A measurement device for measuring electrical impedance of tissue of a subject comprising a probe having a plurality of electrodes (1-5, 23A-23E), said electrodes being adapted to be placed in direct contact with the skin of the subject, and an impedance measuring circuit adapted to apply a voltage or to inject a current at two of said electrodes (1-5, 23A-23E) and to measure a resulting current or to measure a resulting voltage to determine an impedance signal, said measurement device further comprising: a switching circuit for selectively activating electrode pairs by connecting two electrodes of said plurality of electrodes (1-5, 23A-23E) with said impedance measuring circuit and disconnecting the remaining electrodes from said impedance circuit, wherein said voltage is applied or said current is injected at said two electrodes and said resulting current is measured between said two electrodes; and a control device adapted to control said switching circuit to connect each electrode such that said electrode functions in one of at least three states including a first active state where said electrode is connected to the impedance measuring circuit to inject a measuring current into or to apply a voltage at tissue of said subject, a second active state where said electrode is connected to said impedance measuring circuit to measure the resulting current or the resulting voltage from the tissue, and a floating state where said electrode is disconnected from said impedance measuring circuit, and said control device being adapted to control said switching circuit to activate said electrodes in accordance with a predetermined activation scheme, characterized by said predetermined activation scheme including to activate said two electrodes, one in said first state and one in said second state, respectively, and to place the remaining electrodes in said floating state in a successive manner to gradually scan a tissue of said subject at different tissue depths, according to spacing between the activated electrode pair. a switching circuit for selectively activating electrode pairs by connecting two electrodes of said plurality of electrodes (1-5, 23A-23E) with said impedance measuring circuit and disconnecting the remaining electrodes from said impedance circuit, wherein said voltage is applied or said current is injected at said two electrodes and said resulting current is measured between said two electrodes; and a control device adapted to control said switching circuit to connect each electrode such that said electrode functions in one of at least three states including a first active state where said electrode is connected to the impedance measuring circuit to inject a measuring current into or to apply a voltage at tissue of said subject, a second active state where said electrode is connected to said impedance measuring circuit to measure the resulting current or the resulting voltage from the tissue, and a floating state where said electrode is disconnected from said impedance measuring circuit, and said control device being adapted to control said switching circuit to activate said electrodes in accordance with a predetermined activation scheme, characterized by said predetermined activation scheme including to activate said two electrodes, one in said first state and one in said second state, respectively, and to place the remaining electrodes in said floating state in a successive manner to gradually scan a tissue of said subject at different tissue depths, according to spacing between the activated electrode pair.