Dressing
AssigneeSmith and Nephew Associated Companies Limited
InventorDavid F. Webster
Life of this patent
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Abstract
A dressing suitable for application to lesions of the skin comprises a conformable apertured film. The film consists of two layers laminated together, the first layer which is the lesion contacting layer is formed from a material which swells in contact with water. The second layer does not swell or swells less than the first layer when in contact with water. When the first layer is placed in contact with a wet lesion the different swell characteristics causes the apertures to open allowing water to pass through the film from the wet surface to the top of the second layer. On a dry surface the apertures are closed. Preferably the apertures are in the form of slits. A composite dressing in which an absorbent for the fluid passing through the film is in contact with the second layer is also described.
Claims40
A dressing suitable for application to lesions of the skin which dressing comprises a conformable film having apertures therethrough which open and close said film comprising a first layer for contacting the lesion laminated to a second layer, said first layer comprising a material which when in contact with water swells and said second layer comprising a material which when in contact with water does not swell or swells less than said first layer whereby when in contact with a wet lesion the apertures open allowing water to pass through the film and when in contact with a dry surface the apertures are closed.
A dressing suitable for application to lesions of the skin which dressing consists essentially of a conformable film having apertures therethrough which open and close, said film comprising a first layer for contacting the lesion laminated to a second layer, said first layer comprising a synthetic polymer which has a linear expansion coefficient on hydration of 1.05 to 1.65 and said second layer comprising synthetic polymer which has a linear expension coefficient on hydration of 1.00 to 1.025, whereby said apertures are larger when said dressing is on a wet surface than when not on a wet surface.
A sterile dressing which dressing is suitable for application to lesions of the skin and which dressing has apertures which open and close which dressing consists essentially of a conformable film having apertures in the form of slits therethrough said film comprising a first layer for contacting the lesion laminated to a second layer, said first layer comprising a synthetic polymer which when in contact with water swells with a linear coefficient of expansion on hydration of 1.05 to 1.65 and said second layer comprising synthetic elastomer which when in contact with water does not swell or swells less than said first layer with a linear coefficient of expansion of 1.00 to 1.025 whereby when in contact with a wet lesion the slits open allowing water to pass therethrough and when in contact with a dry surface the slits close.
Dependencies are inferred from the claim text.