The UW engineering team, which includes Brian Otis, now with Google Inc., and Cagdas Varel and Yi-Chun Shih, both former doctoral students in electrical engineering, built a prototype that uses radio frequency for wireless power and data transfer. A thin, circular antenna spans the perimeter of the device roughly tracing a person's iris and harnesses enough energy from the surrounding field to power a small pressure sensor chip. The chip communicates with a close-by receiver about any shifts in frequency, which signify a change in pressure. Actual pressure is then calculated and those changes are tracked and recorded in real-time.
The chip's processing mechanism is actually very simple, leaving the computational heavy lifting to the nearby receiver, which could be a handheld device or possibly built into a smartphone, Bhringer said.
The current prototype is larger than it would need to be to fit into an artificial lens, but the research team is confident it can be downscaled through more engineering. The team has successfully tested the sensing device embedded in the same flexible silicon material that's used to create artificial lenses in cataract surgeries.
Similar to how a person's blood pressure varies throughout the day with activity levels, eye pressure is thought to behave similarly, changing perhaps minute by minute. If the pressure in the eye is too high for the optic nerve to function, however, damage to the eye can begin, often with no pain or warning signs. This increased intraocular pressure is the main factor in glaucoma, which causes vision loss and ultimately blindness.
"Oftentimes damage to vision is noticed late in the game, and we can't treat patients effectively by the time they are diagnosed with glaucoma," Shen said. "Or, if medications are given, there
|Contact: Michelle Ma|
University of Washington