Patent ID: 7118551

Claim:
A catheter comprising: an elongated catheter shaft having an inner tubular member with a lumen, and an outer tubular member disposed about the inner tubular member such that a lumen of the outer tubular member is defined therebetween; and a variable stiffness mandrel disposed in said outer tubular member lumen, having a solid core comprised of a non-metal material, a bonded proximal end section which fixedly secures the mandrel relative to the catheter shaft, an annealed proximal section which is located between and spaced apart from an outer surface of the inner tubular member and an inner surface of the outer tubular member and which has a first crystallinity, and a non-annealed distal section with a second crystallinity lower than said proximal section first crystallinity such that the proximal section is stiffer than the distal section.