US Patent 9629980 Variable stiffness catheter, intraluminal treatment system, and method

A variable stiffness catheter includes an elongate tubular body having proximal and distal body ends and defining a lumen extending longitudinally between a fluid inlet in the proximal body end and a fluid outlet in the distal body end. The catheter includes a vacuum responsive stiffener coupled with the elongate tubular body, which may include a stiffening medium such as an open cell foam having an expanded state and a vacuum collapsed state. The stiffening medium can transition between the expanded state at which it is relatively flexible and the vacuum collapsed state at which it is relatively inflexible via withdrawing fluid from the vacuum responsive stiffener by way of a vacuum device.