Development of a portable prototype: pH meter for prolonged esophageal pH monitoring with low cost materials

Objective: to develop a prototype portable register for extended esophageal pHmetry examination with low cost materials. Materials and Methods: Preclinical research, pilot test with preliminal data to evaluate the effectiveness and accuracy of the prototype. From the product assembly and the software used for data reading and measurement. In this software are written the codes for reading the pH values and preparation of the Arduino plate for data transmission. The indicator for pH reading calculates the average value every 10 measurements and the result obtained is displayed as long as this process is necessary. In this same code, the display buttons are configured as well as the calibration mode for each buffer solution. After mounting and proper calibration of the Arduíno and Commercial instruments, both containing two channels were tested in 10 substances in cycles. First, the channels were immersed in a solution containing beer and the pH was read in the times 0 s, 30 s, 90 s, 120 s, 150 s and 180 s in both arduous and commercial for comparative purposes. At the end of the reading, the channels were immersed in water for 3 min for cleaning and then tested in a new solution. The same cycle was repeated for the other solutions, which are: orange juice, energy, mineral water, isotonic, vinegar, coca-cola, guava juice, grape juice and guarana. Results: The differences statistically: 180s of the energetic (p = 0.0178*); 60s Mineral Water time (p = 0.0178*); 150s and 180s of the Isotonic (p = 0.0371* and p = 0.0330* respectively); 0s Coca-Cola time (p = 0.0246*); and 150s Grape juice time (p = 0.0230*); 0s orange juice time (p = 0.0371*); 0s energy time (p = 0.0330*); 0s and 30s vinegar time (p = 0.0075* and p = 0.0216* respectively). Conclusion: The analysis, as to its performance regarding the precision in the recording of pH values (aqueous solutions) are satisfactory for presenting results very close to the measurements indicated by the commercial recorder, in simultaneous measurements during the testing phase.