Viscoelastic characterization of biological tissue by photoacoustic technique
用光声技术测量生物组织粘弹特性的研究

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.