Professor Ravinder Dahiya and his fellow engineers from Glasgow’s Bendable Electronics and Sensing Technologies Group started working on the project in mid-March.

During the early days of the UK Covid-19 outbreak at that time, there were serious concerns that the NHS could be overwhelmed and would not have enough ventilators – medical devices which mechanically assist with breathing for seriously ill patients – for the anticipated deluge of incoming patients.

These concerns sparked calls from the government to engineering companies to build ventilators (specifically expensive and complex invasive ventilators) from scratch; to assist with scaling-up production; or to adapt existing models. Although many efforts were unsuccessful, the introduction of non-pharmaceutical measures to limit the transmission of the virus, such as lockdown and self-isolation, has prevented demand outstripping supply for invasive ventilators.

However, the Glasgow team hopes that its design could still play an important role in emergency medicine due to its low cost and the limited amount of training required to operate it. Its manufacture could also be rapidly scaled-up to allow non-invasive breathing support for large numbers of patients should there be a second wave of coronavirus infections.

The ventilator’s primary component is a bag valve mask; healthcare workers normally squeeze these balloon-like bags by hand to pass air through a tube to assist with breathing. The engineers developed a method to automate the squeezing of the bag, allowing medics to focus on other aspects of care which cannot be automated.

An Arduino microcontroller controls the pressure in the patient’s airways to ensure they receive the right volume of oxygen via the motion of a simple 3D-printed slide crank. This squeezes the sides of the bag to deliver air to the patient.

The researchers have already tested it on a medical mannequin fitted with artificial lungs, provided by a local hospital.

“When the seriousness of the coronavirus pandemic started to become clear, my research group and I were keen to do whatever we could to help save lives,” said Dahiya. “We’re proud that we’ve managed to go from design to build to testing in a matter of weeks […] we hope that once we receive regulatory approval, GlasVent could be used not just to buy some more time for critically ill patients to either fight off disease or be put onto a mechanical ventilator, but to find use in care settings and in the developing world.”

Dahiya and his colleagues have laid out plans for three variants on the ventilator: a basic manual version (around £35); a mains-powered automatic version (£105), and a battery-powered automatic version (around £135).

Surgeon Professor Andrew Hart, who was consulted on the design, commented: “The GlasVent device combines elegant engineering concepts with the engineers’ pragmatic awareness that in a moment of global crisis only a simple system without supply chain restrictions could have helped.”