N. Paulsson et al., Extraction and selection of parameters for evaluation of breath alcohol measurement with an electronic nose, SENS ACTU-A, 84(3), 2000, pp. 187-197
The ethanol concentration in realistic breath samples was analyzed using an
electronic nose. Conditions were selected so that the samples would reflec
t those collected in a real drunk driver situation. Hence, parameters such
as intake of food and beverage, tobacco habits, as well as the order of par
ticipating volunteers were allowed to be variable. The setup was unexpected
ly robust towards inter- and intrapersonal variations in breath samples as
well as long-term variations. The standard error (16 mol ppm) was the limit
ing factor but the statistical detection limit was well below 0.1 ppm. The
standard error corresponds to between 9% (Austria) and 36% (Sweden) of lowe
st legally accepted levels. Even though this is regarded as a significant e
rror, there are several options of optimization. Incorporating feature extr
action and forward selection together with artificial neural network for pr
ediction of the ethanol concentration showed, besides increasing the accura
cy, to be a valuable tool generating feedback of possible improvements of t
he sensor array. (C) 2000 Elsevier Science S.A. All rights reserved.