Columbia Engineering researchers have developed a low-cost smartphone accessory that performs a point-of-care test. In fifteen minutes, the device simultaneously detects three infectious disease markers from a finger prick of blood.
The technology performs an enzyme-linked immunosorbent assay (ELISA) without requiring any stored energy: all necessary power is drawn from the smartphone. The accessory performs a triplexed immunoassay not currently available in a single-test format: HIV antibody, treponemal-specific antibody for syphilis, and non-treponemal antibody for active syphilis infection.
Health care workers in Rwanda recently piloted the accessory dongle, testing 96 patients who were enrolling into prevention-of-mother-to-child-transmission clinics or voluntary counseling and testing centers. The Rwandan team was given 30 minutes of training, which included a user-friendly interface to aid the user through each test, step-by-step pictorial directions, built-in timers to alert the user to next steps, and records of test results for later review.
The team developed the dongle to be small and light enough to fit into one hand, and to run assays on disposable plastic cassettes with pre-loaded reagents, where disease-specific zones provided an objective read-out. Researcher Samuel K. Sia estimates the dongle will have a manufacturing cost of $34.
A “one-push vacuum,” replaces an electric pump. The user mechanically activates a negative-pressure chamber to move the sequence of reagents pre-stored on a cassette. An audio jack replaces the battery and transmits data and power. The dongle can be attached to any compatible smart device (including iPhones and Android phones) in a plug-and-play manner.