Catheter tube having a filamentous reinforcing layer

A catheter tube having a longitudinal axis, a first end for attachment to a hub and a tip portion at an opposite end thereof, comprising:

• a flexible inner tube;
• a flexible outer tube provided around said inner tube;
• and
• a reinforcing material layer disposed between said inner and outer tubes along substantially the entire length of said tubes excepting said tip portion for imparting appropriate rigidity to the catheter tube, said reinforcing material layer having a front side thereof adjacent to the tip portion of the catheter tube, wherein said reinforcing material layer is formed by arranging at least one filamentous element in a lattice manner in such a way that the intervals of the lattice points of said filamentous element along the axial direction of the catheter tube change continuously or in a stepwise manner along the axial direction of the catheter tube so as to form one section thereof in which the respective interval between the lattice points of the filamentous element is relatively small and another section thereof in which the respective interval between the lattice points of the filamentous element is relatively large, and wherein said reinforcing material layer has a tip portion, and a thickness of said outer tube or said inner tube decreases near the tip portion of said reinforcing material layer, wherein said filamentous element is formed of a single wire or by bundling a plurality of wires, whereby the bending rigidity of the catheter tube at which said one section of said reinforcing material layer is located becomes smaller in comparison with that of the catheter tube at which said another section of said reinforcing material layer is located, and wherein said one section of said reinforcing material layer is located at least at the front side of said reinforcing material layer in such a manner that the bending rigidity of the catheter tube is continuously reduced toward said tip portion.

A catheter tube having a longitudinal axis, a first end for attachment to a hub and a tip portion at an opposite end thereof, comprising:

• a flexible inner tube;
• a flexible outer tube provided around said inner tube;
• and
• a reinforcing material layer disposed between said inner and outer tubes along substantially the entire length of said tubes excepting said tip portion for imparting appropriate rigidity to the catheter tube, said reinforcing material layer having a front side thereof adjacent to the tip portion of the catheter tube, wherein said reinforcing material layer is formed by arranging at least one filamentous element in a lattice manner in such a way that the inclination angles of the filamentous element with respect to the axis of the catheter tube change continuously or in a stepwise manner along the axial direction so as to form one section thereof in which the inclination angle is relatively large and another section thereof in which the inclination angle is relatively small, and wherein said reinforcing material layer has a tip portion and a thickness of said outer tube or said inner tube decreases near the tip portion of said reinforcing material layer, wherein said filamentous element is formed of a single wire or by bundling a plurality of wires, wherein sections of the catheter tube containing the filamentous element having relatively larger inclination angles are more flexible in comparison with sections thereof containing the filamentous element having the relatively small inclination angles, and wherein said one section of said reinforcing material layer is located at least at the front side of said reinforcing material layer in such a manner that the bending rigidity of the catheter tube is continuously reduced toward said tip portion.