Department of Fundamental, Prophylactic and Clinical Disciplines, Faculty of Medicine, Transilvania University of Brasov, Brasov, Romania.
Department of Electrical Engineering and Applied Physics, Transilvania University of Brasov, Brasov, Romania.
Lab Chip. 2024 Jun 25;24(13):3305-3314. doi: 10.1039/d4lc00211c.
Physical properties of blood plasma, such as viscosity, serve as crucial indicators of disease. The inherent capillary effect of paper microchannels, coupled with minimal sample requirement, stimulated the advancement of paper-based viscometers. This study presents a precise, non-contact optoelectronic system using a microfluidic platform for the measurement of blood plasma viscosity. Microchannels were defined onto the filter paper using an available and inexpensive wax crayon, without the need for conventional wax printing equipment. The time required for the 5 μL sample to pass a specific distance was measured using two pairs of infrared sensors. Subsequently, this data was sent to the microcontroller, which automatically calculated the viscosity. Throughout the measurements, sample temperature was maintained at a constant 37 °C through an integrated heater with automated control. The microfluidic platform successfully processed real samples, yielding viscosity measurements in under three minutes. Evaluation with fetal bovine serum, spiked with varying protein concentrations in both native and denatured states, demonstrated a precision exceeding 96% compared to conventional Ostwald viscometer readings. For human subjects exhibiting pathologies affecting serum and plasma viscosity compared to physiological norms, strong correlations were observed between resultant values and clinical diagnoses. The proposed device aims to replace expensive and complex optical equipment, offering a safer alternative for measuring plasma viscosity. Unlike similar devices, it eliminates the risk of component deformation due to chemical contact or unsafe irradiation.
血浆的物理性质，如黏度，是疾病的重要指标。纸微通道的固有毛细作用，加上最小的样品需求，刺激了基于纸的粘度计的发展。本研究提出了一种使用微流控平台的精确、非接触光电系统，用于测量血浆黏度。使用现有的廉价蜡笔在滤纸上定义微通道，而无需传统的蜡印设备。使用两对红外传感器测量 5μL 样品通过特定距离所需的时间。然后，将此数据发送到微控制器，微控制器自动计算黏度。在整个测量过程中，通过集成的自动控制加热器将样品温度保持在恒定的 37°C。微流控平台成功处理了真实样本，在不到三分钟的时间内完成了黏度测量。用胎牛血清进行评估，在天然和变性状态下加入不同浓度的蛋白质，与传统的奥斯特瓦尔德粘度计读数相比，精度超过 96%。对于与生理正常值相比血清和血浆黏度发生病变的人体受试者，观察到所得值与临床诊断之间存在很强的相关性。该设备旨在取代昂贵且复杂的光学设备，为测量血浆黏度提供更安全的替代方案。与类似的设备不同，它消除了因化学接触或不安全辐射而导致部件变形的风险。
