Lined variable braided differential durometer multi-lumen shaft with a cross-shaped inner profile
An imaging catheter is provided. In one embodiment, the imaging catheter includes a flexible elongate member that includes a proximal portion formed of a first material embedded with a first braid with a first braid pitch; a distal portion formed of a second material embedded with a second braid with a second braid pitch, wherein the second material is a lower durometer than the first material and wherein the second braid pitch is a higher per inch count than the first braid pitch such that the distal portion is more flexible than the proximal portion; a primary lumen extending between the proximal portion and the distal portion; and a plurality of secondary lumens extending between the proximal portion and the distal portion; and an imaging component coupled to the distal portion of the flexible elongate member.
1. An imaging catheter, comprising:
a flexible elongate member that includes:
a proximal portion comprising a first material embedded with a first braid with a first per inch count;
a distal portion comprising a second material embedded with a second braid with a second per inch count, wherein a hardness of the first material comprises a first durometer and a hardness of the second material comprises a second durometer, wherein the second durometer is lower than the first durometer and the second per inch count is higher than the first per inch count such that the distal portion is more flexible than the proximal portion;
a transition portion located between the proximal portion and the distal portion, wherein the transition portion comprises:
the first material;
the second material;
a distinct transition between the hardness of the first material and the hardness of the second material such that the first material is located on a proximal side of the distinct transition and the second material is located on a distal side of the distinct transition, wherein the distinct transition is spaced from a proximal end of the transition portion and a distal end of the transition portion; and
a third braid embedded within the first material and the second material, wherein the third braid comprises a variable per inch count that smoothly transitions between the first per inch count on the proximal side of the distinct transition and the second per inch count on the distal side of the distinct transition, wherein the variable per inch count smoothly transitions across the distinct transition to alleviate a weak kink point;
a primary lumen extending at least partially through the proximal portion, the transition portion, and the distal portion; and
a plurality of secondary lumens extending at least partially through the proximal portion, the transition portion, and the distal portion; and
an imaging component coupled to the distal portion of the flexible elongate member.
2. The imaging catheter of claim 1 , wherein the first material comprises a polyether block amide of durometer 72D.
3. The imaging catheter of claim 1 , wherein the second material comprises a polyether block amide of durometer 35D or 45D.
4. The imaging catheter of claim 1 , wherein the first braid, the second braid, and the third braid are constructed from flat wires.
5. The imaging catheter of claim 4 , wherein the flat wires are composed of steel.
6. The imaging catheter of claim 1 , wherein the second per inch count is twice the first per inch count.
7. The imaging catheter of claim 1 ,
wherein the primary lumen has a cross-shaped cross-section,
wherein arms of the cross-shaped cross-section form recesses therebetween.
8. The imaging catheter of claim 7 , wherein the plurality of secondary lumens are positioned relative to the primary lumen in the recesses between the arms of the cross-shaped cross-section.
9. The imaging catheter of claim 1 , further comprising a communication cable coupled to the imaging component and extending through the primary lumen.
10. The imaging catheter of claim 1 , further comprising a plurality of steering lines coupled to the distal portion of the flexible elongate member and extending through the plurality of secondary lumens.
11. The imaging catheter of claim 1 , wherein the distal portion is deflectable up to a radius curvature of 14 millimeters (mm).
12. The imaging catheter of claim 1 , wherein the third braid smoothly transitions between the first per inch count at the proximal end of the transition portion and the second per inch count at the distal end of the transition portion.
13. A method of manufacturing an imaging catheter, the method comprising:
forming a proximal portion of a flexible elongate member with a first material embedded with a first braid with a first per inch count, wherein the proximal portion includes a first primary lumen and a first plurality of secondary lumens;
forming a distal portion of the flexible elongate member with a second material embedded with a second braid with a second per inch count, wherein a hardness of the first material comprises a first durometer and a hardness of the second material comprises a second durometer, wherein the second durometer is lower than the first durometer and the second per inch count is higher than the first per inch count such that the distal portion is more flexible than the proximal portion;
forming a transition portion of the flexible elongate member, wherein the transition portion is located between the proximal portion and the distal portion, wherein the transition portion comprises:
the first material;
the second material;
a distinct transition between the hardness of the first material and the hardness of the second material such that the first material is located on a proximal side of the distinct transition and the second material is located on a distal side of the distinct transition, wherein the distinct transition is spaced from a proximal end of the transition portion and a distal end of the transition portion; and
a third braid embedded within the first material and the second material, wherein the third braid comprises a variable per inch count that smoothly transitions between the first per inch count on the proximal side of the distinct transition and the second per inch count on the distal side of the distinct transition, wherein the variable per inch count smoothly transitions across the distinct transition to alleviate a weak kink point; and
coupling an imaging component to the distal portion of the flexible elongate member.
14. The method of claim 13 , wherein the first braid, the second braid, and the third braid are constructed from stainless steel flat wires.
15. The method of claim 13 , wherein the second per inch count is twice the first per inch count.
16. The method of claim 13 ,
wherein the first primary lumen has a cross-shaped cross-section, and
wherein arms of the cross-shaped cross-section form recesses that anchor angular positions of the first plurality of secondary lumens.
17. The method of claim 13 , wherein the forming the distal portion includes forming the distal portion to define a second primary lumen in communication with the first primary lumen and to define a second plurality of secondary lumens in communication with the first plurality of secondary lumens.
18. The method of claim 17 , further comprising:
coupling a communication cable to the imaging component; and
extending the communication cable through the second primary lumen of the distal portion and the first primary lumen of the proximal portion.
19. The method of claim 17 , further comprising:
coupling a plurality of steering lines to the distal portion; and
extending the plurality of steering lines through the second plurality of secondary lumens of the distal portion and the first plurality of secondary lumens of the proximal portion.