An a amination of as rent of blood vessel stiffness by power spectral analysis of blood vessel sounds.

在测量血压时，我们可以用听诊器捕捉到血管的声音，这种声音是由于血管中的血流湍动而产生的。我们假设，通过功率谱分析，血管声音的峰值频率(phz如下)可能与血管壁的状况相一致，例如血管僵硬。为了验证这一假设，我们对17名年龄在19-63岁之间的人进行了一项实验。分别在静息状态和小负荷(20~30w)、轻负荷(50~60w)、中负荷(90~120w)的功率自行车运动中测量血管音频率。3名年轻受试者在安静状态下的PHZ小于100赫兹，1名年轻受试者的PHZ在150赫兹左右。然而，1名受试者(49岁)显示93.8赫兹的低PHZ，另12名中年受试者显示100-170赫兹的高PHZ。在中年人中，经常锻炼的人的PHZ低于不经常锻炼的人。大多数人的phz随着运动的增加而增加，但个体差异表现为增加的模式。安静时phz值较高的受试者在运动中也表现出较高phz的趋势。例如，一名受试者在休息时的phz约为150赫兹，其phz的值约为250赫兹，而另一名受试者的phz为110-230赫兹。4名青年受试者的PHZ为110~170赫兹。这一假说还有待进一步检验，这些结果提示功率谱分析的phz值可能意味着静息状态下的血管僵硬，而运动中phz的值可能放大血管状况的差异。

We can catch blood vessel sounds by a stethoscope at the time of the blood pressure measurement This sound occurs because of turbulence of bloodstream in a blood vessel. We hypothesized that there might be a difference in peak frequency (PHz as follows) of blood vessel sounds by power spectral analysis according with a condition of blood vessel wall, e.g. vessel stiffness. To determine this hypothesis, we performed an experiment about 17 persons whose age were 19-63 years old as subjects. Blood vessel sounds frequency was measured at rest, and during cycle ergometer exercise at light load (20-30 w), mild load (50-60 w), and middle load (90-120 w). The PHzs of three young subjects were less than 100Hz, and one young subject was around 150Hz at rest condition. However, one subject (49 yr) showed low PHz of 93.8 Hz, and another 12 middle-aged subjects showed higher PHz that were 100-170 Hz. Among middle-aged persons, regularly exercised persons showed lower PHz than that of non- regularly exercised persons. The PHz increased by exercise with most people, but individual difference was seen in a pattern of increase. The subjects who had higher values of PHz at rest showed a tendency of higher PHz in exercise, too. For example, a subject who's PHz at rest was about 150Hz showed the value of PHz of about 250Hz, while PHzs of another subjects were 110-230 Hz. The PHzs of 4 young subjects were 110-170 Hz. There is the remainder to examine in detail about this hypothesis, these results suggested that the value of PHz by power spectral analysis may imply blood vessel stiffness at rest, and the value of PHz during exercise may amplify the difference of blood vessel condition.