| abstract |
A catheter includes an inner layer, an outer layer, and an intermediate layer arranged between the inner and outer layers. This intermediate layer including a coil layer having a double layer coil portion composed of an inner coil wound in a first direction and an outer coil wound around the outside of the inner coil in a second direction that is opposite to the first direction, wherein the inner coil and the outer coil are formed from flat members whose ratios of thickness to width of cross section are less than 1. The intermediate layer further includes a rigid layer having a rigidity higher than at least one of the rigidities of the inner and outer layers. The rigid layer is arranged in a main body portion positioned in a proximal side of the catheter and the coil layer is arranged at least in a tip portion of the catheter which is positioned in a distal side of the catheter. The catheter further includes a distal end portion which has the largest flexibility among the portions of the catheter, and the intermediate layer is not arranged in the distal end portion. The distal end portion includes X-ray image forming element. The catheter further includes a hydrophilic lubricant layer provided around the inner layer and/or the outer layer. |