US Patent 8251977 Catheter steering system

A catheter steering mechanism includes a tubular member defining a passage. The tubular member has a longitudinally extending cutaway portion defining a bend-enhancing region formed at a predetermined location along a length of the tubular member. An actuator is received in the passage of the tubular member, a distal part of the actuator being fast with a distal part of the tubular member. A restraining arrangement is defined by the tubular member, the restraining arrangement comprising a structure arranged at the bend-enhancing region to retain the actuator substantially within the confines of the tubular member during bending.