Balasso Andrea, Fritzsche Marco, Liepsch Dieter, Prothmann Sascha, Kirschke Jan Stefan, Sindeev Sergey, Frolov Sergey, Friedrich Benjamin
Department of Earth and Environmental Sciences, Ludwig-Maximilians-Universität, Theresienstr. 41, 80333 Munich, Germany.
Department of Neuroradiology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.
Biomed Tech (Berl). 2019 May 27;64(3):275-284. doi: 10.1515/bmt-2017-0142.
The presence of high-frequency velocity fluctuations in aneurysms have been confirmed by in-vivo measurements and by several numerical simulation studies. Only a few studies have located and recorded wall vibrations in in-vitro experiments using physiological patient models. In this study, we investigated the wall fluctuations produced by a flowing perfusion fluid in a true-to-scale elastic model of a cerebral fusiform aneurysm using a laser Doppler vibrometer (LDV). The model was obtained from patient data. The experimental setup reproduced physiologically relevant conditions using a compliant perfusion system, physiological flow parameters, unsteady flow and a non-Newtonian fluid. Three geometrically identical models with different wall elasticities were used for measurements. The influence of five different flow rates was considered. Wall vibrations were predominantly found at frequencies in the range 40-60 Hz and 255-265 Hz. Their amplitude increased with increasing elasticity of the model, but the spectral peaks remained at about the same frequency. Varying the flow rate produced almost no changes in the frequency domain of the models. The frequency of the spectral peaks varied slightly between points at the lateral wall and at the bottom of the aneurysm. Indeed, embedding the model in a fluid during measurements produced higher and smoother amplitude fluctuations.
动脉瘤中高频速度波动的存在已通过体内测量和多项数值模拟研究得到证实。只有少数研究在使用生理患者模型的体外实验中定位并记录了壁振动。在本研究中，我们使用激光多普勒振动计（LDV），在一个按真实比例制作的脑梭形动脉瘤弹性模型中，研究了流动灌注液产生的壁波动。该模型取自患者数据。实验装置使用顺应性灌注系统、生理流动参数、非定常流动和非牛顿流体，再现了生理相关条件。使用了三个几何形状相同但壁弹性不同的模型进行测量。考虑了五种不同流速的影响。壁振动主要出现在40 - 60Hz和255 - 265Hz范围内的频率处。其振幅随模型弹性的增加而增大，但频谱峰值保持在大致相同的频率。改变流速在模型的频域中几乎没有产生变化。频谱峰值的频率在动脉瘤侧壁和底部的点之间略有不同。实际上，在测量过程中将模型嵌入流体中会产生更高且更平滑的振幅波动。
