Methods and devices for treatment of damaged tissue are disclosed, including treatment of wounds by employing non-electrically powered, reduced pressure therapy devices. Maintenance and control of the sub atmospheric pressure exerted may be provided by such devices while minimizing discomfort to the user. The reduced pressure therapy devices described herein may have one or more one-way valves that control the delivery of negative pressure to the wound region, as well as control the flow of wound exudates and/or air into and out of the therapy devices.
