Estimation of the difference between peak airway and tracheal pressures during HFPV

High frequency percussive ventilation (HFPV) is an advanced ventilatory strategy which has proven very effective in patients with acute respiratory failure. The airway pressure measured by HFPV ventilator represents the sum of the endotracheal tube pressure drop and the tracheal pressure dissipated to inflate a lung. The estimation of the difference between the peak airway and tracheal pressure AP_p may be very useful to the clinician to avoid lung injury. The aim of this study is to provide an in vitro estimation of AP_p based only on the ventilator set parameters (i.e. peak pressures, pulsatile frequencies) and the patient´s respiratory system resistance and compliance. The model for the estimation of AP_p was determined by using the Least Absolute Shrinkage and Selection Operator (LASSO) regularized least-squares regression technique. The identified model was successively assessed on test data set.