Shaft for a medical instrument, comprising a profiled guide, medical instrument, robot, and method for producing a shaft

A shaft for a medical instrument, the elongate shaft extending in a longitudinal direction from a proximal end to a distal end and having at its distal end an end portion, the end portion being able to be deflected relative to a longitudinal center axis of the shaft by means of a distal-side hinge mechanism and a tool being arrangeable at the end portion able to be deflected, and a plurality of steering elements for connecting a proximal-side drive to the distal-side hinge mechanism being guided through the interior of the shaft in the longitudinal direction, the shaft comprising:

• an inner tube aligned in the longitudinal direction around a longitudinal center axis;
• an outer tube concentric to the inner tube;
• and
• an elongate contoured guide for guiding the steering elements between the inner tube and the outer tube, the elongated contoured guide disposed between the outer tube and the inner tube, the elongated contoured guide including plurality of first contact points spaced apart from each other and contacting a portion of an inner surface of the outer tube along a first arc length and a plurality of second contact points contacting a portion of an outer surface of the inner tube along a second arc length so as to form a plurality of first guide channels disposed between an outer surface of the elongate contoured guide and the inner surface of the outer tube and a plurality of second guide channels disposed between an inner surface of the elongate contoured guide and the outer surface of the inner tube;
• and a third contact point spaced apart from the first contact point and the second contact point, the third contact point contacting a portion of the inner surface of the outer tube along a third arc length greater than the first contact point and the second contact point so as to form a third guide channel having an area greater than an area of each of the plurality of first guide channels and second guide channels.