Cell phone imaging system makes light work of diagnostic tests

Researchers at University of California, Los Angeles (UCLA; Los Angeles, CA, USA) have developed a rapid diagnostic test (RDT) system that works in tandem with standard cell phones.

In poor and remote areas of the globe, rapid diagnostic tests (RDTs) are helping to make disease screening quicker and simpler. RDTs are generally small strips on which blood or fluid samples are placed. Specific changes in the color of the strip, which usually occur within minutes, indicate the presence of infection. Different tests can be used to detect various diseases, including HIV, malaria, tuberculosis and syphilis.

But conventional RDTs are currently read manually by eye which is prone to error, especially if different types of tests are being used by a health care worker.

To address such challenges, Aydogan Ozcan, a UCLA professor of electrical engineering and bioengineering, and his colleagues from the UCLA Henry Samueli School of Engineering and Applied Science and the California NanoSystems Institute at UCLA developed the new cell-phone based system.

Their RDT-reader attachment, which clips onto a cell phone, weighs approximately 65 grams and includes an inexpensive lens, three LED arrays and two AAA batteries. An RDT strip is inserted into the attachment, after which an image of the strip is taken by the cell phone camera.

Software then rapidly reads the digitized RDT image to determine, first, whether the test is valid and, second, whether the results are positive or negative, thus eliminating the potential errors that can occur with a human reader.

Because the color changes in RDTs do not last more than a few hours in the field, the ability to store the digitized image indefinitely provides an added benefit.

After this step, the RDT-reader platform wirelessly transmits the results of the tests to a global server, which processes them, stores them and, using Google Maps, creates maps charting the spread of various diseases and conditions -- both geographically and over time -- throughout the world.

Together, the RDT reader and the mapping feature, which have been implemented on both iPhones and Android-based smart-phones, could significantly increase researchers’ ability to track emerging epidemics worldwide.

-- by Dave Wilson, Senior Editor, Vision Systems Design