Palm-sized system created at Rice University would simplify diagnosis of disease

BY MIKE WILLIAMS
Rice News staff

A Rice University project led by bioengineers Rebecca Richards-Kortum and Tomasz Tkaczyk has landed a grant from the Grand Challenges in Global Health, an initiative created by the Bill & Melinda Gates Foundation, to create an affordable, palm-sized, programmable system to diagnose disease in the developing world.

Miniature optics in an easily configurable system — as simple as a child’s LEGO blocks and as sophisticated and effective as a hospital lab — are the basis of a revolutionary method for diagnosing a range of diseases that, till now, have required complex and costly laboratory work. The goal is to revolutionize health care in poor-resource settings around the world.

The Readout and Signal Transduction point-of-care diagnostic system under development by Rice bioengineers Rebecca Richards-Kortum and Tomasz Tkaczyk has earned them a grant from Grand Challenges in Global Health, an initiative of the Bill & Melinda Gates Foundation.

The point-of-care technology, called Readout and Signal Transduction (ROST), is being designed by Richards-Kortum, Rice’s Stanley C. Moore Professor of Bioengineering and director of Rice 360˚: Institute for Global Health Technologies, and Tkaczyk, assistant professor of bioengineering at Rice, who specializes in novel, low-cost optical systems. Development is under way at Rice’s BioScience Research Collaborative.

“Our goal is to develop and implement a new modular design approach to build a reusable ROST component that is more sensitive, robust, compact, power-efficient and cheaper than large-scale counterparts and that can easily be customized to interface with a wide variety of point-of-care sample platforms,” Richards-Kortum said. “We hope that this universal fixture will accelerate advances in point-of-care diagnostic tools.”

The design brings together advances in plastic optics, microelectronics, mass fabrication and microfluidics in what she expects will be a reusable platform that costs less than $10. It would consist of a universal fixture that accepts a library of “plug-and-sense” interrogation units — arrays of light sources and lenses — tuned to detect signs of specific diseases.

Those components would incorporate solar-powered LED light sources for transmission, reflectance, light scattering and fluorescence analysis of biological samples. The interrogation units would analyze samples on plastic or paper microfluidic devices or slides and feed images to low-cost CMOS array detectors, not unlike those used in modern digital cameras.

The approach, Richards-Kortum said, leads to a ROST with the sensitivity of large-scale optical readers while reducing the size and cost by more than two orders of magnitude. The only consumable component of the device would be the solar-rechargeable battery, which she expected would last 8-10 hours on a single charge, with an estimated lifespan of 1,000 charge cycles.

“New and improved diagnostics to use at the point-of-care can help health workers around the world save countless lives,” said Chris Wilson, director of Global Health Discovery at the Bill & Melinda Gates Foundation. “Our hope is that these bold ideas lead to affordable, easy-to-use tools that can rapidly diagnose diseases and trigger timelier treatment in resource-poor communities.”