基于超声成像的眼压非接触测量方法

Non-Contact Measurement Method of Intraocular Pressure Based on Ultrasound Imaging

目的目前市场上主流眼压测量设备以接触式和刺激性激励为主,使用过程中极易给患者带来不适,更有甚者会导致角膜感染。为了解决这一问题,提出一种超声成像眼压非接触式测量方法。方法对该方法进行有限元分析与实验验证,得到角膜形变仿真计算结果,制作模拟眼并搭建眼压测量实验系统,建立眼压、角膜形变与压力的数学模型,并对该模型进行准确性和重复性验证。结果在某一眼压下,角膜的压平直径和顶点位移分别与压力存在幂函数与线性关系;在恒定压力下,压平直径和顶点位移均与眼压存在幂函数关系,可作为眼压测量指标。通过该方法测得的眼压平均相对误差在8%以下,相对平均偏差在9%以下,重测信度均大于0.9。结论该方法测量结果准确,重复性较好。研究结果为眼压的非接触测量提供一种有效途径,具有较好的应用前景。

Objective Currently,the mainstream intraocular pressure(IOP)measurement devices in the market are contact and irritant,which can easily bring discomfort to patients and even lead to corneal infection during use.To solve this problem,a non-contact measurement method of IOP based on ultrasound imaging was proposed.Methods The method was verified by finite element analysis and experiment,and the simulation results of corneal deformation were obtained.A simulated eye was made and an experimental system for measuring IOP was built.A mathematical model of IOP,corneal deformation and pressure was established and its accuracy and repeatability were verified.Results The flattened diameter and vertex displacement of the cornea had a power and linear relationship with pressure under a certain IOP.Both the flattened diameter and the vertex displacement had a power relationship with IOP under constant pressure,which could be used as the index of IOP measurement.The average relative error of IOP measured by this method was smaller than 8%,the relative average deviation was smaller than 9%,and the retest reliability was greater than 0.9.Conclusions The measurement results of the method are accurate and have a good repeatability.The results of this study provide an effective way for non-contact measurement of IOP,which has a good application prospect.