title: A novel method to estimate changes in stress-induced salivary α-amylase using heart rate variability and respiratory rate, as measured in a non-contact manner using a single radar attached to the back of a chair.
abstract: The authors have developed a non-contact system which estimates changes in salivary α-amylase (sAA ratio) induced by stress. Before and after stressful sound exposure, a single 24 GHz compact radar which is attached to the back of a chair measures the low frequency (LF) component of heart rate variability and respiratory rate, α-amylase in the subjects' buccal secretions was measured by using an α-amylase assay kit. Using multiple regression analysis, sAA ratio was estimated using stress-induced LF change (LF ratio) and stress-induced respiratory rate change (respiratory rate ratio). Twelve healthy subjects were tested (12 males, 22 ± 2 years), who were exposed to audio stimuli with a composite tone of 2120 Hz and 2130 Hz sine waves at a sound pressure level of 95 dB after a silent period through a headphone. The result showed that sAA ratio estimated using multiple regression analysis significantly correlated with measured sAA ratio (R = 0.76, p < 0.01). This indicates that the system may serve for a stress management in the future.
authors.affiliation: Department of Management Systems Engineering, Tokyo Metropolitan University , 6-6 Asahigaoka, Hino, Tokyo , Japan.
authors.forename: Takemi
authors.initials: T
authors.lastname: Matsui
authors.forename: Satoshi
authors.initials: S
authors.lastname: Katayose
mesh_terms: D000328:Adult; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008872:Microwaves; D011825:Radar; D056152:Respiratory Rate / Q000502:physiology*; D055291:Salivary alpha-Amylases / Q000378:metabolism*; D013312:Stress, Physiological / Q000502:physiology*; D055815:Young Adult
chemical_list: D055291:Salivary alpha-Amylases
keywords: HRV; microwave radar; non-contact; respiration; stress