A portable urine analyzer based on colorimetric detection

Abstract

Urine examination is a basic program in routine check-ups that can reveal multiple parameters about our health and thus has significant meaning. However, instruments for urine analysis in hospitals are usually bulky and expensive. In this study, we have constructed a pocket-sized and CMOS imaging-based analytical device for urine diagnosis at home or on the spot. The shape of traditional dipsticks was transformed into matrix arrays and pasted on a reaction unit for colorimetric arrays. Chromaticity values were used to establish the functional relationship between the red-green-blue intensities of images and the concentrations of different indices. The size of the entire system was reduced to 30 × 30 × 45 mm, and once charged this device can continuously work for >4 h accommodating more than 1000 tests. To validate the performance of our device, more than 200 real human urine samples were tested and the results generated by our portable device and a commercial instrument show a great consistency (the consistency for most results is >90%) between the two systems.