In Vitro Measurement of Pulsatile Flow Test Method of Modular Artificial Heart Valves
Objective Based on the requirements of ISO 5840 and GB 12279 standards for in vitro pulsatile flow performance testing equipment of artificial heart valves,to explore a modular in vitro pulsatile flow testing model for artificial heart valves with reliable and stable test data.Methods Modular components were utilized and separate models of aortic valve pulsatile flow test A and mitral valve pulsatile flow test B were constructed.The 25AJ-501 and 25MJ-501 America St.Jude Medical valves were respectively installed on the corresponding models for in vitro pulsatile flow test of the valves.The test results were subjected to independent sample t-test hypothesis testing to evaluate the reliability of the valve test results in models A and B.Valve pulsation flow test was performed on model A and model B by exchanging test valve positions and changing forward flow duration(FFD),and the data obtained were recorded for comparative analysis to study the influence of test conditions on model test results before and after the change.The 23A,25A,and 29A CL-V valves were mounted on model A,and the 23M,25M,and 29M CL-V valves were mounted on model B.The changes in the pulsatile flow performance parameters of the CL-V valves,including mean pressure gradient(MPG),effective orifice area(EOA),and regurgitant fraction(RF)were studied,under healthy,exercise,and heart failure physiological conditions.Results The pulse systolic pressure,arterial diastolic pressure,mean aortic pressure,pulsatile flow pressure and flow rate waveforms of the valves monitored under model A and model B were in accordance with the requirements of GB 12279-2008/ISO 5840:1996.When type 25AJ-501 aortic valve was located in model B,the EOA value and the RF were decreased by 5.1% and 22.4%,respectively.While the type 25MJ-501 mitral valve was located in model A,the EOA value was decreased by 7.5% and the RF value was increased by 23.3%,and the difference was significant after the test valve position was exchanged.With the increase of FFD control condition,the root mean square of forward flow and MPG value decreased during the positive pressure difference period.FFD had influence on the EOA test results of model A and model B valves.When CL-V valves of different specifications were operated under this model,the changes of MPG,EOA and RF under the same physiological conditions had nothing to do with the test model,but were only affected by valve size.Under three different physiological conditions,the changes of MPG,EOA and RF were affected by valve size and physiological conditions,and the test results showed regular changes.Conclusion This modular in vitro pulsatile flow test model meets the equipment requirements of ISO 5840 and GB 12279 standards for in vitro pulsatile flow testing of artificial heart valves and can be used as a reference for the in vitro pulsatile flow test model of domestic artificial heart valves.
artificial heart valveperformance test of pulsating flowmodelseffective flap opening areapercentage of reflux
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