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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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Sun XM, Xiao ZW, Luo JQ, Gu QY, Zhang HQ, Li BL, Zhuang SM, Zhang GP. Comparative study of optical coherence tomograph and histological images of eustachian tube nasopharyngeal region and adjacent structures in vivo and ex-vivo miniature pigs. Biomed Eng Online 2023; 22:46. [PMID: 37179353 PMCID: PMC10183122 DOI: 10.1186/s12938-023-01104-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Accepted: 04/25/2023] [Indexed: 05/15/2023] Open
Abstract
OBJECTIVES Optical Coherence Tomograph (OCT) imaging technology can be used to examine, in vivo, the human ET. At present, it is impossible to achieve the OCT scanning vivo and ex vivo in the same individual human body, or study the consistency between OCT images and histological images of the eustachian tube nasopharyngeal region and adjacent structures. The aim of this study was to determine the consistency between OCT images and histological sections in vivo and ex vivo in miniature pigs. METHODS OCT imaging was performed on five adult miniature pigs in vivo and ex vivo. The images of the eustachian tube OCT (ET-OCT), nasopharynx OCT (NP-OCT) and histological cross sections were further studied. RESULTS All five miniature pigs achieved the OCT scan successfully, acquiring ET-OCT and NP-OCT images in vivo and ex vivo on both sides. The acquired ET OCT images closely matched the histological images, revealing details of the cartilage, submucosa, glands, and mucosa. The lower segment of the ET wall mucosa had an abundance of glands and submucosal tissues, with more low-signal areas appearing in the ex vivo images. The NP-OCT images of the nasopharynx matched the details of the mucosa and submucosal tissues. The ex-vivo OCT images showed thicker mucosa and more scattered slightly lower signal areas compared to the vivo OCT images. CONCLUSIONS ET-OCT images and NP-OCT images matched the histological structure of eustachian tube nasopharyngeal region structures in miniature pigs both in vivo and ex vivo. OCT images may be sensitive to changes in edema and ischemia status. There is a great potential for morphological assessment of inflammation, edema, injure, mucus gland status.
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Affiliation(s)
- Xiao-Mei Sun
- Department of Otolaryngology Head and Neck Surgery, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, 510655, China
| | - Zhi-Wen Xiao
- Department of Otolaryngology Head and Neck Surgery, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, 510655, China
| | - Jia-Qi Luo
- Department of Otolaryngology Head and Neck Surgery, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, 510655, China
- Department of Otolaryngology, Shenzhen City Baoan District Women's and Children's Hospital, Baoan District, Shenzhen, 518100, Guangdong, China
| | - Qing-Yu Gu
- Department of Otolaryngology Head and Neck Surgery, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, 510655, China
| | - Hui-Qing Zhang
- Department of Otolaryngology Head and Neck Surgery, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, 510655, China
| | - Bai-Ling Li
- Shenzhen Science & Technology Development Exchange Center, Shenzhen, 518000, China
| | - Shi-Min Zhuang
- Department of Otolaryngology Head and Neck Surgery, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, 510655, China
| | - Guan-Ping Zhang
- Department of Otolaryngology Head and Neck Surgery, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, 510655, China.
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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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