Intraocular Pressure Monitoring Smart Contact Lens with High Environmental Stability

Smart contact lenses (SCLs), integrating various functional components, serve as a platform for wirelessly intraocular pressure (IOP) monitoring. Accurate and dynamic measurements offer crucial clinical references for patients with ocular hypertension. Nevertheless, the complex ocular environment poses great challenges, particularly for inductor-capacitor-resistor (LCR) type IOP sensors, which suffer signal instability due to variations of ocular dielectric properties. Here, an innovative IOP monitoring sensor with robust environmental stability, achieved by integrating the ground shield, is proposed. Employing a capacitive pressure sensor with porous polydimethylsiloxane (PDMS) structure encased in a hydrogel, the study successfully demonstrates high-sensitivity monitoring of IOP changes using in vitro porcine eyes. This optimized design empowers the wireless IOP sensor with a sensitivity of 1.15 parts per thousand/mmHg. It exhibits exceptional frequency stability after undergoing 100 wear cycles on ten distinct porcine eyes and remains reliable across a wide range of metabolite concentrations typical of normal eyes. Notably, any observed frequency shift translates into IOP changes within a 3 mmHg range, showcasing its suitability for repeated use and daily IOP monitoring. An intraocular pressure monitoring smart contact lens is developed that integrates bubble-filled PDMS to enhance the sensitivity to 1.15 parts per thousand/mmHg and shielding layer to maintain frequency stability in complex ocular environments, which holds significant potential to advance as next-generation devices for daily IOP management. image