Poepping Tamie L, Nikolov Hristo N, Rankin Richard N, Lee Mark, Holdsworth David W
Imaging Research Laboratories, The John P. Robarts Research Institute, 100 Perth Drive, London, Ontario N6A 5K8, Canada.
Ultrasound Med Biol. 2002 Apr;28(4):495-506. doi: 10.1016/s0301-5629(02)00479-9.
To investigate the correlation between disease severity and Doppler spectral measurements in the carotid artery bifurcation, a unique in vitro system has been developed that mimics the human vasculature with respect to both anatomy and flow perfusion. Agar-based carotid phantoms are perfused with a blood-mimicking fluid using a computer-controlled pump and realistic pulsatile flow waveform. A three-axis translational stage allows the lumen to be interrogated with a 0.6-microL Doppler sample volume at the desired spatial intervals using a semiautomated acquisition system, to collect 10 cardiac cycles of gated quadrature data at each site. Off-line analysis, including a 1024-point FFT, produces a 4-D (i.e., time-varying 3-D) Doppler velocity data set with 1.3-cm/s velocity resolution and 12-ms temporal resolution. Using this system, in vitro flow in bifurcations with both normal and stenosed lumen geometry (from 30% to 80% stenosis by NASCET criteria) can be studied, along with the effect of factors, such as stenosis geometry (concentric vs. eccentric) and flow rate, on the observed Doppler ultrasound (US) spectra and haemodynamic patterns.
为了研究疾病严重程度与颈动脉分叉处多普勒频谱测量之间的相关性，已开发出一种独特的体外系统，该系统在解剖结构和血流灌注方面均模拟人体血管系统。基于琼脂的颈动脉模型使用计算机控制的泵和逼真的脉动血流波形，用模拟血液的流体进行灌注。一个三轴平移台允许使用半自动采集系统，以所需的空间间隔用0.6微升的多普勒采样容积对管腔进行检测，在每个部位采集10个心动周期的门控正交数据。离线分析，包括1024点快速傅里叶变换，产生一个具有1.3厘米/秒速度分辨率和12毫秒时间分辨率的四维（即时变三维）多普勒速度数据集。使用该系统，可以研究具有正常和狭窄管腔几何形状（根据北美症状性颈动脉内膜切除术试验标准，狭窄程度为30%至80%）的分叉处的体外血流，以及诸如狭窄几何形状（同心与偏心）和流速等因素对观察到的多普勒超声频谱和血流动力学模式的影响。
