The key performance feature for a CPAP system is how well it functions to meet patient demand. The additional patient effort to breathe through the circuit/ventilator system is known as imposed work of breathing (WOB). The higher the WOB, the more difficult it is for the patient to breathe spontaneously.

Traditional transport ventilators have very high WOB limiting spontaneous breathing. Their designs use high resistance demand valves or simple continuous flow systems which require more patient effort. In addition, these ventilators do not provide a choice between 65% and 100% oxygen for the spontaneous breaths.

pNeutons WOB is comparable to many of todays large, expensive critical care ventilators. In laboratory testing, we have found the pNeutons WOB to be essentially the same as the Puritan Bennett 7200ae ventilator. Using a lung model test system described by others we measured WOB at a tidal volume of 500 ml, 50 L/min inspiratory flow, CPAP 10 cm H₂O. The measured WOB for pNeuton was 0.45 J, less than the 7200 which was 0.50 J. The graphs below show the pressure / volume loops for these breaths