Each sensor in one or more pairs of sensors is associated with a particular tissue, for example a first tissue location and a second tissue location respectively. Tissue at a particular tissue location may be solid, for example, muscle tissue, fat tissue, etc., or fluid, for example, blood, fluids associated with edema, etc. The area between the two tissue locations associated with a pair of sensors may comprise solid tissue, fluid tissue, an empty chamber, or combinations thereof. For each pair of sensors in the at least one pair of sensors, a first impedance measurement between the pair of sensors and associated with a first frequency is determined. For each pair of sensors in the at least one pair of sensors, a second impedance measurement between the pair of sensors and associated with a second frequency is determined. A comparison of a ratio of the first impedance measurement at a point in time to the second impedance measurement at a corresponding point in time may be made to determine a volume-related value associated with an area located between the first tissue location and the second tissue location.
