Patent attributes
Patient interfaces for respiratory therapy in the form of nasal interfaces or nasal masks include features that enhance or provide lateral stability of the interface. At least some of the embodiments provide multiple facial contact points or areas located in the general areas of the user's cheeks and/or upper lip. Some embodiments of the nasal interfaces provide advantageous sealing characteristics. The nasal interfaces may provide a controlled expiratory flow to reduce noise. Some embodiments include nasal pillows instead of or in addition to nasal prongs. The nasal pillows can have exhaust vents or can change in length in response to a pressure level within the nasal pillow.