Abstract:For hydrodynamic comparison, 11 mechanical bileaflet valves have been perfused in a mock circulation system under pulsatile flow conditions. Six St. Jude Medical valves with different sizes from No. 21 to No. 31 and five Duromedics prostheses with corresponding sizes from No. 21 to No. 29 have been investigated. Flow, pressure, and orifice area were measured, while cardiac output was varied between 2 and 6 L/min. Insufficiency (I), maximal orifice area (Amax), mean orifice area (A), discharge coefficient (CD), performance index (PI), and efficiency index (EI) were determined. The St. Jude Medical valves show higher values of orifice area when compared with the Duromedics valves. For smaller valve sizes up to No. 25, the values of the orifice area are similar. The Duromedics valves show much lower values of insufficiency; thus, for small valve sizes, the Duromedics prosthesis seems to be superior. For larger valve sizes (No. 27, No. 29, and No. 31), a decision has to be made whether higher insufficiency and higher orifice area of the St. Jude Medical valve or lower insufficiency with lower orifice area is more acceptable.
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机译：摘要：在脉动流动条件下，对11个机械双叶阀进行了灌注，在模拟循环系统中进行了灌注。研究了 21 号至 31 号的 6 个不同尺寸的 St. Jude Medical 瓣膜和 21 号至 29 号相应尺寸的 5 个 Duromedics 假体。测量流量、压力和孔口面积，心输出量在 2 至 6 L/min 之间变化，测定功能不全 （I）、最大孔口面积 （Amax）、平均孔口面积 （A）、放电系数 （CD）、性能指数 （PI） 和效率指数 （EI）。与 Duromedics 瓣膜相比，St. Jude Medical 瓣膜显示出更高的孔口面积值。对于尺寸不超过 25 号的较小阀门，孔口面积的值相似。Duromedics 瓣膜显示出低得多的不足值;因此，对于小尺寸的瓣膜，Duromedics 假体似乎更胜一筹。对于较大的瓣膜尺寸（27 号、29 号和 31 号），必须决定是 St. Jude Medical 瓣膜的较高不足和较高孔口面积，还是较低孔口面积的较低不全更可接受。
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