title: Modeling of dynamic cardiovascular responses during G-transition-induced orthostatic stress in pitch and roll rotations.
abstract: Dynamic and fuzzy models for a typical subject's cardiovascular response to the orthostatic stress have been developed based on experimental data. In our original study (Cheung et al., 1999), arterial blood pressure (BP) time-series data were obtained using a man-rated tilt table that applies gigahertz-acceleration transitions from +0.861 Gz [head-up (HU)] to -0.707 G [head-down (HD)] and back to +0.861 Gz (HU) using either pitch or roll rotations (Cheung et al., 1999). G transitions of different duration and onset rates are common in fighter maneuvers. Based on these data, two types of predictive models have been developed in this paper: 1) second-order discrete-time models that predict BP dynamics during pitch and roll rotations and 2) fuzzy logic models that predict important variations in a subject's cardiovascular dynamics induced by HU-to-HD and HD-to-HU transitions. These two types of models assist in providing an operationally important predictive view on the characteristics of BP responses to orthostatic stress induced by pitch and roll rotations of a fighter jet pilot. The new models are being currently utilized in the design of operational recommendations for more G-tolerant operational flight regimes (e.g., split-S tactical maneuver) than the ones currently in use for modern combat aircraft.
authors.affiliation: Engineering Services Inc., 1 Bedford Road, Toronto, ON M5R 2J7, Canada. melek@mie.utoronto.ca
authors.forename: William W
authors.initials: WW
authors.lastname: Melek
authors.forename: Ziren
authors.initials: Z
authors.lastname: Lu
authors.forename: Alex
authors.initials: A
authors.lastname: Kapps
authors.forename: Bob
authors.initials: B
authors.lastname: Cheung
mesh_terms: D000054:Acceleration; D000337:Aerospace Medicine; D000465:Algorithms; D001794:Blood Pressure; D002170:Canada; D016000:Cluster Analysis; D003198:Computer Simulation; D004244:Dizziness / Q000209:etiology / Q000503:physiopathology; D005260:Female; D017143:Fuzzy Logic; D006112:Gravitation; D006801:Humans; D018471:Hypergravity / Q000009:adverse effects*; D018472:Hypogravity / Q000009:adverse effects*; D007024:Hypotension, Orthostatic / Q000209:etiology* / Q000503:physiopathology*; D008297:Male; D008887:Military Medicine; D008889:Military Personnel; D008955:Models, Cardiovascular; D011187:Posture; D015203:Reproducibility of Results; D012399:Rotation; D012680:Sensitivity and Specificity; D013026:Space Flight; D013314:Stress, Mechanical; D019415:Torque