Edmonton—If he isn’t in class or studying, you’ll find mechanical engineering student Peter Knight pushing himself to extremes in mountain bike races—it’s an extremely demanding sport that causes your legs to scream and forces your heart to beat at speeds nearing 200 beats per minute.
It’s somewhat ironic, then, that Knight has spent the past several months designing and building a type of stationary bicycle for patients who are suffering with cardiac disease.
A mechanical engineering (biomedical option) student in the faculty’s Co-op Engineering Program, Knight is wrapping up a work term in the U of A Department of Biomedical Engineering designing, building an exercise device that can be attached to an MRI machine.
Richard Thompson, a professor in the Department of Biomedical Engineering and Knights supervisor for his co-op term, develops new MRI methods for imaging the heart and other organs and applies these methods to study diseases such as heart failure.
Knight’s new device will enable heart disease researchers to use MRI to generate images of a patient’s heart working and “see” how their blood flows and circulates while under physical exertion. The images will provide unique information about the nature of an individual’s heart disease.
“The most common disease in North America is heart disease—and it is often exposed only when you exert yourself,” said Thompson. “What’s interesting is that in some patients, their heart might not be the primary problem.. There are many heart failure patients whose hearts look like they are pumping normally but its possible that their skeletal muscle or their brain aren’t getting enough blood during exercise, which may be the factors which then define their disease . . . no one has looked at all of these factor together and if we can identify the weak link, it will open up new potential methods to treat this common disease.”
The device Knight has been building, he says “will be an important add-on” in the research. There is a commercial version of the MRI stationary cycle that costs tens of thousands of dollars, but Thompson, an alumnus of the U of A Faculty of Engineering, was happy to put Knight to work on the project.
Knight says designing the device was tricky. For starters, there were physical restrictions to consider: he needed to be sure that patients laying on their backs pedaling in a circular motion wouldn’t hit their knees on the MRI machine.
“Because your range of motion is somewhat restricted traditional cycling wasn’t an option,” said Knight. “What we decided to do instead is use a linear reciprocating motion where your leg moves straight back and forth—it’s similar to a piston in a car.”
Patients would push their feet against rods connected to a large flywheel with adjustable resistance.
Knight also had to consider what materials he’d use. At the core of an MRI machine are magnets so powerful that people with pacemakers are not allowed too close to the machines. Knight couldn’t use metal in the device.
As a result, Knight’s stationary bicycle is made from wood, held together with stainless steel screws—its molecular composition make it virtually immune to magnetic forces. The flywheel is made from plastic and the wheel’s hub—from a mountain bike, of course—is mostly made of aluminum.
Knight says the co-op placement was a natural fit for him not only because he’s a high-level cyclist, but also because of the impact it could have in health care. His previous Co-op placements have included the Canmet Energy Technology Centre in Devon, Alberta, where he examined ways to separate more components from oilsands tailings; another was working with Dean of Rehabilitation Medicine Martin Feguson-Pell on sensors that would monitor a hospital bed’s physical condition, to prevent patients from getting bed sores.
“I don’t want to pigeon hole myself into one particular area,” said Knight. “Being in the co-op program you have a chance to try a lot of different things out, so that’s what I’m doing.”