基于压电双脉冲剪切波加载和光学相干断层扫描的生物组织弹性测试技术

生物组织力学性能的定量测试对疾病发生和发展的研究及诊治非常重要。本文集成压电堆栈振动加载和光学相干断层扫描(OCT)提出对生物组织弹性进行定量测量的剪切波光学相干弹性成像技术。压电堆栈携带探针在双脉冲激励下对生物组织或仿体产生约2μm振幅的振动,生成剪切波。在OCT探测区域,生物组织的变形会引起OCT的相位信号变化,由此提出检测剪切波的相位差法。再根据剪切波的传播速度,计算获得组织的弹性模量。通过比较该方法与拉伸实验对生物组织仿体弹性模量的测量结果,验证了技术的可行性。进而对人体手指指腹皮肤的弹性进行了在体测试,表明该方法有用于在体皮肤力学性能测试的潜力。压电堆栈双脉冲剪切波OCE为离体生物组织弹性测试提供了新的简单有效的手段,并且有潜力进一步发展为生物组织复杂力学性能的测试技术,以及应用于临床上皮肤等疾病的诊断。

On the biological tissue elasticity measurement technique based on piezoelectric double-pulse shear wave loading and optical coherence tomography

Quantitative biomechanical property measurement of biological tissues is essential for the research,diagnosis and treatment of disease occurrence and development.Based on integrated piezoelectric stack vibration loading and optical coherence tomography (OCT),a shear wave optical coherence elastography (OCE)technique for quantitative measurement of biological tissue elasticity is presented in this paper.Under double pulse excitation,piezoelectric stack carrying a probe produces vibration with about 2μm amplitude on biological tissue or phantom and generates shear wave.In OCT detection region,the deformation of biological tissue will cause phase signal change of OCT. Therefore,a shear wave detection method is proposed based on phase difference.According to the velocity of shear wave propagation,the elastic modulus of biological tissue is calculated.The feasibility of this technique is verified by comparing obtained results with that of tensile experiment to measure the elastic modulus of the biological tissue.The elasticity of human finger ventral skin was measured in vivo,which indicates that this method has potential to be used to measure mechanical properties of skin in vivo.Piezoelectric stack double pulse shear wave OCE provides a new simple and effective method for biological tissue elasticity measurement in vitro.It has potential to further development of testing technique for complex mechanical properties of biological tissues,and can be applied to the diagnosis of diseases such as skin diseases etc.