Abstract: A medical system includes a head having an end arranged to face a reference plane and a multistage slide mechanism coupled with the head. The multistage slide mechanism includes a coarse-float mechanism configured to enable movement of the head relative to the reference plane, and to prevent movement of the head toward the reference plane while allowing movement of the head away from the reference plane. A one-way brake associated with the coarse-float mechanism is configured to transition between a locked state and an unlocked state in response to a presence of or an absence of a first triggering event. In the locked state, the one-way brake prevents movement of the head toward the reference plane and simultaneously allows movement of the head away from the reference plane. In the unlocked state, the one-way brake allows movement of the head toward the reference plane and movement of the head away from the reference plane.