Advanced method to mask smoking effect on alcoholic intake detection based on photoplethysmogram signal analysis

This paper proposes an advanced and reliable alcoholic-intake detection method that analyzes the subject´s photoplethysmogram (PPG) signal. Since smoking and physical exercise as well as alcohol intake are crucial determiners of the body´s response, we must analyze how they influence the PPG signal in detecting alcohol intake. In contrast to past studies, it is revealed that the respiratory signal is very useful for alcohol-intake detection regardless of smoking and physical exercise, and a more reliable alcohol intake detection method is demonstrated. The proposed analytical methods consider not only the harmonic intensity ratio of the PPG signal, but also the oxygen-saturation level (SpO₂) in the artery.