Context: Globally, more than 15 million preterm infants are born annually. Oral feeding is a major requirement for discharge from the neonatal intensive care unit. 80% of all preterm infants will struggle to achieve safe and efficient oral feeding, consequently delaying discharge or causing readmission. Inappropriate discharge timing increases risk for neonatal morbidity, infections, chronic complications as well as psychological distress on parents and immense financial burden. Current methods of determining oral feeding readiness are subjective, inconsistent, and ultimately lacks an objective assessment.
Method: This dissertation describes the design, fabrication and characterization of the frontend hardware and software of a portable medical device that will measure transthoracic impedance (TI), pre-process data, ascertain the respiratory waveform variation (RWV) by computing the sample entropy (SE), and output the result as the key contributor to the health score correlating oral feeding readiness and eventually to days till discharge. Two generations of the device, Pedi-Sync, was designed with off-the-shelf components and built to be a plug-in module compatible with existing cardiopulmonary monitors and/or to serve as a standalone device. Additionally, it will also measure blood oxygen saturation (SpO2) as a supplemental data to strengthen the health score correlation with oral feeding readiness and days till discharge. Verification and validation testing of the system was conducted in simulated neonatal data, healthy adults, and preterm infants.
Summary: The device demonstrates technical feasibility to collect and analyze preterm infant TI as a robust oral feeding adaptability score. Moreso, preliminary use of the analysis showed that preterm infants will exhibit a decrease in SE (or less variability) during oral feeding compared to baseline. Further, SpO2 histogram recorded throughout total length of stay may be a supplemental contributor to the health score.
