Abstract: A patient monitoring system comprising: at least two pairs of electrodes in contact with the patient, a controller and a patient measurement system. At least one pair of electrodes passes a known current through a patient's chest. The voltage difference at another position on the patient induced by the known current is detected by a second at least one pair of electrodes and measured by a voltage measuring unit. From the voltage differences measured between the at least one second pair of the electrodes, the controller determines at least one biological parameter in at least one portion of the patient's chest. The patient measurement system ensures correct placement of the pairs of electrodes on the patient's chest, such that the electrodes are consistently placeable in the same positions on the patient's chest.

Abstract: A method for measuring the impedance of a portion of a subject, by passing a known current provided by a current source unit between a first pair of electrodes contacting the skin surface of the subject. The measuring of a voltage with a voltage measuring instrument, between at least one second pair of electrodes contacting the skin surface of the subject when the current source unit is passing the known current through the first pair of electrodes; calculating the bio-impedance of the portion of the subject based on the known current and the calibrated voltage.

Abstract: A method of selecting one or more assay electrodes for use in a device used in an electrical thoracic scan system. The device has a linear multielectrode array, and the method includes providing a device for use in an electrical thoracic scan system. The device includes: a band having an inner surface; and a linear array of electrodes arranged along the length of the band and on the inner surface for contacting the skin surface. Further, each electrode is selectively connectable to a control unit. The method also includes: placing the device on the chest of the subject; designating, as reserve electrodes for potential use, the electrodes making contact with the skin surface; selecting a plurality of assay electrodes from the reserve electrodes; and utilizing the assay electrodes in an electrical thoracic scan process.