Covid-19: the inventor hoping to bring air hoods to frontline medics
Lockdown has forced professor Mike Bradley to work out of his back garden shed. But he's determined to bring his air-fed hood into production. And he says it could help a range of people to work more safely - from doctors and nurses to bus drivers
Produced, filmed and edited by Joe Sinclair
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DOMINIC O'CONNOR: Tube please.
MICK JENNINGS: It's good.
NARRATOR: This is Professor Mike Bradley with his latest invention. A pump feeds filtered air into a hood, protecting the wearer from COVID-19. Mike thinks it could be a lifesaver for doctors on the front line and help workers at risk, like carers and bus drivers. But how does a man with an idea make that idea a reality? It starts in his back garden workshop.
MIKE BRADLEY: So I'm professor Mike Bradley from the University of Greenwich. But you can probably tell that I'm in my home workshop at the moment because, of course, all our university labs are locked up during the lockdown. So we've had to resort to using some somewhat hand-to-mouth facilities.
Let me introduce you to my assistant. I call him Pepe because he's testing PPE for us. He's very patient, but not very good company on a night in. So you can see we've got the clear plastic bubble. We've got the seal that goes around the neck underneath, which is tied in here. Because this has inside it what we call positive pressure. That is to say, we push air into here, and the air permeates out through the fabric at the bottom.
That means that anywhere where there is leakage, it's of clean air outwards. So it's impossible for contamination to get in. So the positive pressure gives us the positive protection that enables us to work with highly dangerous materials, and also will give that level of protection for health care workers against viruses in the air and such like.
What I'll do-- I'll start the air pump.
So we press it there. The fan starts to run.
And that is pumping air now through the tube. And you can see here this is what we call an inclined manometer, and this gives us a measurement of the airflow rate. So where the water moves up the sloped pipe, the relative movement of the water is a measurement of the airflow as indicated through the Venturi metre here.
Sugar is a particulate material.
NARRATOR: Mike is a professor of particle technology. That might mean working out how flavoured powder can adhere evenly to crisps.
MIKE BRADLEY: [SMACKS LIPS] Flavour burst.
NARRATOR: Or it might mean working with nuclear dust, asbestos, or lead. And that's where his expertise in PPE, Personal Protective Equipment, comes in.
MIKE BRADLEY: Some of these materials you only need one particle, and it can seriously spoil your life. Much, much more dangerous than corona. So of course, we're used to wearing PPE that has a very high level of integrity. And it's that high level of integrity in PPE which, of course, our current health care system is not providing our doctors and nurses and so on.
NARRATOR: Mike has assembled a team that includes a viral epidemiologist, anaesthetist, engineers, and a retired merchant banker. And Toyota have designed an assembly line to produce the pumps at volume if there is demand. The aim is to get the hoods into hospitals like this one.
MIKE BRADLEY: OK, so what we've got here is what we call an air-fed hood.
NARRATOR: Doctors and critical care staff here at Lewisham and Greenwich NHS Trust in South London have been evaluating Mike's prototype, alongside two other designs.
MIKE BRADLEY: Pumps the air through the tube and, very importantly, through a silencer here so that there's a minimum of noise inside here. Because the fan, obviously, generates a certain amount of noise. And without a silencer, this tube acts like a speaking tube.
DOMINIC O'CONNOR: How easy is it to have verbal communication with this?
MIKE BRADLEY: Very easy. You'll try it on in a minute.
DOMINIC O'CONNOR: Because that's something that we've found a particular challenge of working with the particular PPE that we have to at the minute. And not only is your hearing muffled and distorted, but you lose any lip read and facial interations.
MIKE BRADLEY: Exactly. When you've got a team that's working together in a busy environment and there's a lot going on, facial communication is a very important. People lip read a lot more than you think they do. So if you'd like to try it on.
NARRATOR: Dozens of doctors, nurses, and health care workers have died in the UK during the pandemic. And some victims' families have blamed the lack of adequate PPE.
MICK JENNINGS: When I first tried it, I was a bit concerned about was that the optics through the plastic wouldn't be good enough for intubation or something like that.
DOMINIC O'CONNOR: There is obviously some element looking through a philtre, but it's actually quite clear.
MIKE BRADLEY: And the acoustics is pretty good too, isn't it?
DOMINIC O'CONNOR: Sorry, what? [CHUCKLES] The acoustics is very good, yeah.
NARRATOR: Each of Mike's pressure hoods will cost around 300 to 500 pounds, depending on the number produced.
MICK JENNINGS: OK, yeah. [INAUDIBLE].
NARRATOR: But he believes the safety benefits will pay off. No gaps for contaminated air to get through. No pressure sores. Improved comfort and communication.
MICK JENNINGS: For anaesthetists and ENT surgeons who are looking down people's throats all day, you are very much exposed to whatever is in the patient's airway. And at the moment, that's COVID-19. But it could be any infective agent. TB, for example. So we're just going to simulate an intubation on this mannequin here, just to give us an idea of what it's like and how it works. Ready?
DOMINIC O'CONNOR: Yep.
MICK JENNINGS: So you need someone's specialised help in order to help you to see what you're doing. And then, once we've got a view--
DOMINIC O'CONNOR: Tube, please.
MICK JENNINGS: Tube in. And that goes into the windpipe. We blow the cup up on the tube and take the scope out, and then we will be able to start the ventilator.
DOMINIC O'CONNOR: Unobstructed view. Very easy.
MICK JENNINGS: Yeah. [INAUDIBLE]
DOMINIC O'CONNOR: Great.
MICK JENNINGS: You need something that's going to keep you safe the whole time you're with the patient. And [INAUDIBLE].
NARRATOR: The Trust is now putting Mike's hood forward for clinical trials, starting in operating theatres.
MICK JENNINGS: What we're trying to do at the moment, and people like Mike helping, is to get rapid solutions to problems that haven't really been properly thought through by the hospitals, but by government, by policymakers, as well. Because we've just not really experienced anything like this before in the modern times.
So we need rapid solutions to very, very serious problems. And if manufacturers and inventors can be mobilised more quickly and flexibly with this approach than a traditional approach, then I'm all for that.
NARRATOR: The outbreak has mobilised a new army of manufacturers to fill the shortfall in PPE. Schools, charities, and hobbyists have put their 3D printers to use making visors. Factories have switched from shirts, dresses, and jeans to medical gowns and masks. Mike also looked to an unlikely source to help with his prototypes. He's a keen dancer, and he enlisted a local dressmaker to sew hoods, collars, and belts.
MIKE BRADLEY: OK, so this is more or less the final version of the hood. There's just a couple of modifications, Juli, that I'd like to ask you to do for me. One is on these tapes. They're a bit too slippery. And so, of course, mobilising all sorts of resources that otherwise would not be used for this kind of thing is advantageous because it enables us to make use of parts of the economy that are underemployed at the moment, and at the same time gives us the capacity that we need to produce what we want.
Where the Velcro is here, leave this as it is.
JULI SAVA: [INAUDIBLE] remove?
MIKE BRADLEY: No, no, no. Leave it. Leave this. Is that OK?
JULI SAVA: The writing is they stop the problem isn't stop the same. And I don't know for how many weeks. And we need to do something that is very important. We help each other.
NARRATOR: Mike isn't the only one to have come up with something like this, though a US and Chinese designs and a team in South Hampton has developed their own respirator hood. After testing on the wards, the university hospital there placed an order for 5,000 units with a local manufacturer. Mike needs to finalise the prototype before he applies for regulatory approval.
Under a fast-track scheme, that should take around three weeks, but it costs thousands of pounds. And once the application is accepted, he can't change the design. Approval for use outside health care could take several months. He says it's a frustrating procedure.
MIKE BRADLEY: At the moment, the situation, to me, seems terribly risk averse, inasmuch as that anything new is not allowed to be used because there may be a risk it may not perform. But how does that stack up against the well-known risk that we have of so many people dying because they're getting sick?
NARRATOR: With no vaccine guaranteed and governments around the world keen to get their economies back to work, masks have already become the norm. Looks like this could be next.