Coaxial bi-directional catheter
A deflectable catheter including an outer member having a proximal portion and a distal portion, an elongated column member extending distally from the outer member and an inner member positioned coaxial with the outer member and attached to the column member. The inner member extends distally of the outer member and has a distal tip portion. A reinforcement member is positioned over the column member to restrict axial movement of the column member such that when one of the inner member or outer member is moved with respect to the other, axial compression of the column member is restricted by the reinforcement member causing the distal tip portion of the inner member to deflect laterally.
1. A bi-directional deflectable catheter comprising:
an outer tubular member having a proximal end, a distal end and a first lumen;
an inner tubular member having a proximal end and a distal end, the inner member positioned within the first lumen of the outer member, the inner member and outer member being relatively movable, and a distal region of the inner member extending distally of the distal end of the outer member;
an elongated column member having a proximal end and a distal end, the column member fixed at the distal end of the inner member and fixed at the distal end of the outer member, wherein the column member is configured to bend in a region between the proximal end and the distal end to form an arc having a first height; and
a restriction member positioned over the column member and distal region of the inner member to restrict the bend of the column member to less than the first height; wherein a distal tip portion of the catheter is deflectable in first and second opposing directions from a longitudinal axis of the catheter.
2. The catheter of claim 1 , wherein the column member has a cross-sectional dimension less than a cross-sectional dimension of the distal region of the inner member.
3. The catheter of claim 1 wherein the column member is composed of a different material than the inner member.
4. The catheter of claim 2 , wherein the column member is rectangular in cross-section.
5. The catheter of claim 3 , wherein the column member is composed of one of stainless steel or nitinol.
6. The catheter of claim 1 , wherein the restriction member comprises a compressible coil.
7. The catheter of claim 6 , wherein the restriction member is composed of nitinol.
8. The catheter of claim 1 , wherein in an absence of the restriction member the column member is bendable into a U-shape.
9. The catheter of claim 1 , wherein the column member is deflectable to an angle of 90 degrees with respect to the longitudinal axis.
10. A bi-directional deflectable catheter comprising:
an outer tubular member having a proximal end, a distal end and a first lumen;
an inner tubular member having a proximal end, a distal end and a second lumen, the inner member positioned within the first lumen of the outer member, the inner member and outer member being relatively movable, and a distal region of the inner member extending distally of the distal end of the outer member;
an elongated column member having a proximal end and a distal end, the proximal end of the column member fixed to the distal end of the outer member;
and the distal end of the column member fixed to the distal end of the inner member, and
a restriction member positioned over the column member and distal region of the inner member, the restriction member restricting buckling of the column member between the proximal and distal ends and further restricting deflection of a distal tip portion of the catheter, the distal tip portion of the catheter is deflectable in first and second opposing directions from a longitudinal axis of the catheter depending on the direction of relative movement of the inner and outer members.
11. The catheter of claim 10 , wherein the column member is composed of a different material than the inner member.
12. The catheter of claim 10 , wherein the distal region of the inner member has a lumen having a central longitudinal axis aligned with a central longitudinal axis of the outer member.
13. The catheter of claim 10 , wherein the second lumen extends to the distal end of the inner member and the column member is radially offset from the second lumen.
14. The catheter of claim 10 , further comprising a marker band at one or both of a region where the column member is fixed to the inner member and a region wherein the column member is fixed to the outer member.
15. The catheter of claim 10 , wherein the distal region of the inner member is tubular.
16. A deflectable microcatheter comprising:
an outer catheter having a proximal end, a distal end and a first lumen;
an inner catheter having a proximal end, a distal end and a deflectable tip, a distal region of the inner member extending distally of the distal end of the outer catheter;
a restriction member positioned over the deflectable tip; and
a column member positioned within the restriction member and attached at the distal end of the outer catheter and at the distal end of the inner catheter;
wherein proximal movement of the inner catheter applies a proximal force to the column member, thereby bending the deflectable tip of the inner catheter in a direction away from the column member; and
wherein distal movement of the inner catheter applies a distal force to the column member, thereby bending the deflectable tip of the inner catheter in a direction toward the column member.
17. The microcatheter of claim 16 , wherein the column member has a cross-sectional dimension less than a cross sectional dimension of the distal region of the inner catheter extending distally of the outer catheter.
18. The microcatheter of claim 17 , wherein the outer catheter has a central longitudinal axis and the column member is radially offset with respect to the central longitudinal axis of the outer catheter.
19. The microcatheter of claim 17 , wherein distal movement of the outer catheter applies a distal force to the column member, thereby bending the deflectable tip of the inner catheter in a direction away from the column member and proximal movement of the outer catheter applies a proximal force to the column member, thereby bending the deflectable tip of the inner catheter in a direction toward the column member.