Figure 4.

3-D EIS mapping using the 15 permutations of the 6-point device. There are 6 electrodes on the device and the individual pairs of electrodes are connected by the solid/dotted lines, each representing one permutation. The design of the 6-point EIS sensor into 2 rows, or rings, of 3-point electrodes permits 3 sets of long axis (vertical) interrogations (a), 6 sets of short axis (horizontal) interrogations (b), and 6 sets of diagonal interrogations (c) to create analysis of three arterial rings (d-f). (g) 3-D mapping of a reconstructed aortic segment with atherosclerosis highlights the 15 (3+6+6) distinct permutations of the EIS impedance measurements with corresponding color scale.