Moore S W
Department of Integrative Biology, University of California at Berkeley, San Francisco 94720.
IEEE Trans Biomed Eng. 1994 Jan;41(1):45-50. doi: 10.1109/10.277270.
Dynamic mechanical properties of embryonic tissues, including viscoelasticity and active motility, play a major role in morphogenesis. Mechanical abnormalities resulting from altered cytoskeletal chemistry presumably contribute to spina bifida and other birth defects, but research in this area has been limited by inadequate mechanical measurement techniques. This paper discusses aspects of embryo tissues that make them difficult to measure and describes a versatile new system developed and used to study the biomechanics of morphogenesis in amphibian embryos. It incorporates a flexible optical-fiber probe driven by piezoceramic elements to impose and measure feedback-controlled, two-dimensional, time-varying patterns of stress or strain in the tissue. Compression, tension, and shear geometries are possible. Capacitive displacement sensors provide the precision and low drift rates required for these measurements. Software control permits the system to perform both standard and customized rheological tests, including interactive ones in which test parameters change in response to measured tissue behavior. Sample size range is 50 microns to 5 mm. Displacement range is 60 microns with a resolution of 0.1 microns. Force range is 10 microN with a resolution of 0.02 microN. Frequency range is DC to 20 Hz.
胚胎组织的动态力学特性，包括粘弹性和主动运动性，在形态发生过程中起着重要作用。由细胞骨架化学改变导致的力学异常可能是脊柱裂和其他出生缺陷的原因之一，但该领域的研究一直受到机械测量技术不足的限制。本文讨论了胚胎组织难以测量的方面，并描述了一种新开发的通用系统，该系统用于研究两栖类胚胎形态发生的生物力学。它包含一个由压电陶瓷元件驱动的柔性光纤探头，用于施加和测量组织中反馈控制的二维时变应力或应变模式。可以实现压缩、拉伸和剪切几何形状。电容式位移传感器提供了这些测量所需的精度和低漂移率。软件控制允许系统执行标准和定制的流变学测试，包括交互式测试，其中测试参数根据测量的组织行为而变化。样本尺寸范围为50微米至5毫米。位移范围为60微米，分辨率为0.1微米。力范围为10微牛顿，分辨率为0.02微牛顿。频率范围为直流至20赫兹。
