A minimally invasive system (100, 200) comprising: an elongate instrument extending from a proximal end to a distal end and including: a flexible proximal portion; a rigid distal portion, the flexible proximal portion fixedly coupled to the rigid distal portion; and a lumen extending from the proximal end to the distal end through the flexible proximal portion and the rigid distal portion and defining a longitudinal axis of the elongate instrument; a stylet slidably disposed within the lumen of the elongate instrument, the stylet including a flexible body fixedly coupled to a steerable portion and a sensor element extending through the flexible body, the stylet being movable within the elongate instrument between a retracted condition in which the steerable portion is retracted within the elongate instrument and an extended configuration in which the steerable portion at least partially extends from the rigid distal portion of the elongate instrument; a plurality of actuation cables extending through the flexible body of the stylet and terminating in the steerable portion of the stylet, wherein the steerable portion comprises a bend-resistive section and a bendable section, the bendable section including a plurality of articulable segments (417, 418, 419) linked by the plurality of actuation cables, the bend-resistive section being distal to the bendable section, the bendable section including a plurality of joint pivots disposed between adjacent articulable segments, each joint pivot of the plurality of joint pivots including a first concave portion and a second concave portion, wherein at least a first actuation cable of the plurality of actuation cables extends through the first concave portion of each joint pivot, and at least a second actuation cable of the plurality of actuation cables extends through the second concave portion of each joint pivot; and a plurality of actuation conduits within the flexible body of the stylet and a plurality of actuation channels within the steerable portion of the stylet, wherein each of the plurality of actuation cables extend through a discrete actuation conduit of the plurality of actuation conduits and anchor within a discrete actuation channel of the plurality of actuation channels. an elongate instrument extending from a proximal end to a distal end and including: a flexible proximal portion; a rigid distal portion, the flexible proximal portion fixedly coupled to the rigid distal portion; and a lumen extending from the proximal end to the distal end through the flexible proximal portion and the rigid distal portion and defining a longitudinal axis of the elongate instrument; a flexible proximal portion; a rigid distal portion, the flexible proximal portion fixedly coupled to the rigid distal portion; and a lumen extending from the proximal end to the distal end through the flexible proximal portion and the rigid distal portion and defining a longitudinal axis of the elongate instrument; a stylet slidably disposed within the lumen of the elongate instrument, the stylet including a flexible body fixedly coupled to a steerable portion and a sensor element extending through the flexible body, the stylet being movable within the elongate instrument between a retracted condition in which the steerable portion is retracted within the elongate instrument and an extended configuration in which the steerable portion at least partially extends from the rigid distal portion of the elongate instrument; a plurality of actuation cables extending through the flexible body of the stylet and terminating in the steerable portion of the stylet, wherein the steerable portion comprises a bend-resistive section and a bendable section, the bendable section including a plurality of articulable segments (417, 418, 419) linked by the plurality of actuation cables, the bend-resistive section being distal to the bendable section, the bendable section including a plurality of joint pivots disposed between adjacent articulable segments, each joint pivot of the plurality of joint pivots including a first concave portion and a second concave portion, wherein at least a first actuation cable of the plurality of actuation cables extends through the first concave portion of each joint pivot, and at least a second actuation cable of the plurality of actuation cables extends through the second concave portion of each joint pivot; and a plurality of actuation conduits within the flexible body of the stylet and a plurality of actuation channels within the steerable portion of the stylet, wherein each of the plurality of actuation cables extend through a discrete actuation conduit of the plurality of actuation conduits and anchor within a discrete actuation channel of the plurality of actuation channels.