In various aspects, the wound therapy apparatus disclosed herein includes a wound interface that defines an enclosed space over a wound bed that is fluid tight when secured to a skin surface around the wound bed. The wound therapy apparatus includes a control group that cooperates with the wound interface to regulate input of input fluid comprising a gas having an O2 concentration greater than atmospheric air into the enclosed space and to regulate the withdrawal of output fluid from the enclosed space in order to vary an actual pressure pa within the enclosed space generally between a minimum pressure pmin and a maximum pressure pmax. Related methods of use of the wound therapy apparatus are disclosed herein.