A reduced-pressure treatment system for providing reduced-pressure treatment to a tissue site on a patient, the reduced-pressure treatment system comprising: a manifold for disposing proximate the tissue site; a sealing member for placing over the tissue site and the manifold and operable to form a fluid seal; and a reduced-pressure treatment device comprising: a canister unit (108, 208, 308, 408) comprising: a pump head including at least one diaphragm (156, 158, 256, 258, 356, 358), the pump head fluidly coupled to the tissue site to provide reduced pressure to the tissue site, and a fluid reservoir fluidly coupled to the pump head for collecting fluid from the tissue site, a pump control unit fluidly separate from the canister unit and operable to provide pump energy to the at least one diaphragm in the pump head to cause the pump head to generate reduced pressure, the pump control unit comprising: a control device, and a power subsystem for providing power to the control device, at least one linking interface (186, 188) associated with the canister unit and the pump control unit, the at least one linking interface for providing the pump energy to the pump head, and wherein the control device and the power subsystem provide the pump energy to the at least one linking interface to generate reduced pressure; characterized in that the pump control unit has at least one sensor for measuring the displacement of the at least one diaphragm (156, 158, 256, 258, 356, 358) included in the pump head. a manifold for disposing proximate the tissue site; a sealing member for placing over the tissue site and the manifold and operable to form a fluid seal; and a reduced-pressure treatment device comprising: a canister unit (108, 208, 308, 408) comprising: a pump head including at least one diaphragm (156, 158, 256, 258, 356, 358), the pump head fluidly coupled to the tissue site to provide reduced pressure to the tissue site, and a fluid reservoir fluidly coupled to the pump head for collecting fluid from the tissue site, a pump control unit fluidly separate from the canister unit and operable to provide pump energy to the at least one diaphragm in the pump head to cause the pump head to generate reduced pressure, the pump control unit comprising: a control device, and a power subsystem for providing power to the control device, at least one linking interface (186, 188) associated with the canister unit and the pump control unit, the at least one linking interface for providing the pump energy to the pump head, and wherein the control device and the power subsystem provide the pump energy to the at least one linking interface to generate reduced pressure; characterized in that the pump control unit has at least one sensor for measuring the displacement of the at least one diaphragm (156, 158, 256, 258, 356, 358) included in the pump head. a canister unit (108, 208, 308, 408) comprising: a pump head including at least one diaphragm (156, 158, 256, 258, 356, 358), the pump head fluidly coupled to the tissue site to provide reduced pressure to the tissue site, and a fluid reservoir fluidly coupled to the pump head for collecting fluid from the tissue site, a pump head including at least one diaphragm (156, 158, 256, 258, 356, 358), the pump head fluidly coupled to the tissue site to provide reduced pressure to the tissue site, and a fluid reservoir fluidly coupled to the pump head for collecting fluid from the tissue site, a pump control unit fluidly separate from the canister unit and operable to provide pump energy to the at least one diaphragm in the pump head to cause the pump head to generate reduced pressure, the pump control unit comprising: a control device, and a power subsystem for providing power to the control device, at least one linking interface (186, 188) associated with the canister unit and the pump control unit, the at least one linking interface for providing the pump energy to the pump head, and a control device, and a power subsystem for providing power to the control device, at least one linking interface (186, 188) associated with the canister unit and the pump control unit, the at least one linking interface for providing the pump energy to the pump head, and wherein the control device and the power subsystem provide the pump energy to the at least one linking interface to generate reduced pressure; characterized in that the pump control unit has at least one sensor for measuring the displacement of the at least one diaphragm (156, 158, 256, 258, 356, 358) included in the pump head.