Steerable medical devices, systems, and methods of use

A steerable medical device, comprising:

• an outer flexible tubular member;
• an inner flexible tubular member disposed within the outer flexible tubular member;
• a steerable portion comprising the outer and inner flexible tubular members, the outer and inner flexible polymeric tubular members each configured to preferentially bend in the steerable portion, and wherein the outer and inner flexible tubular members are axially fixed relative to one another at a fixation location distal to the steerable portion,
• wherein the inner flexible tubular member, in the steerable portion, comprises a single seam between a first segment of material with a first durometer and a second segment of material with a second durometer different than the first durometer, at least a portion of the seam being angled, wherein the configuration of the seam contributes to the direction of the preferential bending of the inner flexible tubular member;
• and
• an external controller operatively coupled to the inner and outer flexible tubular members such that, upon actuation of an actuator, one of the inner and outer tubular flexible members is put in tension and the other of the inner and outer flexible tubular members is put in compression, thereby steering the steerable portion,
• wherein the inner tubular member further comprises a reinforcing member extending parallel to a longitudinal axis of the inner tubular member, and wherein at least one of a distal end and a proximal end of the reinforcing member is everted about a second reinforcing member of the inner tubular member.