A flexible circuit 200 comprises two or more circuit layers 201, 202 separated by one or more insulating layers, one or more nodes 203-206 are located on each of the circuit layers, and a processor configured to estimate the distribution of liquid within the circuit from at least one of electrical conductance and capacitance measured at one or more of the nodes. The circuit may be used in clothing, dressings, or bandages to identify a liquid, pH or salinity. Distortion of the circuit may be measured from the measured parameters. Cardiovascular and other physical parameters may be determined. Stimulations and medicaments may be released from the circuit.
