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

我们可以在测量血压时用听诊器捕捉到血管的声音。这种声音是由于血管中血流的湍流而产生的。我们假设，根据血管壁的条件，例如血管硬度，通过功率谱分析，血管声音的峰值频率（如下所述的PHz）可能存在差异。为了证实这一假设，我们进行了一项实验，约17人，年龄在19-63岁的主题。分别在安静时、踏车运动时（20-30 w）、中等负荷（50-60 w）和中等负荷（90-120 w）测量血管音频率。3名青年受试者的PHz小于100 Hz，1名青年受试者在静息状态下约为150 Hz。然而，1名受试者（49岁）显示出93.8 Hz的低PHz，另外12名中年受试者显示出100-170 Hz的较高PHz。在中年人中，经常锻炼的人比不经常锻炼的人表现出更低的PHz。大多数人的PHz随运动而增加，但增加模式存在个体差异。安静时具有较高Phz值的受试者在运动时也表现出较高Phz的趋势。例如，一个受试者在休息时的PHZ约为150 Hz，显示的PHZ值约为250 Hz，而另一个受试者的PHZ为110-230 Hz。4例青年受试者的PHz为110-170 Hz。关于这一假设还有进一步的研究，这些结果表明，功率谱分析的PHz值可能反映了静息状态下的血管僵硬度，而运动状态下的PHz值可能放大了血管状况的差异。

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.