Dressing with contracting layer for linear tissue sites
Systems, apparatuses, and methods for closing an opening through a surface of a tissue site are described. The system includes a sealing member adapted to cover the opening to form a sealed space and a negative-pressure source adapted to be fluidly coupled to the sealed space to provide negative pressure to the sealed space. The system also includes a contracting layer adapted to be positioned adjacent the opening and formed from a material having a firmness factor and a plurality of holes extending through the contracting layer to form a void space. The holes have a perforation shape factor and a strut angle causing the plurality of holes to collapse in a direction substantially perpendicular to the opening. The contracting layer generates a closing force substantially parallel to the surface of the tissue site to close the opening in response to application of the negative pressure.
1. A dressing for closing an opening through a surface of a tissue site, the dressing comprising:
a tissue interface, comprising:
a contracting layer comprising a porous foam and a plurality of holes extending through the contracting layer to form a void space distinct from pores within the porous foam, wherein the contracting layer further comprises a higher stiffness in a first direction parallel to a thickness of the contracting layer than a second direction perpendicular the thickness, and
a protective layer configured to be positioned between the contracting layer and at least a portion of the surface of the tissue site surrounding the opening; and
a sealing drape configured to cover the tissue interface to form a sealed space, wherein the protective layer extends beyond the contracting layer into contact with a portion of the sealing drape.
2. The dressing of claim 1 , wherein the plurality of holes have a perforation shape factor and a strut angle configured to cause the plurality of holes to collapse in a direction substantially perpendicular to the opening, wherein the contracting layer generates a closing force substantially parallel to the surface of the tissue site to close the opening in response to an application of negative pressure, wherein the strut angle is an angle between a line connecting centers of holes in adjacent rows and an orientation line perpendicular to a direction of the closing force, and wherein the perforation shape factor of a hole of the plurality of holes is a ratio of a first line segment to a second line segment, the first line segment extending from a center of the hole to a perimeter of the hole in a direction perpendicular to a direction of the closing force and the second line segment extending from a center of the hole to a perimeter of the hole in a direction parallel to the direction of the closing force.
3. The dressing of claim 2 , wherein the strut angle is about 90 degrees.
4. The dressing of claim 2 , wherein the strut angle is less than about 90 degrees.
5. The dressing of claim 2 , wherein the perforation shape factor of the hole is less than about 1.
6. The dressing of claim 2 , wherein the perforation shape factor of the hole is more than about 1.
7. The dressing of claim 1 , wherein the plurality of holes are formed in two or more parallel rows, and wherein the plurality of holes in a first row are offset from the plurality of holes in a second row adjacent to the first row.
8. The dressing of claim 7 , wherein the plurality of holes have an average effective diameter, and wherein a first center of one of the holes in the first row is spaced apart from a second center of one of the holes in the second row by a length greater than the effective diameter.
9. The dressing of claim 1 , wherein the contracting layer is formed from a foam material having a firmness factor, wherein the firmness factor is a ratio of density of the foam material in a compressed state to a density of the foam material in an uncompressed state.
10. The dressing of claim 9 , wherein the firmness factor is about 5.
11. The dressing of claim 9 , wherein the firmness factor is about 3.
12. The dressing of claim 1 , wherein a shape of each hole of the plurality of holes is hexagonal.
13. The dressing of claim 1 , wherein a shape of each hole of the plurality of holes is elliptical.
14. The dressing of claim 1 , wherein a shape of each hole of the plurality of holes is circular.
15. The dressing of claim 1 , wherein the contracting layer comprises a compressed foam.
16. The dressing of claim 1 , wherein the contracting layer comprises a felted foam.
17. The dressing of claim 1 , wherein the contracting layer comprises a 3D spacer fabric.
18. The dressing of claim 1 , wherein the contracting layer comprises a thermoplastic elastomer.
19. The dressing of claim 1 , wherein the contracting layer comprises a thermoplastic polyurethane.
20. The dressing of claim 1 , wherein the contracting layer has a thickness of about 15 mm.
21. The dressing of claim 1 , wherein the protective layer comprises a mesh.
22. The dressing of claim 1 , wherein the protective layer comprises a perforated film.
23. The dressing of claim 1 , wherein the protective layer is configured to inhibit irritation of the tissue site.
24. The dressing of claim 1 , wherein the protective layer is laminated to the contracting layer.
25. The dressing of claim 1 , wherein the protective layer is configured to be positioned over the opening.