Faculty of Mechanical Engineering, GIK Institute of Engineering Sciences and Technology, Topi, 23460, KPK, Pakistan.
Department of Civil and Environmental Engineering, Hanyang University, Seoul, 04763, South Korea.
Int J Numer Method Biomed Eng. 2023 Jun;39(6):e3706. doi: 10.1002/cnm.3706. Epub 2023 Apr 11.
Extra corporeal membrane oxygenation (ECMO) is an artificial oxygenation facility, employed in situations of cardio-pulmonary failure. Some diseases i.e., acute respiratory distress syndrome, pulmonary hypertension, corona virus disease (COVID-19) etc. affect oxygenation performance of the lungs thus requiring the need of artificial oxygenation. Critical care teams used ECMO technique during the COVID-19 pandemic to support the heart and lungs of COVID-19 patients who had an acute respiratory or cardiac failure. Double Lumen Cannula (DLC) is one of the most critical components of ECMO as it resides inside the patient and, connects patient with external oxygenation circuit. DLC facilitates delivery and drainage of blood from the patient's body. DLC is characterized by delicate balance of internal and external flows inside a limited space of the right atrium (RA). An optimal performance of the DLC necessitates structural stability under biological and hemodynamic loads, a fact that has been overlooked by previously published studies. In the past, many researchers experimentally and computationally investigated the hemodynamic performance of DLC by employing Eulerian approach, which evaluate instantaneous blood damage without considering blood shear exposure history (qualitative assessment only). The present study is an attempt to address the aforementioned limitations of the previous studies by employing Lagrangian (quantitative assessment) and incorporating the effect of fluid-structure interaction (FSI) to study the hemodynamic performance of neonatal DLC. The study was performed by solving three-dimensional continuity, momentum, and structural mechanics equation(s) by numerical methods for the blood flow through neonatal DLC. A two-way coupled FSI analysis was performed to analyze the effect of DLC structural deformation on its hemodynamic performance. Results show that the return lumen was the most critical section with maximum pressure drop, velocity, shear stresses, and blood damage. Recirculation and residence time of blood in the right atrium (RA) increases with increasing blood flow rates. Considering the structural deformation has led to higher blood damage inside the DLC-atrium system. Maximum Von-Mises stress was present on the side edges of the return lumen that showed direct proportionality with the blood flow rate.
体外膜肺氧合（ECMO）是一种人工供氧设备，用于心肺衰竭的情况。一些疾病，如急性呼吸窘迫综合征、肺动脉高压、新冠病毒病（COVID-19）等，会影响肺部的氧合功能，因此需要人工供氧。在 COVID-19 大流行期间，重症监护团队使用 ECMO 技术来支持 COVID-19 患者的心肺功能，这些患者患有急性呼吸或心脏衰竭。双腔管（DLC）是 ECMO 的最关键组件之一，因为它位于患者体内，并将患者与外部供氧回路连接起来。DLC 促进血液从患者体内的输送和排出。DLC 的特点是在右心房（RA）的有限空间内，内部和外部流量之间的精细平衡。DLC 的最佳性能需要在生物和血液动力学负荷下具有结构稳定性，这一事实被以前发表的研究忽略了。过去，许多研究人员通过采用欧拉方法实验和计算研究 DLC 的血液动力学性能，该方法评估没有考虑血液剪切暴露历史的瞬时血液损伤（仅定性评估）。本研究试图通过采用拉格朗日（定量评估）并纳入流固耦合（FSI）效应来研究新生儿 DLC 的血液动力学性能，以解决以前研究的上述局限性。该研究通过数值方法求解通过新生儿 DLC 的血流的三维连续性、动量和结构力学方程，来进行血流模拟。进行了双向耦合 FSI 分析，以分析 DLC 结构变形对其血液动力学性能的影响。结果表明，返回腔是最关键的部分，具有最大的压降、速度、剪切应力和血液损伤。随着血流量的增加，血液在右心房（RA）中的再循环和停留时间增加。考虑到结构变形，导致 DLC-心房系统内的血液损伤更高。最大 Von-Mises 应力出现在返回腔的边缘上，与血流量呈直接比例关系。
