Patent ID: 9084561
Filing Date: 2015-07-21
Classification: A61B,G01N,G02C

Abstract:
1. An eye-mountable device comprising: a polymeric material having a concave surface and a convex surface, wherein the concave surface is configured to be removably mounted over a corneal surface and the convex surface is configured to be compatible with eyelid motion when the concave surface is so mounted; a substrate at least partially embedded within the polymeric material; an antenna disposed on the substrate; an electrochemical sensor disposed on the substrate and including (i) a working electrode having a first side edge and a second side edge, and (ii) a reference electrode situated such that at least a portion of the first and second side edges of the working electrode are adjacent respective sections of the reference electrode; and a controller electrically connected to the electrochemical sensor and the antenna, wherein the controller is configured to: (i) apply a voltage between the working electrode and the reference electrode sufficient to generate an amperometric current related to the concentration of an analyte in a fluid to which the eye-mountable device is exposed; (ii) measure the amperometric current; and (iii) use the antenna to indicate the measured amperometric current, wherein the substrate is a ring-like structure having inner and outer edges, wherein the working electrode and the reference electrode each include a plurality of interdigitated extensions oriented on the substrate to be locally parallel to the inner and outer edges of the ring-like structure at one or more locations along the interdigitated extensions.