Catheters and related devices and methods of manufacture
Catheters incorporating a thin film polymeric layer or layers. The thin film may have a wall thickness of about 0.00025″+/−less than 0.0001″ to about 0.0015″+/−0.0002″, for example. The thin film may be formed by extruding a sheet and cutting the sheet into elongate ribbons, each having two opposing long edges. The ribbon may be rolled or wrapped to define a tubular shape with a gap between the long edges. Heat and pressure may be applied to close the gap, abut the edges and form a longitudinal joint. The joint may extend along a portion of the length of the tubular shaft or most of the length of the tubular shaft. The tubular-shaped thin film layer may have a uniform wall thickness around the circumference, and the uniform wall thickness may extend across the joint.
1. A tri-layer catheter, comprising:
a longitudinally-extending reinforcement structure including a proximal end and a distal end;
a saddle member, including:
a proximal end having a leading edge,
a distal end connected to the proximal end of the reinforcement structure to form a first mechanical connection of the reinforcement structure and the saddle member, the distal end having a terminal edge and an interlocking portion;
an inner layer formed on an inside surface of the reinforcement structure, the inner layer defining a longitudinally-extending lumen; and
an outer layer formed on an outside surface of the reinforcement structure and connected to the inner layer;
wherein the outer layer engages the interlocking portion of the saddle to form a second mechanical connection of the reinforcement structure and the saddle member via the outer and inner layers; and
wherein the interlocking portion comprises a plurality of embayments and peninsular portions at the terminal edge of the distal end.
2. The catheter of claim 1 , wherein the distal end of the saddle member is directly connected to the proximal end of the reinforcement structure by welding.
3. The catheter of claim 1 , wherein the interlocking portion comprises a plurality of openings defined by the saddle member at the distal end.
4. The catheter of claim 3 , wherein each of the plurality of openings form circles.
5. The catheter of claim 1 , wherein each of the plurality of embayments includes a neck portion in communication with a head portion.
6. The catheter of claim 1 , wherein the saddle member includes an outer surface, and the outer layer contacts the outer surface and penetrates openings in the interlocking portion to contact the inner layer, thereby forming the second mechanical connection.
7. The catheter of claim 1 , wherein the inner layer forms a longitudinal joint extending between the distal end and the proximal end of the reinforcement structure.
8. The catheter of claim 7 , wherein the inner layer forms one or more circumferential joints joining multiple portions of the inner layer.
9. The catheter of claim 7 , wherein the inner layer forms one or more circumferential joints joining multiple portions of the inner layer.
10. The catheter of claim 1 , wherein the leading edge of the saddle member forms a serrated, proximal-facing edge.
11. A tri-layer catheter defining a longitudinal axis, comprising:
a longitudinally-extending reinforcement structure including a proximal end and a distal end;
a saddle member, including:
a proximal end having a leading edge;
a distal end connected to the proximal end of the reinforcement structure, the distal end having a distal-facing terminal edge;
an inner layer formed on an inside portion of the reinforcement structure; and
an outer layer formed on an outside portion of the reinforcement structure;
wherein the reinforcing structure, the inner layer and the outer layer form an elongated tube defining a continuous, longitudinally-extending lumen, with the elongated tube connected at a proximal end to the saddle member; and
wherein the saddle portion forms a plurality of peninsular members defining a plurality of embayments, and the outer layer extends through the embayments to the inner liner in the saddle member such that the outer layer is connected to and extends from the distal-facing terminal edge of the saddle member.
12. The catheter of claim 11 , wherein the leading edge is a serrated leading edge defining a plurality of grooves, and the catheter further comprises a polymeric lip formed over the serrated leading edge.
13. The catheter of claim 11 , wherein the serrated leading edge forms a first angle relative to the longitudinal axis, the terminal edged forms a second angle relative to the longitudinal axis, the first angle is an acute angle, and the second angle is substantially a right angle.
14. The catheter of claim 11 , further comprising an elongated rod connected to proximal end of the saddle member.
15. The catheter of claim 11 , wherein the reinforcement structure is a metallic coil.
16. The catheter of claim 11 , wherein the outer layer comprises a polymeric material having a thickness less than 0.0015″ +/−0.0002″.
17. The catheter of claim 11 , wherein the inner layer comprises a longitudinally-extending joint joining two longitudinally-extending and overlapping edges of the inner layer.
18. The catheter of claim 11 , wherein each of the plurality of embayments includes a neck portion in communication with a head portion.