A device for recording and displaying a pressure-volume curve, in which a gas stream is generated by a gas source under control of a control unit and conveyed via a hose to a patient, wherein a flow sensor determines the gas stream and the control unit computes and records the administered gas volume and wherein a pressure sensor determines the gas pressure and the control unit records the pressure and determines a pressure slope and determines a pressure-volume curve from the pressure and the volume and displays it on a display screen or stores it for a display.
