无心跳供体肺支气管内气体二次流动特性分析  

Analysis on Secondary Flow Characteristics inside Bronchia of Non-Heart Beating Donor Lung

作　　者：胥义[1] 邓如意 刘晶[1,2] 刘道平[2] 赵晓刚[3] 

机构地区：[1]上海理工大学生物系统热科学研究所,上海200093 [2]上海理工大学制冷与低温工程研究所,上海200093 [3]上海市肺科医院胸外科,上海200433

出　　处：《中国生物医学工程学报》2015年第4期429-437,共9页Chinese Journal of Biomedical Engineering

基　　金：国家自然科学基金(50906056);上海市自然科学基金(13ZR1428600)

摘　　要：无心跳供体(NHBD)肺有望解决临床供肺严重不足的问题,肺内低温通气被公认为是NHBD肺在体低温保护的有效方法之一。通过建立3D非对称四级支气管模型,借助计算流体动力学(CFD)方法,分别研究在3种被动呼吸频率(0.125、0.25、0.5 Hz)条件下肺支气管内的二次流结构特性。研究结果表明,被动吸气时主支气管截面上不存在二次流结构,且截面上最大无量纲速度差分别为0.67(@0.125 Hz)、0.5(@0.25 Hz)和0.3(@0.5Hz),但在被动呼气时存在明显的二次流结构,且其截面最大无量纲速度差增大到1.25、1.1和1.06;随着支气管级数的增加,无论是吸气还是呼气状态,其对应截面上都存在明显的二次流动结构,但呼吸频率对其截面上最大无量纲速度差变化的影响不大(维持在1.0左右);总体来讲,左肺各支气管内的流动结构比右肺要复杂一些,这与左右支气管的不对称结构有关。该研究明确了低温保护性气体在NHBD肺支气管内的流动总是伴随着二次流的特性,这对于进一步探索其临床保护工艺研究具有重要的指导意义。Non-heart beating donor（ NHBD） lung is expected to be the most potential donor source for clinical lung transplantation,and low temperature ventilation was normally thought to effectively protect the donor lung in vivo. A 3D asymmetric bronchial model with four levels was reconstructed,and computational fluid dynamics（ CFD） technique was adopted here for investigating the sencond flow structures inside NHBD lung bronchia under three kind respiratory frequencies,i. e. 0. 125 Hz,0. 25 Hz and 0. 5 Hz. The results show that no second flow structures exist inside main bronchia during inspiration process, and the maximum difference of dimensionless velocity across the main section is 0. 67 @ 0. 125 Hz,0. 5 @ 0. 25 Hz and 0. 3 @ 0. 5 Hz,respectively. However,there are obvious differences for the expiration process,and the maximum difference of dimensionless velocity across the main section is 1. 25,1. 1 and 1. 06,respectively. Due to the asymmetric structure of bronchial and bifurcation rotation angles,the second flow structures always present for further daughter bronchias but the maximum difference of dimensionless velocity of them do not change significantly with increasing breathing rates（ about 1. 0）. Generally, the flow structures inside left side are more complicated than the right side. The current work indicates that the second flow structures always exist when lowtemperature ventilation is utilized to pretect NHBD lung,which may be beneficial to develop the optimization method for preserving NHBD lung in situ.

关 键 词：无心跳供体肺(NHBD) 支气管 二次流 低温通气 

分 类 号：R318[医药卫生—生物医学工程]