Simultaneous humidity and temperature fuzzy logic control in neonatal incubators

Preterm infants require an environment with controlled temperature and humidity conditions for their development and survival process. For an adequate regulation, it is necessary that the temperature control be carried out considering the temperature itself and the relative humidity (RH) of the incubator. The classic control strategies (PD, PID) present a limited response for this type of simultaneous regulation. The main objective of this work was to design a fuzzy logic control strategy for an adequate regulation of temperature and active humidity for a neonatal incubator. Ultrasound active humidification was incorporated in a commercial neonatal incubator in which the air control mode was used to implement the fuzzy logic control strategy. For the humidity and temperature control system, 90 fuzzy logic decision rules were established in a Mamdani type system that were implemented in a 32-bit ARM Cortex M4 microcontroller. Various tests were carried out to analyze the performance of the system and compliance with the particular norm of incubators. The Bland-Altman test indicated that the concordance limits show compliance with the norm both for the precision of the temperature indication with deviations less than 0.8 degrees C, and for the values of RH, which were kept below the limit of +/- 10%. It can be concluded that under the experimental conditions of the present work the tests showed that the strategy implemented is robust and with good immunity to noise.