Estimation of Alveolar Recruitment Potential Using Electrical Impedance Tomography Based on an Exponential Model of the Pressure-Volume Curve

Alveolar recruitment maneuver is usually applied as part of the treatment of acute respiratory distress syndrome, consisting of a transitory and controlled increase in mechanical ventilator pressure delivered to the patient in order to promote opening of collapsed alveoli. Knowing alveolar recruitment potential may help prevent overdistention during alveolar recruitment maneuver. In this work, a method to estimate alveolar recruitment potential based on an exponential model of pulmonary pressure-volume curves using electrical impedance tomography is presented in order to determine if this model is adequate to describe both healthy and injured lungs. Least mean square adjustment is used to estimate total lung capacity based on an exponential model of pulmonary pressure-volume curves. Experimental data from swine was used to develop the method. The results show that the use of an exponential model for pulmonary pressure-volume curve is adequate to describe healthy lungs and may provide information regarding proximity of the overdistention region, but it is not adequate to describe injured lungs appropriately.