Development of Miniaturized Mass-Flow Meter for an Axial Flow Blood Pump based on computational analyses
Development of Miniaturized Mass-Flow Meter for an Axial Flow Blood Pump based on computational analyses
复制标题
基于计算分析的轴流血泵微型质量流量计的开发
DOI：
10.1007/s10047-011-0569-5
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发表时间：
2011
期刊：
影响因子：
1.3
通讯作者：
Yamane T
中科院分区：
文献类型：
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作者：
Kosaka R;Nshida M;Maruyama O;Yamane T
为了监测植入式左心室辅助系统（LVAS）患者的病情，对泵流量进行无创连续测量是非常重要的。然而，泵流量的测量是困难的，特别是在植入式轴流血泵中，因为功耗与泵流量既没有线性关系，也没有唯一性。本研究在计算分析的基础上，开发了一种用于出院患者植入轴向血泵的小型化质量流量计，并在体外试验中进行了评估。质量流量计利用弯曲套管周围的质量流量所产生的离心力。采用计算流体力学（CFD）分析方法对其进行了优化设计。在计算分析的基础上，研制了一种小型化的钛合金质量流量计。采用应变片作为传感器元件。第一个应变片，连接在弯曲区域，测量静压和离心力。第二个应变片，连接在直线区域，测量静压。通过从第一个应变片的输出中减去第二个应变片的输出，确定了质量流量。在体外循环试验中，将质量流量计与常规流量计进行了比较。测量误差小于±0.5 L/min，平均延时0.14 s。实验结果表明，该微型化质量流量计能够准确、连续、无创地测量质量流量。
In order to monitor the condition of patients with implantable left ventricular assist systems (LVAS), it is important to measure pump flow rate continuously and noninvasively. However, it is difficult to measure the pump flow rate, especially in an implantable axial flow blood pump, because the power consumption has neither linearity nor uniqueness with regard to the pump flow rate. In this study, a miniaturized mass-flow meter for discharged patients with an implantable axial blood pump was developed on the basis of computational analysis, and was evaluated in in-vitro tests. The mass-flow meter makes use of centrifugal force produced by the mass-flow rate around a curved cannula. An optimized design was investigated by use of computational fluid dynamics (CFD) analysis. On the basis of the computational analysis, a miniaturized mass-flow meter made of titanium alloy was developed. A strain gauge was adopted as a sensor element. The first strain gauge, attached to the curved area, measured both static pressure and centrifugal force. The second strain gauge, attached to the straight area, measured static pressure. By subtracting the output of the second strain gauge from the output of the first strain gauge, the mass-flow rate was determined. In in-vitro tests using a model circulation loop, the mass-flow meter was compared with a conventional flow meter. Measurement error was less than ±0.5 L/min and average time delay was 0.14 s. We confirmed that the miniaturized mass-flow meter could accurately measure the mass-flow rate continuously and noninvasively.