Each disease produces a unique volatile chemical breathprint
Before modern medical lab techniques became available, doctors diagnosed some diseases by smelling a patient’s breath. Scientists have been working for years to develop analytical instruments that can mimic this sniff-and-diagnose ability. Now, researchers report in the journal ACS Nano that they have identified a unique “breathprint” for each disease. Using this information, they have designed a device that screens breath samples to classify and diagnose several types of diseases.
Exhaled breath contains nitrogen, carbon dioxide and oxygen, as well as a small amount of more than 100 other volatile chemical components. The relative amounts of these substances vary depending on the state of a person’s health. As far back as around 400 B.C., Hippocrates told his students to “smell your patients’ breath” to search for clues of diseases such as diabetes (which creates a sweet smell). In more recent times, several teams of scientists have developed experimental breath analyzers, but most of these instruments focus on a single type of disease, such as cancer. In their own work, Hossam Haick and a team of collaborators in 14 clinical departments worldwide wanted to create a breathalyzer that could distinguish among multiple diseases.
The researchers developed an array of nanoscale sensors to detect the individual components in thousands of breath samples from patients who were either healthy or had one of 17 different diseases, such as kidney cancer or Parkinson’s disease. By analyzing the results with artificial intelligence techniques, the team could use the array to classify and diagnose the conditions. The team used mass spectrometry to identify the breath components associated with the diseases. They found that each disease produces a unique volatile chemical breathprint, based on differing amounts of 13 components. They also showed that the presence of one disease would not prevent the detection of others – a prerequisite for developing a practical device to screen and diagnose various diseases in a noninvasive, inexpensive and portable manner.
You Are What You Exhale: Different Diseases Have Distinct Chemical Signatures
An international team of 56 researchers in five countries has confirmed a hypothesis first proposed by the ancient Greeks – that different diseases are characterized by different “chemical signatures” identifiable in breath samples. The findings by the team led by Professor Hossam Haick of the Technion-Israel Institute of Technology Department of Chemical Engineering and Russell Berrie Nanotechnology Institute at the Technion were published today in ACS Nano.
Diagnostic techniques based on breath samples have been demonstrated in the past, but until now, there has not been scientific proof of the hypothesis that different and unrelated diseases are characterized by distinct chemical breath signatures. And technologies developed to date for this type of diagnosis have been limited to detecting a small number of clinical disorders, without differentiation between unrelated diseases.
The study of more than 1,400 patients included 17 different and unrelated diseases: lung cancer, colorectal cancer, head and neck cancer, ovarian cancer, bladder cancer, prostate cancer, kidney cancer, stomach cancer, Crohn’s disease, ulcerative colitis, irritable bowel syndrome, Parkinson’s disease (two types), multiple sclerosis, pulmonary hypertension, preeclampsia and chronic kidney disease. Samples were collected between January 2011 and June 2014 from in 14 departments at 9 medical centers in 5 countries: Israel, France, the USA, Latvia and China.
The researchers tested the chemical composition of the breath samples using an accepted analytical method (mass spectrometry), which enabled accurate quantitative detection of the chemical compounds they contained. 13 chemical components were identified, in different compositions, in all 17 of the diseases.
Learn more: You Are What You Exhale
UT Dallas Team Breathes New Life into Possibilities By Using CMOS Integrated Circuits Technology
Researchers at the Texas Analog Center of Excellence (TxACE) at UT Dallas are working to develop an affordable electronic nose that can be used in breath analysis for a wide range of health diagnosis.
While devices that can conduct breath analysis using compound semiconductors exist, they are bulky and too costly for commercial use, said Dr. Kenneth O, one of the principal investigators of the effort and director of TxACE. The researchers determined that using CMOS integrated circuits technology will make the electronic nose more affordable.
CMOS is the integrated circuits technology used to manufacture the bulk of electronics that have made smartphones, tablets and other devices possible.
The new research was presented Wednesday in a paper titled “200-280GHz CMOS Transmitter for Rotational Spectroscopy and Demonstration in Gas Spectroscopy and Breath Analysis” at the 2016 IEEE Symposia on VLSI Technology and Circuits in Honolulu, Hawaii.