Abstract: A medical breathing assistance apparatus (20) for supplying pressurised gases to a patient is disclosed. The breathing assistance apparatus (20) comprises a heating chamber (29) and a pressure chamber (27) both adapted to contain water, and at least one pressure adjusting means (24,25,26). The pressure chamber (27) is connected to the heating chamber (29) and the pressure adjusting means (24,25,26) is located between the heating chamber (29) and a gases supplying means (23) supplying gas to both the pressure chamber (27) and heating chamber (29). The pressure adjusting means (24,25,26) is adapted to convert pressurised gases from the gases supply means (23) to two different pressures, one to each of the heating chamber (29) and the pressure chamber (27), so that water flows from said pressure chamber (27) to the heating chamber (29).

Abstract: The present invention provides improvements in the feedback and control systems employed in the field of ventilation therapy. In particular, a system for delivering a supply of gases to a patient is described which incorporates a detachable cartridge or open tubular section (22) used to house a mechanism (11) which senses the humidity, temperature, flow and other attributes of the flowing gas. Information obtained from the sensor may be used to provide feedback to a controller (9) which controls the humidification mechanism in order to provide optimally humidified gases to a patient (1). It will be appreciated that the feedback and control system as described in the preferred embodiment of the present invention can be used in respiratory care generally or with a ventilator.