Purpose

To develop a small volume whole blood analyzer capable of measuring the hematocrit and coagulation kinetics of whole blood.

Methods and Results

A co-planar microfluidic chamber designed to facilitate self-driven capillary action across an internal electrical chip was developed and used to measure the electric parameters of whole human blood that had been anticoagulated or allowed to clot. To promote blood clotting, select chip surfaces were coated with a prothrombin time (PT) reagent containing lipidated tissue factor (TF), which activates the extrinsic pathway of coagulation to promote thrombin generation and fibrin formation. Whole human blood was added to the microfluidic device, and voltage changes within the platform were measured and interpreted using basic resistor-capacitor (RC) circuit and fluid dynamics theory. Upon wetting of the sensing zone, a circuit between two co-planar electrodes within the sensing zone was closed to generate a rapid voltage drop from baseline. The voltage then rose due to sedimentation of red blood cells (RBC) in the sensing zone. For anticoagulated blood samples, the time for the voltage to return to baseline was dependent on hematocrit. In the presence of coagulation, the initiation of fibrin formation in the presence of the PT reagent prevented the return of voltage to baseline due to the reduced packing of RBCs in the sensing zone.

Conclusions

The technology presented in this study has potential for monitoring the hematocrit and coagulation parameters of patient samples using a small volume of whole blood, suggesting it may hold clinical utility as a point-of-care test.

中文翻译：

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用于评估血细胞比容和血液凝固的护理点微流体平台的设计和实用性。

目的

研制一种能够测量全血血细胞比容和凝血动力学的小容量全血分析仪。

方法和结果

开发了一种共面微流体室，旨在促进内部电子芯片的自驱动毛细作用，并用于测量已抗凝或允许凝结的全人类血液的电参数。为了促进血液凝固，选择的芯片表面涂有含有脂化组织因子 (TF) 的凝血酶原时间 (PT) 试剂，该试剂激活凝血的外在途径以促进凝血酶的产生和纤维蛋白的形成。将人体全血添加到微流体装置中，并使用基本的电阻电容 (RC) 电路和流体动力学理论测量和解释平台内的电压变化。在感测区域润湿后，感测区域内的两个共面电极之间的电路闭合以从基线产生快速电压降。由于感应区中红细胞 (RBC) 的沉降，电压随后上升。对于抗凝血样，电压恢复到基线的时间取决于血细胞比容。在存在凝血的情况下，在 PT 试剂存在的情况下纤维蛋白形成的开始阻止了电压返回到基线，因为感应区中 RBC 的堆积减少。

结论

本研究中提出的技术具有使用少量全血监测患者样本的血细胞比容和凝血参数的潜力，这表明它可能具有临床实用性，可作为即时检测。