Methods, apparatuses, and systems for determining a pressure in a sealed therapeutic environment provided by a dressing are described. The system can include a tissue interface configured to be positioned adjacent a tissue site. At least a portion of the tissue interface is electrically conductive. The system also includes a sealing member configured to be disposed over the tissue interface to form the sealed therapeutic environment. The system includes a dressing interface configured to fluidly connect the sealed therapeutic environment with a therapy unit. The dressing interface is further configured to be electrically coupled to the tissue interface and the therapy unit.