Systems and methods are provided for sensing fluid in a dressing on a patient and producing an electrical signal. In one instance, a galvanic cell is used as an electronic detection device. The galvanic cell is placed in the dressing and produces voltage when the dressing is substantially saturated. In one instance, the dressing is a reduced-pressure, absorbent dressing. Other systems, methods, and dressings are presented.本發明提供用於在一病患上之一敷件中感測流體且產生一電信號之系統及方法。在一個例項中,使用一賈法尼電池作為一電子偵測裝置。將該賈法尼電池放置在該敷件中且當該敷件係實質上飽和時該賈法尼電池產生電壓。在一個例項中,該敷件係一減壓吸收劑敷件。亦提供其他系統、方法及敷件。