The millimetre computer that could be implanted in the eye

A team of computer engineers and scientists at the University of Michigan have made a prototype of what they believe is the world's smallest computer.

A prototype implantable eye pressure monitor for glaucoma patients is believed to contain the first complete millimetrescale computing system.

The millimetre computer
The first complete millimetre-scale system is targeted toward medical applications. The work presented at The International Solid State Circuits Conference focused on a pressure monitor designed to be implanted in the eye to conveniently and continuously track the progress of glaucoma, a potentially blinding disease. (The device is expected to be commercially available several years from now.)

In a package that's just over 1 cubic millimetre, the system fits an ultra low-power microprocessor, a pressure sensor, memory, a thin-film battery, a solar cell and a wireless radio with an antenna that can transmit data to an external reader device that would be held near the eye.

The processor in the eye pressure monitor is the third generation of the researchers' Phoenix chip, which uses a unique power gating architecture and an extreme sleep mode to achieve ultra-low power consumption. The newest system wakes every 15 minutes to take measurements and consumes an average of 5.3 nanowatts. To keep the battery charged, it requires exposure to 10 hours of indoor light each day or 1.5 hours of sunlight. It can store up to a week's worth of information.

These computers could have a host of applications in the human body, and because they're so small, hundreds of thousands could be manufactured on one wafer.

Image Credit - Greg Chen

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