Jahan Tavakkoli

BSEE, MASc (Sharif U. of Tech.), PhD (U. of Lyon-1)
Assistant Professor

Specialization

• Biomedical Ultrasound (Therapeutic and Diagnostic)
• Image-guided Ultrasound Surgery
• Nonlinear Acoustic Modeling and Simulation
• Ultrasound Signal and Image Processing
• Medical Devices and Technologies

Research Projects

Ultrasound is a unique modality that offers both diagnostic and therapeutic benefits in medicine and biology. Biomedical ultrasound is, therefore, an active area of research and development in various research centers in both academia and industry. My areas of research interest span a range of novel therapeutic and diagnostic applications of ultrasound in medicine and biology including:

• Image-guided HIFU Surgery

  HIFU (high intensity focused ultrasound) is a novel energy-based modality that causes coagulative tissue necrosis in a well-delineated focal zone by rapidly elevating tissue temperature (to above 65°C) in a short exposure duration of a few milliseconds to a few seconds, while keeping the intervening tissue temperatures at physiologically safe levels. HIFU is well known for its ability to produce precisely defined and well-controlled thermal lesions deep inside tissue. Under proper imaging guidance and treatment monitoring, HIFU can effectively be used in a number of non- and/or minimally-invasive surgery procedures. I am mainly interested in applications of HIFU in oncology for non- and/or minimally-invasive treatment of malignant solid tumors, and in neurology and neurosurgery for irreversible and reversible neural tissue manipulations.

• Nonlinear Acoustic Modeling and Simulation

  Interaction of ultrasound energy with biological tissue is a complicated phenomenon, which is governed by various physical and biophysical effects such as diffraction, attenuation, absorption, dispersion, scattering, reflection, refraction, etc. Moreover, in most therapeutic regimes a significant degree of nonlinearity exists in generation and propagation of ultrasound energy in tissue. I am interested in developing more accurate and more efficient numerical models and simulation tools for nonlinear propagation of ultrasound energy in biological tissue. Such models could significantly enhance our understanding of ultrasound bio-effects and also could help us in designing new applications and/or optimizing current applications of ultrasound in medicine and biology.

• Low Intensity Pulsed Ultrasound (LIPUS)

  LIPUS makes use of low intensity pulsed ultrasound (<1 W/cm2) to achieve certain types of therapeutic benefits in tissue. The main biophysical mechanisms of action in tissue are still not fully understood! It is believed that the mechanical effects including radiation pressure, micro-streaming and micro-vibrations play roles in this mode of ultrasound therapy. I am interested in applications of LIPUS in areas such as bone healing and nerve therapy.

• Ultrasound Signal and Image Processing

  Ultrasound signal/image processing toward information enhancement and/or noise reduction is an area of active research with significant interests in both academia and industry communities. SP/IP algorithms can be developed in various domains including: time, space, temporal frequency, spatial frequency, and/or mixed domains. I am interested in developing novel SP/IP methodologies especially in applications such as: HIFU treatment monitoring, ultrasound quantitative imaging, and ultrasound image de-noising.

Selected Publications

Tavakkoli J., Sanghvi N.T. (2011) Ultrasound-guided HIFU and Thermal Ablation. In: Frenkel V., ed. "Therapeutic Ultrasound: Mechanisms to Applications", Chapter 6, 137-161, Nova Science Publishers, Hauppauge, NY, January 2011.

Tavakkoli J., Mashouf S. (2011) Nonlinear acoustic beam propagation modeling in dissipative media. Canadian Acoustics, 39:19-25.

Weidman J., Ginsberg H.G., Tavakkoli J. (2011) The combined effects of low intensity pulsed ultrasound and heat on bone cell mineralization. Canadian Acoustics, 39:37-43.

Butt F., Abhari A., Tavakkoli J., An application of high performance computing to improve linear acoustics simulation. 2011 Spring Simulation Multi-conference (SpringSim'11), April 4 - 7, 2011, Boston, MA, USA, Conference Proceedings, 71-78.

Tavakkoli J. (2010) 9th International Symposium on Therapeutic Ultrasound (ISTU 2009)- Conference Proceedings. Hynynen K., Souquet J., eds., Book Review, J. Acoust. Soc. Am., 128:3263.

Weidman J., Tavakkoli J., The concurrent effects of low intensity pulsed ultrasound and heat on bone cell culture mineralization. 2010 International Conference on Acoustics (ICA), August 23-27, 2010, Sydney, Australia, Conference Proceedings (CD-ROM publication).

Williams R., Cherin E., Lam T.Y.J., Tavakkoli J., Zemp R.J., Foster F.S. (2006) Nonlinear ultrasound propagation through layered liquid and tissue-equivalent media. Physics in Medicine & Biology, 51:5809-5824.

Paterson R.F., Barret E., Siqueira T.M., Tavakkoli J., Rao V.V., Sanghvi N.T., Cheng L., Shalhav A.L. (2003) Laparoscopic partial kidney ablation with high-intensity focused ultrasound. J. Urology, 169:347-351 (Best Urology Scientific Paper Award).

Zemp R.J., Tavakkoli J., Cobbold R.S.C. (2003) Modeling of nonlinear ultrasound propagation in tissue from array transducers. J. Acoust. Soc. Am., 113:139-152.

Tavakkoli J., Cathignol D., Souchon R., Sapozhnikov O.A. (1998) Modeling of pulsed finite-amplitude focused sound beams in time domain. J. Acoust. Soc. Am., 104:2061-2072.

Funding

• NSERC Discovery Grant
• NSERC Research Tools and Instruments Grant
• Ontario Research Fund- Research Excellence (ORF-RE) Grant
• University of Prince Edward Island Collaborative Research Grant
• Neurosurgery Research Fund, St. Michael's Hospital, Toronto, Ontario
• Ryerson Research Tools and Instruments Grant
• Ryerson Startup Fund

Research Laboratory

Advanced Biomedical Ultrasound Imaging and Therapy Laboratory
http://www.physics.ryerson.ca/research/abul

Group Members

Current Graduate Students:
Borna Maraghechi
Pooya Sobhe Bidari
Mosa Alhamami
Elyas Shaswary
Steven Tran
Siavash Rahimian
Mojtaba Hajihasani
Parisa Rangraz

Current Undergraduate Students:
Krzysztof Wawrzyn

Alumni:
Sonal Bhadane
Fouad Butt
Mohammed Yahya
Shahrad Jabbary
Judith Weidman
Shahram Mashouf
Harini Pandithasekera
Negar Zohouri
Siavash Jafarpour
Thi Diem Chau Nguyen
Suleman Ahmad
Rana Attalla
Sharon Faustine
Marjan Kusha
Thirushanthy Subramanaim

Research Collaborators

Clinical:

Dr. Howard Ginsberg, MD, PhD, FRCSC, Neurosurgeon, St. Michael's Hospital, Toronto, Ontario, Canada, and Assistant Professor, University of Toronto, Toronto, Ontario, Canada
http://neurosurgery.utoronto.ca/faculty/list/ginsberg.htm

Dr. Kevin Rod, MD, CCFP, DAAPM, DCAPM, Director, Toronto Poly Clinic, North York, Ontario, Canada, and Lecturer, University of Toronto, Toronto, Ontario, Canada
http://www.tpclinic.com

Industrial:

Circuit Plus Inc., Richmond Hill, Ontario, Canada
http://www.circuit-plus.com

Professional Memberships

Chair, HITU Industry Council, Ultrasonic Industry Association.
Associate Editor, Journal of Medical Physics.
Associate Editor, Bio-acoustics, Journal of Canadian Acoustics.
Member of Technical Committee, Biomedical Ultrasound/Bioresponse to Vibrations, Acoustical Society of America.
Senior Member, IEEE Ultrasonics, Ferroelectrics, and Frequency Control; and Engineering in Medicine and Biology Societies.
Associate Member, Acoustical Society of America.
Member, American Institute of Ultrasound in Medicine.
Member, International Society for Therapeutic Ultrasound.
Member of Reviewers Panel for Journals: Ultrasound in Medicine and Biology, IEEE-Ultrasonics Ferroelectrics and Frequency Control, and Journal of Acoustical Society of America.
Member of Reviewers Panel for Grant Funding Agencies: Canada Foundation for Innovation (CFI), Natural Sciences and Engineering Research Council of Canada (NSERC), the Health Technology Exchange (HTX), Ontario Centers of Excellence (OCE Inc.), and the Industrial Research Assistance Program (IRAP) of the National Research Council (NRC).

Curriculum Vitae

LinkedIn

http://www.linkedin.com/pub/jahan-tavakkoli/15/43b/a54

Research Positions

Graduate Research Positions:
PhD and MSc graduate student positions are available for Fall semester 2012.

Undergraduate Research Positions:
Research assistant (RA) positions are available for summer 2012.

For more information about the above positions, directly contact Dr. Tavakkoli at jtavakkoli@ryerson.ca