title: [The proposal of an index of dynamic property of the airway].
abstract: We propose (-deltaG(rs)/deltat)/G(rs) obtained from Astograph as an index of dynamic property of the airway. G(rs) represents respiratory conductance. Fluid mechanics suggests that (- deltaG(aw)/deltat)/G(aw) is related to a coefficient of airway contraction or dilatation. G(aw) represents airway conductance. R(rs) (=1/G(rs)) is approximately equal to R(aw) (=1/G(aw)) + Constant. R(rs) and R(aw) represent respiratory and airway resistance, respectively. As R(rs) is thought to be closely correlated to R(aw), G(rs) should be correlated to G(aw). Thus, if G(rs) is used as a substitute for G(aw), (-deltaG(rs)/deltat)/G(rs) should also be related to a coefficient of airway contraction or dilatation. We found that asthmatics had significantly higher (-deltaG(rs)/deltat)/G(rs) than normal subjects. That is, the airway smooth muscles of the asthmatics are more contractive than those of normal subjects.
authors.affiliation: Department of Respiratory Medicine, Hokkaido Social Insurance Hospital, Sapporo 062-8618, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Ohe
authors.forename: Michihiro
authors.initials: M
authors.lastname: Fujino
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Akiyama
authors.forename: Fujiya
authors.initials: F
authors.lastname: Kishi
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Hizawa
mesh_terms: D000328:Adult; D000403:Airway Resistance / Q000502:physiology; D001249:Asthma / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008433:Mathematics; D008962:Models, Theoretical; D009130:Muscle, Smooth / Q000502:physiology; D012143:Respiratory Physiological Phenomena