Methods and devices for treatment of damaged tissue are disclosed, including treatment of wounds by employing non-electrically powered, reduced pressure therapy devices. The optical compensation film comprises a substrate, and, on the substrate, at least one optically anisotropic layer of a composition comprising a liquid crystalline compound, wherein a difference between a haze of the whole of the optical compensation film and a haze of the substrate along is not more than 0. A pushbutton switch in the receptacle is triggered by insertion of the probe tip therein, thereby providing an electrical signal.