Russian and Italian researchers have developed a compact sensing array that can analyze exhaled breath, thus identifying pathologies in the respiratory tract and other organs. The device has been tested and its high efficacy proven in diagnosing chronic obstructive pulmonary disease (COPD), a debilitating inflammatory syndrome.
COPD develops in the bronchi’s mucous membranes adversely impacted by gas and volatile particles, and may end up causing major respiratory dysfunctions that in some instances kill a patient. The condition triggers the constriction of the respiratory tract that brings about serious breathing problems. There are methods to identify the problem, such as gas chromatography and mass spectroscopy, but all that are currently available take much time and money.
A collaborative research team from Moscow’s MIET University of Electronic Technology, the Skolkovo University of Science and Technology (Skoltech), and Università Cattolica del Sacro Cuore based in Milan, Italy, supported by a Russian Scientific Fund grant, came up with their own COPD diagnostics technique. At the core of the new method is a study of a patient’s metabolism that changes when a pathological condition is developing, and manifests itself in a change in the person’s exhaled breath. The results of the research have been published in English in Advanced Healthcare Materials.
A series of experiments resulted in the creation of a new “electronic nose” that is said to be able to pinpoint such medical conditions “within a few minutes.” Measured data obtained with the help of a reusable sensing array was then reportedly analyzed by artificial intelligence to diagnose all ailments from a single exhalation.
The device is based on single-walled carbon nanotubes (SWCNTs), a component that makes the “e-nose” bendable and its sensing plates electrically conducting. To create the SWCNTs, the team used gas-phase aerosol chemical deposition, an easily reproducible and scalable method that enables CNT film deposition on any surfaces.
To test the efficacy of the new system, the scientists conducted clinical trials with 12 COPD patients and nine healthy people invited. In the trials, the people were asked to inhale as much air as they could and then breathe it out into a polyethylene bag through a plastic straw. Then the straws were removed and the bags sealed.
Each bag had a sensing array inside. It took all sensors three minutes to fully “feel” the molecules of gases present in the exhaled breath. Between one test and the next (with a span of one hour), the system was cleaned with dry air.
All the 12 that suffered from COPD had in their exhaled samples traces of chemical compounds which are characteristic of the disease, including nitrogen dioxide.
The team also tested the system on gases that may be regarded as biomarkers for a number of other maladies. For example, the presence of 2-propanol, benzene, ethanol and acetone in exhalations points to malignant neoplasms in the lungs, and acetone is also a marker of a diabetic case. If one breathes out too much ammonia, that would likely signal a liver or kidney ailment, while hydrogen sulfide points to asthma. High concentrations of sodium hypochlorite found in a child show bronchial asthma and cystic fibrosis.