| 摘要 |
<p>A flexible inner tube 2 comprises a plastic tubular member having a plurality of part-circumferential slots 21A, 21B. The slots, which are preferably lozenge shaped, form two parallel rows along the length of the tube to impart a transverse flexibility in the tube whilst maintaining its axial rigidity. The openings of the slots are covered by an inner sheath 30 that does not impede their function. Alternatively the slots may be closed by an outer sheath or by filling with a softer more resilient material than the tube. A coupling means 31-36 between the tube and sheath is also provided. The inner cannula may be used in tracheostomy or catheter assemblies and may be straight or naturally curved.</p> |
