Abstract: A method is described for determining biological tissue type based on a complex impedance spectra obtained from a probe with a conducting part adjacent a tissue region of interest, wherein the impedance spectra includes data from a number of frequencies. The method may include: obtaining, from the complex impedance spectra, a first data set representative of impedance modulus values, or equivalent admittance values, at one or more frequencies, obtaining, from the complex impedance spectra, a second data set representative of impedance phase angle values, or equivalent admittance values, at one or more different frequencies, applying a first discrimination criterion to the first data set, applying a second discrimination criterion to the second data set, and thereby determining if the tissue region of interest is a tissue type characterised by the discrimination criteria.

Abstract: A method is described for determining biological tissue type based on a complex impedance spectra obtained from a probe with a conducting part adjacent a tissue region of interest, wherein the impedance spectra includes data from a number of frequencies. The method may include: obtaining, from the complex impedance spectra, a first data set representative of impedance modulus values, or equivalent admittance values, at one or more frequencies, obtaining, from the complex impedance spectra, a second data set representative of impedance phase angle values, or equivalent admittance values, at one or more different frequencies, applying a first discrimination criterion to the first data set, applying a second discrimination criterion to the second data set, and thereby determining if the tissue region of interest is a tissue type characterised by the discrimination criteria.

Abstract: A method and sensor assembly for determining the condition of a structure, especially for confirming if a measured fingerprint is on a live finger, measures characteristics of close to the structure surface. The sensor includes a first pair of current supply electrodes coupled to a current source, providing an electrical current to the skin, at least two pickup electrodes at chosen and different positions relative to the current supply electrodes, at least a first of the pickup electrodes being coupled to an instrument for measuring the voltage between the first pickup electrode and at least one of the pickup or current supply electrodes, storage for a predetermined set of values characterizing a certain condition of the surface, and means for comparing the characteristics from each pickup electrode with the measurements of the other pickup electrodes and with the predetermined set of characteristics for determining the surface condition.

Abstract: This invention relates to a sensor assembly and a method for measuring characteristics of a surface, preferably skin, comprising a first pair of current supply electrodes coupled to a current source, providing an electrical current to the skin, at least one pickup electrodes at chosen positions relative to the current supply electrodes, at least a first of said pickup electrodes being coupled to an instrument for measuring the voltage between said first pickup electrode and at least one of the pickup or current supply electrodes.

Abstract: This invention relates to a sensor assembly and a method for measuring characteristics of a surface, preferably skin, comprising a first pair of current supply electrodes coupled to a current source, providing an electrical current to the skin, at least one pickup electrodes at chosen positions relative to the current supply electrodes, at least a first of said pickup electrodes being coupled to an instrument for measuring the voltage between said first pickup electrode and at least one of the pickup or current supply electrodes.

Abstract: Method and sensor assembly determining the condition of a structure, especially for confirming if a measured fingerprint is on a live finger, by measuring characteristics of close to the structure surface, the sensor comprising a first pair of current supply electrodes coupled to a current source, providing an electrical current to the skin, at least two pickup electrodes at chosen and different positions relative to the current supply electrodes, at least a first of said pickup electrodes being coupled to an instrument for measuring the voltage between said first pickup electrode and at least one of the pickup or current supply electrodes, storage means for a predetermined set of values characterizing a certain condition of the surface, and means for comparing the characteristics from each pickup electrode with the measurements of the other pickup electrodes and with the predetermined set of characteristics for determining the surface condition.

Abstract: A sensor device for performing measurements on an at least partially conductive surface includes a number of conductive structures at or directly below the sensor surface. The conductive structures consist of at least one stimulation or current sink electrode and a number of sensor elements coupled to interrogation electrodes in an electronic circuit for measuring impedance between the electrodes and the stimulation electrode. The sensor device also includes at least one additional clamping electrode positioned in the vicinity of the sensor elements and coupled to a chosen voltage.