Feasibility of neonatal lung imaging using electrical impedance tomography

Area of Science:

• Biomedical Engineering
• Neonatal Physiology
• Medical Imaging

Background:

• Preterm infants often experience respiratory complications.
• Non-invasive monitoring of neonatal respiratory function is crucial.
• Electrical Impedance Tomography (EIT) offers a promising, radiation-free imaging modality.

Purpose of the Study:

• To investigate the feasibility of using EIT for detecting lung function in preterm infants.
• To assess the ability of EIT to visualize dynamic lung changes during respiration.
• To evaluate EIT's capability in identifying breathing patterns and rates in neonates.

Main Methods:

• A custom-built, single-frequency EIT instrument with 16 electrodes was utilized.
• AC current (1.5 mA peak-peak at 20 kHz) was applied, and peripheral voltages were measured.
• Images were reconstructed using a sensitivity-regions backprojection algorithm.
• Data were collected at 10 frames/s from a 9-day-old preterm infant.

Main Results:

• Dynamic EIT images visualizing lung inflation and deflation were successfully generated.
• Initial impedance measurements indicated irregular breathing patterns.
• Region of interest analysis and Fourier transforms detected a fundamental breathing frequency of 1 Hz (60 breaths/min).
• Harmonics in the signal introduced distortions, particularly on the left lung due to cardiac activity.

Conclusions:

• EIT is a feasible method for detecting lungs and monitoring respiratory dynamics in preterm infants.
• The study demonstrated EIT's potential for non-invasive, real-time assessment of neonatal breathing.
• Further research is needed to refine image reconstruction and mitigate cardiac interference for improved accuracy.