Yoshino Kohzoh, Adachi Kimihiro, Ihochi Keiko, Matsuoka Katsunori
Institute for Human Science and Biomedical Engineering, National Institute of Advanced Industrial Science and Technology, 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577, Japan.
Med Biol Eng Comput. 2007 Nov;45(11):1085-93. doi: 10.1007/s11517-007-0282-y. Epub 2007 Nov 6.
After collecting data on the cardiovascular responses to ramp-type exercise tests on a cycle ergometer from 194 healthy male and female subjects aged from 20 to 69 years, we constructed a mathematical model that simulates typical patterns of the cardiovascular variability responses to ramp-type exercise loads below the anaerobic threshold. This was done by reflecting the following physiological mechanisms: (1) suppression of parasympathetic nerve activity, (2) reduction of total peripheral resistance, (3) resetting of the operating point in the baroreflex curve, (4) increase in stroke volume, and (5) increase in the coupling of stroke volume to pulse pressure. We estimated the values of model parameter that best fit the measured experimental data. The estimated steepness of the slope with which parasympathetic nerve activity decreased was lower in subjects with a higher anaerobic threshold, tended to increase with age, and in every age decade was higher for females than for males.
在收集了194名年龄在20至69岁之间的健康男性和女性在自行车测力计上进行斜坡式运动测试时的心血管反应数据后，我们构建了一个数学模型，该模型模拟了低于无氧阈值时心血管变异性对斜坡式运动负荷的典型反应模式。这是通过反映以下生理机制来实现的：（1）副交感神经活动的抑制，（2）总外周阻力的降低，（3）压力反射曲线工作点的重置，（4）每搏输出量的增加，以及（5）每搏输出量与脉压耦合的增加。我们估计了最符合实测实验数据的模型参数值。无氧阈值较高的受试者中，副交感神经活动下降斜率的估计陡度较低，且随年龄增长有增加趋势，在每个年龄十年中，女性的该陡度均高于男性。
