Scientists are developing a smartphone app that can detect COVID-19 in saliva in about 10 minutes.
The technology links a phone to a small microscope that analyzes a saliva sample for evidence of the virus.
Designed by the University of Arizona, the team aims to combine the speed of an antigen test with the accuracy of a polymerase chain reaction, or PCR test.
The technology was originally developed as a low-cost method of identifying norovirus, but has changed in the face of the ongoing pandemic.
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Scientists at the University of Arizona have developed a smartphone app that works with a microscope to test saliva samples for COVID-19. The process only takes about 10 to 15 minutes, and the components cost about $ 45
The process, reported in the journal Nature Protocols, consists of a microscope and a wax-coated sheet, called microfluidic paper, which guides the sample through certain channels.
After a patient places a saliva sample on the paper, a patient introduces antibodies with fluorescent beads.
If enough coronavirus particles are present, antibodies will attach to them.
“Under a microscope, the pathogenic particles appear as clumps of fluorescent spheres, which the user can then count,” the researchers explained.
After a saliva sample is placed on a sheet of microfluidic paper, the user introduces antibodies with fluorescent beads. If enough coronavirus particles are present, the antibodies will attach to each. The virus particles look like small clumps of fluorescent beads, which the user can then count
According to the researchers, the whole process – adding beads to the sample, soaking the paper in the sample, then taking a smartphone photo of it under a microscope and counting the beads – takes 10 to 15 minutes.
Katie Sosnowski, a doctoral student in the university’s department of biomedical engineering, said it was ‘cool’ to work on a test that produced ‘fast results that are also accurate’.
“I have a few friends with COVID-19 who were very frustrated because their PCR results took six or seven days or they got false negatives from rapid antigen tests,” she said.
“But when they got the final PCR tests, they found out they were sick, as they suspected.”
Researchers also developed a 3D printed housing for the microscope mount and microfluidic paper chip. They also developed a method called adaptive thresholding, which uses AI to account for differences in the type of phone used, the quality of the paper, and other factors.
The team, led by biomedical engineering professor Jeong-Yeol Yoon, originally reported on their work in a 2019 paper in the journal ACS Omega.
At the time, they were thinking of quick and easy ways to test for norovirus, the highly contagious virus that often breaks out on cruise ships, but they think it could be adapted to identify any number of viral infections.
For the coronavirus kit, the team added a 3D printed housing for the microscope mount and microfluidic paper chip.
A method called adaptive thresholding has also been introduced that uses artificial intelligence to set the hazard threshold and take into account differences in the type of phone used, the quality of the paper and other factors.
“We’ve outlined it so that other scientists can basically repeat what we’ve done and create a norovirus detection device,” said Lane Breshears, a PhD student studying under Yoon.
“Our goal is that if you want to tweak it for something else, like we’ve tweaked it for COVID-19, you have all the ingredients you need to basically make your own device.”
Most methods of detecting COVID-19 or other pathogens are time consuming, expensive and require medical expertise.
The total cost of the components for the U of Arizona test is about $ 45, and it’s easy enough that a layman could do after watching a short how-to video.
The technology still has a long way to go before it hits the market, but researchers are hoping to get permission to test samples from students already being tested on campus for COVID-19 through other established methods.
Ultimately, they envision spreading the device across campus so an RA can test students in a dorm room.
“Adapting a method designed to detect norovirus – another highly contagious pathogen – is an excellent example of our researchers running in the face of the pandemic,” said Robert C. Robbins, president of the University from Arizona.
“This promising technology could enable us to regularly and easily deliver fast, accurate and affordable tests to the campus community.”
Yoon’s team also figured out how to adapt the technology so that it didn’t even require a microscope, just an app and a microfludic chip with a special QR code.
It would leave a little more room for error, but would require no training and could even be self-administered.
Since the arrival of the new coronavirus, scientists around the world have been working to develop faster, cheaper and easier testing methods.
Current tests require a swab of the nose and back of the throat, usually in a clinic, which can be time consuming and unpleasant.
In May 2020, researchers at the University of Pittsburgh announced they were working on an app that uses artificial intelligence to analyze the sounds from a person’s airway and determine if they matched those of a COVID-19 patient.
Developers are working on smartphone apps that can accurately test for COVID-19, while still being cheap, easy and painless. If successful, testing would increase rapidly and people could avoid congregating in clinics or hospitals
Users should use an adapter as a mouthpiece so that the phone’s microphone and speaker can pick up and transmit acoustic signals from their airways.
The goal is to create a low-cost and simple system that will allow people to be tested for COVID-19 from their own home “and identify carriers of viral diseases quickly and effectively,” said lead researcher Wei Gao.
“We hope this work will also help identify negative cases caused by other illnesses with similar symptoms, thereby preventing unnecessary hospital visits during this pandemic.”
A separate team from Switzerland is trying to develop a similar system with cough.
Clearly it seems a high proportion [of coronavirus patients] have this kind of dry cough that’s different from flu or allergies, ‘Tomas Teijeiro, lead researcher on the Coughvid project, told the Wall Street Journal.
The makers of another app, PocDoc, say it can be paired with your phone’s camera to analyze a blood sample and provide quick results for a COVID-19 antibody test.
A user pricks their finger, puts a drop of blood on the test slide, then takes a picture. The software is designed to detect minor color changes when COVID antibodies are present and provides results within five minutes.
“COVID-19 has accelerated the need for innovative health technology of all kinds,” says PocDoc CEO Steve Roest.