Verdonck P, Kleven A, Verhoeven R, Angelsen B, Vandenbogaerde J
Hydraulics Laboratory, University of Ghent, Belgium.
Med Biol Eng Comput. 1992 Nov;30(6):656-9. doi: 10.1007/BF02446800.
The decision for surgical intervention in the treatment of stenosis and for regurgitation of the mitral valve demands an objective and quantitative evaluation of the severity of mitral valve disease. The availability of ultrasound techniques capable of analysing flow velocities across valves and to produce representative images of valve orifices has increased the interest in the hydraulics of cardiac valves. To isolate and study the determinants of transmitral flow, an in vitro model of the human left heart was built. From the model it is possible to differentiate the influence of the different determinants of left heart performance on transmitral flow: preload, compliance of the left atrium and ventricle, peripheral resistance (afterload) and heart rate. The mechanical part of the model consists of a reservoir connected to an elastic closed circuit (Latex pulmonary veins, left atrium, left ventricle and aortic arch) with replaceable mitral and aortic valves. The electronic part of the model drives and controls the hydraulic part, allowing the independent regulation and monitoring of left atrial and left ventricular pressures p, volumes V and 'pV-loops' throughout the cardiac cycle at different cardiac rhythms. Left atrial filling pressure and aortic resistance are variable in a controlled fashion. Echo-Doppler study of the mitral valve and the transmitral valve flow is possible both from an atrial and a ventricular window in the model. This technical note describes the model.
对于二尖瓣狭窄及反流的治疗，手术干预的决策需要对二尖瓣疾病的严重程度进行客观且定量的评估。能够分析跨瓣膜流速并生成瓣膜口代表性图像的超声技术的出现，增加了人们对心脏瓣膜水力学的兴趣。为了分离并研究经二尖瓣血流的决定因素，构建了一个人体左心体外模型。通过该模型，可以区分左心功能不同决定因素对经二尖瓣血流的影响：前负荷、左心房和左心室的顺应性、外周阻力（后负荷）和心率。该模型的机械部分由一个连接到弹性闭合回路（乳胶肺静脉、左心房、左心室和主动脉弓）的储液器组成，其中二尖瓣和主动脉瓣是可更换的。该模型的电子部分驱动并控制液压部分，允许在不同心律的整个心动周期中独立调节和监测左心房和左心室压力p、容积V以及“pV环”。左心房充盈压和主动脉阻力以可控方式变化。在该模型中，从心房和心室窗口都可以进行二尖瓣及经二尖瓣血流的超声多普勒研究。本技术说明介绍了该模型。
