Undergrad students develop an improved sleep apnea mask

An estimated 930 million people worldwide struggle with sleep apnea, but two of them in particular played an inspirational role in a group of UM-Dearborn students' recent senior design project. Engineering undergrads Saja Samra's and Maggie Bustamante's dads both live with the condition, which causes people to stop and start breathing, sometimes hundreds of times, during their sleep cycle. To treat their condition, their dads both use a CPAP machine, which utilizes a face mask to keep airways open during sleep. The devices can help people get much better - and safer - rest, but the technology isn't without problems. "Both our dads had similar issues - things like air leakage and discomfort, and that it was too bulky," Samra says. "Portability was a big issue for my dad," Bustamante says. "Whenever he would go camping or go on a trip for work, a lot of times he would choose not to bring it, and then he wouldn't sleep nearly as well."

This feedback prompted Samra and Bustamante to take a pitch to their senior design teammates: What if we designed a better CPAP mask? Both Ammel Mutahr and Sajida Tohfe liked the idea, so they started digging into what exactly that would involve. All four students majored in Human-Centered Engineering Design, a relatively new program at UM-Dearborn that emphasizes human needs and blends traditional engineering with skills borrowed from art, anthropology, psychology and sociology. So they quickly deployed the strategies they learned over their previous three years in their program. In typical HCED fashion, they started by talking with potential users, surveying more than a dozen people who have sleep apnea about their specific, real-world challenges with their CPAP devices. They also had more in-depth conversations with both dads. From that feedback, they learned that some of the most common issues involve fit around the nose and chin, comfort, the clumsiness of getting the mask on and the overall bulkiness of the device. With only two semesters to work on the project, they decided to focus on the first three issues, to see if they could create a better CPAP mask.

They began with a design brainstorming session, pulling inspiration from things like military pilot oxygen masks, which have inflatable head straps to create a tight fit, and even the Ironman helmet, a full head covering with interlocking panels. They then created low-fidelity prototypes with simple materials like cardboard and masking tape, and gradually moved through a series of higher-fidelity 3D-printed models. The dads proved to be a huge help in making some important tweaks along the way. "We knew comfort was a concern, so for one of our earlier prototypes we used TPU, which is a kind of plastic that has a little more give to it," Bustamante explains. "But when Saja's dad tested it, he said it was a little rough on his skin. So we tried this silicone resin, which is this relatively new type of resin used in 3D printing, and that ended up being much more comfortable."

In addition to the silicone resin, their final prototype included a number of features designed to improve fit and comfort. Mutahr played a key role in developing the inflatable auto-adjusting straps, which not only make the mask fit better but make it easier to get off and on. Bustamante and Samra focused on an auto-sealing mechanism, which used two small motors around the bridge of the nose to seal the mask if pressure sensors detect an air leakage. One of the biggest breakthroughs was when Tohfe discovered a quick and cheap way to create individualized masks. Using a smartphone app called Scandy Pro: 3D Scanner, people could use their phone cameras to perform detailed scans of their faces, which then could be used to create 3D-printing files for custom masks.

The team's innovative design earned the Best in College Award at this year's Senior Design Competition. Still, the team says their final prototype by no means feels complete, as the compressed timeframe for the competition meant they couldn't do everything they wanted. For example, Samra says the motors added some bulk to the mask, a quality they were trying to avoid, so she'd like to explore using a lighter-footprint technology, like actuators. And they'd likely add those to more places on the mask, like along the chin, where some of the people they surveyed say they experience air leakages. Mutahr, who also designed an app interface for their mask, pointed out that even Senior Design Day, when they presented their design to the public and the competition judges, gave them ideas for improvements. "For example, we got a comment from one of the judges, who had sleep apnea, and he had a really large beard, but he had to shave it because of the mask," she says. "That's something you probably wouldn't think about unless you're actually talking with people who have sleep apnea. We heard comments like that from so many people who have issues with their masks. So you do the research, you read the statistics online, but seeing it in real life and how our solution could actually be helpful, that's probably when you get the best design ideas."

Mutahr says one of the most gratifying pieces of feedback was that their idea "could be on 'Shark Tank.'" Indeed, they're not ruling out trying to commercialize the product. One of their team's faculty advisors is a patent lawyer, and a different project that Samra, Tohfe and Mutahr worked on in one of their HCED classes is already under review for a patent. The big challenge right now is getting the band back together. Bustamante graduated this spring and is busy with her new process engineering position at GM, where she's helping retool a factory for EV production. Samra and Tohfe, who also graduated recently, are interviewing for jobs. And Mutahr still has a semester to go. "But we'd definitely love to pursue that," Samra says. "Maybe after Ammel graduates, we can make it happen."

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Story by Lou Blouin

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