Adaptive transparent film dressings.

Transparent film dressings have many of the attributes of the ideal wound dressing. However, currently available film dressings are deficient in their ability to handle varying levels of wound exudate. The permeability of polymeric films to water vapor is discussed and techniques are described to produce films in which the moisture vapor permeability is a function of the moisture in the environment. Illustrations are provided showing the variation of permeability with relative humidity and water contact. The unique properties of coextruded films are illustrated and the responsiveness of such a film dressing to varying conditions at the wound are discussed.