Syllectometry: The effect of aggregometer geometry in the assessment of red blood cell shape recovery and aggregation
Syllectometry: The effect of aggregometer geometry in the assessment of red blood cell shape recovery and aggregation
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DOI：
10.1109/tbme.2002.807319
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发表时间：
2003-01-01
影响因子：
4.6
通讯作者：
Grimbergen, CA
中科院分区：
文献类型：
--
作者：
Dobbe, JGG;Streekstra, GJ;Grimbergen, CA
Syllectometry 是一种常用于评估红细胞 (RBC) 聚集性的测量方法。在syllectometry中，光入射到最初暴露于剪切流的全血层上。驱动机构突然停止后测量反向散射光。所得的时间相关强度图称为音节图。通过分析音节图获得量化红细胞聚集性的参数。正如我们将在本文中展示的，音节图初始部分的上冲程也包含用于测量全血中红细胞形状恢复的信息。为了估计红细胞形状恢复，我们通过描述上冲程的第三个指数扩展了音节图的现有双指数数学表示。为了研究上冲程红细胞形状恢复测量的可行性，我们推导了驱动机构突然停止后出现的流量衰减的分析模型。该模型表明，对于大间隙，流动衰减可能会干扰真正的红细胞形状恢复过程。这些理论发现通过库埃特型聚合计的速度测量得到了证实。使用大间隙获得的音节图在许多方面与使用小间隙获得的音节图不同。正如我们的模型预测的那样，大间隙显示出较长的表观形状恢复时间常数。此外，观察到强度峰延迟、强度峰上冲程减少以及半衰期参数显着增加。大间隙的聚集指数低于小间隙的聚集指数。本文可以更好地理解突然停止驱动机制后的速度和剪切速率衰减。音节图的更好数学表示和最大间隙宽度的建议使得能够使用音节测量法在全血中进行红细胞形状恢复和聚集测量。
Syllectometry is a measuring method that is commonly used to assess red blood cell (RBC) aggregability. In syllectometry, light is incident on a layer of whole blood initially exposed to shear flow. The backscattered light is measured after abruptly stopping the driving mechanism. The resultant time-dependent intensity plot is called the syllectogram. Parameters that quantify RBC aggregability are obtained by analyzing the syllectogram. As we will show in this paper, the upstroke in the initial part of the syllectogram contains the information for measurement of RBC-shape recovery in whole blood as well.To estimate RBC-shape recovery, we extended the existing two-exponential mathematical representation of the syllectogram by a third exponent that describes the upstroke. To investigate the feasibility of RBC-shape recovery measurement from the upstroke, we derived an analytical model of the flow decay that follows after abruptly stopping the driving mechanism. The model reveals that for large gaps the flow decay may interfere with the true RBC-shape recovery process. These theoretical findings were confirmed by velocity measurements in a Couette-type aggregometer.Syllectograms obtained using large gaps differ in many respects from those obtained using small gaps. As predicted by our model large gaps show a prolonged apparent shape-recovery time-constant. Moreover, a delayed intensity peak, a reduced upstroke of the intensity peak and a considerable increase of the half-life parameter are observed. The aggregation indices for large gaps are lower than for small gaps.This paper yields a better understanding of the velocity and shear-rate decay following upon abruptly stopping the driving mechanism. A better mathematical representation of the syllectogram and recommendations for a maximum gap width enables both RBC-shape recovery and aggregation measurements in whole blood using syllectometry.