The availability of a textile 32-electrode belt for neonatal EIT imaging with simple, fast, accurate and reproducible placement on the chest strengthens the potential of EIT to be used for regional lung monitoring in critically ill neonates and infants.

Based on the gold standard, the most crucial parameters of the proposed algorithms are optimised by using a simple exhaustive search and a weighted metric defined in connection with the receiver operating characterics. This provides a practical way to achieve any desirable trade-off between the sensitivity and the specificity of the detectors.

Electrical impedance tomography (EIT) allows non-invasive and radiation-free monitoring of regional ventilation distribution and changes in end-expiratory lung volume in critically ill patients of all ages. In the vulnerable neonatal and pediatric population, EIT can be used to identify adverse events like atelectasis, pneumothorax and endotracheal tube malposition and potentially guide the personalized selection of ventilator settings. Previous studies have examined EIT in small patient groups during short measurement periods of only a few hours or less under highly controlled circumstances. What This Study Adds to the Field:In the Continuous Regional Analysis Device for Neonate Lungs (CRADL) project, we performed the first multi-center observational study on the use of EIT in critically ill neonates and young children with or at risk for respiratory failure. Including 200 patients, we demonstrated that continuous EIT monitoring for up to 72 hours is feasible, safe and can be used for continuous monitoring of ventilation distribution in neonates and infants in a routine clinical setting.

Abstract.Objective: This paper define a method for optimizing the breath delineation algorithms used in Electrical Impedance Tomography (EIT). In lung EIT the identification of the breath phases is central for generating tidal impedance variation images, subsequent data analysis and clinical evaluation. The optimisation of these algorithms is particularly important in neonatal care since the existing breath detectors developed for adults may give insufficient reliability in neonates due to their very irregular breathing pattern. Approach: Our approach is generic in the sense that it relies on the definition of a gold standard and the associated definition of detector sensitivity and specificity, an optimisation criterion and a set of detector parameters to be investigated. The gold standard has been defined by 11 clinicians with previous experience with EIT and the performance of our approach is described and validated using a neonatal EIT dataset acquired within the EU-funded CRADL project. Main results: Three different algorithms are proposed that are improving the breath detector performance by adding conditions on 1) maximum tidal breath rate obtained from zero-crossings of the EIT breathing signal, 2) minimum tidal impedance amplitude and 3) minimum tidal breath rate obtained from Time-Frequency (TF) analysis. Significance: Based on the gold standard, the most crucial parameters of the proposed algorithms are optimised by using a simple exhaustive search and a weighted metric defined in connection with the Receiver Operating Characterics (ROC). This provides a practical way to achieve any desirable trade-off between the sensitivity and the specificity of the detectors.

A parametric model for the changes in the complex valued conductivity of a lung during tidal breathing. Journal of Physics D: Applied Physics, 51 (20) .