High frequency percussive ventilation (HFPV) is an advancedventilatory strategy which has proven very effectivein patients with acute respiratory failure. The airwaypressure measured by HFPV ventilator represents the sumof the endotracheal tube pressure drop and the trachealpressure dissipated to inflate a lung. The estimation of thedifference between the peak airway and tracheal pressureΔPp may be very useful to the clinician to avoid lung injury.The aim of this study is to provide an in vitro estimationof ΔPp based only on the ventilator set parameters(i.e. peak pressures, pulsatile frequencies) and the patient’srespiratory system resistance and compliance. Themodel for the estimation of ΔPp was determined by usingthe Least Absolute Shrinkage and Selection Operator(LASSO) regularized least-squares regression technique.The identified model was successively assessed on testdata set.