title: Non-contact determination of parasympathetic activation induced by a full stomach using microwave radar.
abstract: In order to evaluate parasympathetic activation which causes driving errors, without placing any burden on the monitored individuals, we conducted a non-contact parasympathetic activation monitoring through the back of a chair using a compact 24-GHz microwave-radar. We measured the high-frequency (HF, 0.15-0.4 Hz) power spectrum of heart rate variability (HRV) which reflects parasympathetic activation, induced by a full stomach. All participants had a large all-you-can-eat meal with beverages for lunch within 20 min. Before and after the large meals for durations of 10 min, the non-contact measurement was conducted for seven healthy male volunteers (mean age: 23 +/- 1-year-old). In both non-contact (microwave radar) and contact (ECG as a reference) measurement, HF shows similar variations before and after large meal. Large meal significantly (p < 0.05) increased non-contact-derived HF from 1,026 +/- 510 to 1,893 +/- 613 ms(2) (922 +/- 628 to 1,861 +/- 940 ms(2), p < 0.05). This technique allows parasympathetic activation monitoring for safety precautions.
authors: Shinji
authors: S
authors: Gotoh
authors: Satoshi
authors: S
authors: Suzuki
authors: Hayato
authors: H
authors: Imuta
authors: Masayuki
authors: M
authors: Kagawa
authors: Zorig
authors: Z
authors: Badarch
authors: Takemi
authors: T
authors: Matsui
mesh_terms: D004562:Electrocardiography; D006801:Humans; D008297:Male; D008872:Microwaves; D008991:Monitoring, Physiologic / Q000379:methods; D010275:Parasympathetic Nervous System / Q000503:physiopathology*; D011825:Radar; D012527:Satiation / Q000502:physiology; D013270:Stomach / Q000294:innervation*; D013315:Stress, Psychological / Q000503:physiopathology; D055815:Young Adult