An intraocular CMOS transponder system implant with an integrated micromachined pressure sensor

For a better treatment and analysis of the eye disease "Glaucoma", a continuous measurement and knowledge of the eye's internal (intraocular) pressure is of particular importance. The transponder system implant presented in this article offers a measurement of the intraocular pressure using a passive transponder ASIC with a fully integrated pressure sensor, and processes the data via a portable reader. The present paper will describe the transponder system and its mode of operation. Furthermore, the working principle of the data transmission and the power supply of the transponder ASIC will be explained. Moreover, it will provide insight into to the circuit design of the ASIC and the concept of the pressure sensor. Finally, the contribution will illustrate the portable reader and its Bluetooth interface.