Extensible dressings

A dressing comprising:

• a. a layer of material having:
• (i) a length direction (L), a width direction (W), and a thickness direction (T) respectively defining axes in three mutually orthogonal directions, the length direction (L) and the width direction W defining a horizontal plane (“the LW plane”), and the thickness direction (T) defining an up-down direction or a vertical direction relative to the LW plane, the layer of material having a thickness taken in the thickness direction;
• and
• (ii) a plurality of material free regions, each of the material free regions extends through the thickness of the layer of material and the plurality of the material free regions is arranged in the form of a pattern of concentric slitted annuli having a center point (P) in the LW plane, the pattern of concentric slitted annuli having, relative to center point P, a radially innermost concentric annulus and a radially outermost concentric annulus, the innermost and the outermost concentric annuli respectively having the shortest and the longest diameters;
• and
• b. a releasable liner releasably contacting the layer of material;
• wherein the material free regions are arranged end to end, separated by spatial intervals, such that any material free region In located in any concentric annulus I subtends a non-zero valued angle αIn at the center point P where n represents the number identifying a material free region in an annulus having material free regions arranged numerically consecutively in such annulus,
• wherein the sum of the non-zero valued angles subtended by the plurality of the material free regions at the center point P, in any one of the concentric annuli, is less than 360 degrees, and
• wherein the material free regions of any one of the concentric annuli are in a radially staggered relation with the material free regions in any adjacent inner and/or adjacent outer concentric annulus,
• wherein the material free regions that are resiliently openable in the thickness direction T of the dressing to expand at least a portion of the dressing into a three dimensional configuration that is conformable to a three dimensional contour of a skin surface to which the dressing may be applied, and
• wherein any material free region Kn located in any concentric annulus K that is adjacent to concentric annulus I and proximate to material free region In subtends a non-zero valued angle own at the center point P and has an axis of symmetry that bisects the non-zero valued angle αKn, wherein the axis of symmetry of the material free region In and the axis of symmetry of the material free region Kn are staggered relative to one another by an angle φ that has a value falling within a range specified by the equation:
• 0°<φ<(αIn+αKn).

A dressing comprising:

• a.) a layer of material having top and bottom surfaces, the layer of material having a thickness direction (T) and configured to be resiliently freely expandable in the thickness direction T by any force applied in the thickness direction T from a skin surface at or around an area covered or contacted by the dressing,
• the layer of material having mutually orthogonal length (L) and width (W) directions jointly defining a horizontal plane (“the LW plane”) of the layer of material, the LW plane being orthogonal to the thickness direction T and the layer of material having a thickness taken in the thickness direction T;
• the layer of material includes a concentric pattern of annuli having a center point P and configured such that it is resiliently freely expandable in the thickness direction T of the layer of material between an initial substantially flat configuration in the LW plane of the layer of material and an expanded configuration in the thickness direction T of the layer of material,
• the concentric pattern of annuli includes a plurality of material free regions that are freely changeable between an initial closed configuration and an open configuration, and the material free regions being arranged such that when a force is applied in the thickness direction T, from a skin surface at or around an area covered or contacted by the dressing, one or more of the material free regions freely change from the initially closed configuration to the open configuration;
• b.) an adhesive on at least one of the surfaces of the layer of material;
• and
• wherein the plurality of the material free regions is arranged end to end, separated by spatial intervals, such any material free region In located in any concentric annulus I subtends a non-zero valued angle am at the center point P, where n represents the number identifying a material free region in an annuli having material free regions arranged numerically consecutively in such annuli, and the material free regions of any one of the concentric annuli are in a radially staggered relation with respect to the material free regions in any adjacent inner and/or adjacent outer concentric annulus,
• wherein the concentric pattern of annuli and the layer of material expand in the thickness direction T to an expanded configuration, and
• wherein once the force is no longer being applied on the layer of material, the one or more material free regions freely return to their initially closed configuration, causing the pattern of concentric slitted annuli to freely return to its initial substantially flat configuration in the LW plane of the material layer.