Composite laminated catheter with flexible segment and method of making same
A medical catheter including a composite laminated shaft having a longitudinal segment that is mechanically deformed to have reduced and varying stiffness. A method of making the catheter is also disclosed.
1. A medical catheter comprising:
a composite elongate catheter shaft comprising:
a flexible polymeric liner;
a flexible polymer jacket adherently surrounding the liner;
a reinforcement layer interposed between the liner and the jacket; and
at least one segment of the composite shaft having internal radial compressive structural deformations characterized by a reduction in longitudinal bending stiffness of the segment such that the longitudinal bending stiffness varies along the length of the segment containing the deformations; and
a fitting mounted at a proximal end of the shaft.
2. The medical catheter of claim 1 wherein the catheter shaft further comprises a wall, the wall, in the at least one shaft segment having deformations being thinner than the wall of a shaft segment without such structural deformations.
3. The medical catheter of claim 1 wherein the catheter shaft further comprises a substantially uniform diameter bore extending therethrough.
4. The medical catheter of claim 1 wherein in the at least one segment having deformations, the reinforcement layer comprises one or more filaments braided about the liner and forming a plurality of interstices, the jacket and the liner being adhered to each other through the interstices.
5. The medical catheter of claim 4 wherein the at least one shaft segment has a braid pitch that is less than a braid pitch of a segment of the shaft that is without such structural deformations.
6. The medical catheter of claim 1 , wherein the internal radial compressive deformations comprise a plurality of regions of delamination.
7. The medical catheter of claim 6 , wherein the regions of delamination are distributed within the wall of the at least one segment having the deformations to provide a substantially consistent reduction in stiffness.
8. The catheter of claim 1 , wherein the stiffness of the at least one segment having the deformations decreases in a distal direction.
9. The catheter of claim 8 , wherein the stiffness of the at least one segment having the deformations decreases continuously in the distal direction.
10. The catheter of claim 1 , wherein the stiffness of the at least one segment containing the deformations varies discontinuously.
11. The catheter of claim 1 , wherein a distal portion of the catheter has a preformed curvilinear shape.