Low friction trocar valve

1. A trocar device comprising:

a trocar cannula;

a valve housing connectable to an end of the trocar cannula; and

a valve formed in an opening of the valve housing, the valve comprising:

a set of sheets arranged circularly and defining an entry point for insertion of an instrument, wherein each sheet of the set of sheets comprises areas that overlap with two adjacent sheets of the set of sheets;

wherein each sheet of the set of sheets comprises a half-circle portion with a first arc length and an arc portion with a second arc length, wherein the half-circle portion of each sheet connects to the arc portion of each sheet along a straight line with a length equal to two times the first arc length; and

wherein, when the set of sheets is arranged circularly, outer perimeters of the arc portions together form an outer circle with a radius equal to the first arc length plus the second arc length.

2. The trocar device of claim 1 , wherein the valve housing further comprises a circular cap placed on top of the set of sheets to prevent the set of sheets from folding.

3. The trocar device of claim 1 , wherein the valve further comprises:

an additional set of sheets placed underneath the set of sheets in the valve housing, wherein the additional set of sheets and the set of sheets are separated by a gap, wherein the additional set of sheets is arranged circularly and defining an additional entry point such that each sheet of the additional set of sheets comprises areas that overlap with two adjacent sheets of the additional set of sheets.

4. The trocar device of claim 1 , wherein the set of sheets comprises material with a friction-coefficient to stainless steel that is lower than a friction-coefficient of silicone to stainless steel.

5. The trocar device of claim 1 , wherein the set of sheets comprises at least one of polyimide film or glass film.

6. The trocar device of claim 1 , wherein the set of sheets comprises Polytetrafluoroethylene (PTFE) material.

7. The trocar device of claim 1 , wherein the set of sheets comprises Polyether ether ketone (PEEK) material.

8. The trocar device of claim 1 , wherein each sheet of the set of sheets is attached to at least another sheet of the set of sheets.

9. The trocar device of claim 1 , wherein the valve housing is formed as a part of the trocar cannula.

10. A trocar valve attached to a valve housing, the trocar valve comprising:

a set of sheets arranged circularly and defining an entry point for insertion of an instrument, wherein each sheet of the set of sheets comprises areas that overlap with two adjacent sheets of the set of sheets;

wherein each sheet of the set of sheets comprises a half-circle portion with a first arc length and an arc portion with a second arc length, wherein the half-circle portion of each sheet connects to the arc portion of each sheet along a straight line with a length equal to two times the first arc length; and

wherein, when the set of sheets is arranged circularly, outer perimeters of the arc portions together form an outer circle with a radius equal to the first arc length plus the second arc length.

11. The trocar valve of claim 10 , wherein the valve housing is connectable to a trocar cannula or formed as part of the trocar cannula.

12. The trocar valve of claim 10 , further comprising:

a circular cap placed on top of the set of sheets to prevent the set of sheets from folding.

13. The trocar valve of claim 10 , wherein the trocar valve further comprises:

an additional set of sheets placed underneath the set of sheets in the valve housing, wherein the additional set of sheets and the set of sheets are separated by a gap, wherein the additional set of sheets is arranged circularly and defining an additional entry point such that each sheet of the additional set of sheets comprises areas that overlap with two adjacent sheets of the additional set of sheets.

14. The trocar valve of claim 10 , wherein the set of sheets comprises material with a friction-coefficient to stainless steel that is lower than a friction-coefficient of silicone to stainless steel.

15. The trocar valve of claim 10 , wherein the set of sheets comprises at least one of polyimide film, glass film, a Polytetrafluoroethylene (PTFE) material, or a Polyether ether ketone (PEEK) material.

16. A trocar valve assembly connectable to a trocar cannula, the trocar valve assembly comprising:

a valve housing; and

a valve coupled to the valve housing, the valve comprising a set of sheets arranged circularly and defining an entry point for insertion of an instrument, wherein each sheet of the set of sheets comprises areas that overlap with two adjacent sheets of the set of sheets;

wherein each sheet of the set of sheets comprises a half-circle portion with a first arc length and an arc portion with a second arc length, wherein the half-circle portion of each sheet connects to the arc portion of each sheet along a straight line with a length equal to two times the first arc length; and

wherein, when the set of sheets is arranged circularly, outer perimeters of the arc portions together form an outer circle with a radius equal to the first arc length plus the second arc length.

17. The trocar valve assembly of claim 16 , wherein the trocar valve assembly is formed as part of the trocar cannula.

18. The trocar valve assembly of claim 16 , wherein the trocar cannula has a first end and a second end, wherein the first end comprises the trocar valve assembly.

19. The trocar device of claim 1 , wherein the half-circle portion and the arc portion of each sheet together form a continuous sheet.

20. The trocar valve of claim 10 , wherein the half-circle portion and the arc portion of each sheet together form a continuous sheet.