Figure 1.

Digital sensor technologies for glaucoma medication adherence monitoring. (A) The Travatan Dosing Aid. Reprinted from Friedman et al¹⁰⁸, Copyright (2007), with permission from Elsevier. (B) The e-Novelia Smart add-on for ophthalmic droppers. Available from: https://www.nemera.net/smart-ophthalmic-add-on-e-novelia/. (C) An intelligent sleeve with embedded sensors to quantify adherence and fluid level for glaucoma medication. Bar magnets (1) are placed in the cap, reed switches (2) in the sleeve sense cap removal, the two-part capacitive sensor (3) has two copper sheets (a) and (b) surrounding the bottle, electronics are embedded in an nRF51422 system-on-a-chip (4), Bluetooth low energy (5) is used for data transfer, and the system is powered with a single rechargeable coin cell battery (6). Reproduced with permission from Payne et al.⁶⁸ (D) A smart drop sensor system comprised a thin conductive pressure-sensitive electronic sensor, for bottle squeezing detection and an electronic circuit (<2 mm thick) for signal processing and wireless transmission, in lateral view (A1) and top view (A2). The flexible sensor is contained underneath the label (B1), with electronics at the base (B2). Reproduced with permission from Aguilar-Rivera et al.⁶⁹