Yambe T, Shizuka K, Izutsu K, Sonobe T, Naganuma S, Kobayashi S, Nanka S, Hashimoto H, Yoshizawa M, Tabayashi K, Takeda H, Nitta S
Department of Medical Engineering and Cardiology, Tohoku University, Sendai, Japan.
Artif Organs. 1997 Jul;21(7):751-4. doi: 10.1111/j.1525-1594.1997.tb03735.x.
Pulmonary arterial impedance is an important and interesting characteristic that can be used to evaluate the physiological properties of the pulmonary vessel. However, power spectrum analysis of the pulmonary artery pressure and flow pattern have suggested that peak power in the relatively high frequency range (> 10 Hz) is significantly low; thus, we cannot analyze the vessel properties in the high frequency range. In this study, we used the newly developed vibrating flow pump (VFP), which can generate oscillated blood flow with a relatively high frequency (10-50 Hz) for right heart bypass, to evaluate the pulmonary arterial impedance pattern in the high frequency range. Acute animal experiments of the right heart bypass from the right atrium to the pulmonary artery using 6 healthy adult goats were performed. The flow pattern and pressure of the pulmonary artery, electrocardiograms (ECGs), and arterial and right atrial pressures were continuously monitored during the experiments. Spectral analysis of the hemodynamic parameters using the fast Fourier transform (FFT) method was performed to evaluate the spectral properties. The coherence function, transfer function, and phase patterns were calculated to analyze the impedance pattern in the relatively high frequency area. Previously, various investigators had tried to analyze the impedance patterns of the pulmonary artery; however, they could not analyze the impedance patterns over 10 Hz because the spectral patterns of the pulmonary flow do not have high power at high frequencies. These physiological analyses may be useful in designing the optimal pulmonary circulation.
肺动脉阻抗是一项重要且有趣的特性，可用于评估肺血管的生理特性。然而，肺动脉压力和血流模式的功率谱分析表明，相对高频范围（>10Hz）的峰值功率显著较低；因此，我们无法在高频范围内分析血管特性。在本研究中，我们使用新开发的振动流泵（VFP），其可为右心旁路产生相对高频（10 - 50Hz）的振荡血流，以评估高频范围内的肺动脉阻抗模式。使用6只健康成年山羊进行了从右心房到肺动脉的右心旁路急性动物实验。实验过程中持续监测肺动脉的血流模式和压力、心电图（ECG）以及动脉和右心房压力。使用快速傅里叶变换（FFT）方法对血流动力学参数进行频谱分析，以评估频谱特性。计算相干函数、传递函数和相位模式，以分析相对高频区域的阻抗模式。此前，许多研究人员曾试图分析肺动脉的阻抗模式；然而，他们无法分析超过10Hz的阻抗模式，因为肺血流的频谱模式在高频处没有高功率。这些生理分析可能有助于设计最佳的肺循环。
