An electronic nose in the discrimination of breath from smokers and non-smokers: a model for toxin exposure

Abstract

Exhaled breath contains hundreds of volatile organic compounds (VOCs) that may be used as non-invasive markers of lung disease. Electronic noses (e-noses) can analyse VOCs by composite nanosensor arrays with learning algorithms. This study investigated the use of an e-nose (Cyranose C320) to distinguish the breath of smokers from that of non-smokers. Smoking and non-smoking subjects exhaled from total lung capacity into a 2 L Tedlar bag and these samples were introduced offline to the e-nose in a random order. Two classes of breath, 'smoker' and 'non-smoker', were established and this model was then cross-validated. Principal component analysis then identified the maximal point of difference between classes. Smellprints of breath from smokers were separated from those of non-smokers (cross-validation value, 95%; Mahalanobis distance, 3.96). Subsequently, 15 smokers (mean age 37.9 ± 4.78 years, FEV(1) 3.15 ± 0.21 L), and 24 non-smokers (add mean age and FEV1 as for smokers) were sampled to revalidate the model. The e-nose correctly identified the smoking status in 37 of the 39 subjects. This demonstrates that the e-nose is simple to use in clinical practice and can differentiate the breath of smokers from that of non-smokers. It may prove to be a useful, non-invasive tool for further breath assessment of exposure to other inhaled noxious substances as well as disease monitoring.

A breath test for malignant mesothelioma using an electronic nose

“…However, MM is not related to previous smoking habit; therefore, smoking as a confounder is not as relevant as it would be for lung cancer diagnosis. The CPA electronic nose is capable of picking up differences due to smoking status [22], but because training is specific for the VOC pattern profile relevant for a particular disease, irrelevant compounds are ignored. This implies that the effects of smoking are unlikely to have a significant confounding effect, as has been found in other studies in lung cancer and also in obstructive lung disease [15,35,36].…”

“…Techniques used for VOC analysis range from gas chromatography-mass spectrometry and ion mobility spectroscopy to colorimetric and gas sensors. The carbon polymer array (CPA) electronic nose relies on an array of complex nanosensors that produce a breath ''smell print'', which can be distinguished from other breath patterns using principal component analysis (PCA) [15,22].…”

Analysis of volatile organic compounds in exhaled breath for lung cancer diagnosis using a sensor system

“…Lastly, there need to be more smokers in the control group as a sensor system can detect such differences [48].…”

Exhaled Breath Analysis of Smokers Using CMV-GC/MS

“…The electronic nose is a miniature portable device composed of a nanocomposite array of 32 organic polymer sensors [30]. It operates as a lab on a chip system and has also been applied to exhaled smoker breath analysis.…”

“…The main drawback of the electronic nose is its susceptibility to baseline drift and its lack of contribution to the identity of the compounds involved in its classification of smoker and nonsmokers [30]. A real time breath analysis techniques' ability to eliminate a sample pre-concentration step may not be as favorable as techniques that use sample pre-concentration.…”