【摘要】 报道了一种用光声技术测量生物组织粘弹特性的新方法,即用脉冲激光在生物组织中激发出光声信号(应力波),从光声信号的振幅弛豫特性曲线中测量出应力波的弛豫时间,根据粘弹性理论,该弛豫时间就等于生物组织的粘弹比。用该方法测量Kelvin-Voigt模型的模拟生物组织的粘弹比,测量结果与用流变仪测量的结果完全一致,符合率达到97%。进而用光声方法测量出Maxwell模型的生物组织的粘弹比。理论分析与实验结果都表明:该方法只与被测物的声阻抗有关,而与它的状态无关,因此可用于任意状态的生物组织粘弹特性的测量。光声测量方法具有实时、快速、测量灵敏度高和重复性好的优点,因此在生物医学领域具有潜在的应用前景。更多还原

【Abstract】 A new method for evaluating the viscoelasical characterization of biological tissue was describled by photoacoustic technique in this paper.From the amplitude attenuation curve of the tissue’s photoacoustic signals (the stress waves) which induced by Q-YAG laser,the decay time of the stress waves can be calculated.According to the theory of viscoelasticity,the decay time is equal to the tissue’s viscosity-elasticity rate.The result of gelatin shows the viscosity-elasticity rate of Kelvin-Voigt model tissue measured by photoacoustic measurement almostly equals that by conventional rheometer,the agreement is almost 97%.Furthermore,the tissue’s viscosity-elasticity rate of Maxwell model was measured by photoacoustic technique.From the theory and the experiments,it is showed that the method had nothing to do with tissue’s state,but its acoustic impedance,that was,it could be applied in any model tissue.In a word,photoacoustic measurement is real-time,noninvasive,high sensitive and good repetitive.Based on the above virtures,it has the wide potential application on biology and medicine.更多还原