Diseño y construcción de un sistema basado en IoT para supervisión remota de la frecuencia cardíaca y el tono simpático a partir de la señal fotopletismográfica (PPG)

Abstract

Automatic and remote monitoring could contribute to diminish treatment costs and to improve attention quality. In this context, the Internet of Things (IoT) emerges as a suitable candidate for developing solutions enabling continuous and remote assessment of patient’s condition and, specifically, his/her heart rate and autonomic balance. These parameters are crucial for patient’s care. However, very few efforts have been focused on developing IoT-based solutions in order to evaluate this indicator. In the present work, an IoT-based system is proposed for remote monitoring of heart rate and sympathetic tone from the photoplethysmographic signal (PPG). Using a combination of Gaussian functions it was possible to simulate variations in blood flow to obtain an artificial PPG signal. To limit the bandwidth consumption of the transmission channel, a pre-processing was applied to the PPG signal, which consisted in extracting the maximum and minimum of the signal, as well as their instant at which they occur. This information was stored and transmitted in 10 second windows. Finally, on the server side, processing was carried out to determine sympathetic activation in 60-second windows. The results show that the TCP protocol maintains a constant and robust transmission rate at different bandwidth capacities, maintaining network reliability. In addition, given the characteristics of the chosen physiological parameters and their adequate preprocessing, computational resources are optimized so that the proposed solution does not require a high data transmission rate, so there would be no limitation regarding the wireless communication standard that could be used to implement it. Nevertheless, a broader range of parameters should be considered to perform a more rigorous performance evaluation, such as larger-scale evaluations.