Dilatation catheter

A dilatation catheter, comprising:

• a length of a tubular shaft of flexible material having a longitudinal axis;
• an inner tubular flexible member coaxially disposed in the shaft and having a distal portion projecting therefrom;
• a balloon portion formed at the distal end of the flexible shaft, the balloon portion formed with a plurality of circumferential crimps running length-wise being capable of expanding radially to a predetermined diameter with minor axial movement when subjected to internal pressure to provide a balloon, the balloon portion fixed to the distal end of the tubular flexible shaft and the distal end of the inner tubular flexible member;
• and
• a transition portion end of the balloon portion surrounding the inner flexible member formed with a plurality of longitudinal crimps across the length of the catheter for coupling the balloon portion to the distal end of the inner tubular flexible member and the distal portion of the tubular flexible shaft, the transition portion being capable of longitudinal extension in response to a minor longitudinal contraction at the two ends of the balloon portion to reduce the axial movement when the balloon portion is inflated.

A balloon catheter for introduction into a blood vessel, comprising:

• an inner tube having a longitudinal axis;
• an outer tube in coaxial relation to the inner tube;
• the inner diameter of the outer tube being larger than the outer diameter of the inner tube so that the two tubes form an annular space between the tubes, and the distal end of the inner tube extending beyond the distal end of the outer tube with the distal end of the outer tube sealed to the inner tube;
• the outer tube formed of a flexible material and having a balloon portion and a transition portion at each end of the balloon portion disposed at the distal end of the outer tube;
• the balloon portion and transition portions formed from a fabric substrate and a fluid impermeable elastomeric material;
• the balloon portion formed with a plurality of circumferential crimps running length-wise along the axis;
• the transition portion formed with a plurality of longitudinal crimps across the axis;
• the balloon portion adapted to be inflated to a predetermined diameter when subject to internal pressure to provide a balloon;
• and
• the transition portions longitudinally extending to compensate exactly for minor longitudinal contraction at the two ends of the balloon portion when the balloon is inflated whereby the baloon portion is not displaced longitudinally in the blood vessel.