Steerable medical devices, systems, and methods of use
Steerable medical devices and methods of use. In some embodiments, the steerable medical devices include a steerable portion with a stiffness that varies along the length of the steerable portion.
1. A steerable medical device, comprising:
an outer flexible tubular member;
an inner flexible tubular member disposed within the outer flexible tubular member;
a steerable portion comprising the outer and inner flexible tubular members, the outer and inner flexible polymeric tubular members each configured to preferentially bend in the steerable portion, and wherein the outer and inner flexible tubular members are axially fixed relative to one another at a fixation location distal to the steerable portion,
wherein the inner flexible tubular member, in the steerable portion, comprises a single seam between a first segment of material with a first durometer and a second segment of material with a second durometer different than the first durometer, at least a portion of the seam being angled, wherein the configuration of the seam contributes to the direction of the preferential bending of the inner flexible tubular member; and
an external controller operatively coupled to the inner and outer flexible tubular members such that, upon actuation of an actuator, one of the inner and outer tubular flexible members is put in tension and the other of the inner and outer flexible tubular members is put in compression, thereby steering the steerable portion,
wherein the inner tubular member further comprises a reinforcing member extending parallel to a longitudinal axis of the inner tubular member, and wherein at least one of a distal end and a proximal end of the reinforcing member is everted about a second reinforcing member of the inner tubular member.
2. The steerable medical device of claim 1 , wherein the single seam is angled along substantially an entire length of the seam.
3. The steerable medical device of claim 1 , wherein the single seam has a length that is at least 50% of a length of the steerable portion.
4. The steerable medical device of claim 3 , wherein the single seam has a length that is at least 75% of the length of the steerable portion.
5. The steerable medical device of claim 4 , wherein the single seam is angled over substantially an entire length of the seam.
6. The steerable medical device of claim 1 , wherein the seam includes first and second seam portions that define an acute angle.
7. The steerable medical device of claim 6 , wherein the first and second seam portions define first and second acute angles.
8. The steerable medical device of claim 1 wherein a proximal end of the seam is 180 degrees around the inner tubular member from a distal end of the seam.
9. The steerable medical device of claim 1 , wherein, in a cross-section transverse to a longitudinal axis of the inner tubular member at a distal end of the steerable portion, there is more of the first segment of material than the second segment of material, and the first durometer is less than the second durometer.
10. The steerable medical device of claim 9 , wherein in a second cross-section transverse to a longitudinal axis of the inner tubular member at a proximal end of the steerable portion, there is more of the second segment of material than the first segment of material.
11. The steerable medical device of claim 1 wherein a length of the first segment of material is the same as a length of the second segment of material.
12. The steerable medical device of claim 1 wherein the first and second segments of material each include polymer segments that have the same configuration, offset by 180 degrees, and facing opposite directions.
13. The steerable medical device of claim 1 , wherein the difference between the first and second durometers is at between 15D and 75D.
14. The steerable medical device of claim 1 wherein the second reinforcing member is a braided reinforcing member.
15. The steerable medical device of claim 1 wherein the reinforcing member is woven in the second reinforcing member.
16. The steerable medical device of claim 1 wherein the inner and outer tubular members comprise constituent components and each have steerable lengths such that the steerable portion, when steered to a fullest extent, has a curve diameter of 1.5 cm to 4.0 cm.
17. A steerable medical device, comprising:
an outer flexible tubular member;
an inner flexible tubular member disposed within the outer flexible tubular member;
a steerable portion comprising the outer and inner flexible tubular members, and wherein the outer and inner flexible tubular members are axially fixed relative to one another at a fixation location distal to the steerable portion; and
an external controller operatively coupled to the inner and outer flexible tubular members such that, upon actuation of an actuator, one of the inner and outer tubular flexible members is put in tension and the other of the inner and outer flexible tubular members is put in compression, thereby steering the steerable portion,
wherein the inner tubular member further comprises a reinforcing member extending parallel to a longitudinal axis of the inner tubular member, and wherein at least one of a distal end and a proximal end of the reinforcing member is everted about a second reinforcing member of the inner tubular member.
18. A steerable medical device of claim 17 , wherein the steerable portions of the outer and inner flexible tubular members comprise polymeric tubular members.
19. A steerable medical device of claim 18 , wherein the outer and inner flexible tubular members are each configured to preferentially bend in the steerable portion.
20. A steerable medical device of claim 17 , wherein the second reinforcing member is a braided reinforcing member.
21. A steerable medical device of claim 17 , wherein the reinforcing member is woven in the second reinforcing member.