A Melbourne doctor and engineer teamed up to design and produce new COVID hoods to offer protection in the pandemic and beyond. Now Victoria is grappling with a second wave, the promise of their invention is becoming more urgent.

When Dr. Forbes McGain, an intensive care physician, first heard about the coronavirus pandemic he thought, if Australia is going to experience anything like the UK, we’re in a lot of trouble. 

“We need negative pressure rooms, but we simply don’t have them,” Dr. McGain said. 

While it initially looked like Australia had almost beaten the virus in early June, this last month has shown how quickly things can change in this pandemic, with a state of disaster declared for Victoria, stage 4 lockdowns across Melbourne and state borders closing down again. 

As is well established SARS-CoV-2 is a highly contagious virus. This factor coupled with potentially inadequate supplies of personal protective equipment (PPE) poses a significant risk to healthcare workers. As of August 8 there were almost 2,000 healthcare workers infected in Victoria, prompting calls for greater infection control measures. 

Even at the onset of the pandemic, Dr. McGain was inventing ways to address this challenge. 

Being an anaesthetist and an intensive care physician with a commitment to innovative and sustainable health systems, Dr. McGain thought about how to free the health system from the high investment of negative pressure rooms and help protect nurses and doctors working on the frontlines. 

“We considered tents, but in that situation the healthcare worker is still exposed to the aerosols, so I thought about shrinking the bubble again to something smaller,” Dr. McGain said. 

This led to the idea of a hood that could be pulled down over the patient, protecting a healthcare worker from the droplets and aerosols coming from the patient. With this concept in mind, he needed someone with both the engineering and scientific skills to bring this device into the highly evidence based environment of the hospital. 

“I knew some engineers from other projects at the University of Melbourne in the last five years, and they recommended Professor Jason Monty,” Dr. McGain said. 

Professor Monty is a specialist in turbulent airflow and an experimental professor at the University of Melbourne. Usually his lab is working full time on projects as varied as defence, shipping and climate change. However, in mid-March, with the pandemic looming, his lab called tools down, and the very next day he received a call from Dr. McGain presenting his hood concept. Unable to proceed with his own projects, Prof. Monty was able to bring all of his team’s resources to bear on this exciting new engineering problem. 

Combining Dr. McGain’s clinical knowledge with Prof. Monty’s engineering and experimental expertise allowed the duo to very quickly produce a functioning prototype. Dr. McGain could contextualise the problem, and provide details on its requirements for staff and patient utility, while Prof. Monty had the lab, tools and experienced staff to design and produce the concept. 

Even before the device was tested it boosted morale. It was important for hospital staff to see the scientific community contributing to the effort against COVID-19. 

“It was crude, but it worked, and it was fantastic to see,” Prof. Monty said. “To walk into the hospital and you could feel the tension in the hospital, you could feel the pressure the nurses were under. And they were so grateful for somebody coming in just trying to help them out.”

How it works

Containing an infectious disease like COVID-19 in a hospital full of other sick patients and staffed by healthcare workers who must go from bed to bed requires negative pressure rooms. These rooms pull air inside the room and prevent airborne agents from spreading throughout the hospital. However, they are expensive to construct and most hospitals only have a few at most. High flow rates of ventilation are required to suck infectious particles in the desired direction, and this airflow becomes more complicated and energy intensive the larger the space. 

Dr. McGain’s concept is essentially a mobile plastic hood for patients that shields healthcare workers from aerosol and droplet spray. This reduces the demands on the ventilation system by decreasing the volume of air surrounding the patient that must be recycled. Building on this concept, Prof.Monty then found a way to redirect aerosol and droplet spray without a seal. 

“If all you're trying to do is get aerosols away from the patient or anything that comes out of the mouth, we don't need to seal it. You just suck so much air out that you make sure everything goes away from the people that are at risk,” Prof. Monty said. 

This opening at the bottom of the hood also allows the air to flow in, if the patient needs additional oxygen they can wear nasal prongs or any other oxygen. 

Because the hood isn’t sealed, it can be easily removed in case of an emergency and is simple to put on and take off the patient. “It’s a completely mobile system, [it] can be attached to the bed frame, but this design choice is important to be able to get it out of the way quickly in case the patient deteriorates,” Dr. McGain said. 

This mobility also means the hood can be used in ambulances and the operation of these mobile hoods would be totally powered by batteries, which opens up the possibility to be powered by sustainable energy sources.  

But you can’t have effective infection control if the apparatus distresses the patient. 

For this reason, from the beginning, patient comfort was central to their design. “Every decision we made, we just stopped and said, is this gonna affect the comfort of the patient? It would be easier for us to do this, it would look better, there would be less parts, it would be cheaper, but if we do that, then this will be closer to the patient's face or it'll be more uncomfortable for the healthcare worker to reach in,” Prof. Monty said.

Initial results

Initial testing was positive. Currently the device is used for additional protection rather than replacing the need for PPE. The hood would be a reassurance. While there is still a risk, there is a massive reduction in the droplets spread across the room. “The hood is effective at reducing aerosols escaping to the wider room, to the point where it is at least as effective as an N95 mask,” Dr. McGain said. 

Hospital tests have also proven to be very promising, in June there was an ICU trial at Western Health with 20 patients, but recently this expanded to a second trial of 50 patients and will  extend to other hospitals such as the Royal Melbourne Hospital, Monash Health, St Vincent’s and The Austin. Surveys about patient experience, ease of use and safety have been completed by staff and patients alike with near unanimous satisfaction. According to Prof. Monty, “no ICU workers have been affected [by COVID-19] at the sites where the hood is being tested.” 

These results have sparked interest from around the country. 

“It's just a matter of time,” Dr. McGain said. “We’ve had interest from hospitals across Australia, Sydney, the Gold Coast and Alice Springs.” 

In addition to the ICU settings, Dr. McGain is most concerned with protecting nursing staff, who spend the most one-on-one time with these patients. This is even more vital on regular wards, as the airflow is poor when more beds are put in smaller rooms. 

Despite these positive results, Dr. McGain acknowledges that the “outstanding issue is finding a major supplier for a constant stream of production.” Recently a manufacturer pulled out, but the team remains optimistic and has turned all efforts to finding support, including discussions with Deputy Chief Medical Officer of the Australian government’s COVID-19 taskforce, Nick Coatsworth.

Beyond the pandemic

While the hood could be useful in offering protection in Victoria’s second wave of the pandemic, it’s unclear how long they have to wait before large scale manufacturing of the hoods can begin. The hoods also need approval from the Therapeutic Goods Administration in addition to the backing of a manufacturer who is ready to guarantee the quality of the hood.

But beyond the coronavirus pandemic, there is potential for the hoods to be used as a means of protection with other illnesses too.  

As they tested the hood with healthy volunteers at Melbourne’s Western Health in April, Prof. Monty and Dr. McGain noticed something unexpected, a lot of the interest in their device wasn’t about protection against COVID-19. Instead, staff were excited about reducing the need for negative pressure rooms for a whole host of other diseases. The hood can be used for “TB, influenza and anything that’s airborne,” Dr. McGain said. 

“Even if there was no COVID they wanted these things. In fact, that was quite bizarre. There's a pandemic and everybody's getting crazy. And all these nurses and doctors were talking about how they just want this thing for these other reasons,” Prof. Monty added. 

The hood has drawn a lot of attention as a possible intermediate between infectious precautions — such as masks, gloves and plastic clothing — and a negative pressure room. It gives many of the benefits of a negative pressure room, while remaining mobile, cheap and rapidly deployable.

Prof. Monty and Dr. McGain particularly see the advantages for smaller hospitals where investment into a negative pressure room doesn’t make sense. Having a relatively cheap and easily deployable solution to increase their capacity for infectious disease patients dramatically changes the equation. “[They] would rather have three or four of these things than nothing,” Prof. Monty said. 

The designers are also using readily accessible components at a low cost, making it suitable for low to middle income countries.

What does this type of collaboration offer for future innovation?

Prof. Monty and Dr. McGain are both very satisfied with their methodology for this project. “When you've got this team of experts all coming together at once, things can happen very fast,” Prof. Monty said. 

The work of months was done in the space of a week by bringing in a group of experts who all had the free time to devote to the concept. “I’ve never published something so quickly from thoughts in my brain to something tangible,” Dr. McGain added . 

This project has opened Prof. Monty’s eyes to the possibilities for future health collaborations — prior to the COVID hood experiments he had only been in hospital for the birth of his children. Now, however, he sees many aspects of the hospital that could be explored with airflow experiments, like ICU high flow nasal prongs and operating theatre airflow.