During the COVID-19 pandemic, patients who required face-to-face attention and tested positive, even showing signs of high risk, were forced to isolate themselves in their own homes immediately without adequate medical monitoring. Continuous remote monitoring of their vital signs would have helped to avoid subsequent hospitalization caused by the progression of the virus. Using deterministic design methods, a system to measure respiratory rate through impedance pneumography was proposed, amplifying microvolt signals to read and process data with a microcontroller. An embedded algorithm was designed to measure inspiration and expiration time. The values captured were sent via WiFi to a server, for posterior evaluation by the clinician. The key findings of this study are as follows (1) a respiratory-rate remote monitoring system was developed, displaying values calculated from impedance pneumography signals, (2) the correlation of the respiratory rate values from a patient during exercising and resting time, measured by a physician and by the device, was 0.96. (3) when analyzing separately the data obtained by the resting test and the exercise test, the performance of the device presented an average error percentage of -5.36% and +1.97%, respectively. As a conclusion, this device has practical applications for acute and chronic respiratory diseases, where respiratory rate is an indicator of the progression of these conditions.