An acquisition device for electrical impedance analysis for determining body composition parameters includes a control and analysis unit including measuring and processing circuitry and at least two electric lines, each of which lines is connected to the control and analysis unit and has an electrode. Each electrode is dedicated for connection at an assigned measuring position out of a set of predetermined measuring positions. The control and analysis unit is arranged to cause application of alternating current through electrodes and to measure a resulting voltage between electrodes； record a time dependent electric signal generated by cardiac activity of the subject for each pair of electrodes； and by comparing the time dependent electric signals with expected electric signals of cardiac activity for the predetermined measuring positions, assign to the electrodes those measuring positions for which the time dependent electric signals best fit the expected electric signal of the cardiac activity.
