Wireless, passive strain sensor in a doughnut-shaped contact lens for continuous non-invasive self-monitoring of intraocular pressure

Abstract

Glaucoma is a leading cause of blindness and real-time monitoring of intraocular pressure is of great demand. We present a stretchable sensor inside a contact lens capable of monitoring change in the curvature of cornea caused by IOP fluctuations.

Outcome, influence factor and development of CLS measurement in continuous IOP monitoring: A narrative review

“…The latter was made of gold and titanium and worked not only as a strain sensor but as an inductive antenna to connect with external apparatus via passive electromagnetic coupling. Moreover, in a canine eye model, it showed that this device had a responsivity of 35.1 kHz/mmHg in PDMS substrate and was stable during repeated stretching and relaxing and during eye movements [82]. This product maintained high-responsivity and reliability, along with a comparatively simple system and low cost.…”

Wearable and Implantable Intraocular Pressure Biosensors: Recent Progress and Future Prospects

“…Reproduced with permission. [ 113 ] Copyright 2020, Royal Society of Chemistry. f) I) Strain sensor‐based wireless IOP sensing contact lens.…”

“…The variable inductorbased pressure sensing technologies address the dielectric chamber leakage problems and undesirable baseline shifts normally seen in capacitive sensors. [113] Moreover, inductive detectors are less susceptible to interference from the environment compared to the transducer-based on capacitive, piezoelectric and piezoresistive mechanisms. [130,131] These strengths bring these sensors into sharp focus.…”

Advances and current challenges in non‐invasive wearable sensors and wearable biosensors—A mini‐review

“…(j) The smart contact lens for energy storage and LED lighting on the lens when AC voltage is applied to the 13.56 MHz eyeglass transmitter (Takamatsu et al, 2019) (reproduced under the terms licence © 2019 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim). (k) WBS in the form of contact lens in mechanical deformation, and the device in free movement, placed in the eye (Kouhani et al, 2019) (reproduced under the terms of licence Copyright © 2001, the authors, Royal Society of Chemistry). (l) Components of smart electronic glasses (E‐glasses) for healthcare systems and human‐computer interfaces (Lee et al, 2020) (reproduced with permission Copyright 2020, the authors, Applied Materials, American Chemical Society)…”