Methods for assessing regional lung characteristics, and related systems

A system for assessing regional lung compliance in a mechanically ventilated patient, the system comprising:

• an electrical impedance tomography acquisition system configured to acquire electrical impedance tomography data representative of a plurality of lung regions while a pressure-volume maneuver is performed on the mechanically ventilated patient;
• one or more sensors or interfaces configured to obtain pressure values from the pressure-volume maneuver;
• and
• a processor configured to:
• associate the pressure values with corresponding regional electrical impedance tomography data to obtain a respective pressure-impedance curve;
• determine regional compliance at more than two different pressures;
• determine a pressure PmaxC at which the regional compliance is greatest;
• determine occurrence of at least one of overdistension at pressures above PmaxC and collapse at pressures below PmaxC;
• calculate cumulative overdistension and cumulative collapse based on the occurrence of overdistension and collapse at the plurality of lung regions at each of the more than two different pressures;
• and
• output a pressure Pmed at which curves representing the cumulative overdistension and the cumulative collapse over the more than two different pressures intersect.