A wrinkle-managed filter support system on mouthpieces that shrink when cooled down in the production process

A mouthpiece for preventing other mouthpieces from producing different measurement results that can be counted as measurement errors by ensuring that plural filters, which protect against contamination during a passage of air flow by sensors in pulmonary function tests, to show common wrinkle characteristics, the mouthpiece comprising:

• a body formed from plastic raw material that is pressed in a female-male mold after the plastic raw material is brought to a melting temperature,
• two filters for allowing a measurement of a speed of a air passing through an airway in the body based on a speed of sound waves moving in a space between the two filters,
• plural wrinkle regions formed on a surface of the two filters since shrinkage in the two filters is different from shrinkage in the body as a width (Xaperture) and length (Yaperture) at a moment t1 reach new width (X′aperture) and new length (Y′aperture) values at a moment t2 after a cooling time of Δt;
• plural support lines, each support line having a biangular zigzag structure that pushes and pulls at least one of the two filters based on the biangular zigzag structure so that the plural support lines are arranged to form a wrinkle that remains in a filter plane on the at least one filter while the aperture is shrinking, and each support line contacts two long edges of the at least one filter and a support line length (Xsupport-zigzag), is between 1.2 and 1.7 times a length of a width (Xfilter) between the two long edges.

A mouthpiece for preventing other mouthpieces from producing different measurement results that can be counted as measurement errors by ensuring that plural filters, which protect against contamination during a passage of air flow by sensors in pulmonary function tests, to show common wrinkle characteristics, the mouthpiece comprising:

• a body formed of plastic raw material that is pressed in a female-male mold after the plastic raw material is brought to a melting temperature,
• two filters for allowing measurement of a speed of air passing through an airway in the body based on a speed of sound waves moving in a space between the two filters,
• plural wrinkle regions formed on a surface of at least one the two filters, wherein shrinkage of the two filters is different from shrinkage of the body as a width (Xaperture) and a length (Yaperture) at a moment t1 reach new width (X′aperture) and new length (Y′aperture) values at a moment t2 after the cooling time of Δt;
• plural support lines having a spring that pushes and pulls at least one of the two filters based on an angular structure of the spring so that the plural support lines are arranged to form a wrinkle that remains in a filter plane on the at least one filter while an aperture is shrinking, the plural support lines contact two long edges of the at least one filter and a support line length (Xsupport-spring), is between 1.2 and 1.7 times a length of a width (Xfilter) between the two long edges.