US Patent 9572957 Steerable medical devices and steering assemblies

A surgical apparatus includes an elongated handle assembly having opposed proximal and distal end portions and an interior cavity. An elongated sheath extends from the proximal end of the handle assembly, through the interior cavity of the handle assembly and out from the distal end portion of the handle assembly. The sheath includes an interior lumen extending therethrough and a distal end portion of the sheath is deflectable. The surgical apparatus includes a steering mechanism operatively associated with the handle assembly for controlling deflection of the deflectable distal end portion of the sheath. The steering mechanism includes a pull wire retraction assembly configured to selectively retract a pull wire to deflect the distal end portion of the sheath and a telescoping tube system for straightly guiding the pull wire as the pull wire retraction assembly moves within the interior cavity of the handle assembly.