Abstract: The invention relates to an instrument for endoscopic therapy. A cutting tool including a rigid tubular shank is so guided within a tubular longitudinally slotted instrument shank having an essentially oval inner cross section, that the cutting tool may be tilted out of the axis of the instrument shank, whereby a cutter of the cutting tool penetrates the longitudinal slit of the instrument shank and projects beyond the diameter of the instrument shank. In this way by varying the tilting angle of the cutting tool the cutting depth of the cutting tool may be delicately set.

Abstract: A surgical manipulator arm has a first and a second control ball rotatably mounted and disposed at a proximal end and a distal end of an outer-shaft tube, respectively. The control balls are coupled to each other through coupling elements such, for example, as control wires so that rotational movements of the first control ball can be transmitted correspondingly to the second control ball or vice versa. The manipulator arm has an actuator portion connected to the first control ball and a follower portion connected to the second control ball for selectively and detachably mounting a handling part and an effector part of an instrument. The first and second control balls are mounted in such a way so as to permit their respective actuator and follower portions to rotate and pivot about the longitudinal axis of the outer-shaft tube. The central bore defines a connective passage from the actuator portion, through the outer-shaft tube, and to the follower portion.