Implantable Flexible-Coiled Wireless Intraocular Pressure Sensor

This work presents an implantable wireless passive pressure sensor for long-range continuous intraocular pressure (IOP) monitoring of glaucoma patients. The sensor is microfabricated with use of parylene C (poly-chloro-p-xylylene) to create a flexible coil substrate that can be folded during implantation for suture-less minimally invasive surgery, while stretched back without damage for enhanced inductive sensor-reader coil coupling and the corresponding sensing signal. Extensive device characterizations including on-bench testing and in vivo and ex vivo animal studies verify the device feasibility in both engineering (1 mmHg pressure sensing accuracy and 2 cm sensing distance) and surgical (robust fixation to the iris and long-term biocompatibility in the intraocular environment) aspects, all meeting specifications for future practical implementation of such IOP sensing technology.