Victor Yang

MASc and MD-PhD (Toronto), PEng
Adjunct Professor

Profile picture - Graham Pearson
350 Victoria Street
Toronto, Ontario
M5B 2K3
t. 416-803-9320 f. 416 542-5876
yangV@ee.ryerson.ca

Specialization

Optical coherence tomography, intra-operative fluorescence imaging, photodynamic therapy, micro-machined electro-mechanical probes/catheters

Research Projects

Utilizing recent advances in photonics technology, optical coherence tomography (OCT) is an emerging imaging modality with high spatial resolution (1 – 10 µm) making it suitable for in vivo subsurface visualization of normal or diseased tissue. Doppler optical coherence tomography (DOCT), employing mature Doppler ultrasound signal processing techniques, is capable of detecting slow blood flow (1 – 10 µm/s) in the microcirculation and is suitable for imaging applications such as embryonic cardiovascular development, angiogenesis, and therapeutic monitoring of treatment directed at neovasculature.

Technological advancement of DOCT: (1) To satisfy the need of 3D/4D imaging of human tissue and high speed imaging of fast hemodynamic events in small animal models, we are developing new DOCT systems with frame rates two to three orders of magnitude higher then currently available. This is being achieved using multiple strategies such as cardiac gating, new fiber ring laser, and multi-channel arrayed OCT. (2) Compared to Doppler ultrasound, a key drawback of current DOCT is the relatively low aliasing frequency which limits velocity detection to values in the mm/s to cm/s range. Utilizing 2D Kasai estimation techniques, we are extending the velocity detection range to m/s which is suitable for imaging high speed blood flow in large vessels. (3) By applying mature ultrasound clutter rejection algorithms to DOCT, we are improving the detection of microcirculation using power Doppler techniques. (4) Using a combination of spectroscopic OCT and contrast agents, we are improving the detection and automatic segmentation of microvasculature within the DOCT images.

The advancements made in the above technology core are synergistically applied to improve pre-clinical and clinical studies in different application areas:

Endoscopic DOCT: Flexible catheter based fiber optic probes (diameter 0.8 - 2 mm) are developed for endoscopic and endolumenal DOCT (EDOCT) applications. We performed the world's first EDOCT clinical study in patients undergoing upper gastrointestinal (GI) endoscopy and demonstrated in vivo microcirculation imaging in non-cancerous, pre-cancerous, and cancerous tissues. Further study aims at (1) in vivo high resolution visualization of tissue morphology and microvasculature pattern in Barrett's esophagus (a pre-cancer condition); (2) detection and monitoring of microvascular changes during photodynamic therapy of Barrett's esophagus; (3) extension of EDOCT to the lower GI tract, biliary tree, and other body sites such as the lung.

Trans-esophageal DOCT: For small animal models (e.g., mice, rats), the esophageal wall is thin and the major vessels are within the penetration depth of DOCT. We have demonstrated the first trans-esophageal DOCT (TE-DOCT) imaging of rat aortic blood flow using 2D Kasai techniques and by combining the cardiac gating methods, detailed study of hemodynamics in the major vessels and cardiac valves of transgenic mice are feasible. We are developing special TE-DOCT catheters (diameter <1 mm) suitable for 3D and 4D imaging of the cardiovascular system in mice, utilizing transgenic models available at the Toronto Mouse Imaging Centre.

Interstitial DOCT: As an extension of EDOCT, further miniaturization of the fiber optic probe allows development of a combined fine needle aspiration (FNA) system with interstitial DOCT (IS-DOCT) imaging, which can provide detailed microstructural and microvascular visualization beyond the FNA needle. Combined with other image guidance techniques (e.g., US, CT, fluoro), lesions deep within solid tissue (e.g., brain, liver, prostate, breast) are accessible to IS-DOCT. Further study aims at (1) stereotactic/image guided IS-DOCT visualization of tissue during biopsy; (2) detection and monitoring of microcirculation deep within tissue in response to photodynamic therapy.

Embryonic DOCT: Combining IS-DOCT and optical cardiac gating, we have demonstrated the first 3D and 4D imaging of Xenopus laevis embryos at speeds up to 1000 frames per second. In collaboration with our industry partner (Thorlabs Inc., NJ), we are developing an embryonic DOCT system suitable for 3D/4D imaging of in utero mouse embryos, with optical cardiac gating to the individual embryo. Such ultra-high resolution imaging at ultra-high frame rate will allow detailed structural and hemodynamic phenotyping of mouse embryos during early developmental stages.

Selected Publications

  1. Webster PJL, Zu JXZ, Leung BYC, Anderson MD, Yang VXD, Fraser JM, In situ 24 kHz coherent imaging of morphology change in laser percussion drilling, Optics Letters, 35:646-8, 2010.
  2. Munce NR, Wright GA, Mariampillai A, Standish BA, Leung KKM, Tan L, Lee K, Courtney BK, Teitelbaum AA, Strauss BH, Vitkin IA, Yang VXD, Doppler optical coherence tomography for interventional cardiovascular guidance: in-vivo feasibility and forward-viewing probe flow phantom demonstration, Journal of Biomedical Optics, 15:011103, 2010.

  3. Cheng KHY, Standish BA, Yang VXD, Cheung KKY, Gu X, Lam EY, Wong KKY, Wavelength-swept spectral and pulse shaping utilizing hybrid Fourier domain mode locking by fiber optical parametric and Erbium-doped fiber amplifiers, Optics Express, 18:1909-15, 2010.

  4. Standish BA, Lee KKC, Mariampillai A, Munce NR, Leung KKM, Yang VXD, Vitkin IA, In-vivo endoscopic multi-beam optical coherence tomography, Physics in Medicine and Biology, 55:615-22, 2010.

  5. Leung KKM, Mariampillai A, Standish BA, Lee KKC, Munce NR, Vitkin IA, Yang VXD, High-power wavelength-swept laser in Littman telescopeless polygon filter and dual amplifier configuration for multichannel optical coherence tomography, Optics Letter, 34:2814-6, 2009.

  6. Muller MS, Webster PJL, Yang VXD, Fraser JM, Ultrafast technology applied to optical coherence tomography, Physics in Canada, 65:93-6, 2009.

  7. Lee KC, Munce NR, Shoa T, Charron LG, Wright G, Madden JD, Yang VXD, Fabrication and characterization of laser-micromachined polypyrrole-based artificial muscle actuated catheters, Sensors and Actuators A: Physical, 153:230-6, 2009.

  8. Sufan RI, Moriyiama EH, Mariampillai A, Evans AJ, Alajez NM, Yang VXD, Liu F, Wilson BC, Ohh M, Oxygen-independent degradation of HIFa via bioengineered VHL tumour suppressor complex, EMBO Molecular Medicine, 1:66-78, 2009.

  9. Standish BA, Lee K, Jin X, Mariampillai A, Munce NR, Wood M, Wilson BC, Vitkin IA, Yang VXD, Interstitial Doppler Optical Coherence Tomography as a Local Tumor Necrosis Predictor in Photodynamic Therapy: An in vivo study, Cancer Research, 68:9987-95, 2008.

  10. Mariampillai A, Standish BA, Moriyama EH, Khurana M, Munce NR, Leung MKK, Jiang J, Cable A, Wilson BC, Vitkin IA, Yang VXD, Speckle Variance Detection of Microvasculature Using Swept-source Optical Coherence Tomography, Optics Letters, 33:1530-32, 2008.

  11. Collins HA, Khurana M, Moriyama EH, Mariampillai A, Dahlstedt E, Balaz M, Kuimova MK, Drobizhev M, Yang VXD, Phillips D, Rebane A, Wilson BC, Anderson HL, Blood-vessel closure using photosensitizers engineered for two-photon excitation, Nature Photonics, (30 May 2008), doi: 10.1038/nphoton.2008.100, Letter.

  12. Lam S, Standish B, Baldwin C, McWilliams A, leRiche J, Gazdar A, Vitkin IA, Yang VXD, Ikeda N, MacAulay C, In-vivo Optical Coherence Tomography Imaging of Pre-invasive Bronchial Lesions, Clinical Cancer Research, 14(7): 2006-11, 2008.

  13. Douplik A, Morofke D, Chiu S, Bouchelev V, Mao L, Yang VXD, Vitkin IA, In vivo Real Time Monitoring of Vasoconstriction and Vasodilation by a Combined Diffuse Refletance Spectroscopy and Doppler Optical Coherence Tomography Approach, Lasers in Surgery and Medicine, 40:323-331, 2008.

  14. Munce NR, Mariampillai A, Standish B, Pop M, Anderson K, Liu G, Luk T, Courtney B, Wright G, Vitkin IA, Yang VXD, Electrostatic Forward-Viewing Scanning Probe for Doppler Optical Coherence Tomography using a Dissipative Polymer Catheter, Optics Letters, 33:657, 2008.

  15. Lunt SJ, Kalliomaki T, Brown A, Yang VXD, Milosevic M, Hill RP, Interstitial fluid pressure, vascularity and metastasis in ectopic, orthotopic and spontaneous tumours, BMC Cancer, 8:2, 2008.

  16. Cheung AM, Brown AS, Cucevic V, Roy M, Needles A, Yang VXD, Hicklin DJ, Kerbel RS, Foster FS, Detecting vascular changes in tumour xenografts using micro-ultrasound and micro-CT following treatment with VEGFR-2 blocking antibodies, Ultrasound in Medicine and Biology, 33: 1259-1268, 2007.

  17. Shoa T, Cole, M, Munce NR, Yang VXD, Madden JD, Polypyrrole operating voltage limits in aqueous sodium hexafluorophosphate, Proceedings of SPIE - The International Society for Optical Engineering, 6524, 652421, 2007.

  18. Mariamplillai A, Standish B, Randall C, Liu G, Munce NR, Vitkin IA, Cable A, Jiang J, Yang VXD, Optical Cardiogram Gated 2D Doppler Flow Imaging at 1000 fps and 4D Imaging at 36 fps on a Swept Source OCT System, Optics Express, 15: 1627-38, 2007.

  19. Standish B, Jin X, Smolen J, Mariamplillai A, Munce NR, Wilson BC, Vitkin IA, Yang VXD, Interstitial Doppler Optical Coherence Tomography Monitors Microvascular Changes during Photodynamic Therapy in a Dunning Prostate Model under Varying Treatment Conditions, Journal of Biomedical Optics, 12: 0304022, 2007.

  20. Standish B, Yang VXD, Munce N, WongKeeSong LM, Buttar NS, Wang KK, Bisland S, Lin A, Mao L, Vitkin IA, Marcon NE, Wilson BC, Doppler Optical Coherence Tomography Monitoring of Microvascular Tissue Response During Photodynamic Therapy in an Animal Model of Barrett’s Esophagus, Gastrointestinal Endoscopy, 66: 326-333, 2007.
  21. Munce NR, Shoa T, Mariampillai A, Standish BA, Butany J, Vitkin IA, Wright G, Madden JD, Yang VXD, Artificial Muscle Based Forward Scanning Catheters for 3D Optical Coherence Tomography of Chronic Total Occlusions – Technical Development and ex-vivo Results, IEEE Proc. SPIE 2007 (accepted).

  22. Morofke D, Kolios MC, Vitkin IA, Yang VXD, Ultra-wide dynamic range detection of bidirectional flow on Doppler optical coherence tomography using 2D Kasai velocity estimator, Optics Letters, 32:253-5, 2007.

  23. Shoa T, Munce NR, Wright G, Yang VXD, Madden JD, Conductive Polymer Driven Catheter, Material Research Society, 2006 (accepted).

  24. Aoudi W, Liebgott H, Needles A, Yang VXD, Foster FS, Vray D, Estimation methods for flow imaging with high frequency ultrasound, Ultrasonics, 44(s1):e135-40, 2006.

  25. Munce NR, Yang VXD, Standish B, Qiang B, Mao Y, Li H, Butany J, Courtney BK, Graham JJ, Dick AJ, Strauss BH, Wright GA, Vitkin IA, Ex vivo Imaging of Chronic Total Occlusions using Forward-Looking Optical Coherence Tomography, Lasers In Surgery and Medicine, 39:28-35, 2006.

  26. Li H, Standish B, Mariamplillai A, Munce NR, Mao Y, Chiu S, Marcon NE, Wilson BC, Vitkin IA, Yang VXD, Feasibility of Interstitial Doppler Optical Coherence Tomography for in vivo Detection of Microvascular Changes During Photodynamic Therapy, Lasers in Surgery and Medicine, 38:754-61 2006.

  27. Yang VXD, Mao Y, Standish BA, Munce NR, Chiu S, Burnes D, Wilson BC, Vitkin IA, Himmer PA, Dickensheet DL, Doppler optical coherence tomography with a micro-electro-mechanical membrane mirror for high speed dynamic focus tracking, Optics Letters, 31: 1262-4, 2006.

  28. Yang VXD, Mao L, Munce N, Standish B, Marcon NE, Kucharczyk W, Wilson BC, Vitkin IA, Interstitial Doppler Optical Coherence Tomography, Optics Letters, 30: 1791-3, 2005.

  29. Yang VXD, Tang SJ, Gordon ML, Qi B, Gardinar G, Kortan P, Haber GB, Kandel G, Vitkin IA, Wilson BC, and Marcon NE, Endoscopic Doppler optical coherence tomography: first clinical experience with a novel imaging technique, Gastrointestinal Endoscopy, 61:879-90, 2005.

  30. Yeow JTW, Yang VXD, Chahwan A, Gordon ML, Qi B, Vitkin IA, Wilson BC, Goldenberg AA, Micromachined 2-D Scanner for 3-D Optical Coherence Tomography, Sensors and Actuators A: Physical, 117:331-40, 2005.

  31. Bogaards A, Varma Abhay, Collens S, Lin A, Giles A, Yang VXD, Bilbao JM, Lilge LD, Muller PJ, and Wilson BC, Increased brain tumor resection using fluorescence image guidance in a preclinical model, Lasers in Surgery and Medicine, 35, 181-190, 2004.

  32. Qi B, Himmer AP, Gordon ML, Yang VXD, Dickensheets DL, Vitkin IA, Dynamic focus control in high-speed optical coherence tomography based on a microelectromechanical mirror, Opt. Comm., 232, 123-8, 2004.

  33. Yang VXD, Munce N, Pekar J, Gordon ML, Lo S, Marcon NE, Wilson BC, and Vitkin IA, Novel micromachined array tip for multi-focus fiber-based optical coherence tomography, Optics Letters 29, 1754-6, 2004.

  34. Yang VXD, Gordon ML, Tang S, Marcon NE, Gardiner G, Qi B, Bisland S, Seng-Yue E, Lo S, Pekar J, Mok A, Wilson BC, Vitkin IA, High speed, wide velocity dynamic range Doppler optical coherence tomography (Part III): in vivo endoscopic imaging of blood flow in the rat and human gastrointestinal tracts, Opt. Express 11, 2416-24, 2003.

  35. Yang VXD, Gordon ML, Qi B, Pekar J, Lo S, Seng-Yue E, Mok A, Wilson BC, and Vitkin IA, High speed, wide velocity dynamic range Doppler optical coherence tomography (Part II): Imaging in vivo cardiac dynamics of Xenopus laevis, Opt. Express 11, 1650-58, 2003.

  36. Tang S, Gordon ML, Yang VXD, Faughnan ME, Cirocco M, Qi B, Seng-Yue E, Gardiner G, Haber GB, Kandel G, Kortan P, Vitkin IA, Wilson BC, Marcon NE, In vivo Doppler optical coherence tomography of mucocutaneous telangiectases in hereditary hemorrhagic telangiectasia, GI Endoscopy 58, 591-8, 2003.

  37. Yang VXD, Gordon ML, Qi B, Pekar J, Lo S, Seng-Yue E, Mok A, Wilson BC, and Vitkin IA, High speed, wide velocity dynamic range Doppler optical coherence tomography (Part I): System design, signal processing, and performance, Opt. Express 11, 794-809, 2003.

  38. Yang VXD, Muller PJ, Herman P, Wilson BC, A Multispectral Fluorescence Imaging System: Design and Initial Clinical Tests in Intra-Operative Photofrin-Photodynamic Therapy of Brain Tumors, Lasers in Medicine and Surgery, 32, 224-232, 2003.

  39. Yang VXD, Pekar J, Lo SW, Gordon ML, Mok A, Wilson BC, Vitkin IA, Optical coherence and Doppler tomography for monitoring tissue changes induced by laser thermal therapy – an in vivo feasibility study, Review of Scientific Instruments, 74, 437-440, 2003.

  40. Yang VXD, Gordon ML, Mok A, Zhao Y, Chen Z, Cobbold RSC, Wilson BC, Vitkin IA, Improved phased-resolved optical Doppler tomography using the Kasai velocity estimator and histogram segmentation, Opt. Comm., 208, 209-214, 2002.

Funding

2007-09 Canadian Institutes of Health Research (team grant) Total: $2,838,000
2006-08 Natural Science and Engineering Research Council (strategic project) Total: $260,000
2005-08 Canadian Foundation for Innovation (equipment) Total: $250,000
2005-08 Canadian Institutes of Health Research (operating) Total: $680,000
2005-07 Photonics Research Ontario (operating) Total: $200,000
2002-04 Canadian Institutes of Health Research (operating - completed) Total: $330,000