角膜接触镜式眼压监测传感器

Abstract

眼压监测对于了解眼睛健康状况、预防和治疗青光眼等疾病具有重要意义。传统的眼压监测需要在医院进行,不仅医生与患者费时费力,而且难以实现24小时连续监测。将眼压监测装置微型化,以角膜接触镜的形式佩戴,可以很好地解决这个问题。本文利用眼压变化与角膜曲率变化的相关性,采用惠斯通电桥的原理设计了一种电阻式应变计,通过测量应变计对角膜直径变化的响应电压,实现对眼压的监测。应变计的制备采用微加工技术制备,通过注模成型技术封装在与角膜接触镜尺寸相同的聚二甲基硅氧烷(PDMS)中。初步实验结果表明,所制备的传感器灵敏度为100.7 μV/μm。理想状态下,当传感器紧密贴附于角膜表面并随着其曲率变化而同步变化时,其监测眼压的灵敏度为125.8 μV/mm Hg。

Intraocular pressure detection has a great significance for understanding the status of eye health, prevention and treatment of diseases such as glaucoma. Traditional intraocular pressure detection needs to be held in the hospital. It is not only time-consuming to doctors and patients, but also difficult to achieve 24 hour-continuous detection. Microminiaturization of the intraocular pressure sensor and wearing it as a contact lens, which is convenient, comfortable and noninvasive, can solve this problem because the soft contact lens with an embedded micro fabricated strain gauge allows the measurement of changes in corneal curvature to correlate to variations of intraocular pressure. We fabricated a strain gauge using micro-electron mechanical systems, and integrated with the contact lens made of polydimethylsiloxane (PDMS) using injection molding. The experimental results showed that the sensitivity was 100.7 μV/μm. When attached to the corneal surface, the average sensitivity of sensor response of intraocular pressure can be 125.8 μV/mm Hg under the ideal condition. ? 2016, Editorial Office of Journal of Biomedical Engineering. All right reserved.