Patent ID: 8195285

Claim:
Sensor assembly for determining the condition of a structure so as to confirm whether the structure is constituted by skin and living tissue, the sensor assembly comprising: at least four electrodes, of which at least two electrodes constitute current supply electrodes which are connected to a current source for providing a current or voltage to said structure, wherein the current or voltage is oscillating within a chosen frequency range, and at least two electrodes constitute pickup electrodes of which at least a first pickup electrode is connected to a measuring instrument for measuring at least one parameter value relating to the impedance of the structure; and wherein said sensor assembly is adapted to alter which electrodes constitute current supply electrodes and/or which electrodes constitute pickup electrodes between different measurements so as to alter the distance(s) between the current supply electrodes and/or the pickup electrodes to thereby alter the depths of the structure at which the measurements are performed; wherein said sensor assembly is further adapted to (1) store a predetermined set of values characteristic of at least one certain condition of the structure, and (2) compare the at least one measured parameter value with the predetermined set of values for determining whether the structure is in said certain condition; wherein said sensor assembly is adapted to measure the impedance at each pickup electrode, and wherein said sensor assembly is adapted to compare imaginary and real parts of impedance signals as functions of the applied frequency.