Before modern medical lab methods became available, doctors diagnosed certain diseases by smelling the breath of patient. Researchers have been attempting to develop analytical instruments that can imitate this sniff-and-diagnose skill.
A team of researchers have identified a unique "breathprint" for each disease. The details of the findings have been report in the ACS Nano journal. With this information, they have designed an instrument that screens breath samples to categorize and diagnose many types of diseases.
Exhaled breath is made up of carbon dioxide, nitrogen, and oxygen, as well as a small quantity of over 100 other volatile chemical components. The relative quantities of these substances differ based on the health condition of a person. In ancient times around 400 B.C., Hippocrates has advised his students to "smell your patients' breath" to look for clues of diseases such as diabetes, which produces a sweet smell.
In very recent times, many teams of researchers have designed experimental breath analyzers, but most of these devices focus on one type of disease, such as cancer. In their own research, Hossam Haick and a team of partners in 14 clinical departments around the world aimed to build a breathalyzer that could differentiate among several diseases.
The researchers created an array of nanoscale sensors to sense the individual components in numerous breath samples from patients who were either healthy or had one of 17 different diseases, such Parkinson's disease or as kidney cancer. By examining the results with artificial intelligence methods, the team could use the array to categorize and diagnose the conditions.
The team used mass spectrometry to detect the breath components related with the diseases. They discovered that each disease creates a unique volatile chemical breathprint, based on varying quantities of 13 components. They also revealed that the existence of one disease would not prevent the detection of others - a precondition for creating a practical device to screen and diagnose different diseases in a non-invasive, economical, and portable manner.