| 摘要 |
The invention is a cannula of changeable length and shape, which can be used in medical practice and other activities, which require the penetration of different devices into a medium, vulnerable to mechanical intervention and/or is without well-shaped confining walls. It is created by turning the end section of a flexible tube in such a way that the external part turns out to be concentrically located around the initial interior tube. The external part acquires the properties of a solid cannula. Hardening immediately after the point of transition by means of freezing the liquid contained in it or by means of vacuuming hollow channels filled with small particles, or by means of swelling the toroids contained in it, or by means of unfolding rings of solid elements, or by means of meshing profile elements included in its walls. |
