A team of around 25 students and faculty members from various departments at Queen’s University has designed a working medical ventilator using readily available parts in just 10 days.

The team is participating in the Code Life Ventilator Challenge, which is a global contest being run by the Montreal General Hospital Foundation and the Research Institute of the McGill University Health Centre.

The objective of the challenge is to create a low-cost, easy-to-manufacture and easy-to-maintain ventilator that could be deployed around the world to save lives during the COVID-19 pandemic.

Teams had two weeks to turn in their designs, but the Queen’s team was a little late in getting started and had to complete its machine in just 10 days. The team did it, though, and has a working prototype that has been submitted to judges.

“We got a message from the challenge website saying we have made it to the next round, which I think means we submitted a successful application. At the moment, it is being judged, and we will find out how that went in the next couple of days. But we were pretty excited that we submitted a complete application in such a short time frame, ” Heidi Ploeg, a Queen’s professor specializing in the design of biomedical devices, said.

The prototype the team built certainly doesn’t look like a sophisticated piece of medical equipment; it looks like a few plastic carrying cases stacked on top of each other with some tubes coming out. But its appearance belies some impressive engineering that had to be done under very unusual circumstances.

The heart of the ventilator is a pair of continuous positive airway pressure machines that provide the air that will assist the patient in breathing. CPAP machines are fairly common devices and are often used for the treatment of sleep apnea.

“Our first challenge was that a CPAP machine can only provide about half of the level of pressure needed to provide a breath. So we needed to connect two CPAP machines in series in order to double the pressure,” Sonja Pejcic, a master’s student in mechanical and materials engineering, explained.

The only problem was that Queen’s only had one machine, so the team put out a call on social media for a donation of a second one. About 20 people responded with offers to use their devices, but they only needed the one.

The next issue was that CPAP machines provide a constant stream of air without interruption. This is not good for assisting someone in breathing, so they had to devise a way to have the air delivered in regulated bursts.

“(We created) a ventilation control module, where we have connected flexible tubes that can be closed off with a simple gate that moved down and bends the tube shut,” Pejcic explained. “This way, we can also open and close one tube at a time, which will simulate the inhalation and expiration.”

To make the ventilation control work, the group 3D-printed the moving pieces and programmed their functions with Raspberry Pi computers and arduino microcontrollers.

The design also has a power source that allows it to be connected to a regular electrical outlet and is mounted on a dolly so it can be easily moved. It is also able to provide anywhere between 20 per cent and 100 per cent oxygen to a patient as needed.

On top of all that, there is a small tablet display attached to the whole system for medical professionals to monitor and control the device.

Creating such a device in a week and a half was not easy, especially since the team of 25 people came from a wide variety of backgrounds and because of social distancing requirements.

“It was a bit of a challenge to work in close quarters while keeping our distance. The majority of people who worked in the McLaughlin Building were all practising social distancing where we tried to maintain a safe distance,” Pejcic said.

“So when the electronics people needed to come in to interface their side with our mechanical side, we stepped out. We tried to keep that flow going where there was always something being done, but there wasn’t 10 people in one room.”

Many of the people working on the project were learning about medical device design and requirements on the fly. But the Queen’s team was fortunate it had a basic design to start with, created by Prof. Rick Sellens, who was working on a ventilator using CPAP machines before the pandemic began.

The team is hoping its design will be one of the top three selected by the judges for possible production and distribution, but even if that doesn’t happen, it plans to keep working on it.

“We have decided that, no matter what the outcome of the design challenge is, we want to move forward on this,” Ploeg said. “This next week will be about building systems in parallel, so we will take the design we have and create five or six of them, and we will do some testing on the parts to make sure they work.

“Then we will have clinicians come in and give us some feedback on how it functions and what kind of features they require.”

ahale@postmedia.com

twitter.com/alan_s_hale