Systems and methods for sensing properties of fluids from a tissue site

A method of applying negative-pressure to a dressing for treating a tissue site, the method comprising:

• positioning a tissue interface on the tissue site, the tissue interface having a first layer comprising a foam and a second layer comprising a plurality of apertures, the second layer adapted to be positioned between the first layer and the tissue site;
• positioning a sensing portion of a pH sensor between the second layer and the tissue site and extending a conductor portion of the pH sensor through the tissue interface;
• positioning a drape having an opening over the tissue interface to cover the tissue interface and the tissue site;
• positioning a dressing interface adjacent the drape and the tissue interface wherein the dressing interface has a therapy cavity fluidly coupled to the first layer of the tissue interface and a component cavity fluidly isolated from the therapy cavity;
• electrically coupling a terminal portion of the pH sensor to an electrical component disposed within the component cavity with an electrical connector, wherein the terminal portion is coupled to the conductor portion disposed on the first layer, the terminal portion being exposed through the opening in the drape, the drape further isolating the tissue interface from the terminal portion;
• mechanically coupling the dressing interface to the tissue interface to enhance the continuity of the electrical connector by coupling a magnetic attachment on the terminal portion to a magnet disposed on the dressing interface within the therapy cavity, the magnet being releasably engageable to the magnetic attachment;
• and
• applying negative pressure to the therapy cavity through a port to draw fluid from the tissue site, through the tissue interface, and into the therapy cavity.

A dressing for treating a tissue site, comprising:

• a tissue interface having a first layer comprising a foam and a second layer comprising a plurality of apertures, the second layer adapted to be positioned between the first layer and the tissue site;
• a dressing interface having a housing including a therapy cavity and a component cavity fluidly isolated from the therapy cavity, the therapy cavity having an opening adapted to be in fluid communication with the first layer and a port adapted to be fluidly coupled to a negative-pressure source;
• a control device disposed within the component cavity and including a microprocessor;
• a first pH sensor having a sensing portion adapted to be positioned between the second layer and the tissue site and a terminal portion electrically coupled to the microprocessor, the first pH sensor configured to detect a pH level of fluid present at the tissue site and to provide a pH output to the microprocessor based on the pH level detected;
• an electrical connector adapted to electrically couple the terminal portion to the microprocessor;
• a mechanical coupler adapted to couple the dressing interface to the tissue interface and enhance the continuity of the electrical connector, the mechanical coupler comprising a magnetic attachment coupled to the terminal portion and a magnet disposed on the dressing interface within the therapy cavity and is releasably engageable to the magnetic attachment;
• and
• a drape having an opening exposing the terminal portion and coupled to the first layer and covering the tissue interface and the tissue site to fluidly isolate the terminal portion from the tissue interface.