Tissue Treatment Systems And Methods Having A Porous Substrate With A Compressed Region And An Expanded Region

Abstract

A system for treating a tissue site of a patient includes a dressing filler adapted to be positioned at the tissue site. The dressing filler is comprised of a porous substrate having at least one compressed region and at least one expanded region. The compressed region of the porous substrate is held in a compressed state by a first coating capable of dissolving in the presence of a fluid, and the expanded region of the porous substrate is held in an expanded state by a second coating.

We claim: 
     
         1 . A system for treating a tissue site of a patient, the system comprising:
 a dressing filler having a wound-facing surface adapted to be positioned at the tissue site, the dressing filler comprising a porous substrate including at least one compressed region initially held away from a relaxed state and in a compressed state, wherein a profile of the wound-facing surface is configured to change when the at least one compressed region expands from the compressed state to the relaxed state;   a cover configured to create a sealed space containing the dressing filler at the tissue site; and   a reduced pressure source configured to be in fluid communication with the sealed space.   
     
     
         2 . The system of  claim 1 , wherein the at least one compressed region is held away from the relaxed state and in the compressed state by a coating, and wherein the at least one compressed region is configured to expand upon removal of the coating. 
     
     
         3 . The system of  claim 1 , wherein a volume of the porous substrate increases when the compressed region expands. 
     
     
         4 . The system of  claim 1 , wherein the porous substrate is an open-cell, reticulated foam. 
     
     
         5 . The system of  claim 1 , wherein the porous substrate is a polyurethane foam. 
     
     
         6 . The system of  claim 2 , wherein the coating is a first coating, wherein the porous substrate comprises at least one expanded region in which the porous substrate is held away from the relaxed state and in an expanded state by a second coating, and wherein the wound facing-surface further includes a protrusion associated with the at least one expanded region when the at least one expanded region is in the expanded state. 
     
     
         7 . The system of  claim 6 , wherein the first coating is the same as the second coating. 
     
     
         8 . The system of  claim 2 , wherein the coating is configured to be removed from the at least one compressed region in a presence of exudate from the tissue site. 
     
     
         9 . The system of  claim 2 , wherein the coating is a starch. 
     
     
         10 . The system of  claim 2 , wherein the coating is polyvinyl alcohol. 
     
     
         11 . The system of  claim 2 , wherein the coating is a polymer. 
     
     
         12 . The system of  claim 1 , wherein the at least one compressed region is arranged in a horizontal layer such that upon expansion of the at least one compressed region, a force produced by the expansion of the least one compressed region redistributes a load on the tissue site. 
     
     
         13 . The system of  claim 12 , further comprising a plurality of nodes at the wound-facing surface, wherein the plurality of nodes are configured to move along the tissue site from a first position when the at least one compressed region is in the compressed state to a second position when the at least one compressed region expands from the compressed state to the relaxed state. 
     
     
         14 . The system of  claim 1 , wherein the wound-facing surface includes an indentation associated with the at least one compressed region when the at least one compressed region is in the compressed state. 
     
     
         15 . The system of  claim 14 , wherein when the at least one compressed region expands from the compressed state to the relaxed state, the profile of the wound-facing surface is configured to change such that the indentation associated with the at least one compressed region in the compressed state decreases as the at least one compressed region expands to the relaxed state. 
     
     
         16 . The system of  claim 1 , wherein the at least one compressed region is configured to expand from the compressed state to the relaxed state in the presence of exudate from the tissue site.