Fig. 6: HEDI results illustrating electrode use for evaluating the registration process.
a Patient at rest with a small maximum displacement of 23 mm and an unstable abdominal wall area of 225 cm2. b Patient at rest with a large maximum displacement of 71 mm and an unstable abdominal wall area of 1492 cm2. Both patients had 30 electrodes placed on the abdominal surface in a 5 cm spaced grid. Comparing manual measurements of electrode displacement with HEDI results showed an average absolute error of 1.6 mm and averaged normalised error with respect to the maximum displacement of the electrodes of 4.6%.
