Fluid-actuated sheath displacement and articulation behavior improving systems, devices, and methods for catheters, continuum manipulators, and other uses
Catheter-supported therapeutic and diagnostic tools can be introduced into a patient body with a sheath slidably disposed over the tool. Once the tool is aligned with a target tissue, a fluid-driven actuator can move the sheath axially from over the tool, for example, to allow a stent, stent-graft, prosthetic valve, or the like to expand radially within the cardiovascular system, without having to transmit large deployment forces along the catheter shaft and sheath from outside the patient. Well-behaved articulation structures will often include simple balloon arrays, with inflation of the balloons interacting with elongate skeletal support structures so as to improve articulation behavior of the skeleton. The array can be used to improve uniformity of bending along a segment of a flexible body such as a catheter. The articulation improvement structures can be employed in minimally invasive medical catheter systems, and also for industrial continuum robotics, for supporting imaging systems, for entertainment and consumer products, and the like.