A wound dressing for an aspirated wound dressing system, with a wound interface region for contacting or facing a wound site； an aspiration port for receiving suction for aspiration of wound exudate； a liquid permeable pressure barrier disposed between the wound interface region and the aspiration port for substantially preventing application of negative pressure from the aspiration port to the wound interface region； at least one atmospheric vent for equalizing with atmosphere the pressure at the wound interface region； and a liquid sensor for sensing liquid within the wound dressing for controlling application of suction by the aspiration unit.
