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Wu X, Ishrak R, Reihanisaransari R, Verma Y, Spring B, Singh K, Reddy R. High-speed forward-viewing optical coherence tomography probe based on Lissajous sampling and sparse reconstruction. OPTICS LETTERS 2024; 49:3652-3655. [PMID: 38950232 DOI: 10.1364/ol.521595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Accepted: 04/26/2024] [Indexed: 07/03/2024]
Abstract
We present a novel endoscopy probe using optical coherence tomography (OCT) that combines sparse Lissajous scanning and compressed sensing (CS) for faster data collection. This compact probe is only 4 mm in diameter and achieves a large field of view (FOV) of 2.25 mm2 and a 10 mm working distance. Unlike traditional OCT systems that use bulky raster scanning, our design features a dual-axis piezoelectric mechanism for efficient Lissajous pattern scanning. It employs compressive data reconstruction algorithms that minimize data collection requirements for efficient, high-speed imaging. This approach significantly enhances imaging speed by over 40%, substantially improving miniaturization and performance for endoscopic applications.
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2
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Zhang X, Han Y, Liu H, Xiao X, Hu Y, Fu Q, Feng L, Hu X, Wang C, Wang J, Wang A. MEMS-based two-photon microscopy with Lissajous scanning and image reconstruction under a feed-forward control strategy. OPTICS EXPRESS 2024; 32:1421-1437. [PMID: 38297694 DOI: 10.1364/oe.510979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Accepted: 12/13/2023] [Indexed: 02/02/2024]
Abstract
Two-photon microscopy (TPM) based on two-dimensional micro-electro-mechanical (MEMS) system mirrors shows promising applications in biomedicine and the life sciences. To improve the imaging quality and real-time performance of TPM, this paper proposes Lissajous scanning control and image reconstruction under a feed-forward control strategy, a dual-parameter alternating drive control algorithm and segmented phase synchronization mechanism, and pipe-lined fusion-mean filtering and median filtering to suppress image noise. A 10 fps frame rate (512 × 512 pixels), a 140 µm × 140 µm field of view, and a 0.62 µm lateral resolution were achieved. The imaging capability of MEMS-based Lissajous scanning TPM was verified by ex vivo and in vivo biological tissue imaging.
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3
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Kaur M, Lane PM, Menon C. Scanning and Actuation Techniques for Cantilever-Based Fiber Optic Endoscopic Scanners-A Review. SENSORS 2021; 21:s21010251. [PMID: 33401728 PMCID: PMC7795415 DOI: 10.3390/s21010251] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 12/30/2020] [Accepted: 12/30/2020] [Indexed: 01/20/2023]
Abstract
Endoscopes are used routinely in modern medicine for in-vivo imaging of luminal organs. Technical advances in the micro-electro-mechanical system (MEMS) and optical fields have enabled the further miniaturization of endoscopes, resulting in the ability to image previously inaccessible small-caliber luminal organs, enabling the early detection of lesions and other abnormalities in these tissues. The development of scanning fiber endoscopes supports the fabrication of small cantilever-based imaging devices without compromising the image resolution. The size of an endoscope is highly dependent on the actuation and scanning method used to illuminate the target image area. Different actuation methods used in the design of small-sized cantilever-based endoscopes are reviewed in this paper along with their working principles, advantages and disadvantages, generated scanning patterns, and applications.
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Affiliation(s)
- Mandeep Kaur
- MENRVA Research Group, Schools of Mechatronic Systems Engineering and Engineering Science, Simon Fraser University, Surrey, B.C. V3T 0A3, Canada;
- School of Engineering Science, Simon Fraser University, Burnaby, B.C. V5A 1S6, Canada;
- Imaging Unit, Integrative Oncology, BC Cancer Research Center, Vancouver, B.C., V5Z 1L3, Canada
| | - Pierre M. Lane
- School of Engineering Science, Simon Fraser University, Burnaby, B.C. V5A 1S6, Canada;
- Imaging Unit, Integrative Oncology, BC Cancer Research Center, Vancouver, B.C., V5Z 1L3, Canada
| | - Carlo Menon
- MENRVA Research Group, Schools of Mechatronic Systems Engineering and Engineering Science, Simon Fraser University, Surrey, B.C. V3T 0A3, Canada;
- School of Engineering Science, Simon Fraser University, Burnaby, B.C. V5A 1S6, Canada;
- Correspondence:
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4
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Hwang K, Seo YH, Kim DY, Ahn J, Lee S, Han KH, Lee KH, Jon S, Kim P, Yu KE, Kim H, Kang SH, Jeong KH. Handheld endomicroscope using a fiber-optic harmonograph enables real-time and in vivo confocal imaging of living cell morphology and capillary perfusion. MICROSYSTEMS & NANOENGINEERING 2020; 6:72. [PMID: 34567682 PMCID: PMC8433427 DOI: 10.1038/s41378-020-00182-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 03/04/2020] [Accepted: 05/14/2020] [Indexed: 06/13/2023]
Abstract
Confocal laser endomicroscopy provides high potential for noninvasive and in vivo optical biopsy at the cellular level. Here, we report a fully packaged handheld confocal endomicroscopic system for real-time, high-resolution, and in vivo cellular imaging using a Lissajous scanning fiber-optic harmonograph. The endomicroscopic system features an endomicroscopic probe with a fiber-optic harmonograph, a confocal microscope unit, and an image signal processor. The fiber-optic harmonograph contains a single mode fiber coupled with a quadrupole piezoelectric tube, which resonantly scans both axes at ~ 1 kHz to obtain a Lissajous pattern. The fiber-optic harmonograph was fully packaged into an endomicroscopic probe with an objective lens. The endomicroscopic probe was hygienically packaged for waterproofing and disinfection of medical instruments within a 2.6-mm outer diameter stainless tube capable of being inserted through the working channel of a clinical endoscope. The probe was further combined with the confocal microscope unit for indocyanine green imaging and the image signal processor for high frame rate and high density Lissajous scanning. The signal processing unit delivers driving signals for probe actuation and reconstructs confocal images using the auto phase matching process of Lissajous fiber scanners. The confocal endomicroscopic system was used to successfully obtain human in vitro fluorescent images and real-time ex vivo and in vivo fluorescent images of the living cell morphology and capillary perfusion inside a single mouse.
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Affiliation(s)
- Kyungmin Hwang
- Department of Bio and Brain Engineering, KAIST and KAIST Institute of Health Science and Technology, Daejeon, 34141 Republic of Korea
- VPIX Medical, Inc, Deajeon, 34141 Republic of Korea
| | - Yeong-Hyeon Seo
- Department of Bio and Brain Engineering, KAIST and KAIST Institute of Health Science and Technology, Daejeon, 34141 Republic of Korea
| | - Daniel Y. Kim
- Department of Bio and Brain Engineering, KAIST and KAIST Institute of Health Science and Technology, Daejeon, 34141 Republic of Korea
| | - Jinhyo Ahn
- Graduate School of Nanoscience and Technology, KAIST and KAIST Institute of Health Science and Technology, Daejeon, 34141 Republic of Korea
| | - Soyoung Lee
- Department of Biological Sciences, KAIST and KAIST Institute for the BioCentury, Daejeon, 34141 Republic of Korea
| | | | - Koun-Hee Lee
- VPIX Medical, Inc, Deajeon, 34141 Republic of Korea
| | - Sangyong Jon
- Department of Biological Sciences, KAIST and KAIST Institute for the BioCentury, Daejeon, 34141 Republic of Korea
| | - Pilhan Kim
- Graduate School of Nanoscience and Technology, KAIST and KAIST Institute of Health Science and Technology, Daejeon, 34141 Republic of Korea
- Graduate School of Medical Science and Engineering, Daejeon, 34141 Republic of Korea
| | - Kate E. Yu
- VPIX Medical, Inc, Deajeon, 34141 Republic of Korea
| | - Hyungsin Kim
- Department of Neurosurgery, Korea University Anam Hospital, Korea University Medicine, Seoul, 02842 Korea
| | - Shin-Hyuk Kang
- Department of Neurosurgery, Korea University Anam Hospital, Korea University Medicine, Seoul, 02842 Korea
| | - Ki-Hun Jeong
- Department of Bio and Brain Engineering, KAIST and KAIST Institute of Health Science and Technology, Daejeon, 34141 Republic of Korea
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5
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Park HC, Guan H, Li A, Yue Y, Li MJ, Lu H, Li X. High-speed fiber-optic scanning nonlinear endomicroscopy for imaging neuron dynamicsin vivo. OPTICS LETTERS 2020; 45:3605-3608. [PMID: 32630910 PMCID: PMC7585368 DOI: 10.1364/ol.396023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 05/23/2020] [Indexed: 06/11/2023]
Abstract
Fiber-optic-based two-photon fluorescence endomicroscopy is emerging as an enabling technology for in vivo histological imaging of internal organs and functional neuronal imaging on freely-behaving animals. However, high-speed imaging remains challenging due to the expense of miniaturization and lack of suited fast beam scanners. For many applications, a higher imaging speed is highly desired, especially for monitoring functional dynamics such as transient dendritic responses in neuroscience. This Letter reports the development of a fast fiber-optic scanning endo-microscope with an imaging speed higher than 26 frames/s. In vivo neural dynamics imaging with the high-speed endomicroscope was performed on a freely-behaving mouse over the primary motor cortex that expressed GCaMP6m. The results demonstrate its capability of real-time monitoring of transient neuronal dynamics with very fine temporal resolution.
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Affiliation(s)
- Hyeon-Cheol Park
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
| | - Honghua Guan
- Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - Ang Li
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
| | - Yuanlei Yue
- Department of Pharmacology and Physiology, George Washington University School of Medicine, Washington, DC 20052, USA
| | - Ming-Jun Li
- Science and Technology Division, Corning Incorporated, Corning, New York 14831, USA
| | - Hui Lu
- Department of Pharmacology and Physiology, George Washington University School of Medicine, Washington, DC 20052, USA
| | - Xingde Li
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
- Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, Maryland 21218, USA
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6
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Zhou G, Lim ZH, Qi Y, Zhou G. Single-Pixel MEMS Imaging Systems. MICROMACHINES 2020; 11:E219. [PMID: 32093324 PMCID: PMC7074650 DOI: 10.3390/mi11020219] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 02/18/2020] [Accepted: 02/19/2020] [Indexed: 11/16/2022]
Abstract
Single-pixel imaging technology is an attractive technology considering the increasing demand of imagers that can operate in wavelengths where traditional cameras have limited efficiency. Meanwhile, the miniaturization of imaging systems is also desired to build affordable and portable devices for field applications. Therefore, single-pixel imaging systems based on microelectromechanical systems (MEMS) is an effective solution to develop truly miniaturized imagers, owing to their ability to integrate multiple functionalities within a small device. MEMS-based single-pixel imaging systems have mainly been explored in two research directions, namely the encoding-based approach and the scanning-based approach. The scanning method utilizes a variety of MEMS scanners to scan the target scenery and has potential applications in the biological imaging field. The encoding-based system typically employs MEMS modulators and a single-pixel detector to encode the light intensities of the scenery, and the images are constructed by harvesting the power of computational technology. This has the capability to capture non-visible images and 3D images. Thus, this review discusses the two approaches in detail, and their applications are also reviewed to evaluate the efficiency and advantages in various fields.
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Affiliation(s)
- Guangcan Zhou
- Micro and Nano Systems Initiative, Department of Mechanical Engineering, National University of Singapore, Singapore 117575, Singapore; (G.Z.); (Z.H.L.); (Y.Q.)
| | - Zi Heng Lim
- Micro and Nano Systems Initiative, Department of Mechanical Engineering, National University of Singapore, Singapore 117575, Singapore; (G.Z.); (Z.H.L.); (Y.Q.)
| | - Yi Qi
- Micro and Nano Systems Initiative, Department of Mechanical Engineering, National University of Singapore, Singapore 117575, Singapore; (G.Z.); (Z.H.L.); (Y.Q.)
| | - Guangya Zhou
- Micro and Nano Systems Initiative, Department of Mechanical Engineering, National University of Singapore, Singapore 117575, Singapore; (G.Z.); (Z.H.L.); (Y.Q.)
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Park HC, Zhang X, Yuan W, Zhou L, Xie H, Li X. Ultralow-voltage electrothermal MEMS based fiber-optic scanning probe for forward-viewing endoscopic OCT. OPTICS LETTERS 2019; 44:2232-2235. [PMID: 31042191 PMCID: PMC6541216 DOI: 10.1364/ol.44.002232] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 04/01/2019] [Indexed: 06/09/2023]
Abstract
We report an ultralow-voltage, electrothermal (ET) micro-electro-mechanical system (MEMS) based probe for forward-viewing endoscopic optical coherence tomography (OCT) imaging. The fully assembled probe has a diameter of 5.5 mm and a length of 55 mm, including the imaging optics and a 40 mm long fiber-optic cantilever attached on a micro-platform of the bimorph ET MEMS actuator. The ET MEMS actuator provides a sufficient mechanical actuation force as well as a large vertical displacement, achieving up to a 3 mm optical scanning range with only a 3 VACp-p drive voltage with a 1.5 VDC offset. The imaging probe was integrated with a swept-source OCT system of a 100 kHz A-scan rate, and its performance was successfully demonstrated with cross-sectional imaging of biological tissues ex vivo and in vivo at a speed up to 200 frames per second.
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Affiliation(s)
- Hyeon-Cheol Park
- Department of Biomedical Engineering, School of Medicine, Johns Hopkins University, Baltimore, Maryland 21205, USA
| | - Xiaoyang Zhang
- Department of Electrical and Computer Engineering, University of Florida, Gainesville, Florida 32611, USA
| | - Wu Yuan
- Department of Biomedical Engineering, School of Medicine, Johns Hopkins University, Baltimore, Maryland 21205, USA
| | - Liang Zhou
- Department of Electrical and Computer Engineering, University of Florida, Gainesville, Florida 32611, USA
| | - Huikai Xie
- Department of Electrical and Computer Engineering, University of Florida, Gainesville, Florida 32611, USA
| | - Xingde Li
- Department of Biomedical Engineering, School of Medicine, Johns Hopkins University, Baltimore, Maryland 21205, USA
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8
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Kim DY, Hwang K, Ahn J, Seo YH, Kim JB, Lee S, Yoon JH, Kong E, Jeong Y, Jon S, Kim P, Jeong KH. Lissajous Scanning Two-photon Endomicroscope for In vivo Tissue Imaging. Sci Rep 2019; 9:3560. [PMID: 30837501 PMCID: PMC6401070 DOI: 10.1038/s41598-019-38762-w] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 12/31/2018] [Indexed: 12/13/2022] Open
Abstract
An endomicroscope opens new frontiers of non-invasive biopsy for in vivo imaging applications. Here we report two-photon laser scanning endomicroscope for in vivo cellular and tissue imaging using a Lissajous fiber scanner. The fiber scanner consists of a piezoelectric (PZT) tube, a single double-clad fiber (DCF) with high fluorescence collection, and a micro-tethered-silicon-oscillator (MTSO) for the separation of biaxial resonant scanning frequencies. The endomicroscopic imaging exhibits 5 frames/s with 99% in scanning density by using the selection rule of scanning frequencies. The endomicroscopic scanner was compactly packaged within a stainless tube of 2.6 mm in diameter with a high NA gradient-index (GRIN) lens, which can be easily inserted into the working channel of a conventional laparoscope. The lateral and axial resolutions of the endomicroscope are 0.70 µm and 7.6 μm, respectively. Two-photon fluorescence images of a stained kidney section and miscellaneous ex vivo and in vivo organs from wild type and green fluorescent protein transgenic (GFP-TG) mice were successfully obtained by using the endomicroscope. The endomicroscope also obtained label free images including autofluorescence and second-harmonic generation of an ear tissue of Thy1-GCaMP6 (GP5.17) mouse. The Lissajous scanning two-photon endomicroscope can provide a compact handheld platform for in vivo tissue imaging or optical biopsy applications.
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Affiliation(s)
- Daniel Youngsuk Kim
- Department of Bio and Brain Engineering, KAIST, Daejeon, 34141, Republic of Korea.,KAIST Institute of Health science and technology, Daejeon, 34141, Republic of Korea
| | - Kyungmin Hwang
- Department of Bio and Brain Engineering, KAIST, Daejeon, 34141, Republic of Korea.,KAIST Institute of Health science and technology, Daejeon, 34141, Republic of Korea
| | - Jinhyo Ahn
- Biomedical Science and Engineering Interdisciplinary Program, KAIST, Daejeon, 34141, Republic of Korea.,KAIST Institute of Health science and technology, Daejeon, 34141, Republic of Korea
| | - Yeong-Hyeon Seo
- Department of Bio and Brain Engineering, KAIST, Daejeon, 34141, Republic of Korea.,KAIST Institute of Health science and technology, Daejeon, 34141, Republic of Korea
| | - Jae-Beom Kim
- Department of Bio and Brain Engineering, KAIST, Daejeon, 34141, Republic of Korea.,KAIST Institute of Health science and technology, Daejeon, 34141, Republic of Korea
| | - Soyoung Lee
- Department of Biological Sciences, KAIST, Daejeon, 34141, Republic of Korea.,KAIST Institute for the BioCentury, Daejeon, 34141, Republic of Korea
| | - Jin-Hui Yoon
- Department of Bio and Brain Engineering, KAIST, Daejeon, 34141, Republic of Korea.,KAIST Institute of Health science and technology, Daejeon, 34141, Republic of Korea
| | - Eunji Kong
- Biomedical Science and Engineering Interdisciplinary Program, KAIST, Daejeon, 34141, Republic of Korea.,KAIST Institute of Health science and technology, Daejeon, 34141, Republic of Korea
| | - Yong Jeong
- Department of Bio and Brain Engineering, KAIST, Daejeon, 34141, Republic of Korea.,KAIST Institute of Health science and technology, Daejeon, 34141, Republic of Korea
| | - Sangyong Jon
- Department of Biological Sciences, KAIST, Daejeon, 34141, Republic of Korea.,KAIST Institute for the BioCentury, Daejeon, 34141, Republic of Korea
| | - Pilhan Kim
- Biomedical Science and Engineering Interdisciplinary Program, KAIST, Daejeon, 34141, Republic of Korea.,KAIST Institute of Health science and technology, Daejeon, 34141, Republic of Korea
| | - Ki-Hun Jeong
- Department of Bio and Brain Engineering, KAIST, Daejeon, 34141, Republic of Korea. .,KAIST Institute of Health science and technology, Daejeon, 34141, Republic of Korea.
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9
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MEMS Actuators for Optical Microendoscopy. MICROMACHINES 2019; 10:mi10020085. [PMID: 30682852 PMCID: PMC6412441 DOI: 10.3390/mi10020085] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 12/26/2018] [Accepted: 12/28/2018] [Indexed: 01/21/2023]
Abstract
Growing demands for affordable, portable, and reliable optical microendoscopic imaging devices are attracting research institutes and industries to find new manufacturing methods. However, the integration of microscopic components into these subsystems is one of today's challenges in manufacturing and packaging. Together with this kind of miniaturization more and more functional parts have to be accommodated in ever smaller spaces. Therefore, solving this challenge with the use of microelectromechanical systems (MEMS) fabrication technology has opened the promising opportunities in enabling a wide variety of novel optical microendoscopy to be miniaturized. MEMS fabrication technology enables abilities to apply batch fabrication methods with high-precision and to include a wide variety of optical functionalities to the optical components. As a result, MEMS technology has enabled greater accessibility to advance optical microendoscopy technology to provide high-resolution and high-performance imaging matching with traditional table-top microscopy. In this review the latest advancements of MEMS actuators for optical microendoscopy will be discussed in detail.
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Seo YH, Hwang K, Kim H, Jeong KH. Scanning MEMS Mirror for High Definition and High Frame Rate Lissajous Patterns. MICROMACHINES 2019; 10:mi10010067. [PMID: 30669314 PMCID: PMC6356757 DOI: 10.3390/mi10010067] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 01/16/2019] [Accepted: 01/17/2019] [Indexed: 11/16/2022]
Abstract
Scanning MEMS (micro-electro-mechanical system) mirrors are attractive given their potential use in a diverse array of laser scanning display and imaging applications. Here we report on an electrostatic MEMS mirror for high definition and high frame rate (HDHF) Lissajous scanning. The MEMS mirror comprised a low Q-factor inner mirror and frame mirror, which provided two-dimensional scanning at two similar resonant scanning frequencies with high mechanical stability. The low Q inner mirror enabled a broad frequency selection range. The high definition and high frame rate (HDHF) Lissajous scanning of the MEMS mirror was achieved by selecting a set of scanning frequencies near its resonance with a high greatest common divisor (GCD) and a high total lobe number. The MEMS mirror had resonant scanning frequencies at 5402 Hz and 6702 Hz in x and y directions, respectively. The selected pseudo-resonant frequencies of 5450 Hz and 6700 Hz for HDHF scanning provided 50 frames per second with 94% fill factor in 256 × 256 pixels. This Lissajous MEMS mirror could be utilized for assorted HDHF laser scanning imaging and display applications.
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Affiliation(s)
- Yeong-Hyeon Seo
- Department of Bio and Brain Engineering, KAIST, Daejeon 34141, Korea.
- KAIST Institute for Health Science and Technology, Daejeon 34141, Korea.
| | - Kyungmin Hwang
- Department of Bio and Brain Engineering, KAIST, Daejeon 34141, Korea.
- KAIST Institute for Health Science and Technology, Daejeon 34141, Korea.
| | - Hyunwoo Kim
- Department of Bio and Brain Engineering, KAIST, Daejeon 34141, Korea.
- KAIST Institute for Health Science and Technology, Daejeon 34141, Korea.
| | - Ki-Hun Jeong
- Department of Bio and Brain Engineering, KAIST, Daejeon 34141, Korea.
- KAIST Institute for Health Science and Technology, Daejeon 34141, Korea.
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Seo YH, Hwang K, Jeong KH. 1.65 mm diameter forward-viewing confocal endomicroscopic catheter using a flip-chip bonded electrothermal MEMS fiber scanner. OPTICS EXPRESS 2018; 26:4780-4785. [PMID: 29475322 DOI: 10.1364/oe.26.004780] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 01/29/2018] [Indexed: 06/08/2023]
Abstract
We report a 1.65 mm diameter forward-viewing confocal endomicroscopic catheter using a flip-chip bonded electrothermal MEMS fiber scanner. Lissajous scanning was implemented by the electrothermal MEMS fiber scanner. The Lissajous scanned MEMS fiber scanner was precisely fabricated to facilitate flip-chip connection, and bonded with a printed circuit board. The scanner was successfully combined with a fiber-based confocal imaging system. A two-dimensional reflectance image of the metal pattern 'OPTICS' was successfully obtained with the scanner. The flip-chip bonded scanner minimizes electrical packaging dimensions. The inner diameter of the flip-chip bonded MEMS fiber scanner is 1.3 mm. The flip-chip bonded MEMS fiber scanner is fully packaged with a 1.65 mm diameter housing tube, 1 mm diameter GRIN lens, and a single mode optical fiber. The packaged confocal endomicroscopic catheter can provide a new breakthrough for diverse in-vivo endomicroscopic applications.
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12
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Hwang K, Seo YH, Ahn J, Kim P, Jeong KH. Frequency selection rule for high definition and high frame rate Lissajous scanning. Sci Rep 2017; 7:14075. [PMID: 29074842 PMCID: PMC5658369 DOI: 10.1038/s41598-017-13634-3] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 09/29/2017] [Indexed: 12/04/2022] Open
Abstract
Lissajous microscanners are very attractive in compact laser scanning applications such as endomicroscopy or pro-projection display owing to high mechanical stability and low operating voltages. The scanning frequency serves as a critical factor for determining the scanning imaging quality. Here we report the selection rule of scanning frequencies that can realize high definition and high frame-rate (HDHF) full-repeated Lissajous scanning imaging. The fill factor (FF) monotonically increases with the total lobe number of a Lissajous curve, i.e., the sum of scanning frequencies divided by the great common divisor (GCD) of bi-axial scanning frequencies. The frames per second (FPS), called the pattern repeated rate or the frame rate, linearly increases with GCD. HDHF Lissajous scanning is achieved at the bi-axial scanning frequencies, where the GCD has the maximum value among various sets of the scanning frequencies satisfying the total lobe number for a target FF. Based on this selection rule, the experimental results clearly demonstrate that conventional Lissajous scanners substantially increase both FF and FPS by slightly modulating the scanning frequencies at near the resonance within the resonance bandwidth of a Lissajous scanner. This selection rule provides a new guideline for HDHF Lissajous scanning in compact laser scanning systems.
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Affiliation(s)
- Kyungmin Hwang
- Department of bio and brain engineering, KAIST, Daejeon, 34141, Republic of Korea
- KAIST Institute for Health science and technology, Daejeon, 34141, Republic of Korea
| | - Yeong-Hyeon Seo
- Department of bio and brain engineering, KAIST, Daejeon, 34141, Republic of Korea
- KAIST Institute for Health science and technology, Daejeon, 34141, Republic of Korea
| | - Jinhyo Ahn
- Graduate School of Nanoscience and Technology, KAIST, Daejeon, 34141, Republic of Korea
- KAIST Institute for Health science and technology, Daejeon, 34141, Republic of Korea
| | - Pilhan Kim
- Graduate School of Nanoscience and Technology, KAIST, Daejeon, 34141, Republic of Korea
- KAIST Institute for Health science and technology, Daejeon, 34141, Republic of Korea
| | - Ki-Hun Jeong
- Department of bio and brain engineering, KAIST, Daejeon, 34141, Republic of Korea.
- KAIST Institute for Health science and technology, Daejeon, 34141, Republic of Korea.
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13
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Qiu Z, Piyawattanamatha W. New Endoscopic Imaging Technology Based on MEMS Sensors and Actuators. MICROMACHINES 2017; 8:mi8070210. [PMID: 30400401 PMCID: PMC6190023 DOI: 10.3390/mi8070210] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2016] [Revised: 03/09/2017] [Accepted: 03/10/2017] [Indexed: 12/14/2022]
Abstract
Over the last decade, optical fiber-based forms of microscopy and endoscopy have extended the realm of applicability for many imaging modalities. Optical fiber-based imaging modalities permit the use of remote illumination sources and enable flexible forms supporting the creation of portable and hand-held imaging instrumentations to interrogate within hollow tissue cavities. A common challenge in the development of such devices is the design and integration of miniaturized optical and mechanical components. Until recently, microelectromechanical systems (MEMS) sensors and actuators have been playing a key role in shaping the miniaturization of these components. This is due to the precision mechanics of MEMS, microfabrication techniques, and optical functionality enabling a wide variety of movable and tunable mirrors, lenses, filters, and other optical structures. Many promising results from MEMS based optical fiber endoscopy have demonstrated great potentials for clinical translation. In this article, reviews of MEMS sensors and actuators for various fiber-optical endoscopy such as fluorescence, optical coherence tomography, confocal, photo-acoustic, and two-photon imaging modalities will be discussed. This advanced MEMS based optical fiber endoscopy can provide cellular and molecular features with deep tissue penetration enabling guided resections and early cancer assessment to better treatment outcomes.
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Affiliation(s)
- Zhen Qiu
- Department of Radiology, Stanford University, Stanford, CA 94305, USA.
| | - Wibool Piyawattanamatha
- Departments of Biomedical and Electronics Engineering, King Mongkut's Institute of Technology Ladkrabang, Bangkok 10520, Thailand.
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Hwang K, Seo YH, Jeong KH. Microscanners for optical endomicroscopic applications. MICRO AND NANO SYSTEMS LETTERS 2017. [DOI: 10.1186/s40486-016-0036-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Seo YH, Hwang K, Park HC, Jeong KH. Electrothermal MEMS fiber scanner for optical endomicroscopy. OPTICS EXPRESS 2016; 24:3903-9. [PMID: 26907043 DOI: 10.1364/oe.24.003903] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We report a novel MEMS fiber scanner with an electrothermal silicon microactuator and a directly mounted optical fiber. The microactuator comprises double hot arm and cold arm structures with a linking bridge and an optical fiber is aligned along a silicon fiber groove. The unique feature induces separation of resonant scanning frequencies of a single optical fiber in lateral and vertical directions, which realizes Lissajous scanning during the resonant motion. The footprint dimension of microactuator is 1.28 x 7 x 0.44 mm3. The resonant scanning frequencies of a 20 mm long optical fiber are 239.4 Hz and 218.4 Hz in lateral and vertical directions, respectively. The full scanned area indicates 451 μm x 558 μm under a 16 Vpp pulse train. This novel laser scanner can provide many opportunities for laser scanning endomicroscopic applications.
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