Xiaoyao Fan

Assistant Professor of Engineering


My research interests are focused on image guidance in neurosurgery, including open and minimally invasive procedures. I have been working on methods and algorithms to improve the accuracy of image guidance and image updating for intraoperative brain deformation and spine motion compensation at multiple stages. We have designed and implemented intraoperative image acquisition systems for calibration, data collection and processing, such as intraoperative stereovision and 3D ultrasound. I have been working in the operating room (OR) as well as the Center for Surgical Innovation (CSI) at DHMC on data collection, intraoperative CT and MR imaging, real time computation, and intraoperative feedback to improve the accuracy of image guidance in 400+ OR cases. I am familiar with image-guided systems, intraoperative imaging techniques and instruments, and the clinical environment in general, and have expertise in image processing, image registration, computational modeling, and optimization. I have also worked closely with Medtronic in an effort to provide model updated images to the Medtronic StealthStation navigation system.

Research Interests

Image guidance; neurosurgery; brain deformation; intervertebral motion; intraoperative imaging; stereovision; ultrasound; computational modeling; image processing; image registration; machine learning


  • BE, Electrical Engineering, Tsinghua University 2007
  • PhD, Biomedical Engineering, Dartmouth 2012

Research Projects

  • Image-based registration and intraoperative updating for guiding spine surgery

    Image-based registration and intraoperative updating for guiding spine surgery

    This project develops and evaluates image-based registration methods involving stereovision for registration and image updating during open spine surgeries for degenerative spondylolisthesis.

  • Preoperative image updating for guidance during brain tumor resection

    Preoperative image updating for guidance during brain tumor resection

    The goal of this project is to optimize and validate, in human and animal studies, intraoperative image updating methods that assimilate intraoperative data acquired with stereovision and ultrasound with computational modeling to update preoperative MRI in order to maintain image registration accuracy throughout surgery.

Selected Publications

  • Cai Y, Wu S, Fan X, Olson J, Evans L, Lollis S, Mirza SK, Paulsen KD, Ji S. A level-wise spine registration framework to account for large pose changes. Int J Comput Assist Radiol Surg. (2021) Jun;16(6):943-953. doi: 10.1007/s11548-021-02395-0. Epub 2021 May 10. PMID: 33973113; PMCID: PMC8358825
  • Fan X, Durtschi MS, Li C, Evans LT, Ji S, Mirza SK, Paulsen KD. Hand-Held Stereovision System for Image Updating in Open Spine Surgery. Oper Neurosurg (Hagerstown). (2020) Sep 15;19(4):461-470. doi: 10.1093/ons/opaa057. PMID: 32365204; PMCID: PMC7490214
  • L.T. Evans, J.D. Olson, Y. Cai, X. Fan, K.D. Paulsen, D.W. Roberts, S. Ji, S.S. Lollis; Stereovision Co-Registration in Image-Guided Spinal Surgery: Accuracy Assessment Using Explanted Porcine Spines, Operative Neurosurgery, opy023 (2018)
  • S.S. Lollis, X. Fan, L.T. Evans, J.D. Olson, K.D. Paulsen, D.W. Roberts, S.K. Mirza, S. Ji; Use of Stereovision for Intraoperative Coregistration of a Spinal Surgical Field: A Human Feasibility Study, Operative Neurosurgery, Volume 14, Issue 1, Pages 29–35 (2018)
  • X. Fan, D.W. Roberts, J.D. Olson, S. Ji, T.J. Schaewe, D.A. Simon, K.D. Paulsen. Image updating for brain shift compensation during resection, Operative Neurosurgery, opx123 (2017)
  • X. Fan, D.W. Roberts, T.J. Schaewe, S. Ji, L.H. Holton, D.A. Simon, K.D. Paulsen. Intraoperative image updating for brain shift following dural opening. Journal of Neurosurgery, 1-10 (2016)
  • X. Fan, D.W. Roberts, S. Ji, A. Hartov, K.D. Paulsen. Intraoperative fiducial-less patient registration using volumetric 3D ultrasound: a prospective series of 32 neurosurgical cases. Journal of Neurosurgery 123:721-731 (2015)
  • X. Fan, S. Ji, A. Hartov, D.W. Roberts, K.D. Paulsen. Stereovision to MR image registration for cortical surface displacement mapping to enhance image-guided neurosurgery. Medical Physics 41:102302 (2014)


  • Hand-held stereovision system for image updating in surgery | 11,406,471
  • Surgical navigation with stereovision and associated methods | 10,568,535
  • Method and apparatus for calibration of stereo-optical three-dimensional surface-mapping system | 9,456,200
  • Method and apparatus for determining tumor shift during surgery using a stereo-optical three-dimensional surface-mapping system | 9,336,592