Neuromodulation catheters with shafts for enhanced flexibility and control and methods of making and using the catheters. A neuromodulation catheter can include an elongated shaft having a distal end portion and a mandrel extending at least along the distal end portion. The mandrel can have an at least substantially solid core. The neuromodulation catheter can further include a transition member and a neuromodulation assembly coupled to the transition member. The transition member can have a proximal portion, a distal portion, and a guide wire lumen extending through the proximal and distal portions. The neuromodulation assembly can extend distally from the distal portion of the transition member, and the mandrel can extend proximally from the proximal portion of the transition member.

A system for deploying a shape memory catheterization device within a patient, includes a catheter for endovascular insertion of the shape memory catheterization device. A heat source heats the shape memory catheterization device above the transition temperature. A transformation data generator includes a circuit driver for driving a circuit that includes at least one resistive element of the shape memory catheterization device and a detection circuit for generating transformation data based on a resistance of the at least one resistive element, wherein the transformation data indicates a shape transformation of the shape memory catheterization device from a catheterization shape to a transformed shape.

A method for operating a catheter provides a mechanical stiffener to a catheter shaft portion, the shaft comprising an inner sheath having a distal end and an outer surface and defining an access lumen extending distally to the distal end and an outer sheath having an inner surface surrounding the inner sheath distally to the distal end, defining an annulus between the outer and inner surfaces, the annulus having a connection at which vacuum applies to the annulus, and having a substantially constant outer diameter over the portion to the distal end. A tool is shaped and sized to pass through the access lumen and past the distal end. The portion is placed in an increased stiffened state by applying vacuum to create a stable base with at least a shaft segment within the anatomy that atraumatically resists reaction forces applied to the shaft by the tool.

The present invention relates to flexible sheath assemblies capable of maintaining a desired positioning at a desired tissue region during medical procedures involving use insertion and withdrawal of medical tools through the flexible sheath, and related systems and methods.

A controllable stiffness catheter comprising a shaft comprising an inner sheath defining an access lumen, an outer sheath surrounding the inner sheath and defining an annulus therebetween, the annulus having a vacuum connection at which a vacuum is applied to the annulus, and a mechanical stiffener disposed at least at a portion of the annulus.

A system for deploying a shape memory catheterization device within a patient, includes a catheter for endovascular insertion of the shape memory catheterization device. A heat source heats the shape memory catheterization device above the transition temperature. A transformation data generator includes a circuit driver for driving a circuit that includes at least one resistive element of the shape memory catheterization device and a detection circuit for generating transformation data based on a resistance of the at least one resistive element, wherein the transformation data indicates a shape transformation of the shape memory catheterization device from a catheterization shape to a transformed shape.

A system for deploying a shape memory catheterization device within a patient, includes a catheter for endovascular insertion of the shape memory catheterization device. A heat source heats the shape memory catheterization device above the transition temperature. A transformation data generator includes a circuit driver for driving a circuit that includes at least one capacitive element of the shape memory catheterization device and a detection circuit for generating transformation data based on a capacitance of the at least one capacitive element, wherein the transformation data indicates a shape transformation of the shape memory catheterization device from a catheterization shape to a transformed shape.

A variable-stiffness actuator is to be installed into a flexible member and provide different degrees of stiffness to the flexible member. The actuator includes two hard members located apart from each other, and a shape-memory member connecting the hard members. The shape-memory member has a property of transitioning in phase between a first phase and a second phase. The shape-memory member is in a low stiffness state when in the first phase, and is in a high stiffness state when in the second phase. The actuator also includes a inducing member configured to cause a portion of the shape-memory member between the hard members to transition in phase between the first and second phases, and a urging member configured to urge the hard members in directions away from each other.

A system for deploying a shape memory catheterization device within a patient, includes a catheter for endovascular insertion of the shape memory catheterization device. A heat source heats the shape memory catheterization device above the transition temperature. A transformation data generator includes a circuit driver for driving a circuit that includes at least one capacitive element of the shape memory catheterization device and a detection circuit for generating transformation data based on a capacitance of the at least one capacitive element, wherein the transformation data indicates a shape transformation of the shape memory catheterization device from a catheterization shape to a transformed shape.

A method for delivering RF energy to living tissue includes the steps of extending a guidewire to a tissue treatment site in a body. A controllable stiffness catheter is provided with a stiffness device having non-metallic properties and a temperature-changing device. The stiffness device is in a stiff state below a given temperature and in a soft state above the given temperature. While supplying power to the temperature-changing device, the catheter is threaded along the guidewire up to the treatment site in the soft state. Power is removed from the temperature-changing device to alter the non-metallic properties of the stiffness device and directly result in a change of the stiffness device to the stiff state without straightening the catheter. The RF energy supply device is physically contacted with the treatment site and RF energy is delivered to the treatment site from the RF energy supply device.