Hypotube construction
A medical device such as a catheter may have an elongate shaft that includes a hypotube having a cut formed therein. The elongate shaft may define a lumen that extends within the elongate shaft. A polymer may be disposed over at least a portion of the hypotube. A medical device may include a cut hypotube having a constant pitch and may be configured to reversibly and temporarily alter the pitch of at least a portion of the cut hypotube. In some cases, the medical device may be configured to reversibly and/or temporarily alter a compressive strength of at least a portion of the cut hypotube.
1. A hypotube comprising:
a hypotube body;
a pair of polymer layers, wherein a first polymer layer of the pair of polymer layers encapsulates an inside surface of the hypotube body, and wherein a second polymer layer of the pair of polymer layers encapsulates an outside surface of the hypotube body;
a liner, wherein the liner is secured to the inside surface of the hypotube body by the first polymer layer; and
a cut pattern, wherein the cut pattern is formed on the hypotube body;
a plurality of interstices formed by the cut pattern on the hypotube body, wherein the interstices created by the cut pattern are filled with a low stiffness polymer of the second polymer layer creating a smooth outer surface; and
a proximal and a distal region, wherein the proximal region possesses a stiffer profile in comparison to the distal region to allow for increased pushability and increased maneuverability;
wherein the hypotube compromises an outside diameter and an inside diameter with a ratio of thickness of the outside diameter to the inside diameter is in the range of 1.15:1 to 1.5:1;
wherein the inside surface of the hypotube body faces a lumen within the hypotube body.
2. The hypotube of claim 1 , wherein the liner is a material selected from the group consisting of: polytetrafluoroethylene, a blend of polytetrafluoroethylene and polyimide, and a high density polyethylene.
3. The hypotube of claim 1 , wherein the second polymer layer encapsulates the plurality of interstices on the hypotube body.
4. The hypotube of claim 1 , wherein the hypotube body is a material selected from the group consisting of: stainless steel, cobalt chrome, and nitinol.
5. The hypotube of claim 1 , wherein the hypotube body is constructed of a higher modulus metal to allow for a thinner hypotube body to achieve a higher stiffness profile of the hypotube.
6. The hypotube of claim 1 , wherein the cut pattern is selected from the group consisting of: a c-cut, a spiral cut, an interrupted cut, and any combination/blend thereof.
7. The hypotube of claim 1 , wherein the cut pitch and cut density of the cut pattern varies along a length of the hypotube to incorporate various stiffness profiles.
8. The hypotube of claim 1 , wherein the low stiffness polymer of the second polymer layer is selected from the group consisting of: polyether block amide, nylons, and polyurethanes.
9. The hypotube of claim 1 , wherein the hypotube forms a catheter construction in the range of one-and-a-half to twenty French.
10. The hypotube of claim 1 , wherein the hypotube forms a catheter construction in the range of three to six French.
11. The hypotube of claim 1 possessing a stiffness profile between 65A to 75D in accordance with the durometer scale.
12. The hypotube of claim 1 wherein the liner comprises a thickness range of 0.00025 to 0.001 inches.