Patent ID: 7662128

Claim:
A steerable needle structure having a direction of advance toward a target that is changeable as said needle structure is being advanced toward said target comprising a hollow outer cannula having a main longitudinal axis and an open end located at the distal end of the outer cannula and a stylet, said stylet being longer than said cannula and having a leading end adjacent to said open end and having a curved portion with a pre-defined curvature adjacent to said leading end, mounting means mounting said stylet coaxially within said outer cannula so that said stylet and cannula may be relatively rotated and translated along said main axis from a sheathed position wherein substantially all of said curved portion of said stylet is within said cannula to and extended position wherein a selected extended part of said curved portion of said stylet distally projects beyond said open end, said cannula being stiffer than said stylet so that when said stylet is in its said sheathed position it assumes a shape primarily defined by said cannula, and when said stylet is in its said extended position, said extended part of said stylet assumes a curved shape primarily determined by said pre-defined curvature and length of said selected extended part, and said leading end extends from said cannula in a direction determined by the rotation of said stylet about said main axis and said curved shape so that when said needle structure is advanced with said stylet in said extended position said cannula is deflected toward said target and said direction of advance is changed as determined by said direction.