Medical instrument and method for manipulating, in particular retracting tissue or an organ

1. A medical instrument for manipulating tissue or an organ in a human or an animal body, comprising:

an elongated shaft having a distal portion introducible into said body, and at least one working element arranged at a distal end portion of said distal portion of said shaft for manipulating said tissue or organ, said at least one working element comprising at least one magnetically acting element producing a magnetic field for manipulating said tissue or organ;

said at least one magnetically acting element being movably arranged at said distal end of said shaft;

said at least one magnetically acting element being rotatably mounted at said distal end portion of said shaft for rotation about a rotation axis running through said at least one magnetically acting element;

said rotation axis extending transverse to a longitudinal axis of the shaft;

said at least one magnetically acting element having magnetic poles and the rotation axis of said at least one magnetically acting element being arranged between said magnetic poles;

wherein rotation of the at least one magnetically acting element about the rotation axis changes the strength of a magnetic force acting between the at least one magnetically acting element and the tissue or organ.

2. The instrument of claim 1 , wherein said at least one magnetically acting element is a permanent magnet.

3. The instrument of claim 1 , wherein said at least one magnetically acting element is rod-shaped.

4. The instrument of claim 1 , wherein said at least one magnetically acting element is a toroidal magnet.

5. The instrument of claim 1 , wherein said at least one magnetically acting element is an electromagnet.

6. The instrument of claim 1 , wherein said at least one magnetically acting element is a magnetic dipole.

7. The instrument of claim 1 , wherein said at least one magnetically acting element is movably mounted at said distal end portion of said shaft for movement in a longitudinal direction of said shaft and transverse to said longitudinal direction of said shaft.

8. The instrument of claim 1 , wherein said at least one magnetically acting element is a magnetic dipole, and said rotation axis is oriented at least approximately perpendicular to a longitudinal direction of said shaft and at least approximately perpendicular to a dipole axis of said magnetic dipole.

9. The instrument of claim 1 , wherein said at least one magnetically acting element is articulatedly mounted at said distal end portion of said shaft for pivoting about at least one pivot axis spaced apart from said at least one magnetically acting element.

10. The instrument of claim 9 , wherein said at least one magnetically acting element is arranged at a distal end of an articulated arm which is mounted to said shaft.

11. The instrument of claim 9 , wherein said at least one magnetically acting element is pivotable about at least a second pivot axis.

12. The instrument of claim 1 , further comprising an actuating device which is operatively connected with said at least one working element for moving said at least one magnetically acting element with respect to said shaft.

13. The instrument of claim 12 , wherein said actuating device is operatively connected with said at least one working element through an elongated force transmission element movable with respect to said shaft in a longitudinal direction of said shaft.

14. The instrument of claim 12 , wherein at least one sensor is arranged at said distal end portion of said shaft for sensing a distance between said at least one magnetically acting element and a surface of said tissue or organ, and said at least one sensor produces an output signal for controlling said actuating device.

15. The instrument of claim 1 , comprising a plurality of magnetically acting elements.

16. The instrument of claim 1 , wherein at least one sensor is arranged at said distal end portion of said shaft for sensing a distance between said at least one magnetically acting element and a surface of said tissue or organ.

17. The instrument of claim 16 , wherein said at least one sensor is chosen from a group consisting of a magnetically sensitive sensor or an optical sensor.