Softening catheter
First Claim
1. A cannula structure for insertion into a living body, comprising:
- a tubular cannula having distal and proximal end portions, a central passageway therethrough from the distal end portion to the proximal end portion, the proximal end portion having larger inner and outer diameters than does the distal end portion, the cannula having a greater thickness along the proximal end portion than along the distal end portion, the proximal end portion extending to within the living body, and a transition section connecting the distal and proximal end portions whereat the diameter differences are effectuated in a gradual manner, the cannula being constructed of a material that has a softening ratio of greater than 2;
1 on being contacted with an aqueous liquid and/or upon insertion into a living body.
1 Assignment
0 Petitions
Accused Products
Abstract
A tubular cannula has distal and proximal end portions, a central passageway from the distal end portion of the proximal portion and a transition section connecting the distal and proximal end portions. The proximal end portion has larger inner and outer diamters and has thicker walls than does the distal end portion. The diameter difference and thickness are effectuated in a gradual manner in a transition section. The cannula is constructed of a material that softens on being inserted into a living body and/or contacted with an aqueous medium. The cannula combines kink resistance external of the living body with the advantages of a softening and generally swellable catheter.
240 Citations
15 Claims
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1. A cannula structure for insertion into a living body, comprising:
a tubular cannula having distal and proximal end portions, a central passageway therethrough from the distal end portion to the proximal end portion, the proximal end portion having larger inner and outer diameters than does the distal end portion, the cannula having a greater thickness along the proximal end portion than along the distal end portion, the proximal end portion extending to within the living body, and a transition section connecting the distal and proximal end portions whereat the diameter differences are effectuated in a gradual manner, the cannula being constructed of a material that has a softening ratio of greater than 2;
1 on being contacted with an aqueous liquid and/or upon insertion into a living body.- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
Specification