Angled Sieve Tracheal Cannula for Secretion Management

The patent transforms the traditional flat, two-dimensional sieve structure into a three-dimensional stepped structure with multiple levels. The sieve openings are arranged in steps that create vertical dimensionality, allowing secretion to be directed away from the tube interior while maintaining effective filtration. This dimensional change enables the sieve to simultaneously achieve complex secretion management functionality and reliable prevention of secretion penetration.

The patent applies local quality by creating non-uniform sieve opening distributions across different regions and levels of the sieve structure. Different areas of the sieve have openings of varying sizes and orientations, with larger openings in certain regions to facilitate secretion drainage while smaller or differently oriented openings in other regions prevent secretion penetration. This localized variation in opening characteristics allows simultaneous optimization of both drainage efficiency and prevention effectiveness.

The patent implements self-service functionality through the stepped sieve structure that automatically directs secretion away from the tube interior and toward external drainage paths. The geometric configuration of the stepped openings creates inherent secretion flow guidance that eliminates the need for active intervention or frequent manual cleaning. The structure performs secretion management autonomously, maintaining respiratory health while minimizing patient disruption and treatment time.