Determination of mask fitting pressure and correct mask fit

Abstract

A CPAP treatment apparatus, as one form of positive pressure ventilatory assistance, includes a turbine/blower, operated by a mechanically coupled electrical motor that receives air or breathable gas at an inlet thereof, and supplies the breathable gas at a delivery pressure to a delivery tube/hose having a connection at the other end thereof with a nose mask. A microcontroller has an operational “Mask-Fit” mode. An initial constant pressure level is applied by the blower to the mask. If the functional mode is a manual mode, then the mask-fit test pressure is the current ‘set’ pressure. If the functional mode is the automatic titration mode, the mask-fit test pressure is the 95th percentile pressure of the previous session, otherwise it is the base treatment pressure, e.g. 10-12 cm H2O. This constant pressure is applied for a period of time, typically 1-3 minutes. The microcontroller continuously determines mask leak as the value, fLEAK, from a flow sensor, comparing this to a threshold, and providing the patent with a visual indication of degree of leak. In this way the patient can manipulate the mask to ensure correct fitting as indicated by the appropriate message or indication.

Dependencies are inferred from the claim text.