Abstract: A nasally introduced catheter (nasal catheter) has a portion in which a user's breath (breathing air) air travels internally and a portion in which the breath travels externally. The portion in which air flow travels internally preferably includes a mesh or a whisk-like portion that expands and contracts, and the portion in which air flow travels externally preferably comprises a proximal tubular element having a sufficiently small cross-sectional area that at least 50% of the breathing air flows externally to the proximal portion. A sheath can optionally be positioned about the distal portion, and pulled back along the proximal portion to allow the distal portion to expand. In other aspects users can anchor the proximal and distal portions relative to the sheath using a nose clip or by removably coupling an extension arm to proximal portion.

Abstract: A nasally introduced catheter (nasal catheter) has a portion in which a user's breath (breathing air) air travels internally and a portion in which the breath travels externally. The portion in which air flow travels internally preferably includes a mesh or a whisk-like portion that expands and contracts, and the portion in which air flow travels externally preferably comprises a proximal tubular element having a sufficiently small cross-sectional area that at least 50% of the breathing air flows externally to the proximal portion. A sheath can optionally be positioned about the distal portion, and pulled back along the proximal portion to allow the distal portion to expand.