Conducting boundary strategy: a new technique for medical EIT

A medical application of a new measurement strategy developed for process tomography is presented. By exchanging the current streamlines with the equipotential lines impedance tomography can be performed using unipolar measurements. The equipotential lines are now parallel to the conducting boundary and voltage measurement is made between this boundary and an insulated electrode. A set of 32 electrodes was placed around the chest with every alternate electrode connected to form the 'conducting boundary'. A total of 120 independent measurements were available. Reciprocity error without common mode feedback was 0.5% with a dynamic range of only 1:1.12. The images were comparable to that reconstructed using adjacent drive strategy.