An affordable ‘stopgap’ ventilator which can be used with minimal training could help keep seriously ill people alive long enough to either recover or receive hospital care, scientists say.
The device, called GlasVent, was developed by the University of Glasgow’s Professor Ravinder Dahiya and a team of engineers from his Bendable Electronics and Sensing Technologies (BEST) group.
They began working on the project in mid-March, during the early stages of the UK’s COVID-19 outbreak, when demand for ventilators was expected to outstrip demand within weeks and anaesthetists and intensive care consultants were working flat-out on patient care and service redesign. The University of Glasgow team turned to surgeon Professor Andrew Hart, who had previously worked with them to design bionic hand prosthetics, for help with basic medical advice.
Although demand for ventilators did not outstrip supply as feared, the team believe their design could still play a lifesaving role in emergency medical settings. It is low cost, and manufacture could be rapidly scaled to allow basic ventilatory support for large numbers of patients if coronavirus infections peak again, or if other pandemics break out in the future.
GlasVent aims to provide a simple, easy-to-use, and affordable method of delivering oxygen to critically ill patients. Its primary component is a bag valve mask – a handheld, balloonlike device which is already commonly used in emergency medical situations. Medics squeeze the device by hand to pass air through a tube, which helps to inflate patients’ lungs and keep oxygen circulating.
In theory, bag valve masks can be used indefinitely. However, they require constant attention from medics and the amount of oxygen delivered with each compression can vary from squeeze to squeeze.
The GlasVent team have developed a way to automate the squeezing of the bag, allowing medics to concentrate on other aspects of care and standardising delivery of oxygen into patients’ lungs.
The system’s affordability comes from its unique mix of high and low-tech parts. The high-tech part is an Arduino microcontroller, which controls the pressure in the patients’ airways to ensure they receive the correct volume of oxygen with each compression of the bag.
The low-tech part is a 3D-printed slide-crank, a design similar to that found in steam engines. The Arduino also controls the motion of the crank, providing a squeezing action on the sides of the bag to deliver oxygen to the patient. In the event of a power outage, the crank’s simple design allows medics to operate it by hand, helping to keep the patient alive.
The team have outlined plans for three GlasVent variants, designed to meet different levels of affordability and complexity. They are:
- A fully manual version, which requires users to continuously turn the slide-crank wheel to keep the patient oxygenated, which would cost around £35 to build
- A mains-powered version with a total parts cost of £105
- A battery-powered version with a total parts cost of £135
Professor Dahiya, of the University of Glasgow’s James Watt School of Engineering, said: “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. We’re proud that we’ve managed to go from design to build to testing in a matter of weeks. We’ve already conducted numerous successful tests on a medical mannequin fitted with artificial lungs, provided by the Royal Alexandra Hospital Paisley, so we’re confident that it is fit for purpose.
“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.
“While other groups around the world have developed other automated emergency ventilator designs, we believe that GlasVent is the only one which offers fully manual control, and which requires little training or medical experience to operate. That makes it ideal for offering lifesaving support in places where access to power is unreliable, and for use in almost any emergency situation where ventilation is required.”
Professor Andrew Hart added: “This project shows the University of Glasgow upholding its social role, and the agility of its academic engineering groups in tackling major social and health problems.
“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.
“Fortunately the NHS did cope with the initial peak of COVID-19, and now there is time to refine Professor Dahiya’s prototype to gain the high reliability and greater controllability needed for safe patient care.
“The UK is justifiably proud that is has some of the highest ethical and healthcare device safety standards in the world. Meeting these is necessary before GlasVent can ethically benefit patients, including the growing need in major refugee centres and low middle income countries.
“Input from consultants in ICU, anaesthetics, and pre-hospital care was critical in defining the specifications that GlasVent still needs to acquire if it is to help patients. They should be credited for this input, and for their immense efforts in saving lives and protecting their colleagues during the first peak in COVID-19. Hopefully industry partners will repay that commitment, bringing this product to market in order to support my colleagues’ future capacity to care for our society, and for others around the world who need the support of the UK’s academic, healthcare, and commercial expertise.”
The GlasVent team are currently working towards getting regulatory approval for the device to be used in clinical settings and are exploring options for commercial partnerships to manufacture the devices.
Some of the components used in GlasVent were originally developed for projects funded by Professor Dahiya’s Engineering and Physical Sciences Research Council (EPSRC) fellowship.