Roll-up wound protector with asymmetric ring

1. A surgical wound protector having a fully extended configuration and a gathered configuration, the wound protector comprising:

a) a distal ring;

b) a proximal ring comprising a central axis and a cross-sectional geometry, the cross-sectional geometry comprising

(i) a centroid, a longitudinal axis parallel to the central axis and crossing the centroid when the wound protector is in the fully extended configuration, and a lateral axis normal to the central axis and crossing the centroid when the wound protector is in the fully extended configuration;

(ii) a shape being asymmetric about the longitudinal axis and asymmetric about the lateral axis;

(iii) a height along the longitudinal axis and a width along the lateral axis as measured when the wound protector is in the fully extended configuration, the height being greater than the width; and

c) a flexible sleeve having a length extending between the proximal and distal rings;

wherein the proximal ring is rollable to gather the flexible sleeve around the proximal ring and shorten the length of the flexible sleeve from the fully extended configuration to a gathered configuration.

2. The surgical wound protector of claim 1 , wherein the cross-sectional geometry is solid.

3. The surgical wound protector of claim 1 , wherein the cross-sectional geometry is generally s-shaped.

4. The surgical wound protector of claim 1 , wherein the cross-sectional geometry is substantially constant around the proximal ring.

5. The surgical wound protector of claim 1 , wherein the proximal ring has substantially no residual hoop stress.

6. The surgical wound protector of claim 1 , wherein the proximal ring rolls in resting increments of 180 degrees.

7. The surgical wound protector of claim 6 , wherein the flip force for the proximal ring is less than 3 in*lbs.

8. The surgical wound protector of claim 6 , wherein the flip force for the proximal ring is substantially the same for each incremental rotation.

9. The surgical wound protector of claim 1 , wherein the longitudinal axis and lateral axis define four quadrants, the shape of the cross-sectional geometry being symmetric between each pair of diagonal quadrants.

10. A surgical wound protector, comprising:

a) a distal ring;

b) a proximal ring extending about a central ring axis, the proximal ring having a proximal ring cross-section having a centroid, a longitudinal axis extending through the centroid and extending substantially parallel to the central ring axis, and a lateral axis extending through the centroid and substantially perpendicular to the longitudinal axis,

wherein the proximal ring cross section is asymmetric about any axis extending through the centroid in the plane of the cross-section axis, and wherein the proximal ring comprises a medial surface having a single continuous circumferential recess and a lateral surface having a single continuous circumferential recess, the two recesses being longitudinally staggered relative one another; and

c) a flexible sleeve extending between the proximal and distal rings;

wherein the proximal ring is rollable to gather the flexible sleeve around the proximal ring and shorten the length of the flexible sleeve between the proximal and distal rings.

11. The surgical wound protector of claim 10 , wherein the proximal ring has a cross-sectional geometry comprising a height and a width, the height being greater than the width.

12. The surgical wound protector of claim 10 , wherein the circumferential recesses in the medial and lateral surfaces are arcuate.

13. The surgical wound protector of claim 10 , wherein the proximal ring is rollable between resting increments and the flip force is substantially the same between resting increments.