Study on novel internal and external electrode configuration and optimization methods for lung impedance imaging in intubated patients

Abstract

This study introduces a novel electrode configuration and optimization method for monitoring pulmonary ventilation in intubated patients using electrical impedance tomography (EIT). By positioning electrodes within the esophagus or trachea through existing intubation, the effectiveness of lung ventilation imaging is significantly enhanced. Furthermore, the optimization of external electrode arrays for lung impedance imaging with internal electrodes is investigated. Electrode placement was optimized as a variable based on the principles of focused imaging, constructing numerical sensitivity field matrices for the lung region and overall sensitivity field condition numbers as optimization objectives. A fast elitist multi-objective genetic algorithm (NSGA-III) was employed to optimize the distribution of peripheral electrode arrays. Experimental results from thoracic physical models demonstrated that, with the same total number of electrodes, the introduction of internal electrodes combined with the optimization of external arrays reduced the average relative error (RE) of image reconstruction by 66.31 %, increased the reconstruction correlation coefficient (CC) by 50.72 %, and enhanced the Structural Similarity Index Measure (SSIM) of reconstruction by 85.96 %. This research presents a non-invasive method for introducing internal electrodes, significantly improving the capability to acquire information from the central thoracic region and the accuracy of pulmonary ventilation imaging in intubated patients. Additionally, the study advances the optimization process for impedance electrode arrays.