摘要
研究轴流式左心辅助泵的出口管道内血流流场的分布情况，根据流动特性与血栓形成的关系，分析轴流血泵管道内的血栓形成风险。用二维粒子成像测速（PIV）系统测试轴流式左心辅助泵的出口管道中心截面内血液沿管道的流动情况，用三维粒子成像测速系统测试整个管道内的血液流动情况，实验过程中辅助泵的转速为（10000±20）r／min，流量为8．05L／min，通过分析出口管道内的血液流场结果，预测左心辅助泵管道内的血栓形成可能。结果表明，辅助泵的出口附近血液存在螺旋流动和明显的垂直于管壁的流动，但在流动中逐渐降低，整个管道内不存在回流、涡流和低速流动区域，管道内血液沿管道的流动速度在管壁边界层外由0m／s迅速增大到极大值1．0m／s以上。沿管道方向，管道内的血液流速分布范围由0．7～2．2m／s降低至1．0～1．5m／s。泵的出口附近紊流度为0．31，距离泵的出口较远处的紊流度降低至0．15，血液流动趋于平稳。由于管道内的流动平稳且不存在回流、涡流和低速流动区域，因此不易形成血栓。出口管道有助于消除轴流式左心辅助泵流出血液的螺旋流动和紊流，使血流平稳，减少对人主动脉的损伤。
The aim of this work is to study the blood flow distribution in outflow cannula of an axial left ventricular pump and analyze the risk of thrombosis in the axial blood pump outflow cannula according to the relationship between blood flow property and thrombogenesis. We obtained the flow distribution in the central section of the axial blood pump outflow cannula with the two dimensional particle image veloeimetry （PIV） system. Then the blood flow distribution in the whole outflow cannula with the three dimensional PIV system was obtained. The rotate speed of the blood pump was set to （10000 =t=20） r/min with flux of 8.05 L/rain in the testing. The possibility of thrombogenesis in the axial blood pump outflow cannula was estimated through analyzing the flow property in the outflow eannula. There were spiral flow and flow normal to the wall of cannula nearby the outlet of the blood pump. The two kinds of flow weaken off when the blood flowed through the outflow cannula, so the blood flow far away from the pump outlet was steady. There was not baekflow, vortex flow or low-speed flow region in the whole cannula. The blood flow velocity along the cannula wall increased to the maximum 1.0 m/s from 0 m/s rapidly outside the boundary layer. The blood speed range reduced from 0.7 m/s - 2.2 m/s to 1.0 m/s - 1.5 m/s along the cannula. The turbulence level near the pump outlet is 0.31.The turbulence level far away from the pump outlet is 0. 15. The flow in the cannula become smooth and steady gradually. It is difficult to form thrombus in the cannula caused by blood flow property because there was no backflow, vortex flow or stagnant flow region in the cannula. The outflow cannula can decrease the spiral flow, which is helpful to improve the flow characteristics of the blood flowing from the axial blood pump. The improved flow characteristics can decrease the injury of aorta caused by disorder blood flow.
出处
《中国生物医学工程学报》
CAS
CSCD
北大核心
2013年第6期678-684,共7页
Chinese Journal of Biomedical Engineering
基金
国家高技术研究发展计划(863计划)(2006AA02Z4D3)
阜外医院特色项目(2012-FWTS02)
关键词
左心辅助泵
粒子成像测速
轴流血泵
出口管道
血栓形成
left ventricular assist pump
particle image velocimetry
axial blood pump
outflow cannula
thrombogenesis
