Developing a Diabetic Foot Ulcer Orthotic

Organizations: Duke University - Biomedical Engineering

Collaborators: Marcus Coleman, Henry Farley, Zach Leytus, Dr. George Truskey, Dr. Paul Mosca

Dates: Fall 2014

Foci: Medical Devices, Diabetes

Synopsis

Diabetic patients can lose feeling in their extremities (diabetic neuropathy), and as a result, can incur wounds on the bottom of their feet they do not notice for long periods. To complicate the problem, lack of feeling makes it highly likely that these patients re-injure themselves.

As a result of never being allowed to heal, these wounds can fester (and even rot), causing foot ulcers that can sometimes only be treated via amputation.

Many of these patients, despite these risks, have no choice but to be on their feet to perform daily household tasks and their duties at work. There was a clear need of somehow enabling these patients with their mobility while removing the risk of them re-injuring their extremities.

The Opportunity

During my senior year of college, I was given the opportunity to work with a team of 3 other engineers in a Biomedical Engineering Practicum. It was our job for a year to find an applied biomedical problem, and develop a novel solution to the core need.

The Work

Through many hours of shadowing a surgical oncologist, talking with patients, and interviewing other related healthcare professionals at the Duke University Medical Center, we discovered - and decided to tackle - the problem of mobility for patients with diabetic neuropathy.

Several brainstorming sessions later, we opted to explore the path of building a prosthetic. We spoke to prosthetists and orthotics experts on current solutions, the best materials to use, issues with fit and sizing, and general best practices, and proceeded to iterate through several prototypes.

Building the actual device was immensely satisfying. The process of working with carbon fiber, 3D printing initial prototypes, and spending hours to get the right polymer finish can be downright meditative. In general, I’m the kind of person who enjoys building products that have tangible impacts I can experience directly with my 5 senses. Physical products check all the boxes! (I.e., you can’t lick or smell software. Not that I lick physical products. But the smell of a workshop? Oh man.)

We also had a few “aha” moments that were enjoyable to experience as a group. One of the problems we faced was how to hold a patient’s leg in the device without constant pressure (if you’ve ever worn shin-pads, you’ll know what I’m talking about). In the course of a brainstorming session, we stumbled upon the idea of using a Chinese finger-trap design to (1) hold the leg securely as weight was being applied toward the ground and (2) to easily reduce the device’s grip on the leg with nothing more than a reduction in weight placed on the leg. Pretty nifty!

The Outcome

Our solution had enough potential that we considered entering a pitch competition. Unfortunately, prior to entering and upon doing more extensive market research, we discovered a niche, competing device that was nearly identical to ours.

This discovery was a great confirmation of our engineering design skills, but killed our hopes of making the big bucks. The next time I work on designing a device, more extensive market research will likely be the first step!