Interstitial fluid pressurization during confined compression cyclical loading of articular cartilage
Interstitial fluid pressurization during confined compression cyclical loading of articular cartilage
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DOI：
10.1114/1.239
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发表时间：
2000-02-01
影响因子：
3.8
通讯作者：
Ateshian, GA
中科院分区：
文献类型：
--
作者：
Soltz, MA;Ateshian, GA
本研究的目的是通过实验验证广为接受但未经检验的假设，即软骨间质液在一定载荷频率范围内的有限压缩中施加的循环应力的作用下会产生不同的加压，对软骨动态刚度有显着影响。在底部装有微芯片压力传感器的密闭压缩室中，使用多孔压头在负载控制下对十八个牛软骨圆柱形样品进行了测试。静应力超过 130 kPa。使用压头以 0.0001 至 0.1 Hz 的频率施加振幅为 33 kPa 的循环应力。同时测量软骨间质液压力和变形作为时间的函数。在时域中对最低测试频率下的位移响应进行曲线拟合，以确定线性双相材料特性，H-A=0.70 +/- 0.10 MPa 和 k(o) = 2.4 x 10(-16) +/- 0.64 x 10(-16) m(4)/N s。这些特性在双相理论中被用来预测间质流体压力响应并将其与实验进行比较，从而产生非线性决定系数，范围从 r(2)=0.89 +/- 0.15 到 0.96 +/- 0.03，具体取决于频率。研究发现，在本研究的样品中，当特征频率高于 0.000 44 Hz 时，流体加压的幅度和相位会加速施加的应力，从而将不渗透底面的组织应变降低至接近零。这项研究的结果验证了这样的假设：软骨动态刚度主要源自线性双相理论所预测的依赖于流动的粘弹性；他们通过实验证明了间质液加压作为宽频率范围内软骨负载支持的基本机制的重要性。 (C) 2000 年生物医学工程学会。 [S0090-6964(00)00202-2]。
The objective of this study was to experimentally verify the well-accepted but untested hypothesis that cartilage interstitial fluid pressurizes variously under the action of an applied cyclical stress in confined compression over a range of loading frequencies, contributing significantly to the cartilage dynamic stiffness. Eighteen bovine cartilage cylindrical samples were tested under load control using a porous indenter in a confined compression chamber fitted with a microchip pressure transducer at its bottom. Over a static stress of 130 kPa. a cyclical stress of amplitude 33 kPa was applied with the indenter at frequencies ranging from 0.0001 to 0.1 Hz. The cartilage interstitial fluid pressure and deformation were measured simultaneously as a function of time. The displacement response at the lowest tested frequency was curvefitted in the time domain to determine the linear biphasic material properties, H-A=0.70 +/- 0.10 MPa and k(o) = 2.4 x 10(-16) +/- 0.64 x 10(-16) m(4)/N s. These properties were employed in the biphasic theory to predict the interstitial fluid pressure response and compare it to experiment, resulting in nonlinear coefficients of determination ranging from r(2)=0.89 +/- 0.15 to 0.96 +/- 0.03 depending on frequency. It was found for the samples of this study that above a characteristic frequency of 0.000 44 Hz, the magnitude and phase of fluid pressurization marched the applied stress, reducing the tissue strain at the impermeable bottom surface to nearly zero. The findings of this study verify the hypothesis that cartilage dynamic stiffness derives primarily from flow-dependent viscoelasticity as predicted by the linear biphasic theory; they demonstrate experimentally the significance of interstitial fluid pressurization as the fundamental mechanism of cartilage load support over a wide range of frequencies. (C) 2000 Biomedical Engineering Society. [S0090-6964(00)00202-2].