An operating handle configured to be coupled to a catheter assembly, the operating handle comprising: a nose configured to be affixed to a proximal end of the catheter assembly; an axial shaft having a distal end affixed to the nose, a proximal end, and a shaft longitudinal axis; a base translationally fixed to the proximal end of the axial shaft; characterised by: a screw having external threads and a non-circular lumen, the axial shaft extending through the non-circular lumen so that the screw is translatable along the axial shaft and nonrotatable relative to the axial shaft; a knob having internal threads engaged with the external threads of the screw, the knob being translationally fixed to the nose; and a collar extending at least partially around the axial shaft in a circumferential direction, the collar being rotationally fixed to the nose, the axial shaft, and the screw, the collar being translatable between a proximal position and a distal position; with the collar in the proximal position, the knob being rotatable relative to the collar and the collar being nonrotatable relative to the base, so that rotation of the knob about the shaft longitudinal axis results in translation of the screw along the axial shaft, and with the collar in the distal position, the base being rotatable relative to the collar and the collar being nonrotatable relative to the knob, so that rotation of the knob about the shaft longitudinal axis results in rotation of the nose, the axial shaft, the screw, and the collar relative to the base. a nose configured to be affixed to a proximal end of the catheter assembly; an axial shaft having a distal end affixed to the nose, a proximal end, and a shaft longitudinal axis; a base translationally fixed to the proximal end of the axial shaft; characterised by: a screw having external threads and a non-circular lumen, the axial shaft extending through the non-circular lumen so that the screw is translatable along the axial shaft and nonrotatable relative to the axial shaft; a knob having internal threads engaged with the external threads of the screw, the knob being translationally fixed to the nose; and a collar extending at least partially around the axial shaft in a circumferential direction, the collar being rotationally fixed to the nose, the axial shaft, and the screw, the collar being translatable between a proximal position and a distal position; with the collar in the proximal position, the knob being rotatable relative to the collar and the collar being nonrotatable relative to the base, so that rotation of the knob about the shaft longitudinal axis results in translation of the screw along the axial shaft, and with the collar in the distal position, the base being rotatable relative to the collar and the collar being nonrotatable relative to the knob, so that rotation of the knob about the shaft longitudinal axis results in rotation of the nose, the axial shaft, the screw, and the collar relative to the base. a screw having external threads and a non-circular lumen, the axial shaft extending through the non-circular lumen so that the screw is translatable along the axial shaft and nonrotatable relative to the axial shaft; a knob having internal threads engaged with the external threads of the screw, the knob being translationally fixed to the nose; and a collar extending at least partially around the axial shaft in a circumferential direction, the collar being rotationally fixed to the nose, the axial shaft, and the screw, the collar being translatable between a proximal position and a distal position; with the collar in the proximal position, the knob being rotatable relative to the collar and the collar being nonrotatable relative to the base, so that rotation of the knob about the shaft longitudinal axis results in translation of the screw along the axial shaft, and with the collar in the distal position, the base being rotatable relative to the collar and the collar being nonrotatable relative to the knob, so that rotation of the knob about the shaft longitudinal axis results in rotation of the nose, the axial shaft, the screw, and the collar relative to the base.