COVID-19: Dental patients may wear CASCHE to suck drops

To protect dentists from getting coronavirus, patients may soon be asked to wear open-faced headphones that aspirate any COVID-laden drops they cough.

Developed by experts at Cornell University in New York, the transparent, disposable headphones are connected to a pump that creates a reverse flow of air around the head.

This ensures that any potentially infected drops remain trapped in the airflow that enters through the mouth opening – and cannot escape the helmet.

Along with dentists, the concept could also be used by so-called otorhinolaryngologists – doctors of the ear, nose and throat – who also need access to patients’ heads and necks.

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

Currently, the protection comes from N95 face masks and shields, along with the use of empty clinical rooms or so-called “negative pressure” chambers with air filtration.

However, experts have warned that these measures are expensive and often neither extremely effective nor affordable – unlike the new safety helmet.

To protect dentists from getting coronavirus, patients may soon be asked to wear open-faced headphones that aspirate any COVID-laden drops they cough, as described.

Helmet designed by the team it is connected to its crown by a medical grade air filtration pump that creates the reverse flow of air that prevents cough drops from coming out of the helmet.

Using a fluid dynamics simulation on the computer, the researchers determined that the helmet would be able to hold 99.6 percent of the drops emitted when the wearer coughed in a tenth of a second.

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

The design has a 0.04 inch (1 millimeter) thick transparent housing that completely closes the head and neck – except for the vacuum hole and the diaphragm that allows access to the mouth.

A nozzle attached to the mouth access port serves to extend the distance of the drops that need to move against the flow – thus reducing their chances of escaping the helmet by opening.

At the same time, this allows for a smoother transition of flow, which 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 negative-pressure chambers with air filtration, which can cost tens of thousands of pounds.

The cost of each headset could be as cheap as a few dollars (about £ 1.50) if it were made from a disposable material, the researchers said.

Medical grade high efficiency particulate air (HEPA) air filtration machines, designed to power headphones, are readily available and cost around GBP 740 (USD 1,000).

Healthcare professionals are at increased risk of COVID-19 infection because they often come into contact with symptomatic or asymptomatic patients. Currently, the protection comes from N95 face masks and shields, along with the use of empty clinical rooms or so-called “negative pressure” chambers with air filtration. However, experts have warned that these measures are costly and often neither extremely effective nor affordable – unlike the new safety helmet.

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

“After that, we aim to build helmet prototypes and perform 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 patterns, the team added.

The full results of the study were published in the journal Physics of Fluids.