Holding arm for positioning a medical instrument or a medical appliance

1. A segment for a holding arm for positioning a medical instrument or a medical appliance, comprising:

several node structures;

a strut that rigidly connects two of the several node structures to each other;

the strut having flat structures that are joined to one another;

wherein at least two of the flat structures are joined to each other with a form fit; and

wherein one of the flat structures has a tenon, which engages in a corresponding recess in another of the flat structures.

2. The segment according to claim 1 , wherein the several node structures are four node structures and the strut is a first strut, and the segment further comprises a second strut, a third strut, and a fourth strut; and

each of the four struts connects two of the four node structures to each other in a mechanically rigid manner.

3. The segment according to claim 1 , wherein the segment is integrated into a holding arm for positioning the medical instrument or the medical appliance.

4. A segment for a holding arm for positioning a medical instrument or a medical appliance, comprising:

several node structures;

a strut that rigidly connects two of the several node structures to each other;

the strut having flat structures that are joined to one another;

wherein the flat structures each have a narrow and elongate shape;

wherein the flat structures comprise an inner structure, an outer structure, and a connecting web;

wherein a first lengthwise edge of the connecting web is joined to the inner structure, and a second lengthwise edge of the connecting web is joined to the outer structure; and

wherein the inner structure, the connecting web, and the outer structure together form an I-shaped cross section of the strut, or the inner structure, the connecting web, a second connecting web, and the outer structure together form a quadrilateral cross section of the strut.

5. The segment according to claim 4 , wherein the first lengthwise edge is substantially straight and the second lengthwise edge is substantially helical.

6. A segment for a holding arm for positioning a medical instrument or a medical appliance, comprising:

several node structures;

a strut that rigidly connects two of the several node structures to each other;

the strut having flat structures that are joined to one another;

wherein the node structures are each substantially ring-shaped and have grooves on their outer circumference, each of the grooves are configured to receive an end of one of the flat structures.

7. A segment for a holding arm for positioning a medical instrument or a medical appliance, comprising:

several node structures;

several struts each rigidly connecting two of the several node structures to each other;

at least one of the several struts having a first flat structure extending from a first of the several node structures to a second of the several node structures, and a second flat structure extending from the first of the several node structures to the second of the several node structures; and

the first flat structure is joined to the second flat structure by a connecting structure extending substantially from a first end of the first and second flat structures to a second end of the first and second flat structures;

wherein at least one of the first flat structure and the second flat structure has a shape of a cutout of a lateral surface of a cylinder or a cone.

8. The segment according to claim 7 , wherein at least one of the first flat structure and the second flat structure has a shape of a cutout of a lateral surface of a cylinder having an axis of symmetry parallel to a longitudinal axis of the segment.

9. The segment according to claim 7 , wherein at least one of the first flat structure and the second flat structure has a shape of a cutout of a lateral surface of a cone having an axis of symmetry parallel to a longitudinal axis of the segment.