John Madden – Biomedical Robotics

“I want my work to be part of a larger narrative and to have a positive impact in the world.”

Program:
- Electrical and Computer Engineering
Campus: Vancouver

Education: PhD in Mechanical Engineering (MIT); MEng in Biomedical Engineering (McGill); BSc in Physics (UBC)

Why did you decide to study engineering?

Perhaps that’s the connection to my interest in literature: that I want my work to be part of a larger narrative and to have a positive impact in the world.

English literature was probably my favourite class in high school and I wasn’t sure what I wanted to study in university. I ended up doing an undergraduate degree in physics because I thought it was a good choice for a general subject. But the career pathways I saw leading on from physics didn’t appeal and I moved into engineering for my master’s degree. I studied Biomedical Engineering at McGill with a professor who was developing micro-robots for surgery. The dream was that we would be able to create something very small that could be released into the body and travel through the bloodstream to perform surgery. It was an inspiring vision.

Biomedical Engineering Physics Undergrad Program

Tell us about your research

I’m involved in many different research projects, but I’ll just focus on two: one on spinal cord repair and one on artificial skin. I’m the director of Mend the Gap, a global interdisciplinary team working on spinal cord repair. When a spinal cord is damaged, there is often a fairly large region, about a centimeter across, where the axons are severed and nerve impulses cannot travel between the body and brain. This is what leads to paralysis, as well as other challenges like loss of control over temperature, blood pressure, perspiration, urination and more. This project is looking at ways to encourage the regrowth and reconnection of the damaged area’s axons. As you might imagine, there are a lot of challenges. Axons are about 1/50th the diameter of a hair and we want them to grow across the distance of a centimetre in a straight line. The wounded environment is not conducive to axon growth and in fact inhibits this growth. Then there’s the issue of injection itself and getting material to this wounded area in a way that does not cause further damage.

Our team is looking at how to inject a gel containing very small magnetic rods into the wounded area, align these magnetic fields across the gap and encourage the axons to grow along these “tracks.”

This involves image-guided robotics to make sure we are injecting the material in the right place and minimizing the chances of doing any more damage.

All of these aspects are being brought together through a multi-university project that involves 32 researchers from 12 academic institutions in five countries, as well as partnerships with three non-profit organizations.

It’s an amazing alignment of top people in a wide range of disciplines working with the spinal cord injury community to make progress on a notoriously difficult challenge. Another big project my lab has been working on over the last few years is developing artificial skin for robots that has similar sensing capabilities to human skin. We’re developing a simple rubbery skin that uses the same principles found on your phone’s touchscreen. It uses a capacitive effect, with electric fields that extend out of the screen and interact with your finger as it approaches. Because of their flexibility, our sensors deform when force is applied, which creates a change in the electric signal. There are numerous applications for this. It will, we hope, be practical for robots, especially for those interacting with people in health-care or elder-care environments where the robots require significant dexterity. It’s also potentially useful for prosthetic limbs or to incorporate into hospital beds to monitor if patients are losing circulation in a certain part of their body.

Do you hire undergrads to work in your lab?

Definitely. In the summers we often have five to seven undergrads working with senior PhD and master’s students. For the artificial skin project, for example, we have two main areas of need. One is building sensors, which involves a lot of 3D printing, molding, bonding, patterning and laser machining, and then the second is building the electronics on flexible printed circuit boards.

We look for students who have experience with design, circuit board testing and soldering. We also need people who can perform finite element simulation, develop the software, firmware and the display, as well as apply signal analysis and machine learning.

Undergraduate Research Experience

What skills do students develop as engineers?

Over the course of their engineering degree, students develop problem-solving approaches and systems-level thinking.

While a scientist generally starts with understanding an issue and then may move through to the application, an engineer generally starts with a problem that needs solving and then determines what they need to know, and how to put that knowledge together to solve the problem.

Engineers often need to create mathematical models, from which they develop designs, test predictions and so on.

Any advice for students?

Learning how to think as an engineer is valuable wherever life takes you.

I think it’s valuable for all engineers, regardless of specialty, to learn some electronics and software. Everything is becoming “smart.” If you look at an automobile, the value of the electronics and sensors exceeds the value of the mechanical parts of the car. Also, as an engineer it’s important to realize that you may start out in one discipline, but that’s not necessarily where you’re going to end up.