An ultrasonic technique for the measurement of the elastic moduli of human cornea.
An ultrasonic technique for the measurement of the elastic moduli of human cornea.
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DOI：
10.1016/s0021-9290(96)80017-0
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发表时间：
1996-12
影响因子：
2.4
通讯作者：
Hsi-Chun Wang;P. Prendiville;Peter J. McDonnell;Wenji V. Chang
中科院分区：
文献类型：
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作者：
Hsi-Chun Wang;P. Prendiville;Peter J. McDonnell;Wenji V. Chang
为了减少与屈光手术相关的不可预测性，并最终改进手术技术，许多研究者试图确定角膜的弹性模量。诸如角膜条的应力-应变测试和全眼在不断增加的压力下汞滴位移的测量等技术已经得出了杨氏模量从105到107N m−2的范围。这两种方法都有局限性，因为这些机械测试不能在生理状态下进行，而且在测试过程中施加的力很大。我们使用超声技术来测定人角膜的弹性模量。分别检测两组不同条件下（生理盐水和葡聚糖）制备的6只角膜，在这12只人眼库眼中产生并检测剪切波。所有波形都被数字化并保存在二进制格式的文件中。采用快速傅里叶变换（FFT）计算剪切波的速度和衰减。利用得到的波速和衰减系数，计算角膜样品的杨氏模量分别为（5.3±1.1）×106N m−2和（2.0±1.0）×107N m−2，分别用于生理盐水和葡聚糖在2.25 MHz下制备的角膜样品。
In the hopes of reducing the unpredictability associated with refractive surgical procedures and ultimately improving surgical techniques, many investigators have attempted to determine the elastic moduli of the cornea. Techniques such as stress-strain tests of corneal strips and the measurement of mercury drop displacement in a whole eye under increasing pressure have resulted in a range of values for Young's modulus from 105to 107N m−2. Both of these methods are limited because these mechanical tests cannot be performed in the physiological state and because of the large amount of force applied during testing. We used an ultrasonic technique to determine the elastic moduli of the human cornea. Two groups of six corneas prepared under different conditions (in saline and in dextran) were examined separately and the shear waves were generated and detected in these 12 human eye bank eyes. All the waveforms were digitized and saved in files of binary format. Fast Fourier transformation (FFT) was applied to calculate the speed and attenuation of the shear wave. Using the resulting wave speeds and attenuation coefficients, the Young's moduli of the corneal samples were calculated as (5.3±1.1)×106N m−2and (2.0±1.0)×107N m−2for cornea samples prepared in saline and in dextran at 2.25 MHz, respectively.