Patent ID: 8634905

Claim:
A detection apparatus, comprising: signal outputting means configured to output signals of a frequency band to electrodes; impedance detection means configured to detect, through the electrodes, impedances of a living organism in response to the signals, wherein the living organism is disposed in quasi-electrostatic fields generated by the electrodes in response to the signals; detection means configured to detect the presence or absence of a blood vessel in the living organism by detecting minimum impedances for unit electrode groups, wherein each unit electrode group includes more than one electrode; and state decision means configured to detect a diameter of the blood vessel in the living organism for at least one unit electrode group by comparing: pre-recorded dictionary data coordinating relationships between a degree of variation of an impedance around a reference position and a distance from the reference position for blood vessels having certain diameters, and a measured relationship between a degree of variation of the impedances around a position of the minimum impedance detected by the electrodes in the at least one unit electrode group and a distance from the position, wherein the frequency band is selected such that a difference in electric characteristics between different tissues of the living organism detected using the signals is higher than a predetermined level.