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Accession number;07A0176809
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| Title;A Mathematical Expression in Transitions of Dynamic Cerebral Autoregulation during Graded Orthostatic Stress in Humans |
| Author;
SHIOZAWA TOMOKI
(Nihon Univ., School of Medicine, JPN)
TAKADA HIROKI
(Nagoya Univ., Graduate School of Engineering, JPN)
TAKADA HIROKI
(Gifuiryokadai)
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Journal Title;IPSJ Transactions on Database
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Journal Code:Z0778A
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ISSN:0387-5806
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VOL.48;NO.SIG2(TOM16);PAGE.17-27(2007)
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| Figure&Table&Reference;FIG.9, TBL.1, REF.44 |
| Pub. Country;Japan |
| Language;Japanese |
| Abstract;The purpose of the present study is to express the transition of dynamic cerebral autoregulation (DCA) during orthostatic stress in humans using first-order differential equations. Thirteen healthy subjects underwent a graded head-up tilt test (HUT; 0, 15, 30, 45, 60, 90 degrees 6 minutes each). The velocity of the middle cerebral arteries (MCAV) [cm/s] and the blood pressure (BP) [mmHg] were measured. Transfer function analysis was implemented with the beat-to-beat values of BP (input) and MCAV (output). Transfer function gain [(cm/s)/mmHg] of low frequency (LF: 0.07-0.20 Hz) and high frequency (HF: 0.20-0.40 Hz) were calculated from the integration of those data. The transition of the gain at each HUT degree was mathematically expressed using non-homogeneous fist-order differential equations and a new concept of cerebral autoregulation was discovered. This type of cerebral autoregulation rapidly leads DCA to a different stationary state after exposure to a sudden change in the gravitational load. (author abst.) |
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