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J. Carl Kumaradas, PhD

Graduate Program Director
Associate Professor

KHS 340B
Ryerson University
350 Victoria Street
Toronto, Ontario M5B 2K3
416-979-5000 x7462
ckumarad@ryerson.ca

Specialization

  • Medical Physics
  • Thermal Therapy
  • Electromagnetism
  • Heat Transfer
  • Numerical Analysis

Research

My research interests are in the area of computational modeling in medical physics using numerical methods. The main focus of my research has been on the development and implementation of finite element methods (FEM) for models involving electromagnetism, heat transfer, ultrasound scattering, and blood flow using arbitrary three-dimensional geometries. These models have been used to develop and optimize novel microwave heating devices for thermal therapy, which is a cancer treatment that uses heat. The modeling has been applied to the development of an optimized variable microwave attenuator array. This array was used in clinical treatments to shape microwave heating profiles produced by single-element waveguide applicators. This system was designed for treating superficial tumours such as those found in breast and head-and-neck cancers, and melanomas.

One area of current research, in collaboration with others, involves the development of FEM electromagnetic and heat transfer models to aid in the characterization of a novel cancer detection and treatment technique Plasmon Photo-thermal Therapy (PPTT). This approach involves binding gold nano-rods to monoclonal antibodies and other molecules that selectively target cancer cells. The tumours can be destroyed by radiating the region with infrared light that causes the nanoparticles to absorb the radiation resulting in thermal energy deposition localized at the tumor site.

Another current area of research involves the use of the finite element method for simulating wave scattering by arbitrary objects to develop models of ultrasound scattering by cells, sub-cellular components, and ultrasound contrast agents. We have developed a model in ultrasound scattering that couples the Helmholtz wave equation (for ultrasound propagation through fluids) with a structural mechanics model (for ultrasound propagation through solids) in three dimensions. This model has the potential for investigations of ultrasound scattering at a level of detail that has not been possible in the past.

A third area of active research involves the development of computational models of blood flow that account for the non-linear nature of blood flow. These models are being developed using two approaches: a discrete model in which the dynamics of individual particles in a linear fluid are simulated (multi-particle method) and a continuum model in which the fluid dynamics are represented using the Navier-Stokes partial differential equations with a flow-dependent viscosity (which is solved using the finite element method).

Publications

“Edge-Element Based Finite Element Analysis of Microwave Hyperthermia Treatments for Superficial Tumours on the Chest Wall”, J.C. Kumaradas and M.D. Sherar (2003), International Journal of Hyperthermia, v19, p.414.

“Optimization of a Beam Shaping Bolus for Superficial Microwave Hyperthermia Waveguide Applicators Using a Finite Element Method”, J.C. Kumaradas and M.D. Sherar (2003), Physics in Medicine and Biology, v48, p.1.

“An Edge-element based Finite Element Model of Microwave Heating in Hyperthermia: Method and Verification”, J.C. Kumaradas and M.D. Sherar (2002), International Journal of Hyperthermia, v18, p.426.

“An Edge-element based Finite Element Model of Microwave Heating in Hyperthermia: Application to a Bolus Design”, J.C. Kumaradas and M.D. Sherar (2002), International Journal of Hyperthermia, v18, p.441.