基于光纤光栅传感器的24h眼压监测系统研究

Glaucoma, characterized by increased intraocular pressure (IOP), is a prevalent irreversible cause of blindness worldwide. Nonetheless, pathological intraocular pressure fluctuation, which is easily neglected, plays an equally important role in the process of glaucoma. Hence, effective monitoring of the 24h IOP fluctuation under daily living condition becomes the common focus and difficulty worldwide. The leading research direction recent years is the non-invasive IOP measurement, in which the single-point corneal deformation caused by IOP variation is detected. However, as is known to all, that corneal thickness, its radius of curvature, the arrangement of collagen fibers differs from the central cornea to the limbus, determines the variation of corneal elastic mechanics under different pressure. Thus defects exist in current achievements that single point of cornea measurement would unavoidably lead to the loss or dilution of significant information. Fortunately, fiber grating pressure sensor offers an ideal solution for it realizes multi-point measurement of corneal deformation and independent analysis. Based on the previous in-depth study and large amounts of data, our project intends to develop a practical 24h IOP monitoring system under daily living condition through mathematically modeling the multi-point relationship between of cornea and IOP fluctuation by placing FBG pressure sensor on contact lens in tandem array distribution form. Our project is beyond doubt of great significance in the research of IOP measurement.

青光眼是不可逆致盲眼病。眼压升高并非青光眼损害唯一危险因素。病理性眼压波动在青光眼发生发展中也扮演重要角色，其表现隐匿。有效监测自然生活状态下24h眼压波动成为世界范围共同关注的焦点和难点。通过测量由眼内压变化引起角膜形变的非侵入式眼压监测方式是目前研究的主导方向。角膜各点厚薄、曲率半径、近角巩缘处胶原纤维排列方式与角膜中央不同，决定了其在眼压变化时角膜形变程度存在弹性力学差异。现测量方法仅能获取角膜局部综合单信号信息，易致信息漏获、有些突出信息在输出分析中被中和或平均掉。光纤光栅压力传感器的突出优势在于可以多点监测角膜形变，并可进行独立或综合分析。 课题组在前期研究已获可行实验方法和大量实验数据的基础上，通过建立角膜多个感兴趣点与眼压变化关系的数学模型，运用光纤光栅压力传感器以串联阵列分布形式置入角膜接触镜内的方式，研制自然生活状态下24h眼压监测系统。本项目将为眼压测量研究开启新篇章。

病理性眼压波动在青光眼发生发展中扮演着重要角色，其表现隐匿，有效监测自然生活状态下24h眼压波动成为临床医生和研究者共同关注的焦点。非侵入式测量方式是目前研究的主导方向， 现临床试用的 24h 眼压监测装置实现了自然生活状态下眼压监测，但还有一些明显的缺陷有待改进。本实验通过基于角膜地形图测量角膜形态，加压过程中发现角膜中央变形最大，得到角膜的变化最敏感区域为角膜中央角；基于光纤光栅光谱仪测量系统测量了传感器在不同眼压变化下的响应，完成了眼压变化下光纤光栅传感器性能测试及光纤光栅性能的改良；采用不同的方法制备了具有不同测量光栅分布的接触镜，对其进行了应变传递相关理论与计算以及眼压测量的灵敏度和准确度的测试和验证。光纤光栅传感器从原理上具有多点监测并能独立分析所获取信息的优点，是更有前景和更理想实现监测 24h 眼压的方法。