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San Diego, Calif., April 28, 2020 -- Inspire: meaning both to breathe in, and to be filled with the urge to take action. The definitions went hand-in-hand for two groups of engineering students at UC San Diego, who spent their spring break harnessing their knowledge to contribute to the ventilator shortage the world is facing with the COVID-19 pandemic.
“We realized that we actually do have the engineering skills to try and make a meaningful difference,” said Anjulie Agrusa, a bioengineering PhD student at the UC San Diego Jacobs School of Engineering, who worked with two fellow bioengineering PhD candidates to form a multidisciplinary, international team for the Code Life Ventilator Challenge.
Their task? To design a low-cost, simple, easy-to-use and easy-to-build ventilator that could serve COVID-19 patients. In eight days.
Agrusa and bioengineering PhD students Sydnee Hyman and Nicholas Harrington spent their spring break designing a pressure-controlled ventilator based on technology used in scuba diving regulators. They worked with a retired electrical engineer and a retired video game developer in Canada that they met through the challenge, who added prototyping and user interface skills to the team, respectively. They also worked closely with a physician in Sacramento who provided input on what capabilities the ventilator needed to have, particularly for serving COVID patients.
“I think that was a call to action for all of us: that realization that we actually do know how to solve this problem-- or at least how to try to solve it,” said Agrusa. “UC San Diego prepared us really, really well to be equipped for something like this. It was a really cool experience to know that you actually have the tools to make a difference.”
None of the three students actually had a background in ventilator technology; Agrusa does computational work to better understand the electrical waves in our gastrointestinal tract; Hyman studies rotator cuff disease and therapies to treat it; and Harrington’s research focuses on developing home health devices to reduce the rate of rehospitalization due to heart failure.
But they did know how to problem solve. They knew how to think critically. They had software engineering skills, knew how to model, design, build and test medical device prototypes, and understood the importance of stakeholder feedback.
“We were given these skills, we were given these first principles in school, and we’re at a point in our careers where we actually know how to try and solve this problem,” Agrusa said. “All of us felt that we couldn't just sit there and have a spring break without trying to help solve this problem.”
More than 1,000 teams participated in the ventilator challenge, which laid out specific criteria that all submitted designs needed to meet.
“One of the primary design specifications was that the ventilator had to be pressure-controlled as opposed to flow-controlled,” Hyman explained. “That’s a distinction that makes it a lot trickier to design for and is important to be able to regulate pressure well for COVID patients specifically, because of all the acute respiratory distress that they experience. That creates a lot of changes to the lung physiology that provide more ventilation challenges.”
After delving deep into the world of breathing devices, the students learned that a key issue of designing a ventilator is the extremely precise modulation of very low pressures at very low flows-- the actuators and sensors used to accomplish this in state-of-the-art ventilators are very expensive and hard to manufacture.
“So we decided to think about what's out there that currently works for people to breathe on that works at low pressures, and we thought about scuba regulators,” said Hyman.
When you inhale using a scuba pressure regulator, a diaphragm in the device gets depressed, creating a negative pressure and allowing air to flow in. The students learned that the same effect can also be achieved in a regulator by pushing what’s called a purge button, used to get water out of the device.
“If you press that button, it depresses the diaphragm and allows air to go through,” said Agrusa. “Because COVID patients, or any patient that needs to be on a ventilator, cannot produce that negative pressure in their lungs since they can't inhale themselves, you force air in by creating a pressure gradient yourself. The way that we did this was by pressing the purge button on the scuba regulator a very specific amount, to let a very specific amount of air flow through.”
The students used an Arduino computer board to precisely control the concentration of oxygen entering the lungs each time the button is pressed. On their ventilator, this is adjusted by a physician based on the individual patient’s needs, through an easy-to-manipulate user interface. The whole system is controlled by a servo motor.
|A CAD design of the graduate students' scuba regulator and actuating apparatus.|
A panel of engineers and judges reviewed all the submissions, and selected three designs as most promising. Those were made open source in an attempt to get the ventilators where they’re most needed as soon as possible.
The team said the process was an empowering learning experience.
“This was all new to us,” Harrington said. “Even from the ground up, as to what exactly a ventilator is and what it does, we didn’t really know the specifics before….So it was interesting to learn about how to balance the different requirements of having a high pressure supply, but then needing to use low pressure to not hurt the patient. The interplay there was interesting.”
For Hyman, the learning also included agile project management.
“Managing a whole multidisciplinary team, virtually, in a very short timeframe with the design specifications which got updated as the challenge continued… that for me I think was the biggest learning opportunity.”
Undergraduates also shoot for the stars
The team of bioengineering graduate students wasn’t the only one to lend their skills to the cause. Undergraduate engineers from the rocket team of Students for the Exploration and Development of Space group also chose to put their engineering know-how to use.
“At the end of the day, a ventilator is there to deliver a specific volume at a specific pressure, which is exactly what mechanical engineering prepares you to do,” said Scott Hall, a mechanical engineering student and member of SEDS’ rocket team.
Hall, who had a job offer rescinded due to COVID-19 related financial woes, was looking for something to fill his time in quarantine that could also add to his resume, when the Agorize ventilator challenge crossed his path.
“That sounded like a great way to spend time meaningfully in quarantine. I ran it past the rocket team, and everyone got super excited. Then I told them the deadline, which was in a week, and we were like ok, well that’s a crazy short deadline, but let’s at least still try.”
|The team of undergraduate students working on their SEDS rocket.|
Hall was joined by Tristan Kinney, Shannon Lin, Patrick Finn, and Harker Russell. The students worked through their spring break to understand the engineering behind ventilators, and started creating a design of their own that would be inexpensive and easy to manufacture, per the hackathon criteria.
They soon realized that they wouldn’t be able to have their design completed in time for the contest deadline, but decided to keep pursuing the goal anyway.
“We’re still working on it. Everyone agreed that we want to build something that could help people, even if it’s not within this particular challenge timeframe,” Hall said.
The students-- three mechanical engineers and one bioengineer-- are working on the ventilator design remotely, since the state is under shelter-at-home orders. Luckily, they’re still able to piecemeal together a prototype.
“What’s nice about SEDS is that we’re all big nerds,” Hall said. “We have our own 3D printers at home, so all of us will be able to 3D print parts and leave them on someone else’s doorstep. So the plan from quarantine is to put this thing together through 3D printing, and buy any other parts we need online from McMaster.”
While the team plans to see their design through to completion, Hall said they all feel that it’s been an invaluable learning experience and use of their spring break and quarantine time, regardless of the outcome.
“I think so far in my undergraduate career there've been six or seven projects that have really taught me how to be an engineer, and this is one of them,” he said. “This is the way you learn engineering--by doing stuff like this. Taking on crazy projects and trying to make it work.”
Jacobs School of Engineering