Endoscope and cleaning instrument for an endoscope

1. An endoscope comprising:

an endoscope shaft with a distal shaft portion, a central shaft portion, and a proximal shaft portion; and

a light admission face at the distal shaft portion;

wherein a cross section of the central shaft portion is smaller than a cross section of the distal shaft portion, and the cross section of the central shaft portion is smaller than a cross section of the proximal shaft portion,

wherein the distal shaft portion, the central shaft portion, and the proximal shaft portion do not share a central longitudinal axis, and

wherein each of the cross section of the central shaft portion, the cross section of the distal shaft portion, and the cross section of the proximal shaft portion is orthogonal to a longitudinal axis of the central shaft portion, and the cross section of the proximal shaft portion is offset with respect to the cross section of the central shaft portion in a first direction that is opposite to or different from a second direction in which the cross section of the distal shaft portion is offset with respect to the cross section of the central shaft portion.

2. The endoscope according to claim 1 , wherein:

an edge of the cross section of the distal shaft portion is circular and has a first radius;

an edge of the cross section of the central shaft portion has a first circular-arc-shaped edge portion having a second radius, and a second circular-arc-shaped edge portion having a third radius;

the second radius and the third radius are each equal to or smaller than the first radius; and

the center points of the first and second circular-arc-shaped edge portions are spaced apart from each other.

3. The endoscope according to claim 1 , wherein a first surface of the central shaft portion is flush at a first side with a surface of the distal shaft portion, and a second surface of the central shaft portion is flush at a second side opposite the first side with a surface of the proximal shaft portion.

4. The endoscope according to claim 1 , wherein in relation to a direction parallel to a longitudinal axis of the central shaft portion, the cross section of the central shaft portion at a first end of the central shaft portion is arranged at a portion of an edge of the cross section of the proximal shaft portion, and the cross section of the central shaft portion at a second end of the central shaft portion is arranged at a portion of an edge of the cross section of the distal shaft portion.

5. The endoscope according to claim 1 , further comprising:

a working channel for receiving an instrument in the proximal shaft portion; wherein a distal outlet opening of the working channel is arranged beside a proximal end of the central shaft portion.

6. The endoscope according to claim 5 , wherein:

a cross section of the working channel in the proximal shaft portion is not circular.

7. The endoscope according to claim 6 , wherein:

the cross section of the working channel fills the cross section of the proximal shaft portion less the cross section of the central shaft portion.

8. The endoscope according to claim 1 , further comprising:

a guide for guiding an instrument at the central shaft portion.

9. The endoscope according to claim 1 , wherein the distal shaft portion has a constant cross section over the length of the distal shaft portion, the cross section taken perpendicular to the length of the distal shaft portion;

wherein the central shaft portion has a constant cross section over the length of the central shaft portion, the cross section taken perpendicular to the length of the central shaft portion.

10. The endoscope according to claim 1 , wherein a longitudinal axis of the central shaft portion and a longitudinal axis of the distal shaft portion are parallel to each other.

11. An endoscope comprising:

an endoscope shaft with a distal shaft portion, a central shaft portion, and a proximal shaft portion; and

a light admission face at the distal shaft portion;

wherein a cross section of the central shaft portion is smaller than a cross section of the distal shaft portion, and the cross section of the central shaft portion is smaller than a cross section of the proximal shaft portion, each of the cross section of the central shaft portion, the cross section of the distal shaft portion, and the cross section of the proximal shaft portion is orthogonal to a longitudinal axis of the central shaft portion,

for each of the cross section of the central shaft portion, the cross section of the distal shaft portion, and the cross section of the proximal shaft portion, the cross section has a first edge point, a second edge point and an intersection point, a line between the first and second edge points intersects with a central longitudinal axis of the central shaft portion at the intersection point, and the lines between the first and second edge points parallel with each other,

a distance between the first edge point and the intersection point of the distal shaft portion is same as a distance between the first edge point and the intersection point of the central shaft portion, a distance between the second edge point and the intersection point of the distal shaft portion is larger than a distance between the second edge point and the intersection point of the central shaft portion, and

a distance between the first edge point and the intersection point of the proximal shaft portion is larger than a distance between the first edge point and the intersection point of the central shaft portion, a distance between the second edge point and the intersection point of the proximal shaft portion is same as a distance between the second edge point and the intersection point of the central shaft portion.

12. An endoscope comprising:

an endoscope shaft with a distal shaft portion, a central shaft portion, and a proximal shaft portion; and

a light admission face at the distal shaft portion;

wherein a cross section of the central shaft portion is smaller than a cross section of the distal shaft portion, and the cross section of the central shaft portion is smaller than a cross section of the proximal shaft portion,

a first peripheral surface of the central shaft portion is flush in a direction parallel to a longitudinal axis of the central shaft portion at a first side evenly with a peripheral surface of the distal shaft portion, and a second peripheral surface of the central shaft portion is flush in the direction parallel to the longitudinal axis of the central shaft portion at a second side opposite the first side evenly with a peripheral surface of the proximal shaft portion.

13. An endoscope comprising:

an endoscope shaft with a distal shaft portion, a central shaft portion, and a proximal shaft portion; and

a light admission face at the distal shaft portion;

wherein a cross section of the central shaft portion is smaller than a cross section of the distal shaft portion, and the cross section of the central shaft portion is smaller than a cross section of the proximal shaft portion,

the distal shaft portion, the central shaft portion, and the proximal shaft portion do not share a central longitudinal axis,

a first edge of the central shaft portion in a direction parallel to a longitudinal axis of the central shaft portion aligns with a first edge of the distal shaft portion in the direction parallel to the longitudinal axis of the central shaft portion, a second edge of the central shaft portion in the direction parallel to the longitudinal axis of the central shaft portion aligns with a second edge of the proximal shaft portion in the direction parallel to the longitudinal axis of the central shaft portion, the first and second edges of the central shaft portion are different edges.