Associate Professor, Department of Electrical and Computer Engineering
Research areas: microwave engineering, heterogeneous computing algorithms and software for electromagnetics/bioelectromagnetics applications.
Many of us use microwave ovens on a daily basis to prepare our meals. The electromagnetic waves that are used to cook the food we eat are quite similar to the electromagnetic waves that are used to enable wireless communication between our cellphones, computers, routers, and cellphone towers.
Is it fair then to assume that the electromagnetic (EM) energy that serves our wireless communication needs can also have the unintended effect of ‘cooking’ our bodies? And are our brains, so close to the cell phones we hold up to our ears, particularly vulnerable?
The proliferation of wireless communication devices has made these kinds of questions all the more pressing. In order to determine exactly how EM waves impact our health — both physical and emotional — quantitative studies of the effects of EM energy on living tissues and organs must first be completed.
Dr. Poman So, an associate professor with the University of Victoria’s Department of Electrical and Computer Engineering, hopes to use his experience with applied computational electromagnetics and object-oriented software engineering to better understand how EM energy interacts with the human body.
Dr. So develops computer models that quantify and simulate the electromagnetic processes that occur when an EM wave interacts with different materials — including the materials that make up the human body, such as bone, muscle and fat.
While the electromagnetic interaction between EM waves and materials is well understood (and governed by Maxwell’s equations), the multiphysics and physiological effects are yet to be investigated.
In a microwave oven, EM energy causes polarized molecules (such as water) inside the food to vibrate, generating heat, which cooks the food. How exactly EM waves affect live human tissue, rather than a T-bone steak, is not entirely clear.
What is clear is that EM waves are capable of penetrating into our cells, transferring thermal energy to them and generating heat along their path of propagation. If the energy is high enough, the EM waves can actually cook our tissues, much like a microwave oven cooks a piece of meat. What is particularly troubling is that the frequency range used in cell phones is similar to that used in microwave ovens.
Naturally, how EM energy affects any given material depends on what is in the line of fire, so to speak. Different materials have different properties — including electrical properties, such as conductivity, permittivity, and permeability — that dictate the degree to which an EM wave can interact with a given material. Human tissues are no exception. Fat, for instance, cooks much faster than muscle.
The medical community has capitalized on this knowledge, using EM waves advantageously in procedures that include: microwave ablation, magnetic resonance imaging and x-ray computed tomography. The physiological effects of electromagnetic energy and the degree to which it can affect the health of the human population, however, are still poorly understood.
Ultimately, the safety of human beings in the presence of EM energy depends upon the energy level (or intensity and frequency of the EM waves), which can be reduced, to certain degree, by increasing one’s distance from the EM source.
“But how much is too much?” asks Dr. So, “and for a particular radiation source, how close is too close?”
To answer this question, So is developing a computer model that can simulate how EM waves interact with the human body. One of his greatest challenges? Computer power. “You can always find a problem that is bigger than any of the computers out there can handle,” says So.
Rather than use traditional “brute force” methods, which require inordinate amounts of computer power and memory, So develops smart algorithms — algorithms based on the physics and biology of the problem — that can overcome the limitations associated with inadequate computer resources.
Smart algorithms and computational modeling work to simplify complex problems, allowing So to create a versatile model that can be applied to a multitude of different systems, from communications to biomedicine. When it comes to biomedicine, So is particularly interested in applying these algorithms to quantify the effects of EM waves on various human organs and, eventually, on the whole human body.
Like most researchers, So is driven by a keen sense of curiosity and pure grit. He often tells his students that success comes with persistence. “If you cannot do it, do not lose hope,” says So. “Keep trying and eventually you will get it.”
So’s ultimate goal? Discover, develop, and deliver; to use the knowledge he generates to create practical applications for the benefit of society.