Identification of wound infection by limited set of volatile products

Based on an array of combined metal oxide and conductive polymer gas sensors electronic an odor recognition system is being developed for detection of bacteria types at the early stages of wound infection. It is proved by GC-MS studies that living bacteria that are typical infectious agents in clinical practice can be distinguished from each other by means of a limited set of key volatile products. Using a set of these reference volatile compounds criteria for selection and calibration of gas sensors were defined. Aiming to increase reliability of bacteria identification SPME preconcentration was used for sampling of the headspace air and response to variable concentrations of volatiles emitted from the SPME fiber is processed for evaluation of the output parameters of the sensor module. Discrimination between classes of volatile products is obtained by a PCA analysis of the dynamic parameters of sensor responses to the headspace air of clinical samples collected by swabbing.