Cheng Tao, Dai Chenkai, Gan Rong Z
School of Aerospace and Mechanical Engineering, Bioengineering Center, University of Oklahoma, 865 Asp Avenue, Room 200, Norman, OK 73019, USA.
Ann Biomed Eng. 2007 Feb;35(2):305-14. doi: 10.1007/s10439-006-9227-0. Epub 2006 Dec 8.
The tympanic membrane or eardrum of human ear transfers sound waves into mechanical vibration from the external ear canal into the middle ear and cochlea. Mechanical properties of the tympanic membrane (TM) play an important role in sound transmission through the ear. Although limited resources about linear elastic properties of the TM are available in literature, there is a lack of measurement or modeling of viscoelastic properties of the TM at low stress levels. In this study, the uniaxial tensile, stress relaxation, and failure tests were conducted on fresh human cadaver TM specimens to explore mechanical properties of the TM. The experimental results were analyzed using the hyperelastic Ogden model and digital image correlation method. The constitutive equation and non-linear elastic properties of the TM were presented by functions of the stress and strain at the stress range from 0 to 1 MPa. Viscoelastic properties of the TM were described by the stress relaxation function and hysteresis. The results show that the uniaxial tensile test with the aid of digital image correlation analysis is a reliable and useful approach for measuring mechanical properties of ear tissues. The data presented in this paper contribute to ear biomechanics in both experimental measurement and theoretical analysis of ear tissues.
人耳的鼓膜将外耳道的声波转化为机械振动，传入中耳和耳蜗。鼓膜（TM）的力学特性在声音通过耳朵的传播过程中起着重要作用。虽然文献中关于TM线性弹性特性的资源有限，但在低应力水平下，TM的粘弹性特性缺乏测量或建模。在本研究中，对新鲜人尸体的TM标本进行了单轴拉伸、应力松弛和失效试验，以探索TM的力学特性。使用超弹性奥格登模型和数字图像相关方法对实验结果进行了分析。通过应力和应变的函数，给出了应力范围从0到1MPa时TM的本构方程和非线性弹性特性。TM的粘弹性特性通过应力松弛函数和滞后现象来描述。结果表明，借助数字图像相关分析的单轴拉伸试验是测量耳部组织力学特性的可靠且有用的方法。本文所呈现的数据有助于耳部生物力学中耳部组织的实验测量和理论分析。
