We've heard of experimental contact lenses that can non-invasively monitor the blood sugar levels of diabetes sufferers before, but where prior research relied on chemical reactions inducing color-change in the lens, new joint research by the University of Washington and Microsoft Research aims to incorporate electronics into such lenses to report blood sugar levels wirelessly. Gizmag spoke to Desney Tan, Senior Researcher at Microsoft Research Connections, to find out what sets this work apart.
In a promotional video from Microsoft Research, Professor Babak Parviz of the University of Washington summarizes the research. "We've been able to put a glucose sensor on a contact lens and show that it can detect glucose at levels that are found in the tear film," he explains. "Our broader group has actually designed and built small radios that can interface with this glucose sensor and send out information wirelessly."
Sufferers of Type 1 diabetes have to monitor their blood sugar levels several times a day. It's a painful procedure requiring the piercing of the skin with a spring-loaded needle. With what Microsoft cites as an example of a Natural User Interface (NUI), it hopes its "Functional Contact Lens" may one day remove the need for this invasive means of monitoring.
Though the Functional Contact Lens aspires to a more advanced means of reporting than mere common change, the means of detection also differs from previous research. "There are now various groups working on non-invasive measurement of tear glucose," Desney Tan told Gizmag. "Professor Zhang's lab has been largely using nanostructured optical probes embedded in hydrophilic hydrogen lenses, and they've had some successes recently."Instead, Tan explained, this research uses an enzyme-based electrochemical process sensitive to glucose. "As the enzyme interacts with the tear fluid, specific measurements are made by observing the change in current measured by bio-compatible electrodes on the contact lens."
Microsoft hopes to get this technology to market "as soon as everything is ready", and, if successful, it's likely that the first models will report information wirelessly to a local device, which "could be an augmented smart phone," Tan suggests.
This will be achieved with tiny, flexible electronics embedded into the lens itself incorporating control circuits, communication circuits, the glucose sensors themselves, and the antenna. "This required a whole new engineering process, since traditional integrated circuit processes would not work," Tan explained.
It's hoped that subsequent models will enhance the NUI-ness of the user experience by removing the need for a secondary device, and instead displaying information directly in the contact lens. Tan told us that current challenges to overcome involve the efficiency of the wireless communications, "bio-compatibility", the practicality of the design with respect to potential mass production, as well as issues with the glucose sensor itself.
Bio-compatibility is clearly an issue when a (admittedly low-powered) electronic device comes into direct contact with the human eye - both in terms of safety and comfort. As such, the Functional Contact Lens is not yet read for what Tan calls "in-situation trials". Tan is a passionate evangelist for the potential of NUI and augmented reality. The team at Microsoft Research and the University of Washington "has only begun to scratch the surface of the opportunities that exist with this type of platform," he enthuses. "The most important challenge is really in the deep exploration of all the things not yet imagined with this platform, and new platforms enabled by this new-found capability to create other technology of this form."