| Project/Area Number |
13610092
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
実験系心理学
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| Research Institution | Sapporo Medical University |
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Principal Investigator |
SAWADA Yukihiro Sapporo Medical University, School of Medicine, Professor, 医学部, 教授 (40045539)
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| Co-Investigator(Kenkyū-buntansha) |
NAGANO Yuichiro Sapporo Medical University, School of Medicine, Instructor, 医学部, 助手 (00325870)
TANAKA Gohichi Sapporo Medical University, School of Medicine, Associate Professor, 医学部, 助教授 (10167497)
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| Project Period (FY) |
2001 – 2002
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| Project Status |
Completed (Fiscal Year 2002)
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| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 2002: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2001: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Keywords | Finger photoplethysmogram / compliance / pressure-volume function / blood pressure / cold pressor / mental arithmetic / reactive hyperemia / aging / 血液容積 / 暗算作業 / 指血管トーヌス |
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| Research Abstract |
A near-infrared finger photoplethysmogram adopting a wavelength of 810 nm provides for the pulsatile ac component (ΔI) superimposed on the transmitted dc components in a normal (I : tissue plus blood) and an ischaemic circulatory state (I_t : tissue only). Simultaneous recording of finger blood pressure provides for the distending pulse (PP) and mean blood pressure (MBP). Based on the Lambert Beer's law, indices of the arterial compliance (CI ; =ΔI/I/PP) is advocated for the finger vasculature. We introduced the exponential pressure-volume model ( V=a-b^*exp(-nP)) and examined arterial blood volume, PP, and transmural pressure on the model parameters (a,b,n). Experiment 1 : Twelve female subjects underwent immersions of the contralateral hand in water at two different temperatures (44℃, 22℃). CI calculated at 90mmHg (CI90) of linear regression between logCI and MBP decreased significantly during 22℃ condition. Experiment 2 : The functional relationship to the transmural pressure for CI was examined using finger-occlusion during mental arithmetics in sixteen females and reactive hyperaemia in five. Logarithmically transformed CI was linearly associated with the transmural pressure. Three parameters (a,b,n) of the exponential P-V relationship were systematically modified by mental arithmetics and reactive hyperaemia. Experiment 3 : Age-associated differences in parameter a, b, and n were examined during resting condition between 30 young students and 12 middle aged workers. In middle aged subjects, the model fitness deteriorated and only the parameter n was lowered compared with young student.
We advocated the exponential P-V model for finger vasculature and developed the new analytical method for the elastic property of finger artery. Experimental findings supported the validity and usefulness of our model. Structural vascular change due to aging and functional vasoconstriction proved to be separated by different changes in model parameters.
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