Bio

Professional Education


  • Doctor of Philosophy, University of Washington (2014)
  • Master of Science, Oregon State University (2008)
  • Bachelor of Science, University Of Tehran (2006)

Stanford Advisors


Patents


  • Siavash Yousefi, Ruikang K. Wang. "United States Patent 464910.01US1 Method and device for imaging lymphatic circulations and its applications", Jul 1, 2014
  • Siavash Yousefi, Ruikang K. Wang. "United States Patent 46337.01US1 Methods and systems for determining hemodynamic properties of a tissue", Apr 1, 2014

Publications

Journal Articles


  • Monocular Extraction of 2.1D Sketch Using Constrained Convex Optimization INTERNATIONAL JOURNAL OF COMPUTER VISION Amer, M. R., Yousefi, S., Raich, R., Todorovic, S. 2015; 112 (1): 23-42
  • Assessment of microcirculation dynamics during cutaneous wound healing phases in vivo using optical microangiography JOURNAL OF BIOMEDICAL OPTICS Yousefi, S., Qin, J., Dziennis, S., Wang, R. K. 2014; 19 (7)

    Abstract

    Cutaneous wound healing consists of multiple overlapping phases starting with blood coagulation following incision of blood vessels. We utilized label-free optical coherence tomography and optical microangiography (OMAG) to noninvasively monitor healing process and dynamics of microcirculation system in a mouse ear pinna wound model. Mouse ear pinna is composed of two layers of skin separated by a layer of cartilage and because its total thickness is around 500 ?m, it can be utilized as an ideal model for optical imaging techniques. These skin layers are identical to human skin structure except for sweat ducts and glands. Microcirculatory system responds to the wound injury by recruiting collateral vessels to supply blood flow to hypoxic region. During the inflammatory phase, lymphatic vessels play an important role in the immune response of the tissue and clearing waste from interstitial fluid. In the final phase of wound healing, tissue maturation, and remodeling, the wound area is fully closed while blood vessels mature to support the tissue cells. We show that using OMAG technology allows noninvasive and label-free monitoring and imaging each phase of wound healing that can be used to replace invasive tissue sample histology and immunochemistry technologies.

    View details for DOI 10.1117/1.JBO.19.7.076015

    View details for Web of Science ID 000340490400039

    View details for PubMedID 25036212

  • Label-Free Optical Imaging of Lymphatic Vessels Within Tissue Beds IN VIVO IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS Yousefi, S., Zhi, Z., Wang, R. K. 2014; 20 (2)
  • Label-free optical lymphangiography: development of an automatic segmentation method applied to optical coherence tomography to visualize lymphatic vessels using Hessian filters JOURNAL OF BIOMEDICAL OPTICS Yousefi, S., Qin, J., Zhi, Z., Wang, R. K. 2013; 18 (8)

    Abstract

    Lymphatic vessels are a part of the circulatory system that collect plasma and other substances that have leaked from the capillaries into interstitial fluid (lymph) and transport lymph back to the circulatory system. Since lymph is transparent, lymphatic vessels appear as dark hallow vessel-like regions in optical coherence tomography (OCT) cross sectional images. We propose an automatic method to segment lymphatic vessel lumen from OCT structural cross sections using eigenvalues of Hessian filters. Compared to the existing method based on intensity threshold, Hessian filters are more selective on vessel shape and less sensitive to intensity variations and noise. Using this segmentation technique along with optical micro-angiography allows label-free noninvasive simultaneous visualization of blood and lymphatic vessels in vivo. Lymphatic vessels play an important role in cancer, immune system response, inflammatory disease, wound healing and tissue regeneration. Development of imaging techniques and visualization tools for lymphatic vessels is valuable in understanding the mechanisms and studying therapeutic methods in related disease and tissue response.

    View details for DOI 10.1117/1.JBO.18.8.086004

    View details for Web of Science ID 000324287700009

    View details for PubMedID 23922124

  • Super-resolution spectral estimation of optical micro-angiography for quantifying blood flow within microcirculatory tissue beds in vivo BIOMEDICAL OPTICS EXPRESS Yousefi, S., Qin, J., Wang, R. K. 2013; 4 (7): 1214-1228

    Abstract

    In this paper, we propose a super-resolution spectral estimation technique to quantify microvascular hemodynamics using optical microangiography (OMAG) based on optical coherence tomography (OCT). The proposed OMAG technique uses both amplitude and phase information of the OCT signals which makes it sensitive to the axial and transverse flows. The scanning protocol for the proposed method is identical to three-dimensional ultrahigh sensitive OMAG, and is applicable for in vivo measurements. In contrast to the existing capillary flow quantification methods, the proposed method is less sensitive to tissue motion and does not have aliasing problems due fast flow within large blood vessels. This method is analogous to power Doppler in ultrasonography and estimates the number of red blood cells passing through the beam as opposed to the velocity of the particles. The technique is tested both qualitatively and quantitatively by using OMAG to image microcirculation within mouse ear flap in vivo.

    View details for DOI 10.1364/BOE.4.001214

    View details for Web of Science ID 000321336500020

    View details for PubMedID 23847744

  • Digital discrimination of neutrons and gamma-rays in liquid scintillators using wavelets NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT Yousefi, S., Lucchese, L., Aspinall, M. D. 2009; 598 (2): 549-553

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