Abstract: There is disclosed a flexible sheet structure having improved conformability yet remaining strong and robust. The structure is made up of a plurality of modules that allow relative rotation in both an axis parallel to the plane and perpendicular to the plane of the sheet when laid flat. This allows the density of the sheet to be locally or globally changed so that improved conformability around complex shapes is provided. There is also disclosed a means for locking and unlocking the modules of the sheet using a locking material in each connection that is activated by the external addition of energy (e.g. heat energy).

Abstract: Apparatus is described for objectively testing the condition of a support surface such as mattress. The apparatus comprises a frame (8, 21, 22) for extending over the support surface, an indenter (5) mounted on said frame and a load sensor (4) disposed between the indenter and the frame, manually operated means (6) for pressing the indenter into the support surface, displacement measuring means for measuring the movement of the indenter into the support surface and data processing means (7) for analyzing the force applied to the indenter in relation to the displacement of the indenter into the support surface.