For many years, scientists have been working on developing analytical instruments capable of accurately diagnosing different medical conditions by assessing a person’s breath – a method doctors used to rely on before the advent of modern lab techniques.
Now, reporting in the journal ACS Nano, a group of researchers claim they have identified a unique “breath-print” for 17 individual diseases, and built a special device for classifying and diagnosing them.
Sniffing a patient’s breath has been advocated since the time of Hippocrates, who advised his students to pay attention to a variety of different odours that might indicate a particular abnormality, such as the sweet breath of a diabetic.
When it comes to equipment we have nowadays, however, it’s no longer odour, but a combination of different compounds that humans and other animals interpret as a distinctive “smell” that is being explored for medical purposes.
Exhaled breath contains mostly nitrogen, carbon dioxide, oxygen and a small amount of over a 100 other volatile chemical elements, used by researchers to advance “breathalysers” aimed at identifying a specific disease, such as cancer.
In their own work, Hossam Haick and a team of collaborators in 14 clinical departments worldwide joined their colleagues in the field hoping to develop a more universal device, capable of distinguishing between multiple illnesses.
To this end, the team created an array of molecularly modified gold nano-particles to detect the individual components in breath samples collected from 1,404 subjects who were either healthy (controls) or had one of 17 different chronic illnesses, such as kidney cancer of Parkinson’s disease.
Combining mass spectrometry to identify the breath components associated with individual diseases, and artificial intelligence algorithms to analyse them, the researchers came up with very promising results.
“Blind experiments showed that 86% accuracy could be achieved with the artificially intelligent nano-array, allowing both detection and discrimination between the different disease conditions examined,” they wrote in their paper.
Analysing the samples, researchers found a unique “breath-print” for every disease, which consists of different concentrations of 13 organic compounds.
The system was also validated by an independent analytical technique (gas chromatography linked with mass spectrometry) and found to be good at distinguishing between different diseases from the same category, and detecting multiple diseases in the same sample.
“Overall, these findings could contribute to one of the most important criteria for successful health intervention in the modern era, viz. Easy-to-use, inexpensive (affordable), and miniaturized tools that could also be used for personalized screening, diagnosis, and follow-up of a number of diseases, which can clearly be extended by further development”.