Scleral mechanics: comparing whole globe inflation and uniaxial testing.
Scleral mechanics: comparing whole globe inflation and uniaxial testing.
复制标题
DOI：
10.1016/j.exer.2011.11.017
复制
发表时间：
2012-01
影响因子：
3.4
通讯作者：
Stewart, Jay M.
中科院分区：
文献类型：
--
作者：
Lari, David R.;Schultz, David S.;Wang, Aaron S.;Lee, On-Tat;Stewart, Jay M.
本研究的目的是评估双眼使用单轴和全球体膨胀测试后巩膜力学的根本差异，重点是测试条件与观察到的组织行为之间的关系。本研究使用了来自10头猪的20只猪眼睛，由成对的猪眼睛组成。在两对中，一只眼睛进行了10个周期的眼球加压至150 mmHg(~10倍正常IOP)，同时通过后巩膜的光学系统跟踪双轴应变。从第二眼切除后条进行传统的单轴测试，记录了从10个周期到0.13 MPa的峰值应力的机械滞后（大致相当于在薄壁压力容器假设下IOP为150 mmHg时产生的周向壁应力）。对于近似相等的载荷，单轴试验的峰值应变是膨胀试验的两倍多。试验之间的载荷-变形图呈现出不同的趋势，包括单轴试验的“趾”区域延长，膨胀试验的曲线普遍更陡，膨胀试验的变异性降低。能够在接近生理条件下与标准单轴测试标本一起机械加载整个球体的独特机会揭示了与大多数单轴测试软组织相关的测试工件的影响。与单轴测试相比，全球膨胀提供了显著改变载荷变形行为的测试条件；因此，对改变巩膜力学的干预措施或条件的实验室研究可能会从这些发现中受益匪浅。
The purpose of this study was to assess fundamental differences between the mechanics of the posterior sclera in paired eyes using uniaxial and whole globe inflation testing, with an emphasis on the relationship between testing conditions and observed tissue behavior. Twenty porcine eyes, consisting of matched pairs from 10 pigs, were used in this study. Within pairs, one eye was tested with 10 cycles of globe pressurization to 150 mmHg (~10x normal IOP) while biaxial strains were tracked via an optical system at the posterior sclera. An excised posterior strip from the second eye was subjected to traditional uniaxial testing in which mechanical hysteresis was recorded from 10 cycles to a peak stress of 0.13 MPa (roughly equivalent to the circumferential wall stress produced by an IOP of 150 mmHg under the thin-walled pressure vessel assumption). For approximately equivalent loads, peak strains were more than twice as high in uniaxial tests than in inflation tests. Different trends in the load-deformation plots were seen between the tests, including an extended “toe” region in the uniaxial test, a generally steeper curve in the inflation tests, and reduced variability in the inflation tests. The unique opportunity of being able to mechanically load a whole globe under near physiologic conditions alongside a standard uniaxially tested specimen reveals the effects of testing artifacts relevant to most uniaxially tested soft tissues. Whole globe inflation offers testing conditions that significantly alter load-deformation behavior relative to uniaxial testing; consequently, laboratory studies of interventions or conditions that alter scleral mechanics may greatly benefit from these findings.
登录
查看更多内容
影响因子：
--
作者：
Bisplinghoff, Jill A.;McNally, Craig;Duma, Stefan M.
通讯作者：
Duma, Stefan M.
影响因子：
3.4
作者：
Ruiz-Ederra, J;García, M;Vecino, E
通讯作者：
Vecino, E
影响因子：
2.4
作者：
Iseli, Hans Peter;Spoerl, Eberhard;Seiler, Theo
通讯作者：
Seiler, Theo
影响因子：
14
作者：
Boyce, Brad L.;Grazier, J. Mark;Nguyen, Thao D.
通讯作者：
Nguyen, Thao D.
影响因子：
9.7
作者：
Myers, Kristin M.;Coudrillier, Baptiste;Nguyen, Thao D.
通讯作者：
Nguyen, Thao D.