Navaeipour Farzaneh, Hepburn Matt S, Li Jiayue, Metzner Kai L, Amos Sebastian E, Vahala Danielle, Maher Samuel, Choi Yu Suk, Kennedy Brendan F
BRITElab, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands and Centre for Medical Research, The University of Western Australia, Perth, Western Australia 6009, Australia.
Department of Electrical, Electronic and Computer Engineering, School of Engineering, The University of Western Australia, 35, Stirling Highway, Perth, Western Australia 6009, Australia.
Biomed Opt Express. 2024 May 3;15(6):3609-3626. doi: 10.1364/BOE.522002. eCollection 2024 Jun 1.
In quantitative micro-elastography (QME), a pre-characterized compliant layer with a known stress-strain curve is utilized to map stress at the sample surface. However, differences in the boundary conditions of the compliant layer when it is mechanically characterized and when it is used in QME experiments lead to inconsistent stress estimation and consequently, inaccurate elasticity measurements. Here, we propose a novel stress estimation method using an optical coherence tomography (OCT)-based uniaxial compression testing system integrated with the QME experimental setup. By combining OCT-measured axial strain with axial stress determined using a load cell in the QME experiments, we can estimate stress for the compliant layer, more accurately considering its boundary conditions. Our proposed method shows improved accuracy, with an error below 10%, compared to 85% using the existing QME technique with no lubrication. Furthermore, demonstrations on hydrogels and cells indicate the potential of this approach for improving the characterization of the micro-scale mechanical properties of cells and their interactions with the surrounding biomaterial, which has potential for application in cell mechanobiology.
在定量显微弹性成像（QME）中，利用具有已知应力-应变曲线的预先表征的柔顺层来绘制样品表面的应力。然而，柔顺层在进行机械表征时和在QME实验中使用时的边界条件差异会导致应力估计不一致，从而导致弹性测量不准确。在此，我们提出一种新颖的应力估计方法，该方法使用基于光学相干断层扫描（OCT）的单轴压缩测试系统，并与QME实验装置集成。通过将OCT测量的轴向应变与QME实验中使用测力传感器确定的轴向应力相结合，我们可以更准确地考虑柔顺层的边界条件来估计其应力。与不使用润滑的现有QME技术误差达85%相比，我们提出的方法显示出更高的准确性，误差低于10%。此外，在水凝胶和细胞上的演示表明了这种方法在改善细胞微观尺度力学性能及其与周围生物材料相互作用表征方面的潜力，这在细胞机械生物学中具有应用潜力。
