bioMMeda, Ghent University, Ghent, Belgium.
Department of Information Technology, Ghent University, Ghent, Belgium.
PLoS One. 2019 Jun 20;14(6):e0218317. doi: 10.1371/journal.pone.0218317. eCollection 2019.
Early detection of asymptomatic carotid stenosis may help identifying individuals at risk of stroke. We explore a new method based on laser Doppler vibrometry (LDV) which could allow the non-contact detection of stenosis from neck skin vibrations due to stenosis-induced flow disturbances. Experimental fluid dynamical tests were performed with water on a severely stenosed patient-specific carotid bifurcation model. Measurements were taken under various physiological flow regimes both in a compliant and stiff-walled version of the model, at 1 to 4 diameters downstream from the stenosis. An inter-arterial pressure catheter was positioned as reference. Increasing flow led to corresponding increase in power spectral density (PSD) of pressure and LDV recordings in the 0-500 Hz range. The stiff model lead to higher PSD. PSD of the LDV signal was less dependent on the downstream measurement location than pressure. The strength of the association between PSD and flow level, model material and measuring location was highest in the 0-50 Hz range, however useful information was found up to 200 Hz. This proof-of-concept suggests that LDV has the potential to detect stenosis-induced disturbed flow. Further computational and clinical validation studies are ongoing to assess the sensitivity and specificity of the technique for clinical screening.
早期无症状颈动脉狭窄的检测有助于识别中风风险个体。我们探索了一种新的方法，基于激光多普勒测振（LDV），可以通过由于狭窄引起的流动干扰导致的颈部皮肤振动来非接触式检测狭窄。在严重狭窄的患者特定颈动脉分叉模型上用水进行了实验流体动力学测试。在顺应性和刚性壁模型的各种生理流动条件下进行了测量，在狭窄下游 1 至 4 个直径处进行了测量。动脉内压力导管被定位为参考。随着流量的增加，压力和 LDV 记录的功率谱密度（PSD）在 0-500 Hz 范围内相应增加。刚性模型导致更高的 PSD。LDV 信号的 PSD 比压力对下游测量位置的依赖性更小。PSD 与流量水平、模型材料和测量位置之间的关联强度在 0-50 Hz 范围内最高，但在 200 Hz 范围内仍可获得有用信息。这一概念验证表明，LDV 具有检测狭窄引起的流动干扰的潜力。正在进行进一步的计算和临床验证研究，以评估该技术用于临床筛查的灵敏度和特异性。
