Reliability of a computational model for evaluating thoracoabdominal mobility in newborns: a cross-sectional study.

The present study aimed to verify the inter and intra-examiner reliability of an interactive custom-made MATLAB® App for bio-photogrammetric analysis of thoracoabdominal mobility in newborns and compare the respiratory rate (RR) results between the automatic MATLAB® App and its manual counterpart. This is a cross-sectional study conducted in 27 healthy newborns of both sexes (gestational age between 37 and 41 weeks and up to 72 h of life) who did not cry during data acquisition. Chest and abdominal areas of the subjects in the supine position were analyzed through 60 s videos, totaling 30,714 photograms. All photograms were analyzed by three examiners on three different occasions. Analysis of variance (ANOVA) and intraclass correlation coefficient (ICC) were applied, adopting a 95% confidence interval and significance level of α = 0.05. Reliability was excellent for intra (ICC 0.81-0.96) and inter-examiner correlations (ICC 0.84-0.99) between the chest and abdominal areas, in both inspiration and expiration, with no differences between them. Evaluation of newborns' thoracoabdominal mobility using the custom-made MATLAB® App for bio-photogrammetric analysis exhibited good to excellent intra- and inter-examiner reliability and an excellent correlation between manual and automatic models for measuring RR. Thus, it proved to be an objective and practical tool for bedside thoracoabdominal mobility assessment in different clinical situations involving neonatal care.

Respiratory synchrony comparison between preterm and full-term neonates using inertial sensors.

INTRODUCTION: Due to inefficient respiratory control, newborns become prone to asynchronous thoracoabdominal (TA) movements. The present study quantitatively estimated the synchrony of TA in preterm and full-term newborns through an inertial and magnetic measurement units (IMMUs) system. METHODS: This cross-sectional study was conducted with 20 newborns divided into Preterm Group (PTG, n = 10) and Full-Term Group (FTG, n = 10). Each neonate had IMMUs placed on the sternum and near the umbilicus, thus the TA motion was estimated through the resultant inclination angles calculated using a sensor fusion filter. The respiratory incursions were also manually counted and video-recorded for two minutes, then used to validate a Matlab custom-written routine for their automatic identification. The respiratory cycles were used to calculate the phase change angle (φ) between the thoracic and abdominal compartments. Association between the manual and automatic methods were verified by Pearson's correlation and root mean squared errors (RMSE), and the comparison between the groups was performed through the Student's t test with α = .05. RESULTS: The values of respiratory incursions measured by both methods showed a high association and low measurement error (r = .96, RMSE = 9.8, p < .001). The FTG presented a higher occurrence of TA synchrony (p = .049) while the PTG group presented a higher occurrence of TA asynchrony (p = .036). No difference was found between the groups regarding the paradoxical classification (p = .071). CONCLUSION: The proposed method was valid to quantitatively assess the TA synchrony of hospitalized neonates. Preterm infants had a higher occurrence of the asynchronous respiratory pattern in comparison to full-term infants.