The U.S.-British team are innovating low-cost technologies could help oxygen-starved COVID019 patients around the globe.
COVID-19 patients are in need of oxygen. Due to scarcity, they even need to be put on machines that will supply oxygen for them. For this reason, the innovators are looking for solutions to the problem.
The project is spearheaded by Shannon Yee, a mechanical engineer and works at the Georgia Institute of Technology in Atlanta. After hearing of shortages, he recalls, his team asked: “How can we design a low-cost ventilator that can be made globally?” His team observed and studied how to use the machine.
“You have to start from the perspective of the person who needs it,” says Kyle Azevedo. He works at the Georgia Tech Research Institute. The team’s goal, he says, has been to figure out “what is essential” to meet someone’s needs. Their primary concern is the ventilators that might not work in long span of time in the hospitals.
Most of the ambulance crews all over the world use hand-operated bags when the patients are in need of good oxygen Yee’s team envisioned a machine could be added to squeeze them.
“The simple motor and mechanical system that they have developed inflates and squeezes the bags that give more oxygen. A plug-in power adapter or standard 12-volt battery runs it. Add separate tubing and volume controls and this device can breathe for two patients at once. Filters in the tubing keep each patient’s exhaled air from infecting others. And the system can hook up to an oxygen supply. Kits can be packaged flat for shipping” Yee says.
Anne Safrath, a nurse in Merrick, N.Y strongly supports the project.“The ambu bag pump system would be great,” she said. This project, she says, “saves a pair of hands that could be doing something else.”
Air is made of about 78 percent nitrogen and 21 percent oxygen. Concentrated oxygen is enriched with extra oxygen. So each breath of it would offer more oxygen and other patients might be able to breathe on their own but will encounter difficulties. But the bad news is that the shortage will be coming. The common process to make it forces air through an expensive material called lithium X-zeolite. Zeolites are a family of minerals. This one filters oxygen from the air. Only a few companies make the type needed to concentrate oxygen. Now researchers with UniSieve in Switzerland have come up with an alternative to the zeolite.
They tweaked a filtering membrane their company had already developed. That membrane’s main use had been to separate carbon dioxide from hydrocarbons. “When COVID-19 came, we realized that we can separate nitrogen and oxygen just as well,” says chemist Elia Schneider. He’s the company’s chief technology officer.
The membrane has teeny, tiny pores. It works as a filter at the molecular level, Schneider explains. Engineers can fine-tune the size of those pores. To separate oxygen from nitrogen, the pore diameter must be roughly one-third of a nanometer (billionth of a meter).
One big advantage with this: “We can supply concentrated oxygen on demand,” Schneider says. The membrane goes into a cartridge measuring about 30 centimeters (12 inches) long and 4.5 centimeters (1.8 inches) across. A compressor squeezes air into one end. The oxygen gets filtered out and the nitrogen molecules exit into the room’s air. Tubing then carries the concentrated oxygen to a patient.
With the promising result of the project, another new system delivers a mix of helium and oxygen. This mix is lighter than regular air, so it takes less effort to breathe it in, says Sairam Parthasarathy, a lung doctor at the University of Arizona College of Medicine in Tucson.
The idea has been known for more than 40 years, he says. But helium is very expensive. And patients would need a lot of the mix. A 1.5-meter (5-foot) tall tank measuring 46 centimeters (18 inches) across would last only eight to 12 hours. The team was able to do recycle the helium that people breathe out. But their exhaling would not release just helium.
“We ended up putting a carbon dioxide scrubber in there,” Slepian says. Scrubbers are devices used to remove materials from a gas. Soda lime — a mix of sodium oxide and calcium oxide — absorbs the carbon dioxide. “It is off-the-shelf technology,” he says. Many useful inventions, he notes, combine existing technologies in such new ways.
