【作者】 杨庆华；

【导师】 邓小燕；

【作者基本信息】 重庆大学 ， 生物医学工程， 2006， 硕士

【摘要】 肺动脉栓塞是一种常见的严重疾病，一般采用抗凝治疗，但是一些患者因存在抗凝禁忌或抗凝失败，无法使用抗凝疗法。此时可以使用腔静脉滤器进行防治。其基本的原理是通过放置在腔静脉处的滤网捕捉住大的致命性栓子，避免其进入肺循环。静脉滤器的使用现在已经越来越广泛。为了提高滤器的使用效果，减少并发症的影响。人们不断地对滤器提出新的设计方案，或对已有滤器加以修饰和改良。一些使用性好，性能优良的滤器在临床上得到了肯定和广泛采用。但是目前还没有出现达到理想状态的滤器，滤器的设计和研究还有很大的提升空间。 作为滤器的最重要的并发症，滤器本身的栓塞及其造成的血管栓塞引起了人们的注意。研究表明滤器栓塞的主要有：穿刺和展开引发的栓塞，器械和血管接触部分的栓塞形成，以及捕获栓子堆积于滤器中央形成的血管栓塞情况。减少输送器械的体积，改进附着钩刺设计等一些办法能成功地减少栓塞的发生。一些临床的观察和实验表明，滤器造成的栓塞很大程度是由于其内部血流动力学的改变所引起的。因此，近年来人们开始利用血流动力学的观点来解释处理血管介入器械的栓塞等问题。 本论文提出了一种漩流式滤器的概念，希望能够构造出一种具有漩流导引装置的滤器，使得滤器中的流动产生旋转流动，形成对被捕捉栓子和血管的光滑冲刷，以降低滤器中血栓堵塞的发生并加速滤器中捕捉栓子的溶解。本论文采用计算机辅助设计，制作出了两种旋动流静脉滤器模型，并采用计算机数值仿真技术，对这些滤器模型的流场及其性能进行了初步的分析。 本论文工作的内容主要包括新型滤器的原型设计，模型的加工和制造，滤器流场的计算机数值仿真，漩流效果的实验测试。本论文的研究结果如下： ①滤器捕获的血栓，如果堆积来不及及时溶解，其背面容易形成低速度滞流区域，流场的恶化将使血栓更易生长； ②支腿形状的不同造成其背后的血流动力学不同。血液通过扁平形的支腿，流动扰动更大，血流恢复正常的速度，方向需要更长的距离。支腿后侧的“阴影”区域也正是血栓容易在支腿，血管连接处生长和蔓延的重要原因； ③对于本课题提出的漩流式滤器，实验和分析的结果表明，其可以达到漩流的结果，初步的效果实验显示较之没有导引部分的一般滤器，大栓子的过滤能力有提高。在滤器回收槽发现有破碎栓子，这表明漩流的冲击作用可以对较大栓子进行机械的冲刷，从而使大血栓化小的理想目的。 本文的最后对于静脉的发展和一些成熟滤器的结构做了对比和归纳，分析了更多还原

【Abstract】 Pulmonary embolism (PE) is a common complication among patient in the intensive care unit. While anticoagulation remains as the standard therapy, vena cava filters (VCFs) are important alternatives when anticoagulation is contraindicated or failed. VCFs use kinds of filters to trap thrombus, especially big sized ones, keeping them away from the pulmonary circulation, and prohibiting the occurrence of PE. Up to now, different measures have been taken to reduce the complications of VCF and promote their performances. As a result, many VCFs with better and better performance are emerged and the utilization of the device has become wider and wider. Nonetheless, even with their potential, VCFs’ design is by no means a mature process and still has large room for improvement.While VCFs have been successfully used in clinic, they are still suffering major failures due to the deployment of the device and the build up of new thrombus in the filters themselves. Clinical studies indicate that there are different kinds of thrombus complications after the deployment of VCF: 1) insertion-site thrombosis; 2) access-site thrombosis; 3) filter blockage caused by the trapped thrombus. Many ways have been tried to reduce these complications, such as facilitating the percutaneous insertion with a small size introducer for the filter to reduce the insertion-site thrombosis. In these ways, short- and long-term complications would be minimal and potential emboli above a reasonably defined size would be prevented without impedance of vena cava flow.Now, it has been well documented that the alteration of vena cava blood flow pattern due to the installation of VCF may result in thrombus complications. Therefore, blood flow itself should be taken into consideration in the design of VCFs in order to reduce these complications after the deployment of VCF and facilitate the lysis of trapped clots.This dissertation proposed a vena cava filter with a new concept in which spiral flows are introduced in the filter’s working zone to minimize filter blockage by the trapped clots and facilitate the lysis of trapped clots.Using Computer Assistant Design (CAD), 2 different types of VCF models with spiral flows were designed and manufactured. Then, the 3-dimensional flow patterns of the VCF models were studied using computational simulation with a Fluent software package. The performances of the filter devices with or without spiral flow were更多还原