Motivated by the recent developments in the research of untethered microrobots for performing minimally invasive procedures inside blood vessels, we have devised a novel microfluidic experiment for studying the haemodynamics around different types of cylinders confined inside a straight, long, $270\times 100\mathrm{\mu }\text{m}$ channel. Two test sections are studied: flow past a confined circular cylinder and past a confined elliptic cylinder. The two cylinders cause a channel blockage of about 28%. We consider a continuous regime for the blood flow, since its pulsatile nature is barely felt in the regions of the human body further away from the heart, and Reynolds numbers (Re) in the range of 0.05–100, which allow to replicate a variety of flow conditions. Human blood is emulated using non-particulate polymer solutions with rheological properties analogue to those of the biofluid. Pressure drop measurement, micro-Particle Image Velocimetry and streak imaging techniques are employed to study the viscoelastic haemodynamics in the test sections, characterised by elasticity numbers (El) in the approximate interval of 1–30. Our findings include a striking dampening effect on the acceleration of the flow in the contractions between the elliptic cylinder and the channel walls, due to the elasticity of blood, and steeper pressure drops and longer recovery lengths measured in the test section of the elliptic obstacle, caused by a stronger shear stress field characterising this flow geometry and higher strain accumulation in its wake, respectively, compared to the circular cylinder.

受非束缚微型机器人在血管内执行微创程序研究的最新发展的激励，我们设计了一种新颖的微流体实验，用于研究局限在笔直，长形， $270\times 100\mathrm{\mu }\text{米}$渠道。研究了两个测试部分：流过一个受限的圆柱体和一个受限的椭圆形圆柱体。这两个气缸造成约28％的通道阻塞。我们认为血流是连续的，因为在远离心脏的人体区域几乎没有感觉到其搏动性，雷诺数（Re）在0.05–100的范围内，可以复制各种流量条件。使用具有与生物流体类似的流变特性的非微粒聚合物溶液来模拟人体血液。压降测量，微颗粒图像测速和条纹成像技术用于研究测试部分的粘弹性血流动力学，其特征是在大约1–30的间隔内具有弹性数（El）。