A Device for Respiratory Monitoring during Nutritive Sucking: Response to Neonatal Breathing Patterns

The quantitative monitoring of breathing, sucking, and swallowing is required to predict newborns’ neurodevelopmental outcomes. In particular, the coordination of breathing timing with respect to sucking cycle is crucial. In this work, we present the characterization of a low-cost flowmeter designed for noninvasive recording of breathing pattern during bottle feeding. The transducer is designed to be integrated on a commercial feeding bottle also instrumented with a system for sucking monitoring. The flowmeter consists of two transistors (hot bodies) supplied at constant current, which are placed in a duct used to convey the inspiratory and expiratory flow coming from the newborn’s nostrils. The transducer design, its static calibration, and its response time are discussed. Moreover, a custom-made active lung simulator was used to perform a feasibility assessment of the proposed flowmeter for respiratory monitoring of neonatal respiratory patterns. The flowmeter has a discrimination threshold  ms. The breathing period estimated by the proposed transducer was compared with the one measured by a high performance flowmeter, used as reference: the mean absolute error was <11%. Results highlighted the ability of the device to track respiratory patterns at frequencies typical of neonatal breathing.