Researchers in the United States created a test of face masks to show the best in fluid drip prevention and ranked many of the current options.
In a proof-of-concept study, Duke University researchers have created a low-cost laser sensor that can identify which masks are best at stopping the spread of droplets.
The research found that healthcare workers’ N95 masks were most effective out of the 14 commonly available face masks in preventing viruses and bacteria from penetrating the body through the nose and mouth by inhibiting the transmission of respiratory droplets while speaking.
The handmade cotton masks also worked well, removing a great deal of dew from ordinary speech.
The researchers say that mask makers can use their tests to see if their products can be scratched.
“This was just a demonstration, more work is needed to investigate the differences in masks and amplifiers and how they are used, but it shows that this type of test can be easily performed by companies and others who provide masks to their workers or customers,” Fisher said.
“We wanted to develop a simple, low-cost method that we could share with others in the community to encourage testing of materials, mask samples, and equipment,” Fisher said.
“We were trying to decide what type of face shield to buy in terms of volume, and there was little information available on these new materials that were used.”
The researchers confirmed that their tests showed that the masks were an effective way to prevent people from spreading the virus.
Martin Fischer said: “We have confirmed that when people speak, tiny droplets are expelled, so the disease can spread through speech, without sneezing or coughing.”
“We were also able to see that some face coverings performed significantly better than others blocking the emitted particles.”
The scientists used a black box equipped with a cell phone camera and a laser to carry out the experiment.
Someone wearing a face mask will speak in the direction of the laser beam inside the box. The camera on the back of the box recorded the number of air droplets scattered around the package. Then a computer algorithm counted the drops seen in the video to determine how many drops had leaked.
“This is a powerful visual tool for raising awareness that very simple masks, like these homemade cotton masks, are most effective to stop most of these respiratory droplets,” Fisher told CNN.
Westman said “A facemask is an easy and simple way to limit the spread of COVID-19.”