Local mechanics of the lung tissue determined by functional EIT

Area of Science:

• Medical Imaging
• Pulmonary Physiology
• Biomedical Engineering

Background:

• Electrical impedance tomography (EIT) offers non-invasive monitoring of lung function.
• Assessing local dynamic behavior within the lungs is crucial for understanding pulmonary physiology and pathology.
• Existing EIT techniques may lack detailed regional dynamic information.

Purpose of the Study:

• To introduce a novel functional EIT (f-EIT) evaluation technique for assessing local dynamic lung behavior.
• To develop a method for imaging regional phase shifts in the thorax related to impedance changes.
• To validate the f-EIT phase imaging technique in spontaneously breathing humans.

Main Methods:

• Extracting local time courses of impedance change from thoracic EIT images.
• Calculating time shifts (phase information) between local and average thoracic impedance signals.
• Generating f-EIT phase images to characterize local dynamic properties.
• Combining f-EIT phase images with f-EIT ventilation images for anatomical correlation.

Main Results:

• The f-EIT phase imaging procedure successfully identified lung regions with differing dynamics.
• Changes in body posture induced detectable alterations in pulmonary dynamics visualized by f-EIT.
• The technique demonstrated the ability to map local phase angles across the thoracic cross-section.

Conclusions:

• The developed f-EIT phase imaging technique provides valuable information on local lung dynamics.
• This method can differentiate regional variations in pulmonary function.
• f-EIT phase imaging holds promise for distinguishing pathological alterations in lung dynamics.