High flexibility, kink resistant catheter shaft
An enhanced flexibility catheter shaft having an elongate flexible body with a proximal end, a distal end, and at least one lumen extending therethrough. A distal, flexible section on the body has a ribbed or corrugated tubular membrane having at least a first reinforcement structure, such as a first helical support, on a radially exterior or interior surface of the tubular membrane and optionally a second reinforcement structure, such as a second helical support, on the other of the radially interior or exterior surface of the tubular membrane.
1. A catheter comprising:
a tubular body defining a central lumen and having a proximal portion and a distal portion, and wherein the tubular body comprises:
an inner tubular layer surrounding the central lumen;
an outer tubular layer forming a plurality of helical ribs having peaks and valleys;
a helical support, carried concentrically over the inner tubular layer and being within the outer tubular layer and having adjacent loops spaced axially apart; and
wherein:
the outer tubular layer forms a tubular sheet of constant thickness extending over the helical support,
the distal portion is more flexible than the proximal portion,
the inner tubular layer and the outer tubular layer are bonded together at least in spaces between the adjacent loops of the helical support to form a helical channel, and
the helical support is (1) within the helical channel, and (2) unbonded from the helical channel.
2. The catheter as in claim 1 , wherein at least one of the inner tubular layer or the outer tubular layer comprises ePTFE, and wherein the ePTFE has a wall thickness of no more than about 0.004 inches.
3. The catheter as in claim 1 , wherein at least one of the inner tubular layer or the outer tubular layer comprises ePTFE, and wherein the ePTFE has a wall thickness of no more than about 0.004 inches.
4. The catheter as in claim 1 , wherein the helical support comprises a Nitinol wire, and wherein the Nitinol wire has a cross section in a radial direction of no more than about 0.006 inches.
5. The catheter as in claim 1 , wherein the inner tubular layer comprises two distinct sections, the two distinct sections comprising a proximal section and a distal section, and wherein the proximal section and the distal section of the inner tubular layer comprise different materials.
6. The catheter as in claim 1 , wherein the plurality of helical ribs are configured to provide controlled hinging.
7. The catheter as in claim 1 , wherein an outer surface of the tubular body transitions to a tubing without the plurality of helical ribs at the proximal portion.
8. The catheter as in claim 1 , wherein at least the inner tubular layer of a distal end of the catheter has a smooth inner surface.
9. The catheter as in claim 1 , wherein the distal portion has a length of at least about 0.4 inches.
10. The catheter as in claim 1 , further comprising an intermediate portion having less flexibility than the distal portion and greater flexibility than the proximal portion.
11. The catheter as in claim 1 , wherein the inner tubular layer comprises ePTFE.
12. The catheter as in claim 11 , wherein the outer tubular layer comprises at least one of Pellethane, Tecoflex, TecoThane, or Carbothane.
13. The catheter as in claim 12 , wherein the outer tubular layer comprises polyether block amide at the proximal portion of the tubular body.
14. The catheter as in claim 1 , wherein the helical channel extends only through the distal portion of the tubular body.
15. The catheter as in claim 1 , wherein the helical support is unbonded within the helical channel, and is configured to move within the helical channel relative to the inner tubular layer and the outer tubular layer.
16. The catheter as in claim 1 , wherein the tubular sheet of constant thickness surrounds only outer and side surfaces of the helical support, but not an inner surface of the helical support.
17. A catheter comprising:
a tubular body defining a central lumen and having a proximal portion and a distal portion, the tubular body having a resting configuration in which the tubular body is parallel to a longitudinal axis of the tubular body and a deflected configuration in which a portion of the tubular body is deflected at an angle relative to the longitudinal axis, and wherein the tubular body comprises:
an inner tubular layer surrounding the central lumen, wherein the inner tubular layer includes a proximal section and a distal section, and wherein a material of the proximal section is different than a material of the distal section;
an outer tubular layer forming a tubular sheet of constant thickness positioned to form peaks and valleys; and
a helical support, carried concentrically over the inner tubular layer and having adjacent loops spaced axially apart between each valley of the valleys of the outer tubular layer when the tubular body is in the resting configuration, and
wherein the distal portion of the tubular body is more flexible than the proximal portion of the tubular body.
18. The catheter as in claim 17 , wherein the inner tubular layer and the outer tubular layer are bonded together at least in spaces between the adjacent loops of the helical support.
19. The catheter as in claim 17 , wherein at least one of the inner tubular layer or the outer tubular layer comprises ePTFE, and wherein the ePTFE has a wall thickness of no more than about 0.004 inches.
20. The catheter as in claim 17 , wherein the helical support comprises a Nitinol wire, and wherein the Nitinol wire has a cross section in a radial direction of no more than about 0.006 inches.
21. The catheter as in claim 17 , wherein the helical support is not attached to the inner tubular layer and the outer tubular layer, and is configured to move relative to the inner tubular layer and the outer tubular layer.
22. A catheter comprising:
a tubular body defining a central lumen and having a proximal portion, an intermediate portion, and a distal portion, and wherein the tubular body comprises:
an inner tubular layer surrounding the central lumen;
an outer tubular layer, wherein the outer tubular layer is a continuous layer extending from the proximal portion of the tubular body to the distal portion of the tubular body;
a helical lumen formed between the outer tubular layer and the inner tubular layer; and
a helical support, carried concentrically over the inner tubular layer, being within the helical lumen, and having adjacent loops spaced axially apart, wherein the helical support is configured to move within the helical lumen relative to the outer tubular layer and the inner tubular layer, wherein the distal portion is more flexible than the intermediate portion, outer tubular layer at the distal portion forms a tubular sheet of constant thickness over the helical support, and
wherein the intermediate portion is more flexible than the proximal portion.
23. The catheter as in claim 22 , wherein the outer tubular layer forms a plurality of helical ribs at the distal portion of the tubular body.
24. The catheter as in claim 22 , wherein the inner tubular layer includes ePTFE having a wall thickness of no more than about 0.004 inches.