COVID-19: Dental patients can wear HELMETS to aspirate droplets

To protect dentists from coronavirus, patients may soon be asked to wear open-faced helmets that soak up any COVID-laden droplets they cough up.

The clear disposable helmets were developed by experts at Cornell University in New York and are connected to a pump that creates a reverse airflow around the head.

This ensures that potentially infected droplets become trapped in the airflow entering through the mouth opening – and cannot escape from the helmet.

In addition to dentists, the concept could also be used by so-called otolaryngologists – ear, nose and throat doctors – who also need access to the head and neck of patients.

Healthcare professionals are at a higher risk of COVID-19 infection because they often come into contact with symptomatic or asymptomatic patients.

Currently, protection is provided by N95 masks and face shields, along with the use of empty clinic rooms or so-called ‘negative pressure chambers’ with air filtration.

However, experts have warned that these measures are expensive and often not very effective or accessible – unlike the new safety helmet.

To protect dentists from coronavirus, patients may soon be asked to wear open-faced helmets that soak up any COVID-laden droplets they cough up, as pictured

The helmet designed by the team is connected at the crown to a medical grade air filter pump that creates the reverse airflow that prevents cough drops from leaving the helmet.

Using a computer-based fluid dynamics simulation, the researchers determined that the helmet could retain 99.6 percent of the droplets that are ejected when the wearer coughs within a tenth of a second.

“To put this into context, if we use the same air pump to create a negative pressure isolation chamber, it takes about 45 minutes to remove 99% of the air pollutants from the chamber,” said author and engineer Mahdi Esmaily.

The design features a 0.04 inch (1 millimeter) clear shell that completely encloses the head and neck – with the exception of the vacuum port and the opening that provides access to the mouth.

A nozzle attached to the mouth opening serves to extend the distance that droplets must travel against the current – minimizing their chance of escaping from the helmet through the opening.

At the same time, this allows for a smoother flow transition that reduces patient discomfort caused by air turbulence, the researchers said.

The helmet could also significantly reduce operating costs by replacing current practices – such as building depressurized chambers through air filtration, which could cost tens of thousands of pounds.

The cost of each helmet can be as cheap as a few dollars (about £ 1.50) when made from disposable materials, the researchers said.

Medical grade high efficiency particulate air (HEPA) filter machines designed to power the helmets are readily available and cost around £ 740 ($ 1,000).

Healthcare professionals are at a higher risk of COVID-19 infection because they often come into contact with symptomatic or asymptomatic patients. Currently, protection is provided by N95 masks and face shields, along with the use of empty clinic rooms or so-called ‘negative pressure chambers’ with air filtration. However, experts have warned that these measures are expensive and often not very effective or accessible – unlike the new safety helmet

“Our next step is to refine the helmet design for greater efficiency and wider application,” explains author and mechanical engineer Dongjie Jia, also from Cornell University.

“After that, we plan to build prototypes of the helmet and run experiments to verify our simulation predictions.”

The simulation framework used to evaluate the helmet concept, meanwhile, could be used to study other particle-related phenomena and designs, the team added.

The full findings of the study are published in the journal Physics of Fluids.