1
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Wang WC, Li MY, Peng KC, Hsu YF, Estroff B, Yen PY, Schipf D, Wu WJ. Mirrorless MEMS imaging: a nonlinear vibrational approach utilizing aerosol-jetted PZT-actuated fiber MEMS scanner for microscale illumination. MICROSYSTEMS & NANOENGINEERING 2024; 10:13. [PMID: 38259520 PMCID: PMC10800347 DOI: 10.1038/s41378-023-00646-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 10/23/2023] [Accepted: 11/22/2023] [Indexed: 01/24/2024]
Abstract
This study introduces a novel image capture and lighting techniques using a cutting-edge hybrid MEMS scanner system designed for compact microscopic imaging. The scanner comprises a tapered optical fiber waveguide and innovative aerosol-jet printed PZT (lead zirconate titanate) bimorph push-pull actuators on a stainless-steel substrate, effectively addressing issues that are commonly associated with PZT on silicon substrates such as fracture and layer separation. By leveraging nonlinear vibration, the scanner achieves a spiral scan pattern from a single signal input, in addition to the expected two-dimensional scanning and target illumination from two phase-shifted inputs. This capability is further enhanced by a novel process to taper the optical fiber, which reduces illumination scattering and tunes the fiber to the resonant frequencies of the scanner. The precisely tapered tip enables large fields of view while maintaining independent 2-axis scanning through one-degree-of-freedom actuation. Experimental validation showcases the successful generation of a spiral scan pattern with a 60 μm diameter scan area and a 10 Hz frame rate, effectively reconstructing scanned images of 5 μm lines, cross patterns (15 μm in length with a 5 μm gap), and structures of a Psychodidae wing.
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Affiliation(s)
- Wei-Chih Wang
- Department of Power Mechanical Engineering, National Tsing Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu, Taiwan 30013 China
- Institute of NanoEngineering and Microsystems, National Tsing Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu, Taiwan 30013 China
- Department of Mechanical Engineering, University of Washington, Seattle, WA 98195 USA
- Department of Electrical Engineering, University of Washington, Seattle, WA 98195 USA
| | - Ming-Yao Li
- Department of Power Mechanical Engineering, National Tsing Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu, Taiwan 30013 China
| | - Kuan-Chang Peng
- Department of Power Mechanical Engineering, National Tsing Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu, Taiwan 30013 China
| | - Yi-Feng Hsu
- Department of Power Mechanical Engineering, National Tsing Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu, Taiwan 30013 China
| | - Benjamin Estroff
- Department of Mechanical Engineering, University of Washington, Seattle, WA 98195 USA
- Department of Electrical Engineering, University of Washington, Seattle, WA 98195 USA
| | - Pao-Yun Yen
- Department of Power Mechanical Engineering, National Tsing Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu, Taiwan 30013 China
| | - David Schipf
- Department of Mechanical Engineering, University of Washington, Seattle, WA 98195 USA
| | - Wen-Jong Wu
- Department of Engineering Science and Ocean Engineering, National Taiwan University, Taiwan, China
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2
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Coleal CN, Hudson WA, Wilson JW. Sparse Lissajous scanning reflectance confocal microscope with an adjustable field of view and fast iterative Fourier filtering reconstruction. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2023; 40:942-954. [PMID: 37133191 DOI: 10.1364/josaa.484370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Medical imaging devices are becoming increasingly compact, necessitating optimization research into different methods of actuation. Actuation influences important parameters of the imaging device such as size, weight, frame rate, field of view (FOV), and image reconstruction for imaging devices point scanning techniques. Current literature around piezoelectric fiber cantilever actuators focuses on device optimization with a fixed FOV but neglects adjustability. In this paper, we introduce an adjustable FOV piezoelectric fiber cantilever microscope and provide a characterization and optimization procedure. To overcome calibration challenges, we utilize a position sensitive detector (PSD) and address trade-offs between FOV and sparsity with a novel inpainting technique. Our work demonstrates the potential for scanner operation when sparsity and distortion dominate the FOV, extending the usable FOV for this form of actuation and others that currently only operate under ideal imaging conditions.
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3
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Bijoch Ł, Włodkowska U, Kasztelanic R, Pawłowska M, Pysz D, Kaczmarek L, Lapkiewicz R, Buczyński R, Czajkowski R. Novel Design and Application of High-NA Fiber Imaging Bundles for In Vivo Brain Imaging with Two-Photon Scanning Fluorescence Microscopy. ACS APPLIED MATERIALS & INTERFACES 2023; 15:12831-12841. [PMID: 36880640 PMCID: PMC10020965 DOI: 10.1021/acsami.2c22985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 02/21/2023] [Indexed: 06/18/2023]
Abstract
Here, we provide experimental verification supporting the use of short-section imaging bundles for two-photon microscopy imaging of the mouse brain. The 8 mm long bundle is made of a pair of heavy-metal oxide glasses with a refractive index contrast of 0.38 to ensure a high numerical aperture NA = 1.15. The bundle is composed of 825 multimode cores, ordered in a hexagonal lattice with a pixel size of 14 μm and a total diameter of 914 μm. We demonstrate successful imaging through custom-made bundles with 14 μm resolution. As the input, we used a 910 nm Ti-sapphire laser with 140 fs pulse and a peak power of 9 × 104 W. The excitation beam and fluorescent image were transferred through the fiber imaging bundle. As test samples, we used 1 μm green fluorescent latex beads, ex vivo hippocampal neurons expressing green fluorescent protein and cortical neurons in vivo expressing the fluorescent reporter GCaMP6s or immediate early gene Fos fluorescent reporter. This system can be used for minimal-invasive in vivo imaging of the cerebral cortex, hippocampus, or deep brain areas as a part of a tabletop system or an implantable setup. It is a low-cost solution, easy to integrate and operate for high-throughput experiments.
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Affiliation(s)
- Łukasz Bijoch
- BRAINCITY, Nencki Institute of Experimental Biology PAS, Pasteura 3, 02-093 Warszawa, Poland
| | - Urszula Włodkowska
- Nencki
Institute of Experimental Biology PAS, Pasteura 3, 02-093 Warszawa, Poland
| | - Rafał Kasztelanic
- Faculty
of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland
- Institute
of Microelectronics and Photonics, Lukasiewicz
Research Network, Al.
Lotników 32/46, 02-668 Warsaw, Poland
| | - Monika Pawłowska
- BRAINCITY, Nencki Institute of Experimental Biology PAS, Pasteura 3, 02-093 Warszawa, Poland
- Faculty
of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland
| | - Dariusz Pysz
- Institute
of Microelectronics and Photonics, Lukasiewicz
Research Network, Al.
Lotników 32/46, 02-668 Warsaw, Poland
| | - Leszek Kaczmarek
- BRAINCITY, Nencki Institute of Experimental Biology PAS, Pasteura 3, 02-093 Warszawa, Poland
| | - Radek Lapkiewicz
- Faculty
of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland
| | - Ryszard Buczyński
- Faculty
of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland
- Institute
of Microelectronics and Photonics, Lukasiewicz
Research Network, Al.
Lotników 32/46, 02-668 Warsaw, Poland
| | - Rafał Czajkowski
- Nencki
Institute of Experimental Biology PAS, Pasteura 3, 02-093 Warszawa, Poland
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4
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Akondi V, Kowalski B, Dubra A. Dynamic wavefront distortion in resonant scanners. APPLIED OPTICS 2021; 60:11189-11195. [PMID: 35201107 PMCID: PMC8887785 DOI: 10.1364/ao.443972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 11/13/2021] [Indexed: 06/14/2023]
Abstract
Dynamic mirror deformation can substantially degrade the performance of optical instruments using resonant scanners. Here, we evaluate two scanners with resonant frequencies >12kHz with low dynamic distortion. First, we tested an existing galvanometric motor with a novel, to the best of our knowledge, mirror substrate material, silicon carbide, which resonates at 13.8 kHz. This material is stiffer than conventional optical glasses and has lower manufacturing toxicity than beryllium, the stiffest material currently used for this application. Then, we tested a biaxial microelectromechanical (MEMS) scanner with the resonant axis operating at 29.4 kHz. Dynamic deformation measurements show that wavefront aberrations in the galvanometric scanner are dominated by linear oblique astigmatism (90%), while wavefront aberrations in the MEMS scanner are dominated by horizontal coma (30%) and oblique trefoil (27%). In both scanners, distortion amplitude increases linearly with deflection angle, yielding diffraction-limited performance over half of the maximum possible deflection for wavelengths longer than 450 nm and over the full deflection range for wavelengths above 850 nm. Diffraction-limited performance for shorter wavelengths or over larger fractions of the deflection range can be achieved by reducing the beam diameter at the mirror surface. The small dynamic distortion of the MEMS scanner offers a promising alternative to galvanometric resonant scanners with desirable but currently unattainably high resonant frequencies.
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5
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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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6
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Kaushik N, Sasaki T, Takahashi Y, Nakazawa T, Hane K. MEMS-based wearable eyeglasses for eye health monitoring. Biomed Phys Eng Express 2019; 6:015006. [DOI: 10.1088/2057-1976/ab562e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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7
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Wang WC, Gu K, Tsui C. Design and Fabrication of a Push-Pull Electrostatic Actuated Cantilever Waveguide Scanner. MICROMACHINES 2019; 10:mi10070432. [PMID: 31261955 PMCID: PMC6680476 DOI: 10.3390/mi10070432] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/18/2019] [Revised: 06/22/2019] [Accepted: 06/27/2019] [Indexed: 12/05/2022]
Abstract
The paper presents a novel fully integrated MEMS-based non-resonating operated 2D mechanical scanning system using a 1D push-pull actuator. Details of the design, fabrication and tests performed are presented. The current design utilizes an integrated electrostatic push-pull actuator and a SU-8 rib waveguide with a large core cross section (4 μm in height and 20 μm in width) in broadband single mode operation (λ = 0.4 μm to 0.65 μm). We have successfully demonstrated a 2D scanning motion using non- resonating operation with 201 Hz in vertical direction and 20 Hz in horizontal direction. This non-resonating scanner system has achieved a field of view (FOV) of 0.019 to 0.072 radians in vertical and horizontal directions, with the advantage of overcoming its frequency shift caused by fabrication uncertainties. In addition, we observed two fundamental resonances at 201 and 536 Hz in the vertical and horizontal directions with corresponding displacements of 130 and 19 μm, or 0.072 and 0.0105 radian field of view operating at a +150 V input. A gradient index (GRIN) lens is placed at the end of the waveguide to focus the diverging beam output from the waveguide and a 20 μm beam diameter is observed at the focal plane. The transmission efficiency of the waveguide is slightly low (~10%) and slight tensile residual stress can be observed at the cantilever portion of the waveguide due to inherent imperfections in the fabrication process.
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Affiliation(s)
- Wei-Chih Wang
- Department of Mechanical Engineering, University of Washington, Seattle, WA 98185, USA.
- Department of Electrical and Computer Engineering, University of Washington, Seattle, WA 98185, USA.
- Institute of Nanoengineering and Microsystems, National Tsinghua University, Hsinchu 300, Taiwan.
- Department of Power Mechanical Engineering, National Tsinghua University, Hsinchu 300, Taiwan.
| | - Kebin Gu
- Department of Mechanical Engineering, University of Washington, Seattle, WA 98185, USA
| | - ChiLeung Tsui
- Department of Electrical and Computer Engineering, University of Washington, Seattle, WA 98185, USA
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8
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Morova B, Bavili N, Yaman O, Yigit B, Zeybel M, Aydın M, Dogan B, Kasztelanic R, Pysz D, Buczynski R, Kiraz A. Fabrication and characterization of large numerical aperture, high-resolution optical fiber bundles based on high-contrast pairs of soft glasses for fluorescence imaging. OPTICS EXPRESS 2019; 27:9502-9515. [PMID: 31045101 DOI: 10.1364/oe.27.009502] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Fabrication and characterization of flexible optical fiber bundles (FBs) with in-house synthesized high-index and low-index thermally matched glasses are presented. The FBs composed of around 15000 single-core fibers with pixel sizes between 1.1 and 10 μm are fabricated using the stack-and-draw technique from sets of thermally matched zirconium-silicate ZR3, borosilicate SK222, sodium-silicate K209, and F2 glasses. With high refractive index contrast pair of glasses ZR3/SK222 and K209/F2, FBs with numerical apertures (NAs) of 0.53 and 0.59 are obtained, respectively. Among the studied glass materials, ZR3, SK222, and K209 are in-house synthesized, while F2 is commercially acquired. Seven different FBs with varying pixel sizes and bundle diameters are characterized. Brightfield imaging of a micro-ruler and a Convallaria majalis sample and fluorescence imaging of a dye-stained paper tissue and a cirrhotic mice liver tissue are demonstrated using these FBs, demonstrating their good potential for microendoscopic imaging. Brightfield and fluorescence imaging performance of the studied FBs are compared. For both sets of glass compositions, good imaging performance is observed for FBs, with core diameter and core-to-core distance values larger than 1.6 μm and 2.3 μm, respectively. FBs fabricated with K209/F2 glass pairs revealed better performance in fluorescence imaging due to their higher NA of 0.59.
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9
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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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10
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Jeon H, Pawlowski ME, Tkaczyk TS. High-resolution endomicroscopy with a spectrally encoded miniature objective. BIOMEDICAL OPTICS EXPRESS 2019; 10:1432-1445. [PMID: 30891357 PMCID: PMC6420270 DOI: 10.1364/boe.10.001432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 01/19/2019] [Accepted: 01/28/2019] [Indexed: 05/15/2023]
Abstract
Fiber bundle endomicroscopy techniques have been used for numerous minimally invasive imaging applications. However, these techniques may provide limited spatial sampling due to the limited number of imaging cores inside the fiber bundle. Here, we present a custom-fabricated miniature objective that can be coupled to a fiber bundle and can overcome the fiber bundle's sampling threshold by utilizing the spectral encoding concept. The objective has an NA of 0.3 and an outer diameter of 2.4 mm, and can yield a maximum spatial resolution of 2 μm. The objective has been validated against a USAF resolution target and ex vivo tissue samples, and as a result yielded images with higher resolution and more details after the spectral encoding concept was employed.
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Affiliation(s)
- Hamin Jeon
- Department of Bioengineering, Rice University, 6100 Main Street, Houston, TX 77005, USA
| | - Michal E. Pawlowski
- Department of Bioengineering, Rice University, 6100 Main Street, Houston, TX 77005, USA
| | - Tomasz S. Tkaczyk
- Department of Bioengineering, Rice University, 6100 Main Street, Houston, TX 77005, USA
- Department of Electrical and Computer Engineering, Rice University, 6100 Main Street, Houston, TX 77005, USA
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11
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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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12
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Liu T, Rajadhyaksha M, Dickensheets DL. MEMS-in-the-lens architecture for a miniature high-NA laser scanning microscope. LIGHT, SCIENCE & APPLICATIONS 2019; 8:59. [PMID: 31263558 PMCID: PMC6592906 DOI: 10.1038/s41377-019-0167-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 05/24/2019] [Accepted: 05/30/2019] [Indexed: 05/16/2023]
Abstract
Laser scanning microscopes can be miniaturized for in vivo imaging by substituting optical microelectromechanical system (MEMS) devices in place of larger components. The emergence of multifunctional active optical devices can support further miniaturization beyond direct component replacement because those active devices enable diffraction-limited performance using simpler optical system designs. In this paper, we propose a catadioptric microscope objective lens that features an integrated MEMS device for performing biaxial scanning, axial focus adjustment, and control of spherical aberration. The MEMS-in-the-lens architecture incorporates a reflective MEMS scanner between a low-numerical-aperture back lens group and an aplanatic hyperhemisphere front refractive element to support high-numerical-aperture imaging. We implemented this new optical system using a recently developed hybrid polymer/silicon MEMS three-dimensional scan mirror that features an annular aperture that allows it to be coaxially aligned within the objective lens without the need for a beam splitter. The optical performance of the active catadioptric system is simulated and imaging of hard targets and human cheek cells is demonstrated with a confocal microscope that is based on the new objective lens design.
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Affiliation(s)
- Tianbo Liu
- Electrical and Computer Engineering Department, Montana State University, Bozeman, MT 59715 USA
| | - Milind Rajadhyaksha
- Dermatology Department, Memorial Sloan Kettering Cancer Center, New York, NY 10022 USA
| | - David L. Dickensheets
- Electrical and Computer Engineering Department, Montana State University, Bozeman, MT 59715 USA
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13
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Wei L, Yin C, Liu JTC. Dual-axis confocal microscopy for point-of-care pathology. IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS : A PUBLICATION OF THE IEEE LASERS AND ELECTRO-OPTICS SOCIETY 2019; 25:7100910. [PMID: 30872909 PMCID: PMC6411089 DOI: 10.1109/jstqe.2018.2854572] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Dual-axis confocal (DAC) microscopy is an optical imaging modality that utilizes simple low-numerical aperture (NA) lenses to achieve effective optical sectioning and superior image contrast in biological tissues. The unique architecture of DAC microscopy also provides some advantages for miniaturization, facilitating the development of endoscopic and handheld DAC systems for in vivo imaging. This article reviews the principles of DAC microscopy, including its differences from conventional confocal microscopy, and surveys several variations of DAC microscopy that have been developed and investigated as non-invasive real-time alternatives to conventional biopsy and histopathology.
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Affiliation(s)
- Linpeng Wei
- Department of Mechanical Engineering, University of Washington, Seattle, WA 98195 USA, JTCL is also with the Department of Pathology at the University of Washington
| | - Chengbo Yin
- Department of Mechanical Engineering, University of Washington, Seattle, WA 98195 USA, JTCL is also with the Department of Pathology at the University of Washington
| | - Jonathan T C Liu
- Department of Mechanical Engineering, University of Washington, Seattle, WA 98195 USA, JTCL is also with the Department of Pathology at the University of Washington
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14
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Vyas K, Hughes M, Rosa BG, Yang GZ. Fiber bundle shifting endomicroscopy for high-resolution imaging. BIOMEDICAL OPTICS EXPRESS 2018; 9:4649-4664. [PMID: 30319893 PMCID: PMC6179396 DOI: 10.1364/boe.9.004649] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 07/27/2018] [Accepted: 07/29/2018] [Indexed: 05/20/2023]
Abstract
Flexible endomicroscopes commonly use coherent fiber bundles with high core densities to facilitate high-resolution in vivo imaging during endoscopic and minimally-invasive procedures. However, under-sampling due to the inter-core spacing limits the spatial resolution, making it difficult to resolve smaller cellular features. Here, we report a compact and rapid piezoelectric transducer (PZT) based bundle-shifting endomicroscopy system in which a super-resolution (SR) image is restored from multiple pixelation-limited images by computational means. A miniaturized PZT tube actuates the fiber bundle behind a GRIN micro-lens and a Delaunay triangulation based algorithm reconstructs an enhanced SR image. To enable real-time cellular-level imaging, imaging is performed using a line-scan confocal laser endomicroscope system with a raw frame rate of 120 fps, delivering up to 2 times spatial resolution improvement for a field of view of 350 µm at a net frame rate of 30 fps. The resolution enhancement is confirmed using resolution phantoms and ex vivo fluorescence endomicroscopy imaging of human breast specimens is demonstrated.
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Affiliation(s)
- Khushi Vyas
- Hamlyn Centre for Robotic Surgery, Imperial College London, South Kensington Campus, London SW7 2AZ,
UK
| | - Michael Hughes
- Applied Optics Group, School of Physical Sciences, University of Kent, Canterbury CT2 7NH,
UK
| | - Bruno Gil Rosa
- Hamlyn Centre for Robotic Surgery, Imperial College London, South Kensington Campus, London SW7 2AZ,
UK
| | - Guang-Zhong Yang
- Hamlyn Centre for Robotic Surgery, Imperial College London, South Kensington Campus, London SW7 2AZ,
UK
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15
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Benedicto-Orenes D, Kowalczyk A, Bongs K, Barontini G. Endoscopic imaging of quantum gases through a fiber bundle. OPTICS EXPRESS 2017; 25:19701-19710. [PMID: 29041658 DOI: 10.1364/oe.25.019701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 07/01/2017] [Indexed: 06/07/2023]
Abstract
We use a coherent fiber bundle to demonstrate the endoscopic absorption imaging of quantum gases. We show that the fiber bundle introduces spurious noise in the picture mainly due to the strong core-to-core coupling. By direct comparison with free-space pictures, we observe that there is a maximum column density that can be reliably measured using our fiber bundle, and we derive a simple criterion to estimate it. We demonstrate that taking care of not exceeding such maximum, we can retrieve exact quantitative information about the atomic system, making this technique appealing for systems requiring isolation form the environment.
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16
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Quang T, Tran EQ, Schwarz RA, Williams MD, Vigneswaran N, Gillenwater AM, Richards-Kortum R. Prospective Evaluation of Multimodal Optical Imaging with Automated Image Analysis to Detect Oral Neoplasia In Vivo. Cancer Prev Res (Phila) 2017; 10:563-570. [PMID: 28765195 DOI: 10.1158/1940-6207.capr-17-0054] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 06/07/2017] [Accepted: 07/26/2017] [Indexed: 12/16/2022]
Abstract
The 5-year survival rate for patients with oral cancer remains low, in part because diagnosis often occurs at a late stage. Early and accurate identification of oral high-grade dysplasia and cancer can help improve patient outcomes. Multimodal optical imaging is an adjunctive diagnostic technique in which autofluorescence imaging is used to identify high-risk regions within the oral cavity, followed by high-resolution microendoscopy to confirm or rule out the presence of neoplasia. Multimodal optical images were obtained from 206 sites in 100 patients. Histologic diagnosis, either from a punch biopsy or an excised surgical specimen, was used as the gold standard for all sites. Histopathologic diagnoses of moderate dysplasia or worse were considered neoplastic. Images from 92 sites in the first 30 patients were used as a training set to develop automated image analysis methods for identification of neoplasia. Diagnostic performance was evaluated prospectively using images from 114 sites in the remaining 70 patients as a test set. In the training set, multimodal optical imaging with automated image analysis correctly classified 95% of nonneoplastic sites and 94% of neoplastic sites. Among the 56 sites in the test set that were biopsied, multimodal optical imaging correctly classified 100% of nonneoplastic sites and 85% of neoplastic sites. Among the 58 sites in the test set that corresponded to a surgical specimen, multimodal imaging correctly classified 100% of nonneoplastic sites and 61% of neoplastic sites. These findings support the potential of multimodal optical imaging to aid in the early detection of oral cancer. Cancer Prev Res; 10(10); 563-70. ©2017 AACR.
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Affiliation(s)
- Timothy Quang
- Department of Bioengineering, Rice University, Houston, Texas
| | - Emily Q Tran
- Department of Bioengineering, Rice University, Houston, Texas
| | | | - Michelle D Williams
- Department of Pathology, University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Nadarajah Vigneswaran
- Department of Diagnostic and Biomedical Sciences, University of Texas School of Dentistry, Houston, Texas
| | - Ann M Gillenwater
- Department of Head and Neck Surgery, University of Texas MD Anderson Cancer Center, Houston, Texas
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17
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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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18
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All-passive pixel super-resolution of time-stretch imaging. Sci Rep 2017; 7:44608. [PMID: 28303936 PMCID: PMC5356014 DOI: 10.1038/srep44608] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 02/09/2017] [Indexed: 12/23/2022] Open
Abstract
Based on image encoding in a serial-temporal format, optical time-stretch imaging entails a stringent requirement of state-of-the-art fast data acquisition unit in order to preserve high image resolution at an ultrahigh frame rate - hampering the widespread utilities of such technology. Here, we propose a pixel super-resolution (pixel-SR) technique tailored for time-stretch imaging that preserves pixel resolution at a relaxed sampling rate. It harnesses the subpixel shifts between image frames inherently introduced by asynchronous digital sampling of the continuous time-stretch imaging process. Precise pixel registration is thus accomplished without any active opto-mechanical subpixel-shift control or other additional hardware. Here, we present the experimental pixel-SR image reconstruction pipeline that restores high-resolution time-stretch images of microparticles and biological cells (phytoplankton) at a relaxed sampling rate (≈2-5 GSa/s)-more than four times lower than the originally required readout rate (20 GSa/s) - is thus effective for high-throughput label-free, morphology-based cellular classification down to single-cell precision. Upon integration with the high-throughput image processing technology, this pixel-SR time-stretch imaging technique represents a cost-effective and practical solution for large scale cell-based phenotypic screening in biomedical diagnosis and machine vision for quality control in manufacturing.
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19
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Zhao Y, Sheng M, Huang L, Tang S. Design of a fiber-optic multiphoton microscopy handheld probe. BIOMEDICAL OPTICS EXPRESS 2016; 7:3425-3437. [PMID: 27699109 PMCID: PMC5030021 DOI: 10.1364/boe.7.003425] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Revised: 07/28/2016] [Accepted: 08/03/2016] [Indexed: 05/20/2023]
Abstract
We have developed a fiber-optic multiphoton microscopy (MPM) system with handheld probe using femtosecond fiber laser. Here we present the detailed optical design and analysis of the handheld probe. The optical systems using Lightpath 352140 and 352150 as objective lens were analyzed. A custom objective module that includes Lightpath 355392 and two customized corrective lenses was designed. Their performances were compared by wavefront error, field curvature, astigmatism, F-θ error, and tolerance in Zemax simulation. Tolerance analysis predicted the focal spot size to be 1.13, 1.19 and 0.83 µm, respectively. Lightpath 352140 and 352150 were implemented in experiment and the measured lateral resolution was 1.22 and 1.3 µm, respectively, which matched with the prediction. MPM imaging by the handheld probe were conducted on leaf, fish scale and rat tail tendon. The MPM resolution can potentially be improved by the custom objective module.
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Affiliation(s)
- Yuan Zhao
- Department of Electrical and Computer Engineering, University of British Columbia, Vancouver, V6T 1Z4, Canada
- School of Engineering Science, Simon Fraser University, Burnaby, V5A 1S6, Canada
| | - Mingyu Sheng
- Department of Electrical and Computer Engineering, University of British Columbia, Vancouver, V6T 1Z4, Canada
- School of Engineering Science, Simon Fraser University, Burnaby, V5A 1S6, Canada
| | - Lin Huang
- Department of Electrical and Computer Engineering, University of British Columbia, Vancouver, V6T 1Z4, Canada
| | - Shuo Tang
- Department of Electrical and Computer Engineering, University of British Columbia, Vancouver, V6T 1Z4, Canada
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20
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Prieto SP, Lai KK, Laryea JA, Mizell JS, Muldoon TJ. Quantitative analysis of ex vivo colorectal epithelium using an automated feature extraction algorithm for microendoscopy image data. J Med Imaging (Bellingham) 2016; 3:024502. [PMID: 27335893 DOI: 10.1117/1.jmi.3.2.024502] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 04/28/2016] [Indexed: 12/20/2022] Open
Abstract
Qualitative screening for colorectal polyps via fiber bundle microendoscopy imaging has shown promising results, with studies reporting high rates of sensitivity and specificity, as well as low interobserver variability with trained clinicians. A quantitative image quality control and image feature extraction algorithm (QFEA) was designed to lessen the burden of training and provide objective data for improved clinical efficacy of this method. After a quantitative image quality control step, QFEA extracts field-of-view area, crypt area, crypt circularity, and crypt number per image. To develop and validate this QFEA, a training set of microendoscopy images was collected from freshly resected porcine colon epithelium. The algorithm was then further validated on ex vivo image data collected from eight human subjects, selected from clinically normal appearing regions distant from grossly visible tumor in surgically resected colorectal tissue. QFEA has proven flexible in application to both mosaics and individual images, and its automated crypt detection sensitivity ranges from 71 to 94% despite intensity and contrast variation within the field of view. It also demonstrates the ability to detect and quantify differences in grossly normal regions among different subjects, suggesting the potential efficacy of this approach in detecting occult regions of dysplasia.
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Affiliation(s)
- Sandra P Prieto
- University of Arkansas , Department of Biomedical Engineering, 1 University Boulevard, Fayetteville, Arkansas 72701, United States
| | - Keith K Lai
- University of Arkansas for Medical Sciences , Department of Pathology, 4301 West Markham Street, Little Rock, Arkansas 72205, United States
| | - Jonathan A Laryea
- University of Arkansas for Medical Sciences , Department of Gastrointestinal Surgery, 4301 West Markham Street, Little Rock, Arkansas 72205, United States
| | - Jason S Mizell
- University of Arkansas for Medical Sciences , Department of Gastrointestinal Surgery, 4301 West Markham Street, Little Rock, Arkansas 72205, United States
| | - Timothy J Muldoon
- University of Arkansas , Department of Biomedical Engineering, 1 University Boulevard, Fayetteville, Arkansas 72701, United States
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21
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Kumar P, Martin H, Jiang X. Towards the development of a hybrid-integrated chip interferometer for online surface profile measurements. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2016; 87:065103. [PMID: 27370493 DOI: 10.1063/1.4952952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Non-destructive testing and online measurement of surface features are pressing demands in manufacturing. Thus optical techniques are gaining importance for characterization of complex engineering surfaces. Harnessing integrated optics for miniaturization of interferometry systems onto a silicon wafer and incorporating a compact optical probe would enable the development of a handheld sensor for embedded metrology applications. In this work, we present the progress in the development of a hybrid photonics based metrology sensor device for online surface profile measurements. The measurement principle along with test and measurement results of individual components has been presented. For non-contact measurement, a spectrally encoded lateral scanning probe based on the laser scanning microscopy has been developed to provide fast measurement with lateral resolution limited to the diffraction limit. The probe demonstrates a lateral resolution of ∼3.6 μm while high axial resolution (sub-nanometre) is inherently achieved by interferometry. Further the performance of the hybrid tuneable laser and the scanning probe was evaluated by measuring a standard step height sample of 100 nm.
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Affiliation(s)
- P Kumar
- EPSRC Centre for Innovative Manufacturing in Advanced Metrology, University of Huddersfield, Huddersfield HD1 3DH, United Kingdom
| | - H Martin
- EPSRC Centre for Innovative Manufacturing in Advanced Metrology, University of Huddersfield, Huddersfield HD1 3DH, United Kingdom
| | - X Jiang
- EPSRC Centre for Innovative Manufacturing in Advanced Metrology, University of Huddersfield, Huddersfield HD1 3DH, United Kingdom
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22
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Lucchese A, Gentile E, Romano A, Maio C, Laino L, Serpico R. The potential role of in vivo reflectance confocal microscopy for evaluating oral cavity lesions: a systematic review. J Oral Pathol Med 2016; 45:723-729. [PMID: 27229884 DOI: 10.1111/jop.12454] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/24/2016] [Indexed: 12/14/2022]
Abstract
BACKGROUND Since the early 2000s, several studies have examined the application of reflectance confocal microscopy (RCM) to the oral cavity. This review gives an overview of the literature on reflectance confocal microscopy analysis of the oral cavity in vivo and identifies flaws in the studies, providing guidance to improve reflectance confocal microscopy applications and inform the design of future studies. METHODS The PubMed, ISI, Scopus, and Cochrane Library databases were searched for publications on RCM using the terms 'reflectance confocal microscopy' in combination with 'mouth' and other terms related to the topic of interest. RESULTS The search gave 617 results. Seventeen studies were included in our final analysis. We decided to organize the selected articles according to four topics: healthy mucosa, autoimmune diseases, cancer and precancerous lesions, and hard dental tissues. CONCLUSION Although reflectance confocal microscopy is promising for diagnosing and monitoring oral pathology, it has shortcomings and there are still too few publications on this topic. Further studies are needed to increase the quantity and quality of the results, to translate research into clinical practice.
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Affiliation(s)
- Alberta Lucchese
- Multidisciplinary Department of Medical-Surgical and Dental Specialties, Second University of Naples, Naples, Italy.
| | - Enrica Gentile
- Multidisciplinary Department of Medical-Surgical and Dental Specialties, Second University of Naples, Naples, Italy
| | - Antonio Romano
- Multidisciplinary Department of Medical-Surgical and Dental Specialties, Second University of Naples, Naples, Italy
| | - Claudio Maio
- Multidisciplinary Department of Medical-Surgical and Dental Specialties, Second University of Naples, Naples, Italy
| | - Luigi Laino
- Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy
| | - Rosario Serpico
- Multidisciplinary Department of Medical-Surgical and Dental Specialties, Second University of Naples, Naples, Italy
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23
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Yin C, Glaser A, Leigh SY, Chen Y, Wei L, Pillai PCS, Rosenberg MC, Abeytunge S, Peterson G, Glazowski C, Sanai N, Mandella MJ, Rajadhyaksha M, Liu JTC. Miniature in vivo MEMS-based line-scanned dual-axis confocal microscope for point-of-care pathology. BIOMEDICAL OPTICS EXPRESS 2016; 7:251-63. [PMID: 26977337 PMCID: PMC4771446 DOI: 10.1364/boe.7.000251] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Revised: 12/03/2015] [Accepted: 12/06/2015] [Indexed: 05/18/2023]
Abstract
There is a need for miniature optical-sectioning microscopes to enable in vivo interrogation of tissues as a real-time and noninvasive alternative to gold-standard histopathology. Such devices could have a transformative impact for the early detection of cancer as well as for guiding tumor-resection procedures. Miniature confocal microscopes have been developed by various researchers and corporations to enable optical sectioning of highly scattering tissues, all of which have necessitated various trade-offs in size, speed, depth selectivity, field of view, resolution, image contrast, and sensitivity. In this study, a miniature line-scanned (LS) dual-axis confocal (DAC) microscope, with a 12-mm diameter distal tip, has been developed for clinical point-of-care pathology. The dual-axis architecture has demonstrated an advantage over the conventional single-axis confocal configuration for reducing background noise from out-of-focus and multiply scattered light. The use of line scanning enables fast frame rates (16 frames/sec is demonstrated here, but faster rates are possible), which mitigates motion artifacts of a hand-held device during clinical use. We have developed a method to actively align the illumination and collection beams in a DAC microscope through the use of a pair of rotatable alignment mirrors. Incorporation of a custom objective lens, with a small form factor for in vivo clinical use, enables our device to achieve an optical-sectioning thickness and lateral resolution of 2.0 and 1.1 microns respectively. Validation measurements with reflective targets, as well as in vivo and ex vivo images of tissues, demonstrate the clinical potential of this high-speed optical-sectioning microscopy device.
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Affiliation(s)
- C. Yin
- University of Washington, Department of Mechanical Engineering, Seattle, WA 98195, USA
| | - A.K. Glaser
- University of Washington, Department of Mechanical Engineering, Seattle, WA 98195, USA
| | - S. Y. Leigh
- University of Washington, Department of Mechanical Engineering, Seattle, WA 98195, USA
| | - Y. Chen
- University of Washington, Department of Mechanical Engineering, Seattle, WA 98195, USA
| | - L. Wei
- University of Washington, Department of Mechanical Engineering, Seattle, WA 98195, USA
| | - P. C. S. Pillai
- University of Washington, Department of Mechanical Engineering, Seattle, WA 98195, USA
| | - M. C. Rosenberg
- University of Washington, Department of Mechanical Engineering, Seattle, WA 98195, USA
| | - S. Abeytunge
- Memorial Sloan-Kettering Cancer Center, Dermatology Services, Department of Medicine, New York, NY 10010, USA
| | - G. Peterson
- Memorial Sloan-Kettering Cancer Center, Dermatology Services, Department of Medicine, New York, NY 10010, USA
| | - C. Glazowski
- Memorial Sloan-Kettering Cancer Center, Dermatology Services, Department of Medicine, New York, NY 10010, USA
| | - N. Sanai
- Barrow Neurological Institute, St. Joseph’s Hospital and Medical Center, Phoenix, AZ 85013 USA
| | - M. J. Mandella
- Stanford University School of Medicine, Department of Pediatrics, Stanford, CA 94305, USA
| | - M. Rajadhyaksha
- Memorial Sloan-Kettering Cancer Center, Dermatology Services, Department of Medicine, New York, NY 10010, USA
| | - J. T. C. Liu
- University of Washington, Department of Mechanical Engineering, Seattle, WA 98195, USA
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24
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Loterie D, Farahi S, Papadopoulos I, Goy A, Psaltis D, Moser C. Digital confocal microscopy through a multimode fiber. OPTICS EXPRESS 2015; 23:23845-58. [PMID: 26368478 DOI: 10.1364/oe.23.023845] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Acquiring high-contrast optical images deep inside biological tissues is still a challenging problem. Confocal microscopy is an important tool for biomedical imaging since it improves image quality by rejecting background signals. However, it suffers from low sensitivity in deep tissues due to light scattering. Recently, multimode fibers have provided a new paradigm for minimally invasive endoscopic imaging by controlling light propagation through them. Here we introduce a combined imaging technique where confocal images are acquired through a multimode fiber. We achieve this by digitally engineering the excitation wavefront and then applying a virtual digital pinhole on the collected signal. In this way, we are able to acquire images through the fiber with significantly increased contrast. With a fiber of numerical aperture 0.22, we achieve a lateral resolution of 1.5µm, and an axial resolution of 12.7µm. The point-scanning rate is currently limited by our spatial light modulator (20Hz).
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25
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Abstract
Mounting evidence suggests that a more extensive surgical resection is associated with an improved life expectancy for both low-grade and high-grade glioma patients. However, radiographically complete resections are not often achieved in many cases because of the lack of sensitivity and specificity of current neurosurgical guidance techniques at the margins of diffuse infiltrative gliomas. Intraoperative fluorescence imaging offers the potential to improve the extent of resection and to investigate the possible benefits of resecting beyond the radiographic margins. Here, we provide a review of wide-field and high-resolution fluorescence-imaging strategies that are being developed for neurosurgical guidance, with a focus on emerging imaging technologies and clinically viable contrast agents. The strengths and weaknesses of these approaches will be discussed, as well as issues that are being addressed to translate these technologies into the standard of care.
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Affiliation(s)
- Jonathan T C Liu
- *Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York; ‡Barrow Brain Tumor Research Center, Division of Neurosurgical Oncology, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona
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26
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Kim S, Hwang J, Heo J, Ryu S, Lee D, Kim SH, Oh SJ, Joo C. Spectrally encoded slit confocal microscopy using a wavelength-swept laser. JOURNAL OF BIOMEDICAL OPTICS 2015; 20:036016. [PMID: 25813913 DOI: 10.1117/1.jbo.20.3.036016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Accepted: 03/10/2015] [Indexed: 06/04/2023]
Abstract
We present an implementation of spectrally encoded slit confocal microscopy. The method employs a rapid wavelength-swept laser as the light source and illuminates a specimen with a line focus that scans through the specimen as the wavelength sweeps. The reflected light from the specimen is imaged with a stationary line scan camera, in which the finite pixel height serves as a slit aperture. This scanner-free operation enables a simple and cost-effective implementation in a small form factor, while allowing for the three-dimensional imaging of biological samples.
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Affiliation(s)
- Soocheol Kim
- Yonsei University, School of Mechanical Engineering, Seoul 120-749, Republic of Korea
| | - Jaehyun Hwang
- Yonsei University, School of Mechanical Engineering, Seoul 120-749, Republic of Korea
| | - Jung Heo
- Yonsei University, School of Mechanical Engineering, Seoul 120-749, Republic of Korea
| | - Suho Ryu
- Yonsei University, School of Mechanical Engineering, Seoul 120-749, Republic of Korea
| | - Donghak Lee
- Yonsei University, School of Mechanical Engineering, Seoul 120-749, Republic of Korea
| | - Sang-Hoon Kim
- Yonsei University, YUHS-KRIBB Medical Convergence Research Institute, Severance Biomedical Science Institute, and Department of Radiology, Seoul 120-749, Republic of Korea
| | - Seung Jae Oh
- Yonsei University, YUHS-KRIBB Medical Convergence Research Institute, Severance Biomedical Science Institute, and Department of Radiology, Seoul 120-749, Republic of Korea
| | - Chulmin Joo
- Yonsei University, School of Mechanical Engineering, Seoul 120-749, Republic of Korea
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27
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Abstract
Confocal fluorescence microendoscopy provides high-resolution cellular-level imaging via a minimally invasive procedure, but requires fast scanning to achieve real-time imaging in vivo. Ideal confocal imaging performance is obtained with a point scanning system, but the scan rates required for in vivo biomedical imaging can be difficult to achieve. By scanning a line of illumination in one direction in conjunction with a stationary confocal slit aperture, very high image acquisition speeds can be achieved, but at the cost of a reduction in image quality. Here, the design, implementation, and experimental verification of a custom multi-point aperture modification to a line-scanning multi-spectral confocal microendoscope is presented. This new design improves the axial resolution of a line-scan system while maintaining high imaging rates. In addition, compared to the line-scanning configuration, previously reported simulations predicted that the multi-point aperture geometry greatly reduces the effects of tissue scatter on image quality. Experimental results confirming this prediction are presented.
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28
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Liu L, Wang E, Zhang X, Liang W, Li X, Xie H. MEMS-BASED 3D CONFOCAL SCANNING MICROENDOSCOPE USING MEMS SCANNERS FOR BOTH LATERAL AND AXIAL SCAN. SENSORS AND ACTUATORS. A, PHYSICAL 2014; 215:89-95. [PMID: 25013304 PMCID: PMC4083856 DOI: 10.1016/j.sna.2013.09.035] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
A fiber-optic 3D confocal scanning microendoscope employing MEMS scanners for both lateral and axial scan was designed and constructed. The MEMS 3D scan engine achieved a lateral scan range of over ± 26° with a 2D MEMS scanning micromirror and a depth scan of over 400 μm with a 1D MEMS tunable microlens. The lateral resolution and axial resolution of this system were experimentally measured as 1.0 μm and 7.0 μm, respectively. 2D and 3D confocal reflectance images of micro-patterns, micro-particles, onion skins and acute rat brain tissue were obtained by this MEMS-based 3D confocal scanning microendoscope.
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Affiliation(s)
- Lin Liu
- Dept. of Electrical & Computer Engineering, University of Florida, Gainesville, FL 32611
| | - Erkang Wang
- Dept. of Electrical & Computer Engineering, University of Florida, Gainesville, FL 32611
| | - Xiaoyang Zhang
- Dept. of Electrical & Computer Engineering, University of Florida, Gainesville, FL 32611
| | - Wenxuan Liang
- Dept. of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21205
| | - Xingde Li
- Dept. of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21205
| | - Huikai Xie
- Dept. of Electrical & Computer Engineering, University of Florida, Gainesville, FL 32611
- Contact Corresponding author: Huikai Xie Tel: 1- 352- 846-0441 Fax: 1-352- 392-8671 Mail address: 221 Larsen Hall, University of Florida, Gainesville, FL 32611
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29
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Keiser G, Xiong F, Cui Y, Shum PP. Review of diverse optical fibers used in biomedical research and clinical practice. JOURNAL OF BIOMEDICAL OPTICS 2014; 19:080902. [PMID: 25166470 DOI: 10.1117/1.jbo.19.8.080902] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Accepted: 08/05/2014] [Indexed: 05/13/2023]
Abstract
Optical fiber technology has significantly bolstered the growth of photonics applications in basic life sciences research and in biomedical diagnosis, therapy, monitoring, and surgery. The unique operational characteristics of diverse fibers have been exploited to realize advanced biomedical functions in areas such as illumination, imaging, minimally invasive surgery, tissue ablation, biological sensing, and tissue diagnosis. This review paper provides the necessary background to understand how optical fibers function, to describe the various categories of available fibers, and to illustrate how specific fibers are used for selected biomedical photonics applications. Research articles and vendor data sheets were consulted to describe the operational characteristics of conventional and specialty multimode and single-mode solid-core fibers, double-clad fibers, hard-clad silica fibers, conventional hollow-core fibers, photonic crystal fibers, polymer optical fibers, side-emitting and side-firing fibers, middle-infrared fibers, and optical fiber bundles. Representative applications from the recent literature illustrate how various fibers can be utilized in a wide range of biomedical disciplines. In addition to helping researchers refine current experimental setups, the material in this review paper will help conceptualize and develop emerging optical fiber-based diagnostic and analysis tools.
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Affiliation(s)
- Gerd Keiser
- Boston University, Department of Electrical and Computer Engineering, 8 Saint Mary's Street, Boston, Massachusetts 02215, United States
| | - Fei Xiong
- City University London, Department of Electrical and Electronic Engineering, Northampton Square, London, EC1V 0HB, United Kingdom
| | - Ying Cui
- Nanyang Technological University, Photonics Centre of Excellence, School of Electrical and Electronic Engineering, 50 Nanyang Avenue, 639798, SingaporedCINTRA CNRS/NTU/THALES, UMI 3288, Research Techno Plaza, 50 Nanyang Drive, 637553, Singapore
| | - Perry Ping Shum
- Nanyang Technological University, Photonics Centre of Excellence, School of Electrical and Electronic Engineering, 50 Nanyang Avenue, 639798, Singapore
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30
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Chen SC, Choi H, So PTC, Culpepper ML. Thermomechanical Actuator-Based Three-Axis Optical Scanner for High-Speed Two-Photon Endomicroscope Imaging. JOURNAL OF MICROELECTROMECHANICAL SYSTEMS : A JOINT IEEE AND ASME PUBLICATION ON MICROSTRUCTURES, MICROACTUATORS, MICROSENSORS, AND MICROSYSTEMS 2014; 23:570-578. [PMID: 25673965 PMCID: PMC4321806 DOI: 10.1109/jmems.2013.2287708] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
This paper presents the design and characterization of a three-axis thermomechanical actuator-based endoscopic scanner for obtaining ex vivo two-photon images. The scanner consisted of two sub-systems: 1) an optical system (prism, gradient index lens, and optical fiber) that was used to deliver and collect light during imaging and 2) a small-scale silicon electromechanical scanner that could raster scan the focal point of the optics through a specimen. The scanner can be housed within a 7 mm Ø endoscope port and can scan at the speed of 3 kHz × 100 Hz × 30 Hz along three axes throughout a 125 × 125 × 100 μm3 volume. The high-speed thermomechanical actuation was achieved through the use of geometric contouring, pulsing technique, and mechanical frequency multiplication (MFM), where MFM is a new method for increasing the device cycling speed by pairing actuators of unequal forward and returning stroke speeds. Sample cross-sectional images of 15-μm fluorescent beads are presented to demonstrate the resolution and optical cross-sectioning capability of the two-photon imaging system.
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Affiliation(s)
- Shih-Chi Chen
- Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Hong Kong
| | - Heejin Choi
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 USA
| | - Peter T. C. So
- Department of Mechanical Engineering, and the Department of Biological Engineering Massachusetts Institute of Technology, Cambridge, MA 02139 USA
| | - Martin L. Culpepper
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 USA
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31
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Mittal R, Balu M, Wilder-Smith P, Potma EO. Achromatic miniature lens system for coherent Raman scattering microscopy. BIOMEDICAL OPTICS EXPRESS 2013; 4:2196-2206. [PMID: 24156075 PMCID: PMC3799677 DOI: 10.1364/boe.4.002196] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Revised: 08/03/2013] [Accepted: 08/23/2013] [Indexed: 06/02/2023]
Abstract
We discuss the design and performance of a miniature objective lens optimized for coherent Raman scattering microscopy. The packaged lens assembly has a numerical aperture of 0.51 in water and an outer diameter of 8 mm. The lens system exhibits minimum chromatic aberrations, and produces coherent Raman scattering images with sub-micrometer lateral resolution (0.648 μm) using near-infrared excitation pulses. We demonstrate that despite the small dimensions of the miniature objective, the performance of this lens system is comparable to standard microscope objective lenses, offering opportunities for miniaturizing coherent Raman scattering imaging probes without sacrificing the image quality.
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32
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Chen SL, Xie Z, Guo LJ, Wang X. A fiber-optic system for dual-modality photoacoustic microscopy and confocal fluorescence microscopy using miniature components. PHOTOACOUSTICS 2013; 1:30-35. [PMID: 24466507 PMCID: PMC3899796 DOI: 10.1016/j.pacs.2013.07.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Imaging of the cells and microvasculature simultaneously is beneficial to the study of tumor angiogenesis and microenvironments. We designed and built a fiber-optic based photoacoustic microscopy (PAM) and confocal fluorescence microscopy (CFM) dual-modality imaging system. To explore the feasibility of this all-optical device for future endoscopic applications, a microelectromechanical systems (MEMS) scanner, a miniature objective lens, and a small size optical microring resonator as an acoustic detector were employed trying to meet the requirements of miniaturization. Both the lateral resolutions of PAM and CFM were quantified to be 8.8 μm. Axial resolutions of PAM and CFM were experimentally measured to be 19 μm and 53 μm, respectively. The experiments on ex vivo animal bladder tissues demonstrate the good performance of this system in imaging not only microvasculature but also cellular structure, suggesting that this novel imaging technique holds potential for improved diagnosis and guided treatment of bladder cancer.
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Affiliation(s)
- Sung-Liang Chen
- Department of Radiology, University of Michigan, Ann Arbor, MI 48109, United States
| | - Zhixing Xie
- Department of Radiology, University of Michigan, Ann Arbor, MI 48109, United States
- Corresponding author. Tel.: +1 734 8468816.
| | - L. Jay Guo
- Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI 48109, United States
| | - Xueding Wang
- Department of Radiology, University of Michigan, Ann Arbor, MI 48109, United States
- Corresponding author. Tel.: +1 734 6472728.
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33
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Qiu Z, Liu Z, Duan X, Khondee S, Joshi B, Mandella MJ, Oldham K, Kurabayashi K, Wang TD. Targeted vertical cross-sectional imaging with handheld near-infrared dual axes confocal fluorescence endomicroscope. BIOMEDICAL OPTICS EXPRESS 2013; 4:322-30. [PMID: 23412564 PMCID: PMC3567718 DOI: 10.1364/boe.4.000322] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Revised: 01/16/2013] [Accepted: 01/16/2013] [Indexed: 05/08/2023]
Abstract
We demonstrate vertical cross-sectional (XZ-plane) images of near-infrared (NIR) fluorescence with a handheld dual axes confocal endomicroscope that reveals specific binding of a Cy5.5-labeled peptide to pre-malignant colonic mucosa. This view is perpendicular to the tissue surface, and is similar to that used by pathologists. The scan head is 10 mm in outer diameter (OD), and integrates a one dimensional (1-D) microelectromechanical systems (MEMS) X-axis scanner and a bulky lead zirconate titanate (PZT) based Z-axis actuator. The microscope images in a raster-scanning pattern with a ±6 degrees (mechanical) scan angle at ~3 kHz in the X-axis (fast) and up to 10 Hz (0-400 μm) in the Z-axis (slow). Vertical cross-sectional fluorescence images are collected with a transverse and axial resolution of 4 and 5 μm, respectively, over a field-of-view of 800 μm (width) × 400 μm (depth). NIR vertical cross-sectional fluorescence images of fresh mouse colonic mucosa demonstrate histology-like imaging performance with this miniature instrument.
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Affiliation(s)
- Zhen Qiu
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
| | - Zhongyao Liu
- Department of Medicine, Division of Gastroenterology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Xiyu Duan
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
| | - Supang Khondee
- Department of Medicine, Division of Gastroenterology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Bishnu Joshi
- Department of Medicine, Division of Gastroenterology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Michael J. Mandella
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Kenn Oldham
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
| | - Katsuo Kurabayashi
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI 48109, USA
| | - Thomas D. Wang
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Medicine, Division of Gastroenterology, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
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34
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Bedard N, Tkaczyk TS. Snapshot spectrally encoded fluorescence imaging through a fiber bundle. JOURNAL OF BIOMEDICAL OPTICS 2012; 17:080508-1. [PMID: 23224159 PMCID: PMC3422462 DOI: 10.1117/1.jbo.17.8.080508] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Revised: 06/18/2012] [Accepted: 07/18/2012] [Indexed: 05/21/2023]
Abstract
Fiber optic endomicroscopy is a valuable tool for clinical diagnostics and animal studies because it can capture images of tissue in vivo with subcellular resolution. Current configurations for endomicroscopes have either limited spatial resolution or require a scanning mechanism at the distal end of the fiber, which can slow imaging speed and increase the probe size. We present a novel configuration that provides high contrast 350 × 350 pixel images at 7.2 frames per second, without the need for mechanical scanning at the proximal or distal end of the fiber. The proof-of-concept benchtop system is tested in fluorescence mode and can resolve 1.5 µm features of a high resolution 1951 USAF target.
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Affiliation(s)
- Noah Bedard
- Rice University, Department of Bioengineering, 6500 Main Street, MS-142, Houston, Texas 77005
| | - Tomasz S. Tkaczyk
- Rice University, Department of Bioengineering, 6500 Main Street, MS-142, Houston, Texas 77005
- Address all correspondence to: Tomasz S. Tkaczyk, Rice University, Department of Bioengineering, 6500 Main Street, MS-142, Houston, Texas 77005. E-mail:
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35
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Mahalati RN, Askarov D, Wilde JP, Kahn JM. Adaptive control of input field to achieve desired output intensity profile in multimode fiber with random mode coupling. OPTICS EXPRESS 2012; 20:14321-14337. [PMID: 22714494 DOI: 10.1364/oe.20.014321] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We develop a method for synthesis of a desired intensity profile at the output of a multimode fiber (MMF) with random mode coupling by controlling the input field distribution using a spatial light modulator (SLM) whose complex reflectance is piecewise constant over a set of disjoint blocks. Depending on the application, the desired intensity profile may be known or unknown a priori. We pose the problem as optimization of an objective function quantifying, and derive a theoretical lower bound on the achievable objective function. We present an adaptive sequential coordinate ascent (SCA) algorithm for controlling the SLM, which does not require characterizing the full transfer characteristic of the MMF, and which converges to near the lower bound after one pass over the SLM blocks. This algorithm is faster than optimizations based on genetic algorithms or random assignment of SLM phases. We present simulated and experimental results applying the algorithm to forming spots of light at a MMF output, and describe how the algorithm can be applied to imaging.
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Affiliation(s)
- Reza Nasiri Mahalati
- Department of Electrical Engineering, Stanford University, Stanford, CA 94305, USA.
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36
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Wang Y, Kumar K, Wang L, Zhang X. Monolithic integration of binary-phase Fresnel zone plate objectives on 2-axis scanning micromirrors for compact microscopes. OPTICS EXPRESS 2012; 20:6657-6668. [PMID: 22418549 DOI: 10.1364/oe.20.006657] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We demonstrated a unique monolithic integration of Fresnel elliptical zone plate (EZP) objective on a 2-axis staggered vertical comb-drive micromirror with 500 μm by 800 μm surface area via direct patterning of reflective binary phase modulation elements on a silicon chip. The need for focusing optics is thus obviated, simplifying the micro-endoscope assembly and improving its form factor. The design of binary phase EZP was guided by simulations based on FFT based Rayleigh-Sommerfeld diffraction model. For dual-axis scanning angles up to 9º by 9º at the image plane, the simulated diffracted Airy disks on a spatial map have been demonstrated to vary from 10.5 μm to 28.6 μm. Micromirrors scanning ±9º (optical) about both axes are patterned with elliptical zones designed for 7 mm focal length and 20þ off-axis 635-nm illumination using 635 nm laser. Videos of samples acquired with ~15 μm lateral resolution over 1mm × 0.35 mm field of view (FOV) at 5.0 frames/second using the device in both transmission and reflectance modes bench-top single-fiber laser scanning confocal microscope confirmed the applicability of the device to micro-endoscopy.
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Affiliation(s)
- Youmin Wang
- Department of Electrical and Computer Engineering, University of Texas at Austin, 1 University Station C0803, Austin, Texas 78712, USA
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37
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Bai Y, Pallapa M, Chen A, Constantinou P, Damaskinos S, Wilson BC, Yeow JTW. A 2D MEMS mirror with sidewall electrodes applied for confocal MACROscope imaging. J Microsc 2011; 245:210-20. [PMID: 22092486 DOI: 10.1111/j.1365-2818.2011.03563.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This paper presents microelectromechanical system micromirrors with sidewall electrodes applied for use as a Confocal MACROscope for biomedical imaging. The MACROscope is a fluorescence and brightfield confocal laser scanning microscope with a very large field of view. In this paper, a microelectromechanical system mirror with sidewall electrodes replaces the galvo-scanner and XYZ-stage to improve the confocal MACROscope design and obtain an image. Two micromirror-based optical configurations are developed and tested to optimize the optical design through scanning angle, field of view and numerical aperture improvement. Meanwhile, the scanning frequency and control waveform of the micromirror are tested. Analysing the scan frequency and waveform becomes a key factor to optimize the micromirror-based confocal MACROscope. When the micromirror is integrated into the MACROscope and works at 40 Hz, the micromirror with open-loop control possesses good repeatability, so that the synchronization among the scanner, XYZ-stage and image acquisition can be realized. A laser scanning microscope system based on the micromirror with 2 μm width torsion bars was built and a 2D image was obtained as well. This work forms the experimental basis for building a practical confocal MACROscope.
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Affiliation(s)
- Y Bai
- Department of Systems Design Engineering, University of Waterloo, Waterloo, Ontario, Canada
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38
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Jabbour JM, Saldua MA, Bixler JN, Maitland KC. Confocal endomicroscopy: instrumentation and medical applications. Ann Biomed Eng 2011; 40:378-97. [PMID: 21994069 DOI: 10.1007/s10439-011-0426-y] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Accepted: 09/29/2011] [Indexed: 12/11/2022]
Abstract
Advances in fiber optic technology and miniaturized optics and mechanics have propelled confocal endomicroscopy into the clinical realm. This high resolution, non-invasive imaging technology provides the ability to microscopically evaluate cellular and sub-cellular features in tissue in vivo by optical sectioning. Because many cancers originate in epithelial tissues accessible by endoscopes, confocal endomicroscopy has been explored to detect regions of possible neoplasia at an earlier stage by imaging morphological features in vivo that are significant in histopathologic evaluation. This technique allows real-time assessment of tissue which may improve diagnostic yield by guiding biopsy. Research and development continues to reduce the overall size of the imaging probe, increase the image acquisition speed, and improve resolution and field of view of confocal endomicroscopes. Technical advances will continue to enable application to less accessible organs and more complex systems in the body. Lateral and axial resolutions down to 0.5 and 3 μm, respectively, field of view as large as 800 × 450 μm, and objective lens and total probe outer diameters down to 0.35 and 1.25 mm, respectively, have been achieved. We provide a review of the historical developments of confocal imaging in vivo, the evolution of endomicroscope instrumentation, and the medical applications of confocal endomicroscopy.
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Affiliation(s)
- Joey M Jabbour
- Department of Biomedical Engineering, Texas A&M University, 3120 TAMU, College Station, TX 77843, USA
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39
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Lin B, Urayama S, Saroufeem RMG, Matthews DL, Demos SG. Endomicroscopy imaging of epithelial structures using tissue autofluorescence. JOURNAL OF BIOMEDICAL OPTICS 2011; 16:046014. [PMID: 21529083 DOI: 10.1117/1.3565216] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We explore autofluorescence endomicroscopy as a potential tool for real-time visualization of epithelial tissue microstructure and organization in a clinical setting. The design parameters are explored using two experimental systems--an Olympus Medical Systems Corp. stand-alone clinical prototype probe, and a custom built bench-top rigid fiber conduit prototype. Both systems entail ultraviolet excitation at 266 nm and/or 325 nm using compact laser sources. Preliminary results using ex vivo animal and human tissue specimens suggest that this technology can be translated toward in vivo application to address the need for real-time histology.
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Affiliation(s)
- Bevin Lin
- University of California, Davis, NSF Center for Biophotonics Science & Technology, 4800 2nd Avenue, Sacramento, California 95817, USA
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40
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Makhlouf H, Rouse AR, Gmitro AF. Dual modality fluorescence confocal and spectral-domain optical coherence tomography microendoscope. BIOMEDICAL OPTICS EXPRESS 2011; 2:634-44. [PMID: 21412468 PMCID: PMC3047368 DOI: 10.1364/boe.2.000634] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2010] [Revised: 01/18/2011] [Accepted: 02/15/2011] [Indexed: 05/07/2023]
Abstract
Optical biopsy facilitates in vivo disease diagnoses by providing a real-time in situ view of tissue in a clinical setting. Fluorescence confocal microendoscopy and optical coherence tomography (OCT) are two methods that have demonstrated significant potential in this context. These techniques provide complementary viewpoints. The high resolution and contrast associated with confocal systems allow en face visualization of sub-cellular details and cellular organization within a thin layer of biological tissue. OCT provides cross-sectional images showing the tissue micro-architecture to a depth beyond the reach of confocal systems. We present a novel design for a bench-top imaging system that incorporates both confocal and OCT modalities in the same optical train allowing the potential for rapid switching between the two imaging techniques. Preliminary results using simple phantoms show that it is possible to realize both confocal microendoscopy and OCT through a fiber bundle based imaging system.
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Affiliation(s)
- Houssine Makhlouf
- College of Optical Sciences, University of Arizona, 1630 East University Boulevard, Tucson, Arizona 85721, USA
- Department of Radiology, University of Arizona, 1609 North Warren Avenue, Tucson, Arizona 85724, USA
| | - Andrew R. Rouse
- Department of Radiology, University of Arizona, 1609 North Warren Avenue, Tucson, Arizona 85724, USA
| | - Arthur F. Gmitro
- College of Optical Sciences, University of Arizona, 1630 East University Boulevard, Tucson, Arizona 85721, USA
- Department of Radiology, University of Arizona, 1609 North Warren Avenue, Tucson, Arizona 85724, USA
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41
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Hendriks BHW, Bierhoff WCJ, Horikx JJL, Desjardins AE, Hezemans CA, 't Hooft GW, Lucassen GW, Mihajlovic N. High-resolution resonant and nonresonant fiber-scanning confocal microscope. JOURNAL OF BIOMEDICAL OPTICS 2011; 16:026007. [PMID: 21361691 DOI: 10.1117/1.3534781] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We present a novel, hand-held microscope probe for acquiring confocal images of biological tissue. This probe generates images by scanning a fiber-lens combination with a miniature electromagnetic actuator, which allows it to be operated in resonant and nonresonant scanning modes. In the resonant scanning mode, a circular field of view with a diameter of 190 μm and an angular frequency of 127 Hz can be achieved. In the nonresonant scanning mode, a maximum field of view with a width of 69 μm can be achieved. The measured transverse and axial resolutions are 0.60 and 7.4 μm, respectively. Images of biological tissue acquired in the resonant mode are presented, which demonstrate its potential for real-time tissue differentiation. With an outer diameter of 3 mm, the microscope probe could be utilized to visualize cellular microstructures in vivo across a broad range of minimally-invasive procedures.
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Affiliation(s)
- Benno H W Hendriks
- Philips Research, Minimally Invasive Healthcare Department, Eindhoven 5656 AE Eindhoven, The Netherlands.
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42
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Shin D, Vigneswaran N, Gillenwater A, Richards-Kortum R. Advances in fluorescence imaging techniques to detect oral cancer and its precursors. Future Oncol 2010; 6:1143-54. [PMID: 20624126 DOI: 10.2217/fon.10.79] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Oral cancer is a significant health problem in the USA and throughout the world. Most oral cancer patients are diagnosed at a late stage, when treatment is less successful and treatment-associated morbidity is more severe. A number of new diagnostic aids to conventional oral examination have recently been introduced to assist in the early detection of oral neoplasia. In particular, autofluorescence imaging has emerged as a promising adjunctive technique to improve early identification of oral premalignant lesions. Direct visual inspection of tissue autofluorescence has shown encouraging results in high-prevalence populations, but the technique requires subjective interpretation and depends on the visual recognition skills of the examiner. Capturing and analyzing digital fluorescence images can reduce subjectivity and potentially improve sensitivity of detection of precancerous changes. Recent studies of wide-field autofluorescence imaging in low-prevalence populations suggest that benign lesions such as inflammation may give rise to false-positive results. High-resolution fluorescence imaging is a new modality that can be used in conjunction with wide-field imaging to improve specificity by imaging subcellular detail of neoplastic tissues. The combination of wide-field and high-resolution fluorescence imaging systems with automated image analysis should be investigated to maximize overall diagnostic performance for early detection of oral neoplasia.
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Affiliation(s)
- Dongsuk Shin
- Rice University, Department of Bioengineering, 6500 Main St., Houston, TX 77030, USA
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43
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Abstract
Optical contrast based on elastic scattering interactions between light and matter can be used to probe cellular structure, cellular dynamics, and image tissue architecture. The quantitative nature and high sensitivity of light scattering signals to subtle alterations in tissue morphology, as well as the ability to visualize unstained tissue in vivo, has recently generated significant interest in optical-scatter-based biosensing and imaging. Here we review the fundamental methodologies used to acquire and interpret optical scatter data. We report on recent findings in this field and present current advances in optical scatter techniques and computational methods. Cellular and tissue data enabled by current advances in optical scatter spectroscopy and imaging stand to impact a variety of biomedical applications including clinical tissue diagnosis, in vivo imaging, drug discovery, and basic cell biology.
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Affiliation(s)
- Nada N. Boustany
- Corresponding Author: Rutgers University, Dept. of Biomedical Engineering, 599 Taylor Road, Piscataway, NJ 08854, Tel: (732) 445-4500 x6320,
| | - Stephen A. Boppart
- University of Illinois Urbana-Champaign, Depts. of Electrical and Computer Engineering, Bioengineering, Medicine, Beckman Institute for Advanced Science and Technology, 405 N. Mathews Avenue, Urbana, IL 61801, Tel: (217) 244-7479
| | - Vadim Backman
- Northwestern University, McCormick School of Engineering and Applied Sciences, Department of Biomedical Engineering, 2145 Sheridan Road, Evanston IL 60208, Tel: (847) 491-3536
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44
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Chia SH, Yu CH, Lin CH, Cheng NC, Liu TM, Chan MC, Chen IH, Sun CK. Miniaturized video-rate epi-third-harmonic-generation fiber-microscope. OPTICS EXPRESS 2010; 18:17382-91. [PMID: 20721125 DOI: 10.1364/oe.18.017382] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
With a micro-electro-mechanical system (MEMS) mirror, we successfully developed a miniaturized epi-third-harmonic-generation (epi-THG) fiber-microscope with a video frame rate (31 Hz), which was designed for in vivo optical biopsy of human skin. With a large-mode-area (LMA) photonic crystal fiber (PCF) and a regular microscopic objective, the nonlinear distortion of the ultrafast pulses delivery could be much reduced while still achieving a 0.4 microm lateral resolution for epi-THG signals. In vivo real time virtual biopsy of the Asian skin with a video rate (31 Hz) and a sub-micron resolution was obtained. The result indicates that this miniaturized system was compact enough for the least invasive hand-held clinical use.
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Affiliation(s)
- Shih-Hsuan Chia
- Department of Electrical Engineering, Graduate Inst of Photonics and Optoelectronics, Natl Taiwan Univ, Taipei 10617, Taiwan
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45
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Park HC, Song C, Jeong KH. Micromachined lens microstages for two-dimensional forward optical scanning. OPTICS EXPRESS 2010; 18:16133-16138. [PMID: 20720998 DOI: 10.1364/oe.18.016133] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
This work presents a novel approach for a miniaturized optical scanning module based on lateral and piston motion of two commercial lenses by MEMS actuation. Two aspheric glass lenses of 1 mm diameter are assembled on two electrostatically actuated microstages moving along perpendicular axes to tilt optical path. The compact integration secures the effective beam aperture of 0.6 mm within the device width of 2 mm. The lens mass provides high-Q motions at low operating voltages of DC 5 V and AC 10 V, i.e., the lateral angle of 4.6 degrees at 277 Hz and the vertical angle of 5.3 degrees at 204 Hz. The device can provide a new direction for miniaturizing laser scanning based endoscopes or handheld projectors.
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Affiliation(s)
- Hyeon-Cheol Park
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Korea
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46
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Piyawattanametha W, Wang TD. MEMS-Based Dual Axes Confocal Microendoscopy. IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS : A PUBLICATION OF THE IEEE LASERS AND ELECTRO-OPTICS SOCIETY 2010; 16:804-814. [PMID: 22190845 PMCID: PMC3242380 DOI: 10.1109/jstqe.2009.2032785] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
We demonstrate a miniature, near-infrared microscope (λ = 785 nm) that uses a novel dual axes confocal architecture. Scalability is achieved with post-objective scanning, and a MEMS mirror provides real time (>4 Hz) in vivo imaging. This instrument can achieve sub-cellular resolution with deep tissue penetration and large field of view. An endoscope-compatible version can image digestive tract epithelium to guide tissue biopsy and monitor therapy.
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Affiliation(s)
- Wibool Piyawattanametha
- National Electronics and Computer Technology Center, Pathumthani 12120, Thailand; Departments of Applied Physics, Biology, Electrical Engineering, Microbiology & Immunology, and Pediatrics, Stanford University, CA 94305 USA ()
| | - Thomas D. Wang
- Department of Medicine, Division of Gastroenterology, and Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48104 ()
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47
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Arrasmith CL, Dickensheets DL, Mahadevan-Jansen A. MEMS-based handheld confocal microscope for in-vivo skin imaging. OPTICS EXPRESS 2010; 18:3805-19. [PMID: 20389391 PMCID: PMC3378354 DOI: 10.1364/oe.18.003805] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2009] [Revised: 01/24/2010] [Accepted: 02/01/2010] [Indexed: 05/20/2023]
Abstract
This paper describes a handheld laser scanning confocal microscope for skin microscopy. Beam scanning is accomplished with an electromagnetic MEMS bi-axial micromirror developed for pico projector applications, providing 800 x 600 (SVGA) resolution at 56 frames per second. The design uses commercial objective lenses with an optional hemisphere front lens, operating with a range of numerical aperture from NA=0.35 to NA=1.1 and corresponding diagonal field of view ranging from 653 microm to 216 microm. Using NA=1.1 and a laser wavelength of 830 nm we measured the axial response to be 1.14 mum full width at half maximum, with a corresponding 10%-90% lateral edge response of 0.39 mum. Image examples showing both epidermal and dermal features including capillary blood flow are provided. These images represent the highest resolution and frame rate yet achieved for tissue imaging with a MEMS bi-axial scan mirror.
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Affiliation(s)
- Christopher L Arrasmith
- Electrical and Computer Engineering Department, Montana State University, 610 Cobleigh Hall, Bozeman, Montana, USA.
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Tanbakuchi AA, Udovich JA, Rouse AR, Hatch KD, Gmitro AF. In vivo imaging of ovarian tissue using a novel confocal microlaparoscope. Am J Obstet Gynecol 2010; 202:90.e1-9. [PMID: 19800605 PMCID: PMC2811223 DOI: 10.1016/j.ajog.2009.07.027] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2009] [Revised: 06/04/2009] [Accepted: 07/14/2009] [Indexed: 11/24/2022]
Abstract
OBJECTIVE The objective of the study was to develop a clinical confocal microlaparoscope for imaging ovary epithelium in vivo with the long-term objective of diagnosing cancer in vivo. STUDY DESIGN A confocal microlaparoscope was developed and used to image the ovaries of 21 patients in vivo using fluorescein sodium and acridine orange as the fluorescent contrast agents. RESULTS The device was tested in vivo and demonstrated to be safe and function as designed. Real-time cellular visualization of ovary epithelium was demonstrated. CONCLUSION The confocal microlaparoscope represents a new type of in vivo imaging device. With its ability to image cellular details in real time, it has the potential to aid in the early diagnosis of cancer. Initially the device may be used to locate unusual regions for guided biopsies. In the long term, the device may be able to supplant traditional biopsies and allow the surgeon to identify early-stage ovarian cancer.
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Affiliation(s)
- Anthony A. Tanbakuchi
- Department of Radiology, University of Arizona, Tucson, Arizona 85724
- College of Optical Sciences. University of Arizona, Tucson, Arizona 85721
| | - Joshua A. Udovich
- Department of Radiology, University of Arizona, Tucson, Arizona 85724
- College of Optical Sciences. University of Arizona, Tucson, Arizona 85721
| | - Andrew R. Rouse
- Department of Radiology, University of Arizona, Tucson, Arizona 85724
| | - Kenneth D. Hatch
- Department of Obstetrics and Gynecology, College of Medicine, University of Arizona, Tucson, Arizona 85724
| | - Arthur F. Gmitro
- Department of Radiology, University of Arizona, Tucson, Arizona 85724
- College of Optical Sciences. University of Arizona, Tucson, Arizona 85721
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Udovich JA, Besselsen DG, Gmitro AF. Assessment of acridine orange and SYTO 16 for in vivo imaging of the peritoneal tissues in mice. J Microsc 2009; 234:124-9. [PMID: 19397741 DOI: 10.1111/j.1365-2818.2009.03153.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The effect of peritoneal injection of acridine orange and SYTO 16 in mice was investigated. Images of peritoneal tissues stained with these dyes and obtained through a confocal micro-endoscope are presented. Seventy-five Balb/c mice were split into five groups and given peritoneal injections of dye or saline. The proportions of negative outcomes in each group were compared using confidence intervals and the Fisher's exact statistical test. A statistically significant increase in adverse events due to dye injection was not observed. These data provide an initial investigation into the safety of acridine orange and SYTO 16 for in vivo imaging.
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Affiliation(s)
- J A Udovich
- College of Optical Sciences, University of Arizona, Tucson, Arizona, USA
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Santos S, Chu KK, Lim D, Bozinovic N, Ford TN, Hourtoule C, Bartoo AC, Singh SK, Mertz J. Optically sectioned fluorescence endomicroscopy with hybrid-illumination imaging through a flexible fiber bundle. JOURNAL OF BIOMEDICAL OPTICS 2009; 14:030502. [PMID: 19566286 DOI: 10.1117/1.3130266] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
We present an endomicroscope apparatus that exhibits out-of-focus background rejection based on wide-field illumination through a flexible imaging fiber bundle. Our technique, called HiLo microscopy, involves acquiring two images, one with grid-pattern illumination and another with standard uniform illumination. An evaluation of the image contrast with grid-pattern illumination provides an optically sectioned image with low resolution. This is complemented with high-resolution information from the uniform illumination image, leading to a full-resolution image that is optically sectioned. HiLo endomicroscope movies are presented of fluorescently labeled rat colonic mucosa.
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