Hologram technology enables monitoring of HIV, malaria, E. coli via cell phone

DECEMBER 29, 2008--Researchers at UCLA (Los Angeles, CA) have constructed a prototype cellular phone capable of testing water quality and monitoring the condition of HIV and malaria patients. The unit incorporates holographic imaging technology known as LUCAS (Lensless Ultra-wide-field Cell monitoring Array platform based on Shadow imaging), which is meant to complement microscopy techniques. The advance could greatly empower healthcare in developing countries and disaster sites.

DECEMBER 29, 2008--Researchers at the University of California Los Angeles (UCLA) have constructed a prototype cellular telephone capable of testing water quality and monitoring the condition of HIV and malaria patients. The prototype incorporates innovative imaging technology invented by electrical engineering professor Aydogan Ozcan, which Ozcan's associates have miniaturized. The advance could greatly empower people in underdeveloped areas and disaster sites.

The imaging platform, known as LUCAS (Lensless Ultra-wide-field Cell monitoring Array platform based on Shadow imaging), has 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.

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 not a substitute for a microscope but rather a complement. While microscopes can produce detailed images, images produced by LUCAS are grainy and pixelated. The LUCAS platform's advantage lies in its ability to 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.

"This technology will not only have great impact in health care applications, it also has the potential to replace cytometers in research labs at a fraction of the cost," said Ozcan, a member of UCLA's California NanoSystems Institute. "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."

In research published online in the journal Lab on a Chip, Ozcan described an improvement in the LUCAS system which he calls holographic LUCAS. This improvement allows for identification of smaller particles such as E. coli that were not previously possible. By controlling the spatial properties of the light source, a two-dimensional holographic shadow image of the microparticles can be captured that contains much more information than the classic shadow image.

Now that Ozcan has successfully created prototypes with a cell phone and webcam, his 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.

The system also can be used to monitor water quality by detecting hazardous microparticles. In addition to undeveloped areas, LUCAS would be useful for water testing in the event of a disaster which compromises water quality. After making a presentation on LUCAS in Japan, Ozcan was approached by researchers from the University of Tokyo and Kyushu University interested in earthquake preparedness.

Posted by Barbara G. Goode, barbarag@pennwell.com.

More information:
The paper, Lensfree holographic imaging for on-chip cytometry and diagnostics, in Lab on a Chip
Ozcan's lab

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