Electrical impedance tomography

An apparatus for measuring the distribution of electrical impedance of a fluid comprising:

• a cylindrical electrically conductive ring electrode surrounding the fluid, the ring electrode comprising a plurality of metallic contacts embedded into the conductive ring and spatially distributed around the axis of the ring, in electric contact with an outside wall of the ring, the the metallic contacts being responsive to a sequentially applied input electrical signal, which while applied to a pair of the contacts, causes respective output signals to be generated between any other pair of contacts, the contacts of each pair of contacts selected for signal generation and for signal reception, respectively, span an azimuthal angle of about σ/2 with respect to the axis of the conductive ring electrode.

A method of determining an internal structure of a body comprising:

• surrounding a body fluid with an electrically conductive ring electrode that comprises a plurality of metallic contacts embedded into the conductive ring and spatially distributed around the axis of the ring, in electric contact with an outside wall of the ring;
• applying between two contacts, sequentially, an input electrical signal, which while applied to a pair of the contacts, causes respective output signals to be generated between any other pair of contacts;
• measuring said output electrical signals between successive pairs of contacts, the contacts of each pair of contacts selected for signal generation and for signal reception, respectively, span an azimuthal angle of about π/2 with respect to the axis of the conductive ring electrode.