There are some jobs where it’s very difficult to socially distance – but an ingenious invention could mean dentists can operate while staying COVID-secure.
Cornell University researchers have designed an open-faced disposable plastic helmet, connected to an air filtration pump – meaning it ‘holds on’ to cough droplets and minimises the risk of transmission.
The mask holds on to 99.6% of cough droplets from a patient, according to computer simulation data.
Dentists are at particular risk of COVID-19, since they need direct access to a patient’s head, neck and mouth.
Previous measures include face shields, negative pressure rooms and air filtration – but these are expensive and not very effective, according to the Cornell researchers behind the new face mask.
The Cornell researchers created a design for patients that is connected to a medical-grade air filtration pump from the top, creating a reverse flow of air to prevent cough droplets from exiting the helmet.
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In a computer simulation using computational fluid dynamics, they showed the helmet design can hold 99.6% of droplets emitted from coughing within 0.1 seconds.
The findings were published in the journal Physics of Fluids.
Lead author Mahdi Esmaily, said: "To put this into context, if we use the same air pump to create a negative pressure isolation room, it will take about 45 minutes to remove 99% of the airborne contaminants from the room."
The proposed helmet has a shell that is one millimetre thick and fully encloses the head with access and vacuum ports.
A nozzle is attached to the access port to extend the distance droplets must travel against the flow and minimize their chance of escape through the opening.
This allows for a smoother flow transition that reduces patient discomfort generated by flow turbulence.
The cost of each helmet could be as cheap as a couple of dollars if made out of disposable material, the researchers said.
Medical-grade high-efficiency particulate air (Hepa) filter negative air machines designed to power the helmets are readily available and cost around £740.
Dongjie Jia, another study author, said: "Our next step is to refine the helmet design to have higher efficiency and broader application.
"After that, we plan to build prototypes of the helmet and perform experiments to verify our simulation predictions."
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