Microfluidic Contact Lenses for Tear Analysis and Disease Diagnosis

  • Aysha Alghailani

Student thesis: Master's Thesis

Abstract

This study discusses a novel design of a microfluidic eye contact lens sensor for unpowered, continuous, and non-invasive intraocular pressure (IOP) monitoring. Normal IOP ranges between 10 to 21 mmHg, IOP greater than this range is directly related to glaucoma. The proposed contact lens includes twelve capillary bursting valves (CBVs) designed with different microchannels' widths. Each designed CBV corresponds to a specific IOP. The increase of IOP is represented by a noticeable fluid movement from the microchannel to the reaction chamber of the CBV. The first designed CBV bursts when the IOP is larger than 10 mmHg, while the last one bursts when the IOP is larger than 37.5 mmHg, following a clockwise direction. The uncertainty of the measured IOP is 2.5 mmHg, which is the difference between two adjacent burst pressures (BP). Volume of Fluid (VOF) method is employed in the numerical analysis of this study to track the glycerol flow inside these CBVs and check whether the reaction chamber would burst for different mirochannels' widths. The flow inside the microchannels is governed by Navier Stokes equation. Two main analyses are done in this research to obtain the optimum dimensions of the CBVs. The first analysis is performed to obtain the effect of the IOP on the CBV using ABAQUS software. Prior to this analysis, a previous numerical study of the eyeball pressure effect on a microfluidic contact lens is replicated in COMSOL software to ensure the validity of the set-up. However, the second analysis is performed to find the corresponding widths to different IOPs using ANSYS Fluent. The final results obtained show a variety of microchannels' widths that correspond to different IOPs.
Date of AwardDec 2021
Original languageAmerican English

Keywords

  • microfluidic; contact lens; glaucoma; intraocular pressure; capillary bursting valves

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