Abstract: A method and apparatus for non-invasive analysing the structure and chemical composition of bone tissue eliminating the influence of surrounding tissues, is provided. The method consists in using a system of at least four electrodes (1, 2, 3, 4, 5, 6, 7, 8) placed in electrical contact with tissues surrounding the analysed bone, preferably a long bone to establish screening potential distribution using screening electrodes (7, 8). Measuring current injecting electrodes (1, 2) are used to force the measuring current flow through the internal part of the analysed bone. At the same time the screening electrodes (7, 8) reduce the measuring current flow through the tissues surrounding the analysed bone almost to zero. Then measuring current and potential at the measuring current injecting electrodes (1, 2) as well as phase difference between potential at measuring current injecting electrodes (1, 2) and measuring current are measured.

Abstract: Method for Controlling Electrodes for Bio-impedance Measurements and Apparatus for Bio-impedance Measurements There is provided a control circuit for electrodes in a bio-impedance measurement system, the bio-impedance measurement system comprising screening current injecting electrodes and measuring current injecting electrodes, the control circuit comprising: a current generator for connection to at least one screening current injecting electrode; and an measuring signal output configured to establish a measuring potential between the measuring current injecting electrodes, wherein the control circuit is configured such that the measuring potential is dependent on a measure of a potential difference resulting from the screening current. The control circuit uses the value of the potential resulting from the screening current to determine the potential difference between the measuring current injecting electrodes.

Abstract: A method and apparatus for non-invasive analysing the structure and chemical composition of bone tissue eliminating the influence of surrounding tissues, is provided. The method consists in using a system of at least four electrodes (1, 2, 3, 4, 5, 6, 7, 8) placed in electrical contact with tissues surrounding the analysed bone, preferably a long bone to establish screening potential distribution using screening electrodes (7, 8). Measuring current injecting electrodes (1, 2) are used to force the measuring current flow through the internal part of the analysed bone. At the same time the screening electrodes (7, 8) reduce the measuring current flow through the tissues surrounding the analysed bone almost to zero. Then measuring current and potential at the measuring current injecting electrodes (1, 2) as well as phase difference between potential at measuring current injecting electrodes (1, 2) and measuring current are measured.