1
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Dong J, Grant C, Vuong B, Nishioka N, Gao AH, Beatty M, Baldwin G, Bailargeon A, Bablouzian A, Grahmann P, Bhat N, Ryan E, Barrios A, Giddings S, Ford T, Beaulieu-Ouellet E, Hosseiny SH, Lerman I, Trasischker W, Reddy R, Singh K, Gora M, Hyun D, Queneherve L, Wallace M, Wolfsen H, Sharma P, Wang KK, Leggett CL, Poneros J, Abrams JA, Lightdale C, Leeds S, Rosenberg M, Tearney G. Feasibility and Safety of Tethered Capsule Endomicroscopy in Patients With Barrett's Esophagus in a Multi-Center Study. Clin Gastroenterol Hepatol 2022; 20:756-765.e3. [PMID: 33549871 PMCID: PMC8715859 DOI: 10.1016/j.cgh.2021.02.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 02/02/2021] [Indexed: 02/07/2023]
Abstract
BACKGROUND & AIMS Tethered capsule endomicroscopy (TCE) involves swallowing a small tethered pill that implements optical coherence tomography (OCT) imaging, procuring high resolution images of the whole esophagus. Here, we demonstrate and evaluate the feasibility and safety of TCE and a portable OCT imaging system in patients with Barrett's esophagus (BE) in a multi-center (5-site) clinical study. METHODS Untreated patients with BE as per endoscopic biopsy diagnosis were eligible to participate in the study. TCE procedures were performed in unsedated patients by either doctors or nurses. After the capsule was swallowed, the device continuously obtained 10-μm-resolution cross-sectional images as it traversed the esophagus. Following imaging, the device was withdrawn through mouth, and disinfected for subsequent reuse. BE lengths were compared to endoscopy findings when available. OCT-TCE images were compared to volumetric laser endomicroscopy (VLE) images from a patient who had undergone VLE on the same day as TCE. RESULTS 147 patients with BE were enrolled across all sites. 116 swallowed the capsule (79%), 95/114 (83.3%) men and 21/33 (63.6%) women (P = .01). High-quality OCT images were obtained in 104/111 swallowers (93.7%) who completed the procedure. The average imaging duration was 5.55 ± 1.92 minutes. The mean length of esophagus imaged per patient was 21.69 ± 5.90 cm. A blinded comparison of maximum extent of BE measured by OCT-TCE and EGD showed a strong correlation (r = 0.77-0.79). OCT-TCE images were of similar quality to those obtained by OCT-VLE. CONCLUSIONS The capabilities of TCE to be used across multiple sites, be administered to unsedated patients by either physicians or nurses who are not expert in OCT-TCE, and to rapidly and safely evaluate the microscopic structure of the esophagus make it an emerging tool for screening and surveillance of BE patients. Clinical trial registry website and trial number: NCT02994693 and NCT03459339.
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Affiliation(s)
- Jing Dong
- Wellman Center for Photomedicine, Massachusetts General Hospital, MA,Harvard Medical School, MA
| | - Catriona Grant
- Wellman Center for Photomedicine, Massachusetts General Hospital, MA
| | - Barry Vuong
- Wellman Center for Photomedicine, Massachusetts General Hospital, MA,Harvard Medical School, MA
| | - Norman Nishioka
- Wellman Center for Photomedicine, Massachusetts General Hospital, MA,Harvard Medical School, MA
| | - Anna Huizi Gao
- Wellman Center for Photomedicine, Massachusetts General Hospital, MA
| | - Matthew Beatty
- Wellman Center for Photomedicine, Massachusetts General Hospital, MA
| | - Grace Baldwin
- Wellman Center for Photomedicine, Massachusetts General Hospital, MA
| | - Aaron Bailargeon
- Wellman Center for Photomedicine, Massachusetts General Hospital, MA
| | - Ara Bablouzian
- Wellman Center for Photomedicine, Massachusetts General Hospital, MA
| | - Patricia Grahmann
- Wellman Center for Photomedicine, Massachusetts General Hospital, MA
| | - Nitasha Bhat
- Wellman Center for Photomedicine, Massachusetts General Hospital, MA
| | - Emily Ryan
- Wellman Center for Photomedicine, Massachusetts General Hospital, MA
| | - Amilcar Barrios
- Wellman Center for Photomedicine, Massachusetts General Hospital, MA
| | - Sarah Giddings
- Wellman Center for Photomedicine, Massachusetts General Hospital, MA
| | - Timothy Ford
- Wellman Center for Photomedicine, Massachusetts General Hospital, MA,Harvard Medical School, MA
| | | | | | - Irene Lerman
- Wellman Center for Photomedicine, Massachusetts General Hospital, MA
| | - Wolfgang Trasischker
- Wellman Center for Photomedicine, Massachusetts General Hospital, MA,Harvard Medical School, MA
| | - Rohith Reddy
- Wellman Center for Photomedicine, Massachusetts General Hospital, MA,Harvard Medical School, MA
| | - Kanwarpal Singh
- Wellman Center for Photomedicine, Massachusetts General Hospital, MA,Harvard Medical School, MA
| | - Michalina Gora
- Wellman Center for Photomedicine, Massachusetts General Hospital, MA,Harvard Medical School, MA,ICube Laboratory, CNRS, Strasbourg University, France
| | - Daryl Hyun
- Wellman Center for Photomedicine, Massachusetts General Hospital, MA
| | - Lucille Queneherve
- Wellman Center for Photomedicine, Massachusetts General Hospital, MA,Harvard Medical School, MA
| | - Michael Wallace
- Division of Gastroenterology and Hepatology, Mayo Clinic Jacksonville, FL
| | - Herbert Wolfsen
- Division of Gastroenterology and Hepatology, Mayo Clinic Jacksonville, FL
| | - Prateek Sharma
- Department of Gastroenterology, Kansas City Veterans Administration and University of Kansas School of Medicine, MO
| | - Kenneth K. Wang
- Division of Gastroenterology and Hepatology,, Mayo Clinic Rochester, MN
| | - Cadman L. Leggett
- Division of Gastroenterology and Hepatology,, Mayo Clinic Rochester, MN
| | | | | | | | | | - Mireille Rosenberg
- Wellman Center for Photomedicine, Massachusetts General Hospital, MA,Harvard Medical School, MA
| | - Guillermo Tearney
- Wellman Center for Photomedicine, Massachusetts General Hospital, MA,Harvard Medical School, MA,Department of Pathology, Massachusetts General Hospital, MA,Harvard-MIT Division of Health Science and Technology (HST)
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Liang CP, Dong J, Ford T, Reddy R, Hosseiny H, Farrokhi H, Beatty M, Singh K, Osman H, Vuong B, Baldwin G, Grant C, Giddings S, Gora MJ, Rosenberg M, Nishioka N, Tearney G. Optical coherence tomography-guided laser marking with tethered capsule endomicroscopy in unsedated patients. Biomed Opt Express 2019; 10:1207-1222. [PMID: 30891340 PMCID: PMC6420285 DOI: 10.1364/boe.10.001207] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 12/23/2018] [Accepted: 01/06/2019] [Indexed: 05/28/2023]
Abstract
Tethered capsule endomicroscopy (TCE) is an emerging screening technology that comprehensively obtains microstructural OCT images of the gastrointestinal (GI) tract in unsedated patients. To advance clinical adoption of this imaging technique, it will be important to validate TCE images with co-localized histology, the current diagnostic gold standard. One method for co-localizing OCT images with histology is image-targeted laser marking, which has previously been implemented using a driveshaft-based, balloon OCT catheter, deployed during endoscopy. In this paper, we present a TCE device that scans and targets the imaging beam using a low-cost stepper motor that is integrated inside the capsule. In combination with a 4-laser-diode, high power 1430/1450 nm marking laser system (800 mW on the sample and 1s pulse duration), this technology generated clearly visible marks, with a spatial targeting accuracy of better than 0.5 mm. A laser safety study was done on swine esophagus ex vivo, showing that these exposure parameters did not alter the submucosa, with a large, 4-5x safety margin. The technology was demonstrated in living human subjects and shown to be effective for co-localizing OCT TCE images to biopsies obtained during subsequent endoscopy.
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Affiliation(s)
- Chia-Pin Liang
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA
| | - Jing Dong
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA
| | - Tim Ford
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA
| | - Rohith Reddy
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA
| | - Hamid Hosseiny
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA
| | - Hamid Farrokhi
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA
| | - Matthew Beatty
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA
| | - Kanwarpal Singh
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA
| | - Hany Osman
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA
| | - Barry Vuong
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA
| | - Grace Baldwin
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA
| | - Catriona Grant
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA
| | - Sarah Giddings
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA
| | - Michalina J. Gora
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA
- ICube Laboratory, CNRS, Strasbourg University, Strasbourg, France
| | - Mireille Rosenberg
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA
| | - Norman Nishioka
- Department of Gastroenterology, Harvard Medical School and Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA
| | - Guillermo Tearney
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA
- Harvard-MIT Division of Health Sciences and Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
- Department of Pathology, Harvard Medical School and Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA
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Jivraj J, Chen C, Huang Y, Ramjist J, Lu Y, Vuong B, Gu X, Yang VXD. Smart laser osteotomy: integrating a pulsed 1064nm fiber laser into the sample arm of a fiber optic 1310nm OCT system for ablation monitoring. Biomed Opt Express 2018; 9:6374-6387. [PMID: 31065435 PMCID: PMC6491001 DOI: 10.1364/boe.9.006374] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 11/09/2018] [Accepted: 11/12/2018] [Indexed: 06/09/2023]
Abstract
Real-time depth metrology during material removal via laser ablation is useful in many forms of laser machining. Until now, coaxial optical coherence tomography (OCT) metrology was achieved by the coupling of an OCT imaging beam and ablating beams using a dichroic filter. We present an alternative design with all fiber delivery that is more suitable for surgical laser ablation applications. The novel system design integrates a high peak-power pulsed Yb-doped fiber laser (1064nm) coupled directly into the sample arm of a swept-source OCT system (λc = 1310nm). We measured the OCT signal degradation due to dispersion and attenuation through the ablation fiber laser cavity. Ablation progression is measured in real-time using M-mode OCT. The mean depth targeting error was found to range from 10µm to 80µm in phantom ablation experiments and 21µm to 60µm in bone ablation. A number of issues have been solved, including point-spread function (PSF) peak broadening due to signal delay and dispersion, high bending loss due to dissimilar fiber used throughout the design, and problems due to the extremely high ablation power to swept-source power ratio (> 2×104 peak to average power). To our knowledge, this is the first demonstration of thermal-mediated laser ablation drilling integrated with coaxial OCT imaging through a single-mode, single-cladded output fiber, without using dichroic beam splitters or free-space optic filters anywhere in the optical path and with this high ablation laser power to OCT source power ratio. The removal of bulk optics compared to existing designs opens a new path for compact integration of the entire system. Also, since the ablation laser and OCT feedback system exist along the same fiber path, the need for maintenance and repair are greatly reduced since spatial beam alignment and the potential open-air contamination of optical surfaces are virtually eliminated. We believe that this integrated system is a great candidate for adoption in depth-controlled surgical ablation applications.
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Affiliation(s)
- Jamil Jivraj
- Biophotonics and Bioengineering Lab, Department of Electrical and Computer Engineering, Ryerson University, Toronto,
Canada
| | - Chaoliang Chen
- Biophotonics and Bioengineering Lab, Department of Electrical and Computer Engineering, Ryerson University, Toronto,
Canada
| | - Yize Huang
- Biophotonics and Bioengineering Lab, Department of Electrical and Computer Engineering, Ryerson University, Toronto,
Canada
| | - Joel Ramjist
- Biophotonics and Bioengineering Lab, Department of Electrical and Computer Engineering, Ryerson University, Toronto,
Canada
| | - Yi Lu
- Fiber Optics Communications and Sensing Lab, Department of Electrical and Computer Engineering, Ryerson University, Toronto,
Canada
| | - Barry Vuong
- Biophotonics and Bioengineering Lab, Department of Electrical and Computer Engineering, Ryerson University, Toronto,
Canada
| | - Xijia Gu
- Fiber Optics Communications and Sensing Lab, Department of Electrical and Computer Engineering, Ryerson University, Toronto,
Canada
| | - Victor X. D. Yang
- Biophotonics and Bioengineering Lab, Department of Electrical and Computer Engineering, Ryerson University, Toronto,
Canada
- Division of Neurosurgery, Sunnybrook Health Sciences Centre, Toronto,
Canada
- Department of Surgery, Faculty of Medicine, University of Toronto,
Canada
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4
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Vuong B, Skowron P, Kiehl TR, Kyan M, Garzia L, Sun C, Taylor MD, Yang VX. Measuring the optical characteristics of medulloblastoma with optical coherence tomography. Biomed Opt Express 2015; 6:1487-501. [PMID: 25909030 PMCID: PMC4399685 DOI: 10.1364/boe.6.001487] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Revised: 03/19/2015] [Accepted: 03/19/2015] [Indexed: 05/22/2023]
Abstract
Medulloblastoma is the most common malignant pediatric brain tumor. Standard treatment consists of surgical resection, followed by radiation and high-dose chemotherapy. Despite these efforts, recurrence is common, leading to reduced patient survival. Even with successful treatment, there are often severe long-term neurologic impacts on the developing nervous system. We present two quantitative techniques that use a high-resolution optical imaging modality: optical coherence tomography (OCT) to measure refractive index, and the optical attenuation coefficient. To the best of our knowledge, this study is the first to demonstrate OCT analysis of medulloblastoma. Refractive index and optical attenuation coefficient were able to differentiate between normal brain tissue and medulloblastoma in mouse models. More specifically, optical attenuation coefficient imaging of normal cerebellum displayed layers of grey matter and white matter, which were indistinguishable in the structural OCT image. The morphology of the tumor was distinct in the optical attenuation coefficient imaging. These inherent properties may be useful during neurosurgical intervention to better delineate tumor boundaries and minimize resection of normal tissue.
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Affiliation(s)
- Barry Vuong
- Biophotonics and Bioengineering Laboratory, Ryerson University, 350 Victoria Street, Toronto, ON, M5B 2K3,
Canada
- Department of Electrical and Computer Engineering, Ryerson University, 350 Victoria St., Toronto, M4B 2K3,
Canada
| | - Patryk Skowron
- Biophotonics and Bioengineering Laboratory, Ryerson University, 350 Victoria Street, Toronto, ON, M5B 2K3,
Canada
- Hospital for Sick Children, Arthur and Sonia Labatt Brain Tumour Research Centre and Division of Neurosurgery, 686 Bay Street, Toronto, M5G 1L7,
Canada
| | - Tim-Rasmus Kiehl
- Universiy Health Network, Department of Pathology, 190 Elizabeth St., Toronto, M5G 2C4,
Canada
- University of Toronto, Department of Laboratory Medicine and Pathobiology, 172 St George St, Toronto, M5R 0A3,
Canada
| | - Matthew Kyan
- Department of Electrical and Computer Engineering, Ryerson University, 350 Victoria St., Toronto, M4B 2K3,
Canada
| | - Livia Garzia
- Hospital for Sick Children, Arthur and Sonia Labatt Brain Tumour Research Centre and Division of Neurosurgery, 686 Bay Street, Toronto, M5G 1L7,
Canada
- Hospital for Sick Children,Program in Developmental and Stem Cell Biology, 555 University Avenue, Toronto, M5G 1X8,
Canada
- University of Toronto, Department of Laboratory Medicine and Pathobiology, 1 King’s College Circle, Toronto, M5S 1A8,
Canada
| | - Cuiru Sun
- Biophotonics and Bioengineering Laboratory, Ryerson University, 350 Victoria Street, Toronto, ON, M5B 2K3,
Canada
| | - Michael D. Taylor
- Department of Electrical and Computer Engineering, Ryerson University, 350 Victoria St., Toronto, M4B 2K3,
Canada
- Hospital for Sick Children,Program in Developmental and Stem Cell Biology, 555 University Avenue, Toronto, M5G 1X8,
Canada
- University of Toronto, Department of Laboratory Medicine and Pathobiology, 1 King’s College Circle, Toronto, M5S 1A8,
Canada
- Division of Neurosurgery, Faculty of Medicine, University of Toronto, 1 King’s College Circle, Toronto, ON, M5S 1A8,
Canada
| | - Victor X.D. Yang
- Biophotonics and Bioengineering Laboratory, Ryerson University, 350 Victoria Street, Toronto, ON, M5B 2K3,
Canada
- Division of Neurosurgery, Faculty of Medicine, University of Toronto, 1 King’s College Circle, Toronto, ON, M5S 1A8,
Canada
- Physical Science - Brain Sciences Research Program, Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, ON, M4N 3M5,
Canada
- Division of Neurosurgery, Sunnybrook Health Sciences Centre, 2075 Bayview Avenue Toronto, ON, M4N 3M5,
Canada
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5
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Farooq H, Genis H, Alarcon J, Vuong B, Jivraj J, Yang VXD, Cohen-Adad J, Fehlings MG, Cadotte DW. High-resolution imaging of the central nervous system: how novel imaging methods combined with navigation strategies will advance patient care. Prog Brain Res 2015; 218:55-78. [PMID: 25890132 DOI: 10.1016/bs.pbr.2014.12.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
This narrative review captures a subset of recent advances in imaging of the central nervous system. First, we focus on improvements in the spatial and temporal profile afforded by optical coherence tomography, fluorescence-guided surgery, and Coherent Anti-Stokes Raman Scattering Microscopy. Next, we highlight advances in the generation and uses of imaging-based atlases and discuss how this will be applied to specific clinical situations. To conclude, we discuss how these and other imaging tools will be combined with neuronavigation techniques to guide surgeons in the operating room. Collectively, this work aims to highlight emerging biomedical imaging strategies that hold potential to be a valuable tool for both clinicians and researchers in the years to come.
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Affiliation(s)
- Hamza Farooq
- Biophotonics and Bioengineering Laboratory, Department of Electrical and Computer Engineering, Ryerson University, Toronto, ON, Canada
| | - Helen Genis
- Biophotonics and Bioengineering Laboratory, Department of Electrical and Computer Engineering, Ryerson University, Toronto, ON, Canada
| | - Joseph Alarcon
- Biophotonics and Bioengineering Laboratory, Department of Electrical and Computer Engineering, Ryerson University, Toronto, ON, Canada
| | - Barry Vuong
- Biophotonics and Bioengineering Laboratory, Department of Electrical and Computer Engineering, Ryerson University, Toronto, ON, Canada
| | - Jamil Jivraj
- Biophotonics and Bioengineering Laboratory, Department of Electrical and Computer Engineering, Ryerson University, Toronto, ON, Canada
| | - Victor X D Yang
- Biophotonics and Bioengineering Laboratory, Department of Electrical and Computer Engineering, Ryerson University, Toronto, ON, Canada; Physical Science-Brain Sciences Research Program, Sunnybrook Research Institute, University of Toronto, Toronto, ON, Canada; Division of Neurosurgery, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, Canada; Division of Neurosurgery, Department of Surgery, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Julien Cohen-Adad
- Institute of Biomedical Engineering, Ecole Polytechnique de Montréal, SensoriMotor Rehabilitation Research Team of the Canadian Institute of Health Research, Montreal, QC, Canada
| | - Michael G Fehlings
- Division of Neurosurgery, Department of Surgery, Faculty of Medicine, University of Toronto, Toronto, ON, Canada; Toronto Western Hospital, University Health Network, Toronto, ON, Canada
| | - David W Cadotte
- Division of Neurosurgery, Department of Surgery, Faculty of Medicine, University of Toronto, Toronto, ON, Canada; Toronto Western Hospital, University Health Network, Toronto, ON, Canada.
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Wong R, Jivraj J, Vuong B, Ramjist J, Dinn NA, Sun C, Huang Y, Smith JA, Yang VX. Development of an integrated optical coherence tomography-gas nozzle system for surgical laser ablation applications: preliminary findings of in situ spinal cord deformation due to gas flow effects. Biomed Opt Express 2015; 6:43-53. [PMID: 25657873 PMCID: PMC4317111 DOI: 10.1364/boe.6.000043] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Revised: 11/26/2014] [Accepted: 11/26/2014] [Indexed: 06/04/2023]
Abstract
Gas assisted laser machining of materials is a common practice in the manufacturing industry. Advantages in using gas assistance include reducing the likelihood of flare-ups in flammable materials and clearing away ablated material in the cutting path. Current surgical procedures and research do not take advantage of this and in the case for resecting osseous tissue, gas assisted ablation can help minimize charring and clear away debris from the surgical site. In the context of neurosurgery, the objective is to cut through osseous tissue without damaging the underlying neural structures. Different inert gas flow rates used in laser machining could cause deformations in compliant materials. Complications may arise during surgical procedures if the dura and spinal cord are damaged by these deformations. We present preliminary spinal deformation findings for various gas flow rates by using optical coherence tomography to measure the depression depth at the site of gas delivery.
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Affiliation(s)
- Ronnie Wong
- Biophotonics and Bioengineering Laboratory, Department of Electrical and Computer Engineering, Ryerson University, Toronto, Ontario, M5B 2K3,
Canada
| | - Jamil Jivraj
- Biophotonics and Bioengineering Laboratory, Department of Electrical and Computer Engineering, Ryerson University, Toronto, Ontario, M5B 2K3,
Canada
| | - Barry Vuong
- Biophotonics and Bioengineering Laboratory, Department of Electrical and Computer Engineering, Ryerson University, Toronto, Ontario, M5B 2K3,
Canada
| | - Joel Ramjist
- Biophotonics and Bioengineering Laboratory, Department of Electrical and Computer Engineering, Ryerson University, Toronto, Ontario, M5B 2K3,
Canada
| | - Nicole A. Dinn
- Biophotonics and Bioengineering Laboratory, Department of Electrical and Computer Engineering, Ryerson University, Toronto, Ontario, M5B 2K3,
Canada
- Department of Surgical Neuromonitoring, Sunnybrook Health Sciences Centre, 2075 Bayview Ave., Toronto, Ontario, M4N 3M5,
Canada
| | - Cuiru Sun
- Biophotonics and Bioengineering Laboratory, Department of Electrical and Computer Engineering, Ryerson University, Toronto, Ontario, M5B 2K3,
Canada
| | - Yize Huang
- Biophotonics and Bioengineering Laboratory, Department of Electrical and Computer Engineering, Ryerson University, Toronto, Ontario, M5B 2K3,
Canada
| | - James A. Smith
- Department of Electrical and Computer Engineering, Ryerson University, Toronto, Ontario, M5B 2K3,
Canada
| | - Victor X.D. Yang
- Biophotonics and Bioengineering Laboratory, Department of Electrical and Computer Engineering, Ryerson University, Toronto, Ontario, M5B 2K3,
Canada
- Division of Neurosurgery, Faculty of Medicine, University of Toronto, 27 King’s College Circle, Toronto, Ontario, M5S 1A1,
Canada
- Division of Neurosurgery, Sunnybrook Health Sciences Centre, 2075 Bayview Ave., Toronto, Ontario, M4N 3M5,
Canada
- Physical Sciences Program, Sunnybrook Research Institute, 2075 Bayview Ave., Toronto, Ontario, M4N 3M5,
Canada
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Vuong B, Genis H, Wong R, Ramjist J, Jivraj J, Farooq H, Sun C, Yang VX. Evaluation of flow velocities after carotid artery stenting through split spectrum Doppler optical coherence tomography and computational fluid dynamics modeling. Biomed Opt Express 2014; 5:4405-16. [PMID: 25574447 PMCID: PMC4285614 DOI: 10.1364/boe.5.004405] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Revised: 11/17/2014] [Accepted: 11/19/2014] [Indexed: 06/04/2023]
Abstract
Hemodynamics plays a critical role in the development of atherosclerosis, specifically in regions of curved vasculature such as bifurcations exhibiting irregular blood flow profiles. Carotid atherosclerotic disease can be intervened by stent implantation, but this may result in greater alterations to local blood flow and consequently further complications. This study demonstrates the use of a variant of Doppler optical coherence tomography (DOCT) known as split spectrum DOCT (ssDOCT) to evaluate hemodynamic patterns both before and after stent implantation in the bifurcation junction in the internal carotid artery (ICA). Computational fluid dynamics (CFD) models were constructed to simulate blood velocity profiles and compared to the findings achieved through ssDOCT images. Both methods demonstrated noticeable alterations in hemodynamic patterns following stent implantation, with features such as slow velocity regions at the neck of the bifurcation and recirculation zones at the stent struts. Strong correlation between CFD models and ssDOCT images demonstrate the potential of ssDOCT imaging in the optimization of stent implantation in the clinical setting.
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Affiliation(s)
- Barry Vuong
- Biophotonics and Bioengineering Laboratory, Dept. Electrical and Computer Engineering, Ryerson University, 350 Victoria Street, Toronto, ON, M5B 2K3,
Canada
| | - Helen Genis
- Biophotonics and Bioengineering Laboratory, Dept. Electrical and Computer Engineering, Ryerson University, 350 Victoria Street, Toronto, ON, M5B 2K3,
Canada
| | - Ronnie Wong
- Biophotonics and Bioengineering Laboratory, Dept. Electrical and Computer Engineering, Ryerson University, 350 Victoria Street, Toronto, ON, M5B 2K3,
Canada
| | - Joel Ramjist
- Biophotonics and Bioengineering Laboratory, Dept. Electrical and Computer Engineering, Ryerson University, 350 Victoria Street, Toronto, ON, M5B 2K3,
Canada
| | - Jamil Jivraj
- Biophotonics and Bioengineering Laboratory, Dept. Electrical and Computer Engineering, Ryerson University, 350 Victoria Street, Toronto, ON, M5B 2K3,
Canada
| | - Hamza Farooq
- Biophotonics and Bioengineering Laboratory, Dept. Electrical and Computer Engineering, Ryerson University, 350 Victoria Street, Toronto, ON, M5B 2K3,
Canada
| | - Cuiru Sun
- Biophotonics and Bioengineering Laboratory, Dept. Electrical and Computer Engineering, Ryerson University, 350 Victoria Street, Toronto, ON, M5B 2K3,
Canada
| | - Victor X.D. Yang
- Biophotonics and Bioengineering Laboratory, Dept. Electrical and Computer Engineering, Ryerson University, 350 Victoria Street, Toronto, ON, M5B 2K3,
Canada
- Physical Science - Brain Sciences Research Program, Sunnybrook Research Institute, 2075 Bayview Avenue,Toronto, ON, M4N 3M5,
Canada
- Division of Neurosurgery, Sunnybrook Health Sciences Centre, 2075 Bayview Avenue Toronto, ON, M4N 3M5,
Canada
- Division of Neurosurgery, Faculty of Medicine, University of Toronto, 1 King’s College Circle, Toronto, ON, M5S 1A8,
Canada
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8
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Cheng KHY, Mariampillai A, Lee KKC, Vuong B, Luk TWH, Ramjist J, Curtis A, Jakubovic H, Kertes P, Letarte M, Faughnan ME, HHT Investigator Group BVMC, Yang VXD. Histogram flow mapping with optical coherence tomography for in vivo skin angiography of hereditary hemorrhagic telangiectasia. J Biomed Opt 2014; 19:086015. [PMID: 25140883 PMCID: PMC4407667 DOI: 10.1117/1.jbo.19.8.086015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Revised: 07/09/2014] [Accepted: 07/21/2014] [Indexed: 05/24/2023]
Abstract
Speckle statistics of flowing scatterers have been well documented in the literature. Speckle variance optical coherence tomography exploits the large variance values of intensity changes in time caused mainly by the random backscattering of light resulting from translational activity of red blood cells to map out the microvascular networks. A method to map out the microvasculature malformation of skin based on the time-domain histograms of individual pixels is presented with results obtained from both normal skin and skin containing vascular malformation. Results demonstrated that this method can potentially map out deeper blood vessels and enhance the visualization of microvasculature in low signal regions, while being resistant against motion (e.g., patient tremor or internal reflex movements). The overall results are manifested as more uniform en face projection maps of microvessels. Potential applications include clinical imaging of skin vascular abnormalities and wide-field skin angiography for the study of complex vascular networks.
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Affiliation(s)
- Kyle H. Y. Cheng
- University of Toronto, Edward S. Rogers Sr. Department of Electrical and Computer Engineering, Toronto M5S 3G4, Canada
- Ryerson University, Biophotonics and Bioengineering Laboratory, Toronto M5B 2K3, Canada
| | - Adrian Mariampillai
- Ryerson University, Biophotonics and Bioengineering Laboratory, Toronto M5B 2K3, Canada
- Ryerson University, Department of Electrical and Computer Engineering, Toronto M5B 2K3, Canada
| | - Kenneth K. C. Lee
- University of Toronto, Edward S. Rogers Sr. Department of Electrical and Computer Engineering, Toronto M5S 3G4, Canada
- Ryerson University, Biophotonics and Bioengineering Laboratory, Toronto M5B 2K3, Canada
| | - Barry Vuong
- Ryerson University, Biophotonics and Bioengineering Laboratory, Toronto M5B 2K3, Canada
- Ryerson University, Department of Electrical and Computer Engineering, Toronto M5B 2K3, Canada
| | - Timothy W. H. Luk
- Ryerson University, Biophotonics and Bioengineering Laboratory, Toronto M5B 2K3, Canada
- Ryerson University, Department of Electrical and Computer Engineering, Toronto M5B 2K3, Canada
| | - Joel Ramjist
- Ryerson University, Biophotonics and Bioengineering Laboratory, Toronto M5B 2K3, Canada
| | - Anne Curtis
- University of Toronto, Department of Medicine, Toronto M5S 1A8, Canada
| | - Henry Jakubovic
- University of Toronto, St. Michael’s Hospital, Dermatopathology, Department of Laboratory Medicine, Toronto M5B 1W8, Canada
| | - Peter Kertes
- University of Toronto, John and Liz Tory Eye Centre, Sunnybrook Health Sciences Centre, Department of Ophthalmology and Vision Sciences, Toronto M4N 3M5, Canada
| | - Michelle Letarte
- SickKids Research Institute, Hospital for Sick Children, Toronto M5G 1X8, Canada
- University of Toronto, Department of Immunology, Toronto M5S 1A8, Canada
| | - Marie E. Faughnan
- University of Toronto, St. Michael’s Hospital, Toronto HHT Program, Division of Respirology, Department of Medicine, Toronto M5B 1W8, Canada
- St. Michaels Hospital, Li Ka Shing Knowledge Institute, Toronto M5B 1W8, Canada
| | | | - Victor X. D. Yang
- Ryerson University, Biophotonics and Bioengineering Laboratory, Toronto M5B 2K3, Canada
- Ryerson University, Department of Electrical and Computer Engineering, Toronto M5B 2K3, Canada
- Sunnybrook Health Science Centre, Division of Neurosurgery, Toronto M4N 3M5, Canada
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9
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Vuong B, Lee AMD, Luk TWH, Sun C, Lam S, Lane P, Yang VXD. High speed, wide velocity dynamic range Doppler optical coherence tomography (Part IV): split spectrum processing in rotary catheter probes. Opt Express 2014; 22:7399-415. [PMID: 24718115 DOI: 10.1364/oe.22.007399] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
We report a technique for blood flow detection using split spectrum Doppler optical coherence tomography (ssDOCT) that shows improved sensitivity over existing Doppler OCT methods. In ssDOCT, the Doppler signal is averaged over multiple sub-bands of the interferogram, increasing the SNR of the Doppler signal. We explore the parameterization of this technique in terms of number of sub-band windows, width and overlap of the windows, and their effect on the Doppler signal to noise in a flow phantom. Compared to conventional DOCT, ssDOCT processing has increased flow sensitivity. We demonstrate the effectiveness of ssDOCT in-vivo for intravascular flow detection within a porcine carotid artery and for microvascular vessel detection in human pulmonary imaging, using rotary catheter probes. To our knowledge, this is the first report of visualizing in-vivo Doppler flow patterns adjacent to stent struts in the carotid artery.
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10
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Sun C, Standish B, Vuong B, Wen XY, Yang V. Digital image correlation-based optical coherence elastography. J Biomed Opt 2013; 18:121515. [PMID: 24346855 DOI: 10.1117/1.jbo.18.12.121515] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Accepted: 12/02/2013] [Indexed: 05/21/2023]
Abstract
Optical coherence elastography (OCE) provides deformation or material properties, mapping of soft tissue. We aim to develop a robust speckle tracking OCE technique with improved resolution and accuracy. A digital image correlation (DIC)-based OCE technique was developed by combining an advanced DIC algorithm with optical coherence tomography (OCT). System calibration and measurement error evaluation demonstrated that this DIC-based OCE technique had a resolution of ~0.6 μm displacement and <0.5% strain measurement in the axial scan direction. The measured displacement ranged from 0.6 to 150 μm, obtained via phantom imaging. The capability of the DIC-based OCE technique, for differentiation of stiffness, was evaluated by imaging a candle gel phantom with an irregularly shaped stiff inclusion. OCE imaging of a chicken breast sample differentiated the fat, membrane, and muscle layers. Strain elastograms of an aneurysm sample showed heterogeneity of the tissue and clear contrast between the adventitia and media. These promising results demonstrated the capability of the DIC-based OCE for the characterization of the various components of the tissue sample. Further improvement of the system will be conducted to make this OCE technique a practical tool for measuring and differentiating material properties of soft tissue.
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Affiliation(s)
- Cuiru Sun
- Ryerson University, Biophotonics and Bioengineering Laboratory, Toronto, Ontario, Canada M5B 2K3bRyerson University, Department of Electrical and Computer Engineering, Toronto, Ontario, Canada M5B 2K3cUniversity of Toronto, Faculty of Medicine, Department of Medicine, Toronto, Ontario, Canada M5S1A1
| | - Beau Standish
- Ryerson University, Biophotonics and Bioengineering Laboratory, Toronto, Ontario, Canada M5B 2K3bRyerson University, Department of Electrical and Computer Engineering, Toronto, Ontario, Canada M5B 2K3
| | - Barry Vuong
- Ryerson University, Biophotonics and Bioengineering Laboratory, Toronto, Ontario, Canada M5B 2K3bRyerson University, Department of Electrical and Computer Engineering, Toronto, Ontario, Canada M5B 2K3
| | - Xiao-Yan Wen
- University of Toronto, Faculty of Medicine, Department of Medicine, Toronto, Ontario, Canada M5S1A1dSt. Michael's Hospital, Li Ka Shing Knowledge Institute, Keenan Research Center, Toronto, Ontario, Canada M5B 1W8
| | - Victor Yang
- Ryerson University, Biophotonics and Bioengineering Laboratory, Toronto, Ontario, Canada M5B 2K3bRyerson University, Department of Electrical and Computer Engineering, Toronto, Ontario, Canada M5B 2K3eUniversity of Toronto, Department of Electrical and Computer Engineering, Toronto, Ontario, Canada M5S1A1fSunnybrook Health Sciences Centre, Division of Neurosurgery, Toronto, Ontario, Canada M4N 3M5gUniversity of Toronto, Faculty of Medicine, Division of Neurosurgery, Toronto, Ontario, Canada M5S1A1
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11
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Wawrzyn K, Demidov V, Vuong B, Harduar MK, Sun C, Yang VXD, Doganay O, Toronov V, Xu Y. Imaging the electro-kinetic response of biological tissues with optical coherence tomography. Opt Lett 2013; 38:2572-2574. [PMID: 23939115 DOI: 10.1364/ol.38.002572] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We demonstrate the feasibility of using optical coherence tomography (OCT) to detect and image an electro-kinetic response: electric-field induced optical changes (EIOC) in soft biological tissues. A low-frequency electric field was applied to ex vivo samples of porcine heart tissues, while OCT signals were acquired continuously. Experimental results show that the amplitude of the OCT signal change is proportional to the amplitude and inversely proportional to the frequency of the applied electric field. We show that the nonconductive component of the sample was eliminated in the normalized EIOC image. To the best our knowledge, this is the first time a two-dimensional image related to the electro-kinetic response of soft tissues is obtained with depth resolution. Since electro-kinetic properties can change during cancerogenesis, EIOC imaging can potentially be used for cancer detection.
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Affiliation(s)
- K Wawrzyn
- Department of Physics, Ryerson University, Toronto, Canada
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12
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Mahmud MS, Cadotte DW, Vuong B, Sun C, Luk TWH, Mariampillai A, Yang VXD. Review of speckle and phase variance optical coherence tomography to visualize microvascular networks. J Biomed Opt 2013; 18:50901. [PMID: 23616094 DOI: 10.1117/1.jbo.18.5.050901] [Citation(s) in RCA: 119] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
High-resolution mapping of microvasculature has been applied to diverse body systems, including the retinal and choroidal vasculature, cardiac vasculature, the central nervous system, and various tumor models. Many imaging techniques have been developed to address specific research questions, and each has its own merits and drawbacks. Understanding, optimization, and proper implementation of these imaging techniques can significantly improve the data obtained along the spectrum of unique research projects to obtain diagnostic clinical information. We describe the recently developed algorithms and applications of two general classes of microvascular imaging techniques: speckle-variance and phase-variance optical coherence tomography (OCT). We compare and contrast their performance with Doppler OCT and optical microangiography. In addition, we highlight ongoing work in the development of variance-based techniques to further refine the characterization of microvascular networks.
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Affiliation(s)
- Mohammad Sultan Mahmud
- Ryerson University, Department of Electrical and Computer Engineering, 350 Victoria Street, Toronto, Ontario M5B 2K3, Canada
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13
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Sun C, Nolte F, Cheng KHY, Vuong B, Lee KKC, Standish BA, Courtney B, Marotta TR, Mariampillai A, Yang VXD. In vivo feasibility of endovascular Doppler optical coherence tomography. Biomed Opt Express 2012; 3:2600-10. [PMID: 23082299 PMCID: PMC3470007 DOI: 10.1364/boe.3.002600] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Revised: 09/12/2012] [Accepted: 09/15/2012] [Indexed: 05/20/2023]
Abstract
Feasibility of detecting intravascular flow using a catheter based endovascular optical coherence tomography (OCT) system is demonstrated in a porcine carotid model in vivo. The effects of A-line density, radial distance, signal-to-noise ratio, non-uniform rotational distortion (NURD), phase stability of the swept wavelength laser and interferometer system on Doppler shift detection limit were investigated in stationary and flow phantoms. Techniques for NURD induced phase shift artifact removal were developed by tracking the catheter sheath. Detection of high flow velocity (~51 cm/s) present in the porcine carotid artery was obtained by phase unwrapping techniques and compared to numerical simulation, taking into consideration flow profile distortion by the eccentrically positioned imaging catheter. Using diluted blood in saline mixture as clearing agent, simultaneous Doppler OCT imaging of intravascular flow and structural OCT imaging of the carotid artery wall was feasible. To our knowledge, this is the first in vivo demonstration of Doppler imaging and absolute measurement of intravascular flow using a rotating fiber catheter in carotid artery.
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Affiliation(s)
- Cuiru Sun
- Biophotonics and Bioengineering Laboratory, Dept.
Electrical and Computer Engineering, Ryerson University, 350 Victoria St.
Toronto, ON, M5B2K3 Canada
- These authors contributed equally to this work
| | - Felix Nolte
- Biophotonics and Bioengineering Laboratory, Dept.
Electrical and Computer Engineering, Ryerson University, 350 Victoria St.
Toronto, ON, M5B2K3 Canada
- Faculty of Electrical Engineering and Information
Technology, University of Applied Sciences, Karlsruhe, Moltkestraße 30,
76133 Karlsruhe, Germany
- These authors contributed equally to this work
| | - Kyle H. Y. Cheng
- Biophotonics and Bioengineering Laboratory, Dept.
Electrical and Computer Engineering, Ryerson University, 350 Victoria St.
Toronto, ON, M5B2K3 Canada
- Dept. Electrical and Computer Engineering, University
of Toronto, 27 King's College Circle, Toronto, Ontario, M5S 1A1,
Canada
| | - Barry Vuong
- Biophotonics and Bioengineering Laboratory, Dept.
Electrical and Computer Engineering, Ryerson University, 350 Victoria St.
Toronto, ON, M5B2K3 Canada
| | - Kenneth K. C. Lee
- Biophotonics and Bioengineering Laboratory, Dept.
Electrical and Computer Engineering, Ryerson University, 350 Victoria St.
Toronto, ON, M5B2K3 Canada
- Dept. Electrical and Computer Engineering, University
of Toronto, 27 King's College Circle, Toronto, Ontario, M5S 1A1,
Canada
| | - Beau A. Standish
- Biophotonics and Bioengineering Laboratory, Dept.
Electrical and Computer Engineering, Ryerson University, 350 Victoria St.
Toronto, ON, M5B2K3 Canada
- Faculty of Electrical Engineering and Information
Technology, University of Applied Sciences, Karlsruhe, Moltkestraße 30,
76133 Karlsruhe, Germany
| | - Brian Courtney
- Colibri Technologies Inc., 3080 Yonge Street,
Toronto, ON, M4N 3N1, Canada
| | - Thomas R. Marotta
- Dept. of Medical Imaging, St. Michael’s
Hospital, 30 Bond Street, Toronto, ON, M5B 1W8, Canada
| | - Adrian Mariampillai
- Biophotonics and Bioengineering Laboratory, Dept.
Electrical and Computer Engineering, Ryerson University, 350 Victoria St.
Toronto, ON, M5B2K3 Canada
| | - Victor X. D. Yang
- Biophotonics and Bioengineering Laboratory, Dept.
Electrical and Computer Engineering, Ryerson University, 350 Victoria St.
Toronto, ON, M5B2K3 Canada
- Dept. Electrical and Computer Engineering, University
of Toronto, 27 King's College Circle, Toronto, Ontario, M5S 1A1,
Canada
- Dept. of Medical Imaging, St. Michael’s
Hospital, 30 Bond Street, Toronto, ON, M5B 1W8, Canada
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14
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Vuong B, Sun C, Harduar MK, Mariampillai A, Isamoto K, Chong C, Standish BA, Yang VXD. 23 kHz MEMS based swept source for optical coherence tomography imaging. Annu Int Conf IEEE Eng Med Biol Soc 2012; 2011:6134-7. [PMID: 22255739 DOI: 10.1109/iembs.2011.6091515] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The transition from benchtop to clinical system often requires the medical technology to be robust, portable and accurate. This poses a challenge to current swept source optical coherence tomography imaging systems, as the bulk of the systems footprint is due to laser components. With the recent advancement of micromachining technology, we demonstrate the characterization of a microelectromechanical system (MEMS) swept source laser for optical coherence tomography imaging (OCT). This laser utilizes a 2 degree of freedom MEMS scanning mirror and a diffraction grating, which are arranged in a Littrow configuration. This resulted in a swept source laser that was capable of scanning at 23.165 kHz (bidirectional) or 11.582 kHz (unidirectional). The free spectral range of the laser was ≈ 100 nm with a central wavelength of ≈ 1330 nm. The 6 dB roll off depth was measured to be at 2.5 mm. Furthermore, the structural morphology of a human finger and tadpole (Xenopus laevis) were evaluated. The overall volumetric footprint of the laser source was measured to be 70 times less than non-MEMS swept sources. Continued work on the miniaturization of OCT system is on going. It is hypothesized that the overall laser size can be reduced for suitable OCT imaging for a point of care application.
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Affiliation(s)
- Barry Vuong
- Department of Electrical and Computer Engineering, Ryerson University, ON M5B 2K3, Canada
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15
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Sun C, Lee KKC, Vuong B, Cusimano MD, Brukson A, Mauro A, Munce N, Courtney BK, Standish BA, Yang VXD. Intraoperative handheld optical coherence tomography forward-viewing probe: physical performance and preliminary animal imaging. Biomed Opt Express 2012; 3:1404-12. [PMID: 22741085 PMCID: PMC3370979 DOI: 10.1364/boe.3.001404] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2012] [Revised: 05/07/2012] [Accepted: 05/08/2012] [Indexed: 05/23/2023]
Abstract
A prototype intraoperative hand-held optical coherence tomography (OCT) imaging probe was developed to provide micron resolution cross-sectional images of subsurface tissue during open surgery. This new ergonomic probe was designed based on electrostatically driven optical fibers, and packaged into a catheter probe in the form factor of clinically accepted Bayonet shaped neurosurgical probes. Optical properties of the probe were measured to have a ~20 μm spot size, 5 mm working distance and 4 mm field of view. Feasibility of this probe for structural and Doppler shift imaging was tested on porcine femoral blood vessel imaging.
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Affiliation(s)
- Cuiru Sun
- Biophotonics and Bioengineering Laboratory, Department of Electrical and Computer Engineering, Ryerson University, 350 Victoria St. Toronto ON, M5B2K3 Canada
| | - Kenneth K. C. Lee
- Biophotonics and Bioengineering Laboratory, Department of Electrical and Computer Engineering, Ryerson University, 350 Victoria St. Toronto ON, M5B2K3 Canada
- Department of Electrical and Computer Engineering, University of Toronto, 27 King's College Circle, Toronto, Ontario, M5S 1A1, Canada
| | - Barry Vuong
- Biophotonics and Bioengineering Laboratory, Department of Electrical and Computer Engineering, Ryerson University, 350 Victoria St. Toronto ON, M5B2K3 Canada
| | - Michael D. Cusimano
- Neurosurgery, St. Michael’s Hospital, Li Ka Shing Building, 209 Victoria St, Toronto, ON, M5B 1T8, Canada
| | - Alexander Brukson
- Department of Biomedical Engineering, Ryerson University, 350 Victoria St. Toronto ON, M5B2K3 Canada
| | - Antonio Mauro
- Institute of Medical Science, University of Toronto, St. Michael's Hospital, 209 Victoria Street, Toronto, Ontario, M5B 1T8, Canada
| | - Nigel Munce
- Faculty of Medicine, 1 King's College Circle, Toronto, ON, M5S 1A8, Canada
| | - Brian K. Courtney
- Colibri Technologies Inc., 3080 Yonge Street, Toronto, ON, M4N 3N1, Canada
- Division of Cardiology, Sunnybrook Health Sciences Centre, 2075 Bayview Ave., Toronto, ON, M4N 3M5, Canada
| | - Beau A. Standish
- Biophotonics and Bioengineering Laboratory, Department of Electrical and Computer Engineering, Ryerson University, 350 Victoria St. Toronto ON, M5B2K3 Canada
| | - Victor X. D. Yang
- Biophotonics and Bioengineering Laboratory, Department of Electrical and Computer Engineering, Ryerson University, 350 Victoria St. Toronto ON, M5B2K3 Canada
- Department of Electrical and Computer Engineering, University of Toronto, 27 King's College Circle, Toronto, Ontario, M5S 1A1, Canada
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16
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Cheng KHY, Sun C, Vuong B, Lee KKC, Mariampillai A, Marotta TR, Spears J, Montanera WJ, Herman PR, Kiehl TR, Standish BA, Yang VXD. Endovascular optical coherence tomography intensity kurtosis: visualization of vasa vasorum in porcine carotid artery. Biomed Opt Express 2012; 3:388-99. [PMID: 22435088 PMCID: PMC3296528 DOI: 10.1364/boe.3.000388] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Revised: 01/24/2012] [Accepted: 01/24/2012] [Indexed: 05/15/2023]
Abstract
Application of speckle variance optical coherence tomography (OCT) to endovascular imaging faces difficulty of extensive motion artifacts inherently associated with arterial pulsations in addition to other physiological movements. In this study, we employed a technique involving a fourth order statistical method, kurtosis, operating on the endovascular OCT intensity images to visualize the vasa vasorum of carotid artery in vivo and identify its flow dynamic in a porcine model. The intensity kurtosis technique can distinguish vasa vasorum from the surrounding tissues in the presence of extensive time varying noises and dynamic motions of the arterial wall. Imaging of vasa vasorum and its proliferation, may compliment the growing knowledge of structural endovascular OCT in assessment and treatment of atherosclerosis in coronary and carotid arteries.
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Affiliation(s)
- Kyle H. Y. Cheng
- Biophotonics and Bioengineering Laboratory, Ryerson University, Toronto, Ontario, Canada
- Department of Electrical and Computer Engineering, University of Toronto, Toronto, Ontario, Canada
| | - Cuiru Sun
- Biophotonics and Bioengineering Laboratory, Ryerson University, Toronto, Ontario, Canada
- Department of Electrical and Computer Engineering, Ryerson University, Toronto, Ontario, Canada
| | - Barry Vuong
- Biophotonics and Bioengineering Laboratory, Ryerson University, Toronto, Ontario, Canada
- Department of Electrical and Computer Engineering, Ryerson University, Toronto, Ontario, Canada
| | - Kenneth K. C. Lee
- Biophotonics and Bioengineering Laboratory, Ryerson University, Toronto, Ontario, Canada
- Department of Electrical and Computer Engineering, University of Toronto, Toronto, Ontario, Canada
| | - Adrian Mariampillai
- Biophotonics and Bioengineering Laboratory, Ryerson University, Toronto, Ontario, Canada
- Department of Electrical and Computer Engineering, Ryerson University, Toronto, Ontario, Canada
| | - Thomas R. Marotta
- Department of Medical Imaging, St. Michael’s Hospital, Toronto, Ontario, Canada
| | - Julian Spears
- Department of Medical Imaging, St. Michael’s Hospital, Toronto, Ontario, Canada
- Department of Pathology, University of Toronto, Toronto, Ontario, Canada
| | - Walter J. Montanera
- Department of Medical Imaging, St. Michael’s Hospital, Toronto, Ontario, Canada
| | - Peter. R. Herman
- Department of Electrical and Computer Engineering, University of Toronto, Toronto, Ontario, Canada
| | - Tim-Rasmus Kiehl
- Department of Pathology, University of Toronto, Toronto, Ontario, Canada
| | - Beau A. Standish
- Biophotonics and Bioengineering Laboratory, Ryerson University, Toronto, Ontario, Canada
- Department of Electrical and Computer Engineering, Ryerson University, Toronto, Ontario, Canada
| | - Victor X. D. Yang
- Biophotonics and Bioengineering Laboratory, Ryerson University, Toronto, Ontario, Canada
- Department of Electrical and Computer Engineering, University of Toronto, Toronto, Ontario, Canada
- Department of Electrical and Computer Engineering, Ryerson University, Toronto, Ontario, Canada
- Department of Medical Imaging, St. Michael’s Hospital, Toronto, Ontario, Canada
- Division of Neurosurgery, St. Michael’s Hospital, Toronto, Ontario, Canada
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17
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Harduar MK, Mariampillai A, Vuong B, Gu X, Standish BA, Yang VXD. Dual-core ytterbium fiber amplifier for high-power 1060 nm swept source multichannel optical coherence tomography imaging. Opt Lett 2011; 36:2976-2978. [PMID: 21808377 DOI: 10.1364/ol.36.002976] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
A novel (to our knowledge) dual-core ytterbium (Yb(3+)) doped fiber, as an optically pumped amplifier, boosts the output power from a 1060 nm swept source laser beyond 250 mW, while providing a wavelength tuning range of 93 nm, for optical coherence tomography (OCT) imaging. The design of the dual-core Yb-doped fiber amplifier and its multiple wavelength optical pumping scheme to optimize output bandwidth are discussed. Use of the dual-core fiber amplifier showed no appreciable degradation to the coherence length of the seed laser. The signal intensity improvement of this amplifier is demonstrated on a multichannel in vivo OCT imaging system at 1060 nm.
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Affiliation(s)
- Mark K Harduar
- Department of Electrical and Computer Engineering, Ryerson University, Toronto, Canada M5B 2K3
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18
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Jiang H, Foltenyi K, Kashiwada M, Donahue L, Vuong B, Hehn B, Rothman P. Fes mediates the IL-4 activation of insulin receptor substrate-2 and cellular proliferation. J Immunol 2001; 166:2627-34. [PMID: 11160325 DOI: 10.4049/jimmunol.166.4.2627] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Although Jak kinases are essential for initiating cytokine signaling, the role of other nonreceptor tyrosine kinases in this process remains unclear. We have examined the role of Fes in IL-4 signaling. Examination of Jak1-deficient cell lines demonstrates that Jak1 is required for the activation of Fes by IL-4. Experiments studying signaling molecules activated by IL-4 receptor suggest that IL-4 signaling can be subdivided into Fes-dependent and Fes-independent pathways. Overexpression of kinase-inactive Fes blocks the IL-4 activation of insulin receptor substrate-2, but not STAT6. Fes appears to be a downstream kinase from Jak1/Jak3 in this process. Further examination of downstream signaling demonstrates that kinase-inactive Fes inhibits the recruitment of phosphoinositide 3-kinase to the activated IL-4 receptor complex and decreases the activation of p70(S6k) kinase in response to IL-4. This inhibition correlates with a decrease in IL-4-induced proliferation. In contrast, mutant Fes does not inhibit the activation of Akt by IL-4. These data demonstrate that signaling pathways activated by IL-4 require different tyrosine kinases. This differential requirement predicts that specific kinase inhibitors may permit the disruption of specific IL-4-induced functions.
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Affiliation(s)
- H Jiang
- Department of Medicine and Microbiology, Columbia University, College of Physicians and Surgeons, New York, NY 10032, USA
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19
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Kovari LC, Momany CA, Miyagi F, Lee S, Campbell S, Vuong B, Vogt VM, Rossmann MG. Crystals of Rous sarcoma virus capsid protein show a helical arrangement of protein subunits. Virology 1997; 238:79-84. [PMID: 9375011 DOI: 10.1006/viro.1997.8807] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Crystals of Rous sarcoma virus (RSV) capsid protein diffract X rays to 3.5 A resolution and belong to the monoclinic space group C2 with unit cell parameters a = 374.4 A, b = 128.1 A, c = 200.2 A, and beta = 121.8 degrees. One asymmetric unit of the crystal may contain between 28 and 35 molecules, based on reasonable crystal density assumptions. A self-rotation function and Patterson synthesis suggest that RSV capsid protein crystallizes as a helical array. The determinants of the viral particle morphology are not encoded in the capsid alone. The assembly of a helical array in the crystal reflects the absence of any conformational switching. However, it is expected that the subunit interactions seen in the crystal will be preferred and will relate to those found in the immature or mature virion.
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Affiliation(s)
- L C Kovari
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907, USA
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