A new method of estimating gauge length for porcine aortic valve test specimens.
A new method of estimating gauge length for porcine aortic valve test specimens.
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一种估算猪主动脉瓣测试样本标距长度的新方法。
DOI：
10.1016/s0021-9290(03)00035-6
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发表时间：
2003
影响因子：
2.4
通讯作者：
Vesely,Ivan
中科院分区：
文献类型：
--
作者：
Carew,EvelynO;Vesely,Ivan
猪主动脉瓣（PAV）瓣尖在体外状态下折叠和起皱。在PAV样本的拉伸试验中，估计标距（样本开始提供可测量的负载阻力的长度）通常是困难和主观的。因此，我们开发了一种新的方法来估计这种组织的标距长度。该方法是基于观察到的试样的标距长度可以与其负载长度曲线的斜率上的一个固定点，如果加载从一个起皱的状态，或轻微的压缩状态。我们表示的负载长度响应的测试样本在低负载，高柔度区域由一个三次函数，并使用初等微积分确定的函数的斜率上的稳定点。通过减小或扩展最初选择的“测试区域”来微调三次函数表示，直到三次拟合的相关系数最大化。新方法被应用于从心脏瓣膜组织条的拉伸试验获得的数据，并被发现是客观的，可重复的和稳健的。
Porcine aortic valve (PAV) cusps are folded and wrinkled in the in vitro state. In the tensile testing of PAV specimens, estimating gauge length (the length at which a specimen starts to offer measurable resistance to load) is often difficult and subjective. We have therefore developed a new method for estimating the gauge length of such tissues. The method is based on the observation that the specimen's gauge length can be associated with a stationary point on the slope of its load-length curve if loaded from a wrinkled state, or a state of slight compression. We represented the load-length response of test specimens in the low-load, high-compliance region by a cubic function and determined the stationary point on the slope of the function using elementary calculus. The cubic function representation is fine-tuned by reducing or expanding an originally selected “test region” until the correlation coefficient of the cubic fit is maximized. The new method was applied to data obtained from the tensile testing of strips of heart valve tissue and was found to be objective, repeatable and robust.