Guo G X, Chiang T H, Quijano R C, Hwang N H
Baxter Healthcare Corporation, Edwards Cardiovascular Surgery Division, Irvine, California 92714.
Med Eng Phys. 1994 Nov;16(6):458-64. doi: 10.1016/1350-4533(94)90069-8.
The closing motion of the occluder leaflets in bileaflet type mechanical heart valves (MHV) was monitored with a laser sweeping technique. The angular displacements of the leaflets were registered with precision of 0.2 microsecond steps. Experimental measurements were made using five 29 mm Edwards-Duromedics including three original specification (EDOS) and two modified specification (EDMS), and two 29 mm St Jude Medical MHVs. The testing valve was installed in the mitral position of a physiologic pulsatile mock circulatory flow loop using water-glycerine solution as the testing fluid. Each valve was tested by: (1) direct mounting the valve on metal washers, and (2) mounting the valve with its sewing ring. Experiments were carried out at pulse rates of 70, 90, and 120 beats min-1, with the corresponding cardiac output of 5, 6, and 7.5 litres min-1, and maximum left ventricular pressure gradients (dp/dt) of 1,800, 3,000 and 5,600 mm Hg s-1, respectively. The maximum leaflet closing velocity of each of the tested valve types are presented. The difference in leaflet closing movements between the direct rigid mounting and the sewing ring mounting are discussed. The details of the laser sweeping technique are presented.
采用激光扫描技术监测双叶型机械心脏瓣膜（MHV）中封堵叶瓣的关闭运动。叶瓣的角位移以0.2微秒的步长精确记录。使用五个29毫米的爱德华兹-杜罗梅迪克斯瓣膜进行实验测量，其中包括三个原始规格（EDOS）和两个改进规格（EDMS），以及两个29毫米的圣犹达医疗公司的MHV。将测试瓣膜安装在生理脉动模拟循环血流回路的二尖瓣位置，使用水-甘油溶液作为测试流体。每个瓣膜通过以下方式进行测试：（1）将瓣膜直接安装在金属垫圈上，以及（2）将瓣膜与其缝合环一起安装。实验在心率分别为70、90和120次/分钟的情况下进行，相应的心输出量分别为5、6和7.5升/分钟，最大左心室压力梯度（dp/dt）分别为1800、3000和5600毫米汞柱/秒。给出了每种测试瓣膜类型的最大叶瓣关闭速度。讨论了直接刚性安装和缝合环安装之间叶瓣关闭运动的差异。介绍了激光扫描技术的细节。
