Cell phone imaging could improve health monitoring

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A cell phone prototype has been developed that can monitor the condition of HIV and malaria patients, as well as test water quality in undeveloped areas or disaster sites, according to researchers at the University of California Los Angeles (UCLA).

Electrical engineering professor Aydogan Ozcan, a member of the California NanoSystems Institute at UCLA, developed the imaging platform, which was miniaturized by researchers in his lab to the point that it can fit in standard cell phones.

The platform, known as LUCAS (Lensless Ultra-wide-field Cell monitoring Array platform based on Shadow imaging), has now been installed in both a cell phone and a webcam. Both devices acquire an image in the same way, using a short wavelength blue light to illuminate a blood, saliva or other fluid sample. LUCAS captures an image of the microparticles in the solution using a sensor array, according to Ozcan.

Because red blood cells and other microparticles have a distinct diffraction pattern, or shadow image, they can be identified and counted virtually instantaneously by LUCAS using a custom-developed "decision algorithm" that compares the captured shadow images to a library of training images. Data collected by LUCAS can then be sent to a hospital for analysis and diagnosis using the cell phone, or transferred via USB to a computer for transmission to a hospital.

LUCAS is a complement to microscopes, since images produced by LUCAS are grainy and pixelated. The LUCAS platform can “nearly instantaneously identify and count microparticles, something that is time consuming and difficult to do with a microscope in resource-limited settings. Also, because LUCAS does not use a lens, the only constraint on size is the size of the chip it is built on,” according to researchers.

"This technology will not only have great impact in healthcare applications, it also has the potential to replace cytometers in research labs at a fraction of the cost," said Ozcan. "A conventional flow-cytometer identifies cells serially, one at a time, whereas tabletop versions of LUCAS can identify thousands of cells in a second, all in parallel, with the same accuracy."

Ozcan described an improvement in the LUCAS system which he calls holographic LUCAS in research published online Dec. 5 in the journal Lab on a Chip. The improvement allows for identification of smaller particles, such as E. coli. By controlling the spatial properties of the light source, a 2D holographic shadow image of the microparticles can be captured that contains much more information than the classic shadow image.

Ozcan said the next step is to build from scratch a handheld device incorporating the LUCAS imaging system. Using this device, people in remote areas of the world would be able to monitor the spread of disease, allowing doctors to focus limited resources in the areas of greatest need.