Lateral flow diagnostic tests are widely used for applications like pregnancy testing. Several other applications such as infectious disease, immunisation and liver function testing could be feasible if there was a low-cost and reliable method of interpreting results. Smartphones with high-resolution cameras and robust processors could provide just the answer.
Cambridge Consultants undertook a project to demonstrate use of a smart phone for diagnostic testing.
Cambridge Consultants applied its optics and image analysis expertise to define a repeatable diagnostic testing process for capturing images of the test strip or cartridge and analysing them with custom algorithms to detect features and provide results. The intelligent algorithm can compensate for variations in the image due to lighting and contrast. Moreover, the built-in calibration features mean that the algorithms can be made robust enough to cope with manufacturing batch variations in the test strip.
Results can be stored or transmitted wirelessly via the cellular network. The user-focused app includes graphical instructions for use and an intuitive workflow for image capture in order to minimise errors and deliver repeatable results from diagnostic tests.
Using smartphones to read and interpret diagnostic tests can provide a low-cost solution and enables complex tests to be conducted near the user. Multi-assay tests which typically require dedicated, expensive readers in the lab can now be interpreted immediately after sample collection. Moreover, the precise algorithm-based approach removes the subjectivity and errors typically involved in interpreting the ‘line colours’ on lateral flow strips. Eliminating the need for a custom reader opens the door to point-of-care diagnostic testing in the clinic as well as in-the-field solutions for emerging countries and remote areas.