According to a study published in the journal Scientific Reports, researchers have developed a hydroalcoholic gel with a QR code that enables people to access a test. The test is based on artificial intelligence (AI), which assesses their ability to identify the smell of the product and eight symptoms of COVID. The prototype developed by the researchers from the Universitat Rovira I Virgili in conjunction with the Pere Virgili Health Research Institute, Spain, instantly determines people who have a low, medium or high risk of COVID at that moment with a sensitivity of 97%.

As per the study, citrus fruits and apples are two of the first aromas that people with the SARS-CoV-2 virus stop detecting. Therefore, the AI system that has been patented is based on a hydroalcoholic gel to which a particular concentration of citrus essence has been added.

In the study, the test was performed on 500 patients. The patients had to rub their hands with the gel and then smell them after three seconds. The result was considered negative if they recognized a citrus fruit and positive if they could not smell the gel or could not detect a citrus aroma. After the test, the participants in the study had to fill out a short questionnaire with the result of the smell test and other data such as age, gender, and the presence or absence of different symptoms. 

(Source: https://www.daijiworld.com/news/newsDisplay?newsID=1030203)