System for EIT imaging, in particular for determining pulmonary function and/or cardiac function, comprising - a sensor device comprising a belt structure comprising an electrode array for positioning on a patient and measuring an impedance distribution, - a data entry unit, and - a calculation unit, - the system being adapted to calculate an EIT image by means of an image creation algorithm taking into account a measured impedance distribution and patient specific data entries, wherein - the electrode array contains at least one visual aid coupled to the electrode array for the purpose of visually indicating the position of at least a first electrode or electrode pair, - the visual aid comprises a visual marker being affixed at a fixed position on the electrode array indicating a reference position on the belt, - the visual aid comprises means which allows to read or to measure the position of the electrode array with respect to a characteristic feature of the patient's body, namely a value for belt displacement, - the data entry module is adapted to accept an entry of data describing the position of the electrode array, namely a value for belt displacement; - the calculation unit is adapted to calculate the position of the individual electrodes relative to the patient's body and to provide correction for the image creation algorithm in order to correct, preferably to compensate for, the belt displacement, wherein based on the data describing the position of the visual aid, a rotational deviation of the electrode array from a predefined position is taken into account, and wherein the visual aid comprises scales preferably along a longitudinal edge of the electrode array or the system comprises a measuring tape which is adapted to be employed for the purpose of measuring the deviation of the visual aid from the sternum. - a sensor device comprising a belt structure comprising an electrode array for positioning on a patient and measuring an impedance distribution, - a data entry unit, and - a calculation unit, - the system being adapted to calculate an EIT image by means of an image creation algorithm taking into account a measured impedance distribution and patient specific data entries, - the electrode array contains at least one visual aid coupled to the electrode array for the purpose of visually indicating the position of at least a first electrode or electrode pair, - the visual aid comprises a visual marker being affixed at a fixed position on the electrode array indicating a reference position on the belt, - the visual aid comprises means which allows to read or to measure the position of the electrode array with respect to a characteristic feature of the patient's body, namely a value for belt displacement, - the data entry module is adapted to accept an entry of data describing the position of the electrode array, namely a value for belt displacement; - the calculation unit is adapted to calculate the position of the individual electrodes relative to the patient's body and to provide correction for the image creation algorithm in order to correct, preferably to compensate for, the belt displacement, wherein based on the data describing the position of the visual aid, a rotational deviation of the electrode array from a predefined position is taken into account, and wherein the visual aid comprises scales preferably along a longitudinal edge of the electrode array or the system comprises a measuring tape which is adapted to be employed for the purpose of measuring the deviation of the visual aid from the sternum.