A bench test system for developing E-nose diagnostic tools with exhaled breath sampling

Lung diseases are difficult to diagnose, and exhaled breath analysis by electronic nose may represent a useful tool to improve sensitivity and specificity. Preliminary studies showed promising results using commercial E-noses. Limits for direct exhaled breath sampling are related to the effect of flow and temperature on MOS sensors response. In order to optimize sensors responses it is usefuel to control the abovementioned variables. To this aim we proposed a new electronic nose bench test system. We considered an input flow equal to 1 l/s, greater than the maximum expiratory flow during normal breathing. We performed CFD analysis and direct velocity measurement in the position of the sensor. Results confirmed that flow velocity in all the sensors' positions is similar, and the gas is equally spread in all the points of the chamber.