Pressure monitoring is useful for recording subtle changes in intraocular pressure to detect the onset of glaucoma. A sufficiently small implantable solution addresses the challenges of obtaining accurate pressure measurements in inaccessible regions of the body, and a wireless solution addresses the challenge of continuous access. Such a device promotes effective intervention and treatment for chronic, pressure-dependent conditions such as glaucoma.

In order to promote continuous monitoring, a home-based, user-friendly monitoring device is needed. The current standard is to use small form-factor tonometry measurements, which have wide uncertainty ranges and are far less accurate than an implantable or even a contact lens-based sensor. In order to obtain data from a wireless pressure sensor, a USB-enabled monitoring device was designed and tested.

The sensors utilize high frequency resonance akin to RFID, where a passive device is excited by an external scanner. Here the response frequency varies as the sensed pressure varies. Using an external antenna, this developed hardware scans a known frequency range and picks up such passive devices that resonate at a particular frequency. PC software was developed in tandem to record and interpret this measured frequency data as pressure information.

Since the implanted sensors are often very small and have very low response levels, special care was taken to maximize the transmitter power and lower the receiver noise floor. RF generator circuitry is shielded and generic RF connectors are used to test a variety of antennas. The use of RF connectors also allow the scanning antenna to be placed in surgical environments while keeping the monitoring circuitry at a safe distance.