A delivery device for a collapsible prosthetic heart valve, the delivery device comprising: a catheter assembly including an inner shaft around which a compartment is defined, and a distal sheath having a proximal segment and a distal segment together configured to enclose the compartment; and an operating handle coupled to the catheter assembly, the operating handle including: a housing defining a movement space therein; and, a first lead screw fixedly coupled to the proximal segment of the distal sheath and moveable in first and second opposite longitudinal directions within the movement space; characterized in that the operating handle includes: a second lead screw coupled to the distal segment of the distal sheath and moveable in the first and second longitudinal directions within the movement space; a knob coupled to the housing and rotatable relative to the housing, the knob being threadedly engaged with the first lead screw; and a coupling assembly having a first condition in which rotation of the knob in one direction moves the first lead screw in the first longitudinal direction and does not move the second lead screw in the first or second longitudinal directions, and a second condition in which rotation of the knob in the one direction simultaneously moves the first lead screw in the first longitudinal direction and the second lead screw in the second longitudinal direction. a catheter assembly including an inner shaft around which a compartment is defined, and a distal sheath having a proximal segment and a distal segment together configured to enclose the compartment; and an operating handle coupled to the catheter assembly, the operating handle including: a housing defining a movement space therein; and, a first lead screw fixedly coupled to the proximal segment of the distal sheath and moveable in first and second opposite longitudinal directions within the movement space; characterized in that the operating handle includes: a second lead screw coupled to the distal segment of the distal sheath and moveable in the first and second longitudinal directions within the movement space; a knob coupled to the housing and rotatable relative to the housing, the knob being threadedly engaged with the first lead screw; and a coupling assembly having a first condition in which rotation of the knob in one direction moves the first lead screw in the first longitudinal direction and does not move the second lead screw in the first or second longitudinal directions, and a second condition in which rotation of the knob in the one direction simultaneously moves the first lead screw in the first longitudinal direction and the second lead screw in the second longitudinal direction. a housing defining a movement space therein; and, a first lead screw fixedly coupled to the proximal segment of the distal sheath and moveable in first and second opposite longitudinal directions within the movement space; characterized in that the operating handle includes: a second lead screw coupled to the distal segment of the distal sheath and moveable in the first and second longitudinal directions within the movement space; a knob coupled to the housing and rotatable relative to the housing, the knob being threadedly engaged with the first lead screw; and a coupling assembly having a first condition in which rotation of the knob in one direction moves the first lead screw in the first longitudinal direction and does not move the second lead screw in the first or second longitudinal directions, and a second condition in which rotation of the knob in the one direction simultaneously moves the first lead screw in the first longitudinal direction and the second lead screw in the second longitudinal direction. a second lead screw coupled to the distal segment of the distal sheath and moveable in the first and second longitudinal directions within the movement space; a knob coupled to the housing and rotatable relative to the housing, the knob being threadedly engaged with the first lead screw; and a coupling assembly having a first condition in which rotation of the knob in one direction moves the first lead screw in the first longitudinal direction and does not move the second lead screw in the first or second longitudinal directions, and a second condition in which rotation of the knob in the one direction simultaneously moves the first lead screw in the first longitudinal direction and the second lead screw in the second longitudinal direction.