The design and evaluation of a mobile system for rapid diagnostic test interpretation by Park, C, Ngo, H, Lavitt, LR, Karuri, V, Bhatt, S, Lubell-Doughtie, P, Shankar, AH, Ndwiga, L, Osoti, V, Wambua, JK, Bejon, P, Ochola-Oyier, LI, Chilver, M, Stocks, N, Lyon, V, Lutz, BR, Thompson, M, Mariakakis, A, Patel, S