Researchers Create Tests To Determine Which Mask Is Most Effective-WISH-TV | Indianapolis News | Indiana Weather

(CNN)—Schools are reopening, amusement parks welcome visitors, and dining out is a new dining option. However, despite the signs of life returning to normal, the coronavirus pandemic has gone nowhere.

As a result, a group of researchers at Duke University have developed a simple method to analyze the effectiveness of different types of masks, which are key factors in stopping the spread of the virus.

The quest began when a professor at Duke’s School of Medicine was helping a local group buy bulk masks and distribute them to community members in need. The professor wanted to make sure the group actually bought an effective mask.

In this study Release On Friday, researchers at Duke’s Department of Physics showed the use of a simple method to assess mask efficiency by studying the transmission of respiratory droplets during normal speech using a laser beam and a cell phone. ..

“We use black boxes, lasers, and cameras,” Martin Fisher, one of the study’s authors, told CNN. “The laser beam is vertically expanded to form a thin sheet of light that shines through the slits on the left and right of the box.”

In front of the box is a hole through which the speaker can speak. A cell phone camera is placed on the back of the box to record the light scattered in all directions by the respiratory droplets that pass through the laser beam as it speaks.

Then a simple computer algorithm counts the droplets that appear in the video.

Encourage the use of effective masks

Public health professionals have spent many months highlighting that masks are one of the most effective tools to help fight a pandemic. Many US states now have some mask requirements in place.

But when I tested its effectiveness, I found that some masks were literally useless.

Researchers have tested 14 commonly available masks, including the professional N95 masks, which are usually reserved for healthcare professionals. Initially, the test was done by the speaker speaking without wearing a mask. Then they did it again while the speaker was wearing a mask. Each mask was tested 10 times.

The most effective mask was the fitted N95. The three-layer surgical masks and cotton masks that many people made at home also performed well.

Also called a gate mask, the neck fleece that runners often use has the least effect. In fact, wearing a fleece mask produced a higher number of respiratory droplets. This is because the substance breaks down large droplets into smaller particles that are easier to carry by air.

Folded bandanas and knit masks also had poor performance and were not very protective.

“We were very surprised to find that the number of particles measured in the fleece actually exceeded the number of particles measured without wearing a mask,” Fisher said. “We really encourage people to wear masks, but I want to emphasize that you want them to work.”

The test setup is very simple, but all you need is a box, a laser for less than $200, a lens, and a cell phone camera. Fisher does not recommend setting up at home.

Mishandling of a strong laser can cause permanent eye damage unless a person is familiar with the safety of lasers or has optical experience. However, researchers want companies, museums, and community outreach centers to set up tests to show people which masks are most effective.

“This is a very powerful visual tool to raise the awareness that very simple masks like these homemade cotton masks are really effective in stopping most of these respiratory splashes. “Fisher said. “Companies and manufacturers can set this up to test their mask designs before they are manufactured. This is also very handy.”

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