train and test the dataset. The impact of transfer learning on the classification of neck tissue OCT images was also studied. Through the comparison of accuracy, it was found that ResNet has the best classification accuracy among the three networks. In addition, transfer learning did not significantly improve the accuracy, but it can somewhat accelerate the convergence of the network and shorten the network training time.
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Affiliation(s)
- Hongming Pan
- Institute of Modern Optics, Nankai University, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, Tianjin, 300350, China
| | - Zihan Yang
- Institute of Modern Optics, Nankai University, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, Tianjin, 300350, China
| | - Fang Hou
- Institute of Modern Optics, Nankai University, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, Tianjin, 300350, China
| | - Jingzhu Zhao
- Department of Thyroid and Neck Tumor, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin, 300060, China
| | - Yang Yu
- Department of Thyroid and Neck Tumor, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin, 300060, China
| | - Yanmei Liang
- Institute of Modern Optics, Nankai University, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, Tianjin, 300350, China.
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32
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Maliszewski KA, Kolenderski P, Vetrova V, Kolenderska SM. Towards retrieving dispersion profiles using quantum-mimic optical coherence tomography and machine learning. OPTICS EXPRESS 2022; 30:45624-45634. [PMID: 36522965 DOI: 10.1364/oe.460079] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Artefacts in quantum-mimic optical coherence tomography are considered detrimental because they scramble the images even for the simplest objects. They are a side effect of autocorrelation, which is used in the quantum entanglement mimicking algorithm behind this method. Interestingly, the autocorrelation imprints certain characteristics onto an artefact - it makes its shape and characteristics depend on the amount of dispersion exhibited by the layer that artefact corresponds to. In our method, a neural network learns the unique relationship between the artefacts' shape and GVD, and consequently, it is able to provide a good qualitative representation of object's dispersion profile for never-seen-before data: computer-generated single dispersive layers and experimental pieces of glass. We show that the autocorrelation peaks - additional peaks in the A-scan appearing due to the interference of light reflected from the object - affect the GVD profiles. Through relevant calculations, simulations and experimental testing, the mechanism leading to the observed GVD changes is identified and explained. Finally, the network performance is tested in the presence of noise in the data and with the experimental data representing single layers of quartz, sapphire and BK7.
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33
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Bhatti HS, Khan S, Zahra M, Mustafa S, Ashraf S, Ahmad I. Characterization of radiofrequency ablated myocardium with optical coherence tomography. Photodiagnosis Photodyn Ther 2022; 40:103151. [PMID: 36228980 DOI: 10.1016/j.pdpdt.2022.103151] [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: 08/05/2022] [Revised: 10/05/2022] [Accepted: 10/07/2022] [Indexed: 11/07/2022]
Abstract
Certain types of cardiac arrhythmias are best treated with radiofrequency (RF) ablation, in which an electrode is inserted into the targeted area of the myocardium and then RF electrical current is applied to heat and destroy surrounding tissue. The resulting ablation lesion usually consists of a coagulative necrotic core surrounded by a rim region of mixed viable and non-viable cells. The characterization of the RF ablated lesion is of potential clinical importance. Here we aim to elaborate optical coherence tomography (OCT) imaging for the characterization of RF-ablated myocardial tissue. In particular, the underlying principles of OCT and its polarization-sensitive counterpart (PS-OCT) are presented, followed by the knowledge needed to interpret their optical images. Studies focused on real-time monitoring of RF lesion formation in the myocardium using OCT systems are summarized. The design and development of various hybrid probes incorporating both OCT guidance and RF ablation catheters are also discussed. Finally, the challenges related to the transmission of OCT imaging systems to cardiac clinics for real-time monitoring of RF lesions are outlined.
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Affiliation(s)
| | - Shamim Khan
- Department of Physics, Islamia College Peshawar, Khyber Pakhtunkhwa, Pakistan
| | - Madeeha Zahra
- Department of Physics, The Women University Multan, Pakistan
| | - Sonia Mustafa
- Department of Physics, The Women University Multan, Pakistan
| | - Sumara Ashraf
- Department of Physics, The Women University Multan, Pakistan
| | - Iftikhar Ahmad
- Institute of Radiotherapy and Nuclear Medicine (IRNUM), Peshawar, Pakistan.
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Canales-Benavides A, Zavislan J, Carney PS. Suppression of the conjugate signal for broadband computed imaging via synthetic phase modulation. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2022; 39:C203-C213. [PMID: 36520772 DOI: 10.1364/josaa.473089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Accepted: 11/15/2022] [Indexed: 06/17/2023]
Abstract
We present synthetic-phase-modulated interferometric synthetic aperture microscopy (SPM-ISAM), a method to perform 3D object reconstructions from data acquired with confocal broadband interferometric microscopy (BIM) that reconstructs images virtually free of coherent and depth-dependent defocus artifacts. This is achieved by implementing a sinusoidal SPM method in combination with an ISAM reconstruction algorithm that uses relatively low-modulation frequencies compared with acquisition frequencies. A theoretical framework and numerical results are provided here.
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35
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Dey R, Alexandrov S, Owens P, Kelly J, Phelan S, Leahy M. Skin cancer margin detection using nanosensitive optical coherence tomography and a comparative study with confocal microscopy. BIOMEDICAL OPTICS EXPRESS 2022; 13:5654-5666. [PMID: 36733740 PMCID: PMC9872867 DOI: 10.1364/boe.474334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 09/23/2022] [Accepted: 09/26/2022] [Indexed: 05/08/2023]
Abstract
Excision biopsy and histology represent the gold standard for morphological investigation of the skin, in particular for cancer diagnostics. Nevertheless, a biopsy may alter the original morphology, usually requires several weeks for results, is non-repeatable on the same site and always requires an iatrogenic trauma. Hence, diagnosis and clinical management of diseases may be substantially improved by new non-invasive imaging techniques. Optical Coherence Tomography (OCT) is a non-invasive depth-resolved optical imaging modality based on low coherence interferometry that enables high-resolution, cross-sectional imaging in biological tissues and it can be used to obtain both structural and functional information. Beyond the resolution limit, it is not possible to detect structural and functional information using conventional OCT. In this paper, we present a recently developed technique, nanosensitive OCT (nsOCT), improved using broadband supercontinuum laser, and demonstrate nanoscale sensitivity to structural changes within ex vivo human skin tissue. The extended spectral bandwidth permitted access to a wider distribution of spatial frequencies and improved the dynamic range of the nsOCT. Firstly, we demonstrate numerical and experimental detection of a few nanometers structural difference using the nsOCT method from single B-scan images of phantoms with sub-micron periodic structures, acting like Bragg gratings, along the depth. Secondly, our study shows that nsOCT can distinguish nanoscale structural changes at the skin cancer margin from the healthy region in en face images at clinically relevant depths. Finally, we compare the nsOCT en face image with a high-resolution confocal microscopy image to confirm the structural differences between the healthy and lesional/cancerous regions, allowing the detection of the skin cancer margin.
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Affiliation(s)
- Rajib Dey
- Tissue Optics and Microcirculation Imaging (TOMI) Facility, National Biophotonics and Imaging Platform School of Physics, National University of Ireland, Galway, Galway, Ireland
| | - Sergey Alexandrov
- Tissue Optics and Microcirculation Imaging (TOMI) Facility, National Biophotonics and Imaging Platform School of Physics, National University of Ireland, Galway, Galway, Ireland
| | - Peter Owens
- Center for Microscopy and Imaging, National University of Ireland, Galway, Galway, Ireland
| | - Jack Kelly
- Plastic and Reconstructive Surgery, Galway University Hospital, Galway, Ireland
| | - Sine Phelan
- Department of Anatomic Pathology, Galway University Hospital and Department of Pathology, National University of Ireland, Galway, Galway, Ireland
| | - Martin Leahy
- Tissue Optics and Microcirculation Imaging (TOMI) Facility, National Biophotonics and Imaging Platform School of Physics, National University of Ireland, Galway, Galway, Ireland
- Institute of Photonic Sciences (ICFO), Barcelona, Spain
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36
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Kirfel A, Scheer T, Jung N, Busch C. Robust Identification and Segmentation of the Outer Skin Layers in Volumetric Fingerprint Data. SENSORS (BASEL, SWITZERLAND) 2022; 22:8229. [PMID: 36365934 PMCID: PMC9658246 DOI: 10.3390/s22218229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 10/13/2022] [Accepted: 10/19/2022] [Indexed: 06/16/2023]
Abstract
Despite the long history of fingerprint biometrics and its use to authenticate individuals, there are still some unsolved challenges with fingerprint acquisition and presentation attack detection (PAD). Currently available commercial fingerprint capture devices struggle with non-ideal skin conditions, including soft skin in infants. They are also susceptible to presentation attacks, which limits their applicability in unsupervised scenarios such as border control. Optical coherence tomography (OCT) could be a promising solution to these problems. In this work, we propose a digital signal processing chain for segmenting two complementary fingerprints from the same OCT fingertip scan: One fingerprint is captured as usual from the epidermis ("outer fingerprint"), whereas the other is taken from inside the skin, at the junction between the epidermis and the underlying dermis ("inner fingerprint"). The resulting 3D fingerprints are then converted to a conventional 2D grayscale representation from which minutiae points can be extracted using existing methods. Our approach is device-independent and has been proven to work with two different time domain OCT scanners. Using efficient GPGPU computing, it took less than a second to process an entire gigabyte of OCT data. To validate the results, we captured OCT fingerprints of 130 individual fingers and compared them with conventional 2D fingerprints of the same fingers. We found that both the outer and inner OCT fingerprints were backward compatible with conventional 2D fingerprints, with the inner fingerprint generally being less damaged and, therefore, more reliable.
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Affiliation(s)
- Alexander Kirfel
- Institute of Safety and Security Research, Bonn-Rhine-Sieg University of Applied Sciences, 53757 Sankt Augustin, Germany
| | - Tobias Scheer
- Institute of Safety and Security Research, Bonn-Rhine-Sieg University of Applied Sciences, 53757 Sankt Augustin, Germany
| | - Norbert Jung
- Institute of Safety and Security Research, Bonn-Rhine-Sieg University of Applied Sciences, 53757 Sankt Augustin, Germany
| | - Christoph Busch
- Norwegian Biometrics Laboratory, Norwegian University of Science and Technology, 2815 Gjøvik, Norway
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37
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Optical Coherence Tomography Findings in Rhegmatogenous Retinal Detachment: A Systematic Review. J Clin Med 2022; 11:jcm11195819. [PMID: 36233684 PMCID: PMC9571044 DOI: 10.3390/jcm11195819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 09/25/2022] [Accepted: 09/28/2022] [Indexed: 11/05/2022] Open
Abstract
Rhegmatogenous retinal detachment is a sight-threatening condition that may lead to blindness if left untreated. Surgical treatments may vary and are tailored to a single patient. Anatomical and functional results may vary, due to factors that are currently under study. Optical coherence tomography (OCT) allows a detailed visualization of the retinal structure. Some studies have been performed using OCT on eyes with retinal detachment. We performed a review on the subject. Several data have been obtained using different OCT applications. Some alterations may represent potential biomarkers since they are associated with visual and anatomical prognoses. Increased knowledge on the subject may be helpful to choose among different surgical strategies and endotamponades. More research on the topic is needed.
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38
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Khan S, Neuhaus K, Thaware O, Ni S, Ju MJ, Redd T, Huang D, Jian Y. Corneal imaging with blue-light optical coherence microscopy. BIOMEDICAL OPTICS EXPRESS 2022; 13:5004-5014. [PMID: 36187260 PMCID: PMC9484440 DOI: 10.1364/boe.465707] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 08/17/2022] [Accepted: 08/17/2022] [Indexed: 06/16/2023]
Abstract
Corneal imaging is important for the diagnostic and therapeutic evaluation of many eye diseases. Optical coherence tomography (OCT) is extensively used in ocular imaging due to its non-invasive and high-resolution volumetric imaging characteristics. Optical coherence microscopy (OCM) is a technical variation of OCT that can image the cornea with cellular resolution. Here, we demonstrate a blue-light OCM as a low-cost and easily reproducible system to visualize corneal cellular structures such as epithelial cells, endothelial cells, keratocytes, and collagen bundles within stromal lamellae. Our blue-light OCM system achieved an axial resolution of 12 µm in tissue over a 1.2 mm imaging depth, and a lateral resolution of 1.6 µm over a field of view of 750 µm × 750 µm.
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Affiliation(s)
- Shanjida Khan
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR 97239, USA
| | - Kai Neuhaus
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Omkar Thaware
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR 97239, USA
| | - Shuibin Ni
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR 97239, USA
| | - Myeong Jin Ju
- Department of Ophthalmology and Visual
Sciences, University of British Columbia,
Vancouver, BC, Canada
- School of Biomedical Engineering,
University of British Columbia, Vancouver,
BC, Canada
| | - Travis Redd
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - David Huang
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR 97239, USA
| | - Yifan Jian
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR 97239, USA
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39
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Kaluzny BJ, Mlyniuk P, Liberski S, Jimenez-Villar A, Machalińska A, Grulkowski I. Swept-source OCT for corneal graft quantitative evaluation in the eye bank and the correlation of the measurements to pre-excision values. Sci Rep 2022; 12:14834. [PMID: 36050445 PMCID: PMC9437096 DOI: 10.1038/s41598-022-19225-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 08/25/2022] [Indexed: 11/15/2022] Open
Abstract
Quantitative evaluation of the human corneal grafts stored in the tissue banks is usually limited to endothelial cell density and central thickness. Swept-source OCT (SS-OCT) is capable of measuring the central curvatures of the corneal tissue prepared for transplantation without loss of sterileness, providing insights on its refractive state. The aim of the paper is to compare in vitro SS-OCT measurements with pre-excision values. Hand-held keratometry and ultrasound pachymetry was performed on 22 corneas before excision of corneoscleral button and insertion in the vial with Eusol-C solution (AlchimiaS.r.l, Nicolò, Italy). After 12 to 36 h of hypothermic storage the corneas were examined within the vials with custom built SS-OCT system maintaining a sterile environment. The anterior and posterior central curvatures, and central corneal thickness (CCT) were measured. Rotation of the corneoscleral button was controlled by making a 6-o'clock mark during excision. Mean pre-excision CCT was 626.45 ± 28.71 µm and 468.05 ± 52.96 µm when measured with SS OCT (r = 0.55; p < 0.001). Respective values for average keratometry were 7.74 ± 0.39 mm and 7.92 ± 0.57 mm (r = 0.6; p = 0.22). Although high differences were observed in corneal thickness, keratometric radius of curvature at the flat (r = 0.42; p < 0.001) and steep (r = 0.62; p = 0.014) meridian of the anterior corneal surface, as well as corneal anterior astigmatism (r = 0.3; p < 0.001), showed good correlation with pre-excision values. SS-OCT is capable of providing quantitative evaluation of the human corneal grafts in hypothermic storage. Good correlation between curvature measurements before excision and during banking in the vial indicates its clinical utility.
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Affiliation(s)
- Bartlomiej J Kaluzny
- Division of Ophthalmology and Optometry, Department of Ophthalmology, Collegium Medicum, Nicolaus Copernicus University, Ul. K. Ujejskiego 75, 85-168, Bydgoszcz, Poland.,Oftalmika Eye Hospital, Bydgoszcz, Poland
| | - Patryk Mlyniuk
- Division of Ophthalmology and Optometry, Department of Ophthalmology, Collegium Medicum, Nicolaus Copernicus University, Ul. K. Ujejskiego 75, 85-168, Bydgoszcz, Poland.,Oftalmika Eye Hospital, Bydgoszcz, Poland
| | - Slawomir Liberski
- Department of Ophthalmology, Poznan University of Medical Sciences, Ul. A. Szamarzewskiego 84, 61-848, Poznań, Poland.
| | - Alfonso Jimenez-Villar
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Ul. Grudziądzka 5, 87-100, Toruń, Poland
| | - Anna Machalińska
- First Department of Ophthalmology, Pomeranian Medical University, Al. Powstańców Wielkopolskich 72, 70-111, Szczecin, Poland
| | - Ireneusz Grulkowski
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Ul. Grudziądzka 5, 87-100, Toruń, Poland
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40
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Frequency wavelength multiplexed optoacoustic tomography. Nat Commun 2022; 13:4448. [PMID: 35915111 PMCID: PMC9343396 DOI: 10.1038/s41467-022-32175-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 07/20/2022] [Indexed: 11/11/2022] Open
Abstract
Optoacoustics (OA) is overwhelmingly implemented in the Time Domain (TD) to achieve high signal-to-noise ratios by maximizing the excitation light energy transient. Implementations in the Frequency Domain (FD) have been proposed, but suffer from low signal-to-noise ratios and have not offered competitive advantages over time domain methods to reach high dissemination. It is therefore commonly believed that TD is the optimal way to perform optoacoustics. Here we introduce an optoacoustic concept based on pulse train illumination and frequency domain multiplexing and theoretically demonstrate the superior merits of the approach compared to the time domain. Then, using recent advances in laser diode illumination, we launch Frequency Wavelength Multiplexing Optoacoustic Tomography (FWMOT), at multiple wavelengths, and experimentally showcase how FWMOT optimizes the signal-to-noise ratios of spectral measurements over time-domain methods in phantoms and in vivo. We further find that FWMOT offers the fastest multi-spectral operation ever demonstrated in optoacoustics. Optoacoustic imaging is mostly performed in the time domain. Here the authors demonstrate frequency wavelength multiplexed optoacoustic tomography that can operate at multiple wavelengths simultaneously and offers signal-to-noise ratio advantages over time domain methods.
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41
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Rubinoff I, Miller DA, Kuranov R, Wang Y, Fang R, Volpe NJ, Zhang HF. High-Speed Balanced-Detection Visible-Light Optical Coherence Tomography in the Human Retina Using Subpixel Spectrometer Calibration. IEEE TRANSACTIONS ON MEDICAL IMAGING 2022; 41:1724-1734. [PMID: 35089857 PMCID: PMC9921460 DOI: 10.1109/tmi.2022.3147497] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Increases in speed and sensitivity enabled rapid clinical adoption of optical coherence tomography (OCT) in ophthalmology. Recently, visible-light OCT (vis-OCT) achieved ultrahigh axial resolution, improved tissue contrast, and provided new functional imaging capabilities, demonstrating the potential to improve clinical care further. However, limited speed and sensitivity caused by the high relative intensity noise (RIN) in supercontinuum lasers impeded the clinical adoption of vis-OCT. To overcome these limitations, we developed balanced-detection vis-OCT (BD-vis-OCT), which uses two calibrated spectrometers to cancel RIN and other noises. We analyzed the RIN to achieve robust subpixel calibration between the two spectrometers and showed that BD-vis-OCT reduced the A-line noise floor by up to 20.5 dB. Metrics comparing signal-to-noise-ratios showed similar image qualities across multiple reference arm powers, a hallmark of operation near the shot-noise limit. We imaged healthy human retinas at an A-line rate of 125 kHz and a field-of-view up to 10 mm ×4 mm. We found that BD-vis-OCT revealed retinal anatomical features previously obscured by the noise floor.
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Impact of Penetration and Image Analysis in Optical Coherence Tomography on the Measurement of Choroidal Vascularity Parameters. Retina 2022; 42:1965-1974. [DOI: 10.1097/iae.0000000000003547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Twayana K, Rebolledo-Salgado I, Deriushkina E, Schröder J, Karlsson M, Torres-Company V. Spectral Interferometry with Frequency Combs. MICROMACHINES 2022; 13:mi13040614. [PMID: 35457918 PMCID: PMC9026469 DOI: 10.3390/mi13040614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 04/08/2022] [Accepted: 04/10/2022] [Indexed: 02/01/2023]
Abstract
In this review paper, we provide an overview of the state of the art in linear interferometric techniques using laser frequency comb sources. Diverse techniques including Fourier transform spectroscopy, linear spectral interferometry and swept-wavelength interferometry are covered in detail. The unique features brought by laser frequency comb sources are shown, and specific applications highlighted in molecular spectroscopy, optical coherence tomography and the characterization of photonic integrated devices and components. Finally, the possibilities enabled by advances in chip scale swept sources and frequency combs are discussed.
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Affiliation(s)
- Krishna Twayana
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-41296 Gothenburg, Sweden; (K.T.); (I.R.-S.); (E.D.); (J.S.); (M.K.)
| | - Israel Rebolledo-Salgado
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-41296 Gothenburg, Sweden; (K.T.); (I.R.-S.); (E.D.); (J.S.); (M.K.)
- Measurement Science and Technology, RISE Research Institutes of Sweden, SE-50115 Borås, Sweden
| | - Ekaterina Deriushkina
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-41296 Gothenburg, Sweden; (K.T.); (I.R.-S.); (E.D.); (J.S.); (M.K.)
| | - Jochen Schröder
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-41296 Gothenburg, Sweden; (K.T.); (I.R.-S.); (E.D.); (J.S.); (M.K.)
| | - Magnus Karlsson
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-41296 Gothenburg, Sweden; (K.T.); (I.R.-S.); (E.D.); (J.S.); (M.K.)
| | - Victor Torres-Company
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-41296 Gothenburg, Sweden; (K.T.); (I.R.-S.); (E.D.); (J.S.); (M.K.)
- Correspondence:
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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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Qian R, Zhou KC, Zhang J, Viehland C, Dhalla AH, Izatt JA. Video-rate high-precision time-frequency multiplexed 3D coherent ranging. Nat Commun 2022; 13:1476. [PMID: 35351891 PMCID: PMC8964719 DOI: 10.1038/s41467-022-29177-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 02/25/2022] [Indexed: 01/02/2023] Open
Abstract
AbstractFrequency-modulated continuous wave (FMCW) light detection and ranging (LiDAR) is an emerging 3D ranging technology that offers high sensitivity and ranging precision. Due to the limited bandwidth of digitizers and the speed limitations of beam steering using mechanical scanners, meter-scale FMCW LiDAR systems typically suffer from a low 3D frame rate, which greatly restricts their applications in real-time imaging of dynamic scenes. In this work, we report a high-speed FMCW based 3D imaging system, combining a grating for beam steering with a compressed time-frequency analysis approach for depth retrieval. We thoroughly investigate the localization accuracy and precision of our system both theoretically and experimentally. Finally, we demonstrate 3D imaging results of multiple static and moving objects, including a flexing human hand. The demonstrated technique achieves submillimeter localization accuracy over a tens-of-centimeter imaging range with an overall depth voxel acquisition rate of 7.6 MHz, enabling densely sampled 3D imaging at video rate.
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Biliary Tree Diagnostics: Advances in Endoscopic Imaging and Tissue Sampling. MEDICINA (KAUNAS, LITHUANIA) 2022; 58:medicina58010135. [PMID: 35056443 PMCID: PMC8781810 DOI: 10.3390/medicina58010135] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Revised: 01/10/2022] [Accepted: 01/11/2022] [Indexed: 12/12/2022]
Abstract
The diagnostic approach to the biliary tree disorders can be challenging, especially for biliary strictures. Albeit the great diagnostic impact of endoscopic retrograde cholangiopancreatography (ERCP) which allows one to obtain fluoroscopic imaging and tissue sampling through brush cytology and/or forceps biopsy, a considerable proportion of cases remain indeterminate, leading to the risk of under/over treated patients. In the last two decades, several endoscopic techniques have been introduced in clinical practice, shrinking cases of uncertainties and improving diagnostic accuracy. The aim of this review is to discuss recent advances and emerging technologies applied to the management of biliary tree disorders through peroral endoscopy procedures.
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Saxena A, Tsakonas C, Chappell D, Cheung CS, Edwards AMJ, Liang H, Sage IC, Brown CV. Static and Dynamic Optical Analysis of Micro Wrinkle Formation on a Liquid Surface. MICROMACHINES 2021; 12:mi12121583. [PMID: 34945433 PMCID: PMC8704472 DOI: 10.3390/mi12121583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 12/13/2021] [Accepted: 12/16/2021] [Indexed: 11/16/2022]
Abstract
A spatially periodic voltage was used to create a dielectrophoresis induced periodic micro wrinkle deformation on the surface of a liquid film. Optical Coherence Tomography provided the equilibrium wrinkle profile at submicron accuracy. The dynamic wrinkle amplitude was derived from optical diffraction analysis during sub-millisecond wrinkle formation and decay, after abruptly increasing or reducing the voltage, respectively. The decay time constant closely followed the film thickness dependence expected for surface tension driven viscous levelling. Modelling of the system using numerical solution of the Stokes flow equations with electrostatic forcing predicted that wrinkle formation was faster than decay, in accord with observations.
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Affiliation(s)
- Antariksh Saxena
- SOFT Group, School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, UK; (A.S.); (C.T.); (D.C.); (A.M.J.E.); (I.C.S.)
| | - Costas Tsakonas
- SOFT Group, School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, UK; (A.S.); (C.T.); (D.C.); (A.M.J.E.); (I.C.S.)
| | - David Chappell
- SOFT Group, School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, UK; (A.S.); (C.T.); (D.C.); (A.M.J.E.); (I.C.S.)
| | - Chi Shing Cheung
- Imaging & Sensing for Archaeology, Art History & Conservation (ISAAC) Group, School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, UK; (C.S.C.); (H.L.)
| | - Andrew Michael John Edwards
- SOFT Group, School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, UK; (A.S.); (C.T.); (D.C.); (A.M.J.E.); (I.C.S.)
| | - Haida Liang
- Imaging & Sensing for Archaeology, Art History & Conservation (ISAAC) Group, School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, UK; (C.S.C.); (H.L.)
| | - Ian Charles Sage
- SOFT Group, School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, UK; (A.S.); (C.T.); (D.C.); (A.M.J.E.); (I.C.S.)
| | - Carl Vernon Brown
- SOFT Group, School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, UK; (A.S.); (C.T.); (D.C.); (A.M.J.E.); (I.C.S.)
- Correspondence:
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Chen R, Zeng W, Fan W, Lai F, Chen Y, Lin X, Tang L, Ouyang W, Liu Z, Luop X. Automatic Recognition of Ocular Surface Diseases on Smartphone Images Using Densely Connected Convolutional Networks. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2021; 2021:2786-2789. [PMID: 34891827 DOI: 10.1109/embc46164.2021.9630359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Ocular surface disorder is one of common and prevalence eye diseases and complex to be recognized accurately. This work presents automatic classification of ocular surface disorders in accordance with densely connected convolutional networks and smartphone imaging. We use various smartphone cameras to collect clinical images that contain normal and abnormal, and modify end-to-end densely connected convolutional networks that use a hybrid unit to learn more diverse features, significantly reducing the network depth, the total number of parameters and the float calculation. The validation results demonstrate that our proposed method provides a promising and effective strategy to accurately screen ocular surface disorders. In particular, our deeply learned smartphone photographs based classification method achieved an average automatic recognition accuracy of 90.6%, while it is conveniently used by patients and integrated into smartphone applications for automatic patient-self screening ocular surface diseases without seeing a doctor in person in a hospital.
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Münter M, Pieper M, Kohlfaerber T, Bodenstorfer E, Ahrens M, Winter C, Huber R, König P, Hüttmann G, Schulz-Hildebrandt H. Microscopic optical coherence tomography (mOCT) at 600 kHz for 4D volumetric imaging and dynamic contrast. BIOMEDICAL OPTICS EXPRESS 2021; 12:6024-6039. [PMID: 34745719 PMCID: PMC8547980 DOI: 10.1364/boe.425001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 08/03/2021] [Accepted: 08/06/2021] [Indexed: 05/11/2023]
Abstract
Volumetric imaging of dynamic processes with microscopic resolution holds a huge potential in biomedical research and clinical diagnosis. Using supercontinuum light sources and high numerical aperture (NA) objectives, optical coherence tomography (OCT) achieves microscopic resolution and is well suited for imaging cellular and subcellular structures of biological tissues. Currently, the imaging speed of microscopic OCT (mOCT) is limited by the line-scan rate of the spectrometer camera and ranges from 30 to 250 kHz. This is not fast enough for volumetric imaging of dynamic processes in vivo and limits endoscopic application. Using a novel CMOS camera, we demonstrate fast 3-dimensional OCT imaging with 600,000 A-scans/s at 1.8 µm axial and 1.1 µm lateral resolution. The improved speed is used for imaging of ciliary motion and particle transport in ex vivo mouse trachea. Furthermore, we demonstrate dynamic contrast OCT by evaluating the recorded volumes rather than en face planes or B-scans. High-speed volumetric mOCT will enable the correction of global tissue motion and is a prerequisite for applying dynamic contrast mOCT in vivo. With further increase in imaging speed and integration in flexible endoscopes, volumetric mOCT may be used to complement or partly replace biopsies.
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Affiliation(s)
- Michael Münter
- University of Lübeck,
Institute of Biomedical Optics,
Peter-Monnik-Weg 4, 23562 Lübeck, Germany
- Medizinisches Laserzentrum
Lübeck GmbH, Peter-Monnik-Weg 4, 23562 Lübeck, Germany
| | - Mario Pieper
- University of
Lübeck, Institute of Anatomy, Ratzeburger Allee 160,
23562 Lübeck, Germany
- Airway Research Center North
Member of the German Center for Lung Research, DZL,
22927 Großhansdorf, Germany
| | - Tabea Kohlfaerber
- Medizinisches Laserzentrum
Lübeck GmbH, Peter-Monnik-Weg 4, 23562 Lübeck, Germany
| | - Ernst Bodenstorfer
- Austrian Institute of
Technology GmbH, Giefinggasse 4, 1210 Vienna, Austria
| | - Martin Ahrens
- University of Lübeck,
Institute of Biomedical Optics,
Peter-Monnik-Weg 4, 23562 Lübeck, Germany
- Airway Research Center North
Member of the German Center for Lung Research, DZL,
22927 Großhansdorf, Germany
| | | | - Robert Huber
- University of Lübeck,
Institute of Biomedical Optics,
Peter-Monnik-Weg 4, 23562 Lübeck, Germany
| | - Peter König
- University of
Lübeck, Institute of Anatomy, Ratzeburger Allee 160,
23562 Lübeck, Germany
- Airway Research Center North
Member of the German Center for Lung Research, DZL,
22927 Großhansdorf, Germany
| | - Gereon Hüttmann
- University of Lübeck,
Institute of Biomedical Optics,
Peter-Monnik-Weg 4, 23562 Lübeck, Germany
- Medizinisches Laserzentrum
Lübeck GmbH, Peter-Monnik-Weg 4, 23562 Lübeck, Germany
- Airway Research Center North
Member of the German Center for Lung Research, DZL,
22927 Großhansdorf, Germany
| | - Hinnerk Schulz-Hildebrandt
- University of Lübeck,
Institute of Biomedical Optics,
Peter-Monnik-Weg 4, 23562 Lübeck, Germany
- Medizinisches Laserzentrum
Lübeck GmbH, Peter-Monnik-Weg 4, 23562 Lübeck, Germany
- Airway Research Center North
Member of the German Center for Lung Research, DZL,
22927 Großhansdorf, Germany
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50
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Alexandrov S, Arangath A, Zhou Y, Murphy M, Duffy N, Neuhaus K, Shaw G, McAuley R, Leahy M. Accessing depth-resolved high spatial frequency content from the optical coherence tomography signal. Sci Rep 2021; 11:17123. [PMID: 34429483 PMCID: PMC8385072 DOI: 10.1038/s41598-021-96619-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Accepted: 07/28/2021] [Indexed: 11/17/2022] Open
Abstract
Optical coherence tomography (OCT) is a rapidly evolving technology with a broad range of applications, including biomedical imaging and diagnosis. Conventional intensity-based OCT provides depth-resolved imaging with a typical resolution and sensitivity to structural alterations of about 5–10 microns. It would be desirable for functional biological imaging to detect smaller features in tissues due to the nature of pathological processes. In this article, we perform the analysis of the spatial frequency content of the OCT signal based on scattering theory. We demonstrate that the OCT signal, even at limited spectral bandwidth, contains information about high spatial frequencies present in the object which relates to the small, sub-wavelength size structures. Experimental single frame imaging of phantoms with well-known sub-micron internal structures confirms the theory. Examples of visualization of the nanoscale structural changes within mesenchymal stem cells (MSC), which are invisible using conventional OCT, are also shown. Presented results provide a theoretical and experimental basis for the extraction of high spatial frequency information to substantially improve the sensitivity of OCT to structural alterations at clinically relevant depths.
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Affiliation(s)
- Sergey Alexandrov
- National University of Ireland, National Biophotonics and Imaging Platform, School of Physics, Tissue Optics and Microcirculation Imaging Group, Galway, H91 TK33, Ireland.
| | - Anand Arangath
- National University of Ireland, National Biophotonics and Imaging Platform, School of Physics, Tissue Optics and Microcirculation Imaging Group, Galway, H91 TK33, Ireland
| | - Yi Zhou
- National University of Ireland, National Biophotonics and Imaging Platform, School of Physics, Tissue Optics and Microcirculation Imaging Group, Galway, H91 TK33, Ireland
| | - Mary Murphy
- Regenerative Medicine Institute, School of Medicine, National University of Ireland, Galway, Ireland
| | - Niamh Duffy
- Regenerative Medicine Institute, School of Medicine, National University of Ireland, Galway, Ireland
| | - Kai Neuhaus
- National University of Ireland, National Biophotonics and Imaging Platform, School of Physics, Tissue Optics and Microcirculation Imaging Group, Galway, H91 TK33, Ireland
| | - Georgina Shaw
- Regenerative Medicine Institute, School of Medicine, National University of Ireland, Galway, Ireland
| | - Ryan McAuley
- National University of Ireland, National Biophotonics and Imaging Platform, School of Physics, Tissue Optics and Microcirculation Imaging Group, Galway, H91 TK33, Ireland
| | - Martin Leahy
- National University of Ireland, National Biophotonics and Imaging Platform, School of Physics, Tissue Optics and Microcirculation Imaging Group, Galway, H91 TK33, Ireland.,Institute of Photonic Sciences (ICFO), Barcelona, Spain
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