A medical device, comprising: a catheter body defining a proximal portion and a distal portion; a steering actuator coupled to the proximal portion of the catheter body; a first steering element having a first end attached to the steering actuator and a second end attached to the distal portion of the catheter body at a first position; a second steering element having a first end attached to the steering actuator and a second end attached to the catheter body at a second position distal to the first position; manipulation of the steering actuator in a first direction tensions the first steering element to deflect a portion of the catheter body in a first direction in a first plane; manipulation of the steering actuator in a second direction tensions the second steering element to deflect a portion of the catheter body in a second direction in a second plane; an electrode array disposed on the distal end of the catheter body; a first deflectable segment proximal to the electrode array, the first deflectable segment being biased to deflect in a plane substantially perpendicular to the first plane; a guide plate within the catheter body, the guide plate defining a proximal portion having a first plane of preferential bending, and a distal portion having a second plane of preferential bending substantially perpendicular to the first plane, characterised in that the proximal portion of the guide plate is concave; and the catheter body including a plurality of adjacent segments having alternating relative flexibilities, the plurality of adjacent segments spanning at least a portion of the proximal and distal portion. a catheter body defining a proximal portion and a distal portion; a steering actuator coupled to the proximal portion of the catheter body; a first steering element having a first end attached to the steering actuator and a second end attached to the distal portion of the catheter body at a first position; a second steering element having a first end attached to the steering actuator and a second end attached to the catheter body at a second position distal to the first position; manipulation of the steering actuator in a first direction tensions the first steering element to deflect a portion of the catheter body in a first direction in a first plane; manipulation of the steering actuator in a second direction tensions the second steering element to deflect a portion of the catheter body in a second direction in a second plane; an electrode array disposed on the distal end of the catheter body; a first deflectable segment proximal to the electrode array, the first deflectable segment being biased to deflect in a plane substantially perpendicular to the first plane; a guide plate within the catheter body, the guide plate defining a proximal portion having a first plane of preferential bending, and a distal portion having a second plane of preferential bending substantially perpendicular to the first plane, characterised in that the proximal portion of the guide plate is concave; and the catheter body including a plurality of adjacent segments having alternating relative flexibilities, the plurality of adjacent segments spanning at least a portion of the proximal and distal portion.