Tongue diagnostic systems help detect disease

Tongue diagnostic systems are fast gaining traction due to an increase in remote health monitoring worldwide, with a new study by Iraqi and Australian researchers providing more evidence of the increasing accuracy of this technology to detect disease.

Engineers from Middle Technical University (MTU) and the University of South Australia (UniSA) reviewed worldwide advances in computer-aided disease diagnosis, based on tongue colour, in a new paper in AIP Conference Proceedings. They also conducted their own study using a USB webcam and computer to capture tongue images from 50 patients with diabetes, renal failure and anaemia, comparing colours with a database of 9000 tongue images. Using image processing techniques, they correctly diagnosed the diseases in 94% of cases compared to laboratory results.

“Thousands of years ago, Chinese medicine pioneered the practice of examining the tongue to detect illness,” said MTU and UniSA Adjunct Associate Professor Ali Al-Naji.

“Conventional medicine has long endorsed this method, demonstrating that the colour, shape and thickness of the tongue can reveal signs of diabetes, liver issues, circulatory and digestive problems, as well as blood and heart diseases,” Al-Naji continued. For example, diabetes patients typically have a yellow tongue, cancer patients a purple tongue with a thick greasy coating, and acute stroke patients present with a red tongue that is often crooked.

“Taking this a step further, new methods for diagnosing disease from the tongue’s appearance are now being done remotely using artificial intelligence and a camera — even a smartphone.”

A 2022 study in Ukraine analysing tongue images of 135 COVID patients via a smartphone showed that 64% of patients with a mild infection had a pale pink tongue, 62% of patients with a moderate infection had a red tongue, and 99% of patients with a severe COVID infection had a dark red tongue. Previous studies using tongue diagnostic systems have accurately diagnosed appendicitis, diabetes and thyroid disease.

“Computerised tongue analysis is highly accurate and could help diagnose diseases remotely in a safe, effective, easy, painless and cost-effective way,” Al-Naji said.

“It is possible to diagnose with 80% accuracy more than 10 diseases that cause a visible change in tongue colour. In our study we achieved a 94% accuracy with three diseases, so the potential is there to fine-tune this research even further.”

Image credit: iStock.com/seb_ra