An instrument comprising: a handle portion; an actuator movably coupled to the handle portion and configured to move between a start position and an end position; a shaft having a proximal end coupled to the handle portion and the actuator , a distal end comprising an electrode region , and a flexible region between the proximal and distal ends, wherein a movement of the actuator causes portions of the flexible region positioned distally of a pivot region to bend such that both an angular orientation and a radial offset of the electrode region relative to an unbent axis of the shaft increase as the actuator approaches the end position and reach a maximum angular orientation and a maximum radial offset, respectively, when the actuator reaches the end position, the pivot region being positioned along a length of the shaft, wherein said angular orientation is defined as the angle between the axis of the shaft at a distal tip of the electrode region and said unbent axis of the shaft and wherein said radial offset is defined as the distance between the distal tip of the electrode region and said unbent axis of the shaft; a rigid member having a proximal portion and a distal portion, the rigid member being movably coupled to the shaft such that the distal portion of the rigid member defines the pivot region, wherein movement of a position of the rigid member along the length of the shaft causes a position of the pivot region to translate axially along the length of the shaft , the maximum radial offset varying depending on the position of the pivot region along the length of the shaft ; and an angular control mechanism configured to control the angular orientation of the electrode region such that the maximum angular orientation is the same regardless of the position of the rigid member along the length of the shaft . a handle portion; an actuator movably coupled to the handle portion and configured to move between a start position and an end position; a shaft having a proximal end coupled to the handle portion and the actuator , a distal end comprising an electrode region , and a flexible region between the proximal and distal ends, wherein a movement of the actuator causes portions of the flexible region positioned distally of a pivot region to bend such that both an angular orientation and a radial offset of the electrode region relative to an unbent axis of the shaft increase as the actuator approaches the end position and reach a maximum angular orientation and a maximum radial offset, respectively, when the actuator reaches the end position, the pivot region being positioned along a length of the shaft, wherein said angular orientation is defined as the angle between the axis of the shaft at a distal tip of the electrode region and said unbent axis of the shaft and wherein said radial offset is defined as the distance between the distal tip of the electrode region and said unbent axis of the shaft; a rigid member having a proximal portion and a distal portion, the rigid member being movably coupled to the shaft such that the distal portion of the rigid member defines the pivot region, wherein movement of a position of the rigid member along the length of the shaft causes a position of the pivot region to translate axially along the length of the shaft , the maximum radial offset varying depending on the position of the pivot region along the length of the shaft ; and an angular control mechanism configured to control the angular orientation of the electrode region such that the maximum angular orientation is the same regardless of the position of the rigid member along the length of the shaft . <EOS>