一種眼角膜楊氏模數測量法

Abstract

眼睛為人類的一個很重要的器官，而目前仍然會有一些因無法準確判斷眼睛疾病而造成病患會有延誤就醫的情形發生，因此，本論文主要目的為提出一種可以計算出眼角膜本身的材料特性之方法，希望能藉由得到眼角膜之材料特性來幫助醫師做一個更為準確之判斷。 在工程上，楊氏模數常被用來表示為材料本身的特性，而眼角膜又是屬於一種特殊的材料，因此，若將眼角膜從工程上的角度來看，其在不同情形下應該也會有著不一樣的楊氏模數。而本論文為了得到眼角膜的楊氏模數，將建立一個眼角膜的數學模型，並且利用一種最新的量測儀器Corvis St將量測得到的輸出資料代入已建立好的數學模型中進而得到眼角膜之楊氏模數。本論文將25筆資料的楊氏模數透過此數學模型計算後再扣掉所受到之張力影響的平均約為0.08062MPa，而此值又較過去文獻所計算之楊氏模數還要小。

The eye is very important to human. When there is a problem with the eye, it is always desirable to seek medical care early on; however, delay still exists due to miscalculation and examination uncertainties. This thesis thus tries to provide a more accurate non-intrusive measurement of the cornea properties for doctors’ reference. One of the properties that is very sensitive to the condition of the eye is the Young’s modulus of the cornea. The cornea material exhibits different behavior in patients with different conditions. This thesis proposes a mathematical model for describing the mechanical properties of the cornea. By comparing the model behavior with the non-intrusive measurement data taken off the Oculus Corvis ST non-contact tonometer, it is possible to deduce the corneal Young’s modulus. By examining the data from 25 patients, the average value for the cornea Young’s modulus, after removing the effect of tension, is about 0.08062MPa. This value is smaller than most of the available literature based on deduction; however, it is closer to the direct measurement results using atomic force microscope.