Arduino UNO-Based pH and Viscosity Sensor Prototype for Comparative Analysis of Urine Characteristics in Pregnant and Non-Pregnant Women

Abstract

This study aimed to design and validate a microcontroller-based instrument prototype for comparing urine characteristics between pregnant and non-pregnant women. Using a Research and Development (R&D) approach, the study proceeded through two main stages: validation of the instrument against a laboratory-standard device and implementation on biological samples. The device's main components consist of an Arduino UNO with 10-bit ADC resolution, a pH-4502C sensor with a glass electrode, and a through-beam optical sensor integrated into a 1/2-inch PVC pipe. Accuracy testing showed very high instrument performance, with a mean error of 0.81% (99.18% accuracy) for pH measurement and 0.15% (99.84% accuracy) for viscosity measurement. Comparative analysis of the study subjects showed a physiologically significant difference: the average pregnant woman's urine sample had a pH of 7.05 and a viscosity of 5.33 mPas, while the average non-pregnant woman's urine sample had a pH of 6.19 and a viscosity of 6.86 mPas. These findings show that pregnant women's urine tends to be more alkaline and more dilute, consistent with theories of urinary system changes during gestation.