The present invention pertains to a portable apparatus for quantitatively measuring the concentration of specific substances in test samples of a lateral flow or microplate 
assay in medical, biomedical and chemical applications, and for making subsequent analysis and diagnosis. The portable apparatus includes a sample tray for carrying and aligning the 
test sample in the apparatus; a 
enclosure that may also serves as the frame of the apparatus; a 
digital image acquisition 
system that is used to obtain the 
digital image of the 
test sample on the sample tray; and a 
data display, 
processing, and analysis unit that is a 
general purpose or dedicated computer, such as a handheld computer (HHC), a pocket 
personal computer (PPC), a personal digital assistant (PDA), a palm-top computer, a 
laptop computer, or a dedicated 
microprocessor and associated hardware, for measuring the concentration of specific substances in the 
test sample, and making subsequent analysis and diagnosis, based on the measurement, statistical data, prior knowledge and 
mathematical model. The stated 
enclosure and frame, the 
digital image acquisition 
system, and the 
data display, 
processing and analysis unit are integrated to form the portable apparatus for various applications. The integrated apparatus of this invention, with a possible name—Portable Intelligent Multi-Diagnoser (PIMD), thus forms a portable and multiple-purpose tool for measuring the concentration of specific substances in test samples, and making subsequent analysis and diagnosis in a variety of settings, such as a mobile site, 
point of care or near 
patient care, and small laboratories.