A steerable catheter with braking mechanism, the steerable catheter comprising: a proximal handle body from which extends distally an elongate steerable catheter body including a deflectable distal catheter body end; where the proximal handle body includes: at least a first control wheel in mechanical communication, via a first spool, with the distal catheter body end, where the at least a first control wheel and the first spool are rotatable around a common control wheel axis; a brake knob mounted rotatingly to the proximal handle body and configured to rotate around a brake knob axis that is orthogonal to the control wheel axis; a brake arm in mechanical communication with the brake knob and disposed between the brake knob and the first spool, said brake arm including at least one spool-engagement surface; and ramped and planar handle body surfaces (164w-y, 166b-c) that complementarily interface with ramped and planar brake knob surfaces (194w-y) such that in a first brake-actuation knob position the at least one spool-engagement surface does not contactingly engage the first spool, and in a second brake-actuation knob position the at least one spool-engagement surface does contactingly engage the first spool. a proximal handle body from which extends distally an elongate steerable catheter body including a deflectable distal catheter body end; where the proximal handle body includes: at least a first control wheel in mechanical communication, via a first spool, with the distal catheter body end, where the at least a first control wheel and the first spool are rotatable around a common control wheel axis; a brake knob mounted rotatingly to the proximal handle body and configured to rotate around a brake knob axis that is orthogonal to the control wheel axis; a brake arm in mechanical communication with the brake knob and disposed between the brake knob and the first spool, said brake arm including at least one spool-engagement surface; and ramped and planar handle body surfaces (164w-y, 166b-c) that complementarily interface with ramped and planar brake knob surfaces (194w-y) such that in a first brake-actuation knob position the at least one spool-engagement surface does not contactingly engage the first spool, and in a second brake-actuation knob position the at least one spool-engagement surface does contactingly engage the first spool. at least a first control wheel in mechanical communication, via a first spool, with the distal catheter body end, where the at least a first control wheel and the first spool are rotatable around a common control wheel axis; a brake knob mounted rotatingly to the proximal handle body and configured to rotate around a brake knob axis that is orthogonal to the control wheel axis; a brake arm in mechanical communication with the brake knob and disposed between the brake knob and the first spool, said brake arm including at least one spool-engagement surface; and ramped and planar handle body surfaces (164w-y, 166b-c) that complementarily interface with ramped and planar brake knob surfaces (194w-y) such that in a first brake-actuation knob position the at least one spool-engagement surface does not contactingly engage the first spool, and in a second brake-actuation knob position the at least one spool-engagement surface does contactingly engage the first spool. in a first brake-actuation knob position the at least one spool-engagement surface does not contactingly engage the first spool, and in a second brake-actuation knob position the at least one spool-engagement surface does contactingly engage the first spool.