正常人的血液粘弹性和触变性研究

应用ＬｏｗＳｈｅａｒ４０流变仪对正常人的血液粘弹性、触变性等指标进行测定与分析，得到了全血滞后环和应力衰减曲线，发现应力的变化在突加一个切变率后并不是单纯的指数衰减，而是先经过０６ｓ左右的振荡过程，然后才开始指数衰减。弹性模量Ｇ′及耗散模量Ｇ″随振荡频率的变化在三个频点出现局部极大（极小）值，在０８Ｈｚ时Ｇ′、Ｇ″都达到谷值，应力与应变的相位差δ达到极小值，说明此振荡频率下血液的粘性分量与弹性分量之比达到最小。在０２Ｈｚ、３３Ｈｚ时Ｇ′达到谷值，Ｇ″保持上升趋势，相位差δ达到局部峰值，说明此二个振荡频率下血液的粘性分量与弹性分量之比达到最大。血液粘度的测量结果表明同心圆筒式粘度计在测量不同切变率范围（０～２００ｓ－１）的全血粘度时稳定性较锥板式差，而且在较高切变率时（１６０２００ｓ－１）数据不稳定。因此在进行一般的全血粘度测量时仍以锥板式为好。

Study on Viscoelasticity and Thixotropy of Healthy Blood

With the Low Shear 40 rheometer the viscoelasticity and thixotropy of healthy blood were measured and the hysteresis loop and torque-decay curve were obtained. It's found that when a sudden shear rate affect to the blood, the change of shear stress was not a simple exponential attenuation. The shear stress began an exponential attenuation after an 0.6 s oscillation. The storage shear modulus G′ and loss shear modulus G″ reached the local maximum(minimum) value at three oscillatory frequency. G′ and G″ reached the local lowest values at 0.8 Hz and the phase difference of stress and strain reached the minimum value. At oscillatory frequency of 0.2 Hz and 3.3 Hz, G′ reached the local lowest values but the phase difference of the maximum value. The results of blood measurement showed that the stability of cone-plate viscometer was better than cylinder viscometer when measure the blood viscosity at ahear rate of 0 to 200 s -1 。 It suggested that cone-plate viscometer was the first choice when measure blood viscosity. The results provided two rheograms and the normal values of viscoelasticity and thixotropy for clinical medicine.