Stinnett H, Wheeldon J, Hennes M
Department of Physiology, School of Medicine, University of North Dakota, Grand Forks 58202.
Biomed Sci Instrum. 1993;29:443-50.
The postulate that dynamic intra vascular pressure is a function of positional wall properties has been difficult to verify due to non-linear viscoelastic influences in arteries. It was tested, in rabbit carotid artery in vitro segments using dynamic and static input. A Multifunction Pressure Generator (MPG, Millar Inc.) provide dynamic input of defined swept frequency (2-200 Hz) pressure superimposed on multiple levels of mean intraluminal pressure (IP). Bode plots were analyzed for natural frequency (omega n), gain (dB) and damping (zeta) of the IP/MPG transfer function. An increase in omega n (all zeta > 0.25) was found with increase in mean IP. An increase in segment Elastic modulus (Em) was found with increase in static force input. Relation between Em and omega n results was demonstrative of non-linear elasticity. Results supported the postulate and verified estimating vessel properties by harmonic analysis.
由于动脉中存在非线性粘弹性影响，动态血管内压力是位置性血管壁特性的函数这一假设难以得到验证。在兔体外颈动脉节段中，使用动态和静态输入对其进行了测试。多功能压力发生器（MPG，Millar公司）提供定义的扫频（2 - 200 Hz）压力的动态输入，并叠加在多个平均管腔内压力（IP）水平上。对IP/MPG传递函数的固有频率（ωn）、增益（dB）和阻尼（ζ）进行了Bode图分析。发现随着平均IP的增加，ωn增加（所有ζ>0.25）。随着静态力输入的增加，节段弹性模量（Em）增加。Em与ωn结果之间的关系证明了非线性弹性。结果支持了该假设，并通过谐波分析验证了对血管特性的估计。
