Mask and vent assembly therefor

A method for attaching a removable, washout vent insert to a CPAP mask, the CPAP mask comprised of a rigid plastics shell having an inlet tube, the rigid plastics shell having an opening bounded by a rim, the vent insert being made of a material more flexible than the rigid plastic shell, the vent insert having a plurality of orifices, the vent insert, in a cross-sectional view, having a recess located at its periphery, the method comprising:

• squeezing the vent insert along its longitudinal axis;
• aligning the vent insert so it is oriented to match the shape of the opening;
• inserting the vent insert into the opening;
• releasing the vent insert once it is within the opening, the vent insert resiliently expanding to engage the rim of the opening.

A method for attaching a washout vent insert to a CPAP mask, the CPAP mask comprised of a rigid plastics shell having an inlet tube, the CPAP mask having an opening bounded by a rim, the vent insert comprising a material more flexible than the rigid plastic shell, the vent insert having a plurality of orifices, the vent insert having a recess located at its periphery, the method comprising:

• squeezing the vent insert;
• aligning the vent insert so it is oriented to match the shape of the opening;
• inserting at least a portion of the vent insert into the opening;
• releasing the vent insert once it is within the opening, the vent insert resiliently expanding to engage the rim of the opening.

A method for attaching a washout vent insert to a CPAP mask, the CPAP mask comprised of a shell having an inlet tube, the shell having an opening bounded by a rim, the vent insert constructed and arranged to be flexible, the vent insert having a plurality of orifices, the vent insert, in a cross-sectional view, having a recess located at its periphery, the method comprising:

• squeezing the vent insert;
• aligning the vent insert so it is oriented to match the shape of the opening;
• inserting at least a portion of the vent insert into the opening;
• releasing the vent insert once it is within the opening, the vent insert resiliently expanding to engage the rim of the opening.