Abstract: A controllable stiffness endoscope overtube includes an overtube shaft including an inner sheath defining an access lumen and an outer sheath surrounding the inner sheath from proximal to distal end of inner sheath to define an annulus therebetween having a proximal portion with a vacuum connection. The sheath distal ends are longitudinally fixed to one another and sized to receive an endoscope. The outer sheath has a constant outer diameter over at least a distal portion of the annulus proximate to the distal ends of the sheaths. A vacuum device is fluidically connected to the vacuum connection and applies vacuum to the annulus. Responsive thereto, annulus pressure is lowered, the sheaths are drawn together, and the overtube shaft is stiffened over at least the distal portion to stiffen and maintain a current shape of the overtube shaft over at least the distal portion of the annulus.

Abstract: 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.

Abstract: A controllable stiffness catheter includes a shaft comprising inner and outer sheaths, the sheaths each having proximal and distal ends. The outer surrounds the inner from the proximal to the distal end of the inner sheath, defining an annulus therebetween including a proximal portion having a vacuum connection to which vacuum is applied. The distal ends of the sheaths are longitudinally fixed to one another and sized for neurological vascular procedures. The outer has a substantially constant outer diameter over a distal portion of the annulus proximate to the distal ends. A vacuum device fluidically connects to the vacuum connection and is configured to apply vacuum thereto. Responsive to vacuum, annulus pressure lowers to draw the sheaths toward one another and stiffen the shaft over at least the distal portion to substantially and passively stiffen and maintain a current shape of the shaft over at least the distal portion.

Abstract: A controllable stiffness catheter includes a shaft comprising inner and outer sheaths, the sheaths each having proximal and distal ends. The outer surrounds the inner from the proximal to the distal end of the inner sheath, defining an annulus therebetween including a proximal portion having a vacuum connection to which vacuum is applied. The distal ends of the sheaths are longitudinally fixed to one another and sized for neurological vascular procedures. The outer has a substantially constant outer diameter over a distal portion of the annulus proximate to the distal ends. A vacuum device fluidically connects to the vacuum connection and is configured to apply vacuum thereto. Responsive to vacuum, annulus pressure lowers to draw the sheaths toward one another and stiffen the shaft over at least the distal portion to substantially and passively stiffen and maintain a current shape of the shaft over at least the distal portion.

Abstract: A catheter comprises a heater control supplying power, a handle, a base catheter with lumen and comprising a proximal section and a distal segment, and a variable stiffness element. The element comprises a heater connected to the heater control, coiled at least at the distal segment, and comprising a shaft portion of a first metallic conductive material and a heater portion of a second metallic conductive material. A jacket is disposed about the heater portion. A variable flex sub-assembly between the catheter and jacket comprises a non-conducting braid and a binding material. Without power, the binding material is stiffened. Responsive to heating of the binding material, the binding material softens to increase flexibility of the variable flex sub-assembly at least at the distal segment. Responsive to removing power, the binding material cools and stiffens to decrease flexibility of the variable flex sub-assembly at least at the distal segment.

Abstract: 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.

Abstract: 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.