心脏瓣膜双轴力学特性测试系统的设计

Design of mechanical properties test system for the heart valves biaxial

目的为了获得心脏瓣膜力学特性,设计一套高精度双轴拉伸机系统。方法采用上、下位机结构。上位机采用Labview软件编程,设计人机界面,提高系统灵活性和数据处理能力;下位机采用数控语言编程,提高用户编程的简易性和灵活性;采用灵敏度1μm的机械运动硬件模块、16位数据采集卡、光学位移测量方法,提高系统测量精度。对猪的二尖瓣前瓣进行双轴拉伸实验,并将实验结果与国外研究者测试数据进行对比。结果猪二尖瓣前瓣的应力-应变数据与国外研究者测试数据差别为0.4%~3.7%。结论本系统可灵活地对心脏瓣膜和其他生物软组织进行力学特性测试。

Objective In order to obtain the mechanical properties of the heart valve,a high-precision biaxial tension machine system was designed. Methods The system adopted the structure of upper machine and lower machine. The host computer used Labview software programming,the man-machine interface was designed and enhances the flexibility and the data processing ability of the system. The lower computer supported NC language programming and improved the simplicity and flexibility of user programming. The system used the mechanical motion hardware module with sensitivity of 1μm,16-bit data acquisition card,optical displacement measurement,and improved the accuracy of the system measuring stress and strain. In this paper,the mechanical properties of porcine mitral valve were measured by biaxial tension,and the results were compared with those of the foreign counterparts. Results The difference was between 0. 4% and 3. 7%. Conclusions The experimental system can flexibly test the mechanical properties of heart valves and other biological soft tissues.