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

在测量血压时，我们可以通过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。通过功率谱分析，我们假设血管声音的峰值频率（PHz）可能会根据血管壁的不同情况（如血管刚度）而有所不同。为了确定这一假设，我们对17名年龄在19-63岁之间的人进行了实验。测量静息时血管声音频率，以及在轻负荷（20-30 w）、轻负荷（50-60 w）和中负荷（90-120 w）下进行循环测力仪运动时血管声音频率。3名年轻被试在静息状态下的phz小于100Hz， 1名年轻被试在150Hz左右。然而，1名49岁的受试者显示低PHz，为93.8 Hz，另有12名中年受试者显示高PHz，为100-170 Hz。在中年人中，经常运动的人的PHz低于不经常运动的人。大多数人的PHz值随着锻炼而增加，但个体差异表现为增加的模式。休息时PHz值较高的被试在运动时也有较高PHz值的趋势。例如，一个受试者在休息时的PHz约为150Hz，其PHz值约为250Hz，而另一个受试者的PHz值为110-230 Hz。4名青年受试者的phz为110 ~ 170 Hz。关于这一假设，还需要进一步的检验，这些结果表明，功率谱分析的PHz值可能暗示了静止时血管的刚度，而运动时的PHz值可能放大了血管状态的差异。

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.