Table 1.
Literature survey of sensors and classification models for e-nose studies.
Table 2.
Literature survey of gc methods for the quantitation of ethanol in biological matrices.
Fig 1.
The Electronic Volatile Analyzer (EVA).
(A) Sensor array prototype with parts labeled. (B) A block diagram of key components of the EVA.
Table 3.
MOX sensors for the electronic volatile analyzer.
Fig 2.
Example of a temperature profile modulation for MOX sensors for IBM EVA™: (i) periodic waveform of heater voltage, expressed as a percentage of the maximum operating voltage recommended by the sensor manufacturer; (ii) corresponding variations in MOX sensor resistance under constant environment.
Table 4.
Serial dilution of calibration standards.
Table 5.
Preparation details for QC standards.
Fig 3.
Chromatograms of (a) blank urine, (b) urine sample spiked with 50 ppm IPA, and (c) urine sample spiked with 10 ppm ethanol and 50 ppm IPA.
Fig 4.
A representative standard curve.
The y-axis plots the response ratio between the internal standard and the analyte.
Table 6.
Standard curve equations and their coefficients of determination.
Table 7.
Within-assay coefficients of variation and mean inaccuracies.
Table 8.
Between-assay coefficients of variation and mean inaccuracies.
Fig 5.
Visualization of VOC fingerprints shows different patterns in electrical resistance across calculated sample features for each sensor.
Fig 6.
Percent change in ethanol concentration after each EVA measurement cycle.
Table 9.
Classification accuracies from training with the first three cycles.
Fig 7.
Cross-validation accuracies between days for 90-min and 30-min measurements.