However, these machines are very expensive and need special skills and experience. Gas-chromatography mass-spectometry (GC-MS) is the gold standard for exhaled volatile compound measurement. This fact is particularly important in lung cancer, as early diagnosis is associated with significantly better prognosis. īreath tests have unique advantages that they are completely non-invasive, well-tolerable, hold no risks for side effects and can be performed even in very sick patients therefore they pose an ideal tool for disease screening. Therefore, it is not surprising that altered exhaled volatile compound levels were found in various disorders of the respiratory system such as lung cancer, malignant mesothelioma, obstructive airway diseases, sarcoidosis, obstructive sleep apnoea, respiratory infections and in patients with lung transplantation. These findings suggest critical methodological recommendations to standardise sample collections for electronic nose measurements.Įxhaled breath contains thousands of volatile molecules and their levels change with cellular metabolism and oxidative stress. We have shown that expiratory flow, breath hold and dead space influence exhaled volatile compound pattern assessed with electronic nose. These factors also influenced the discrimination ability of the electronic nose to detect lung cancer significantly.

ResultsĮxpiratory flow rate, breath hold and the inclusion of anatomic dead space significantly altered “breathprints” in healthy individuals (p 0.05). Exhaled air samples were processed with Cyranose 320 electronic nose. We also studied the effect of anatomic dead space by excluding this fraction and comparing alveolar air to mixed (alveolar + anatomic dead space) air samples. The effect of breath hold was analysed after 10 seconds of deep inhalation. After deep inhalation through a volatile organic compound filter, subjects exhaled at two different flow rates (50 ml/sec and 75 ml/sec) into Teflon-coated bags.

Methodsģ7 healthy subjects (44 ± 14 years) and 27 patients with lung cancer (60 ± 10 years) participated in the study. Therefore, the aim of the study was to investigate these effects. Expiratory flow rate, breath hold and inclusion of anatomic dead space may influence the exhaled levels of some volatile compounds however it has not been fully addressed how these factors affect electronic nose data. Numerous studies showed their potential to detect lung cancer from breath samples by analysing exhaled volatile compound pattern (“breathprint”). Electronic noses are composites of nanosensor arrays.

Dead space in lung advantage