Rotary knob assembly for a steerable medical device

A steerable medical device, comprising:

• a housing;
• an insertion tube;
• a rotary knob assembly rotatably mounted on and extending out of the housing and affixed to the insertion tube, the rotary knob assembly comprising:
• a bushing configured for rotatable mounting about a longitudinal axis of the housing;
• a user-controllable knob having a longitudinally-extending tubular section, the knob affixed to the bushing such that the bushing rotates in unison with the knob and tubular section about the longitudinal axis;
• and
• an endotracheal tube retainer affixed to the knob such that the knob rotates in unison with the tube retainer, wherein the tube retainer is fabricated from an elastomer material and an outer surface of the tube retainer is configured for frictional engagement with an inner surface of a tube connector of an endotracheal tube, wherein a longitudinally-extending channel is formed in the endotracheal tube retainer and defines a tube retainer sidewall, wherein at least one longitudinally extending slot is formed in the tube retainer sidewall, and wherein at least one shoulder is formed on an inner surface of the tube retainer sidewall and configured to engage radially-extending barbs formed on the tubular section.