A device for insertion of a medical tool held in an end effector, the device comprising moveable platforms providing motion in two generally orthogonal directions, and two piston mechanisms operating within cylinders, coupled to the moveable platforms, and being attached at their distal end to the end effector by means of a common joint. The pistons may be linear actuators. The end effector is manipulated by driving mechanisms propelling the pistons linearly. The proximal ends of the cylinders may be coupled to a common shaft. The axes of the cylinders and the pistons, the line connecting the pistons axes through the common joint and the axis of the cylinders' common shaft may all be located substantially in a single plane. Coordinated motion of the moveable platforms and the piston mechanisms enables the maintenance of a virtual remote center of motion of the medical tool as its orientation changes.
