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首页> 外文期刊>IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control >Cyclic and radial variation of the Doppler power from porcine whole blood
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Cyclic and radial variation of the Doppler power from porcine whole blood

机译：猪全血多普勒能量的周期性和径向变化

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摘要

The Doppler power from porcine blood was observed in a mock flow loop to have cyclic and radial variation during a pulsatile cycle. It was found to decrease with shear rate under steady flow, except near the center of the tube at which other mechanisms such as the effects of radial distribution on the rouleaux might be involved. Under pulsatile flow, the timing of the peak of the Doppler power measured at the center of the tube became closer to the peak systole from 20 to 60 beats/minute (BPM), and the power and velocity peaks coincided at 60 BPM. The overall radial variation of the Doppler power during a whole pulsatile cycle was prominent due to the increase of shear rate from the center to 4.5 mm radial position within a tube of 6.35 mm radius. The cyclic variation of the Doppler power varied with the radial position, being relatively large at the center, reaching a minimum at an intermediate radial Position, and increasing again near the wall. The peak of the Doppler power occurred at early systole near the tube wall and lagged the flow closer to the center. The "black hole" phenomenon was observed only over portions of the flow cycle. All these complex variations of the Doppler power across the tube over a cycle are thought to be the result of red cell aggregation, which can be affected by shear rate and acceleration.
机译：在模拟流动回路中观察到来自猪血的多普勒能量在脉动周期中具有周期性和径向变化。发现在稳定流动下，它会随着剪切速率而降低，除了在管子中心附近可能会涉及其他机制（例如，径向分布对圆环的影响）之外。在脉动血流下，在管中心测得的多普勒功率峰值的定时从20到60次搏动/分钟（BPM）变得更接近收缩期峰值，功率和速度峰值重合于60 BPM。在整个脉动周期中，多普勒功率的总体径向变化非常明显，这是因为在半径为6.35 mm的管中，从中心位置到径向4.5 mm的剪切速率增加了。多普勒功率的周期性变化随径向位置而变化，在中心处相对较大，在中间径向位置处达到最小值，并在壁附近再次增大。多普勒功率峰值出现在靠近管壁的早期收缩期，使血流滞后于中心附近。仅在整个流动周期的一部分上观察到“黑洞”现象。整个周期内，整个管中多普勒功率的所有这些复杂变化被认为是红细胞聚集的结果，这可能会受到剪切速率和加速度的影响。

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