Optimal electrode placement and frequency range selection for the detection of lung water using Bioimpedance Spectroscopy

Bioimpedance spectroscopy (BIS) is a noninvasive technique for the determination of human body composition such as water or fat content. Next to absolute body water determination, it enables also the detection of body water shifts. Therefore, it seems to be a good candidate to detect cardiac lung edema at an early stage and to monitor its medical treatment. However, stable long term BIS measurements are very difficult to make. The measurement conditions and hardware specifications of BIS devices must be well chosen in order to get correct and reproducible results. Thus, a finite element simulation of the human thorax is implemented to find the most sensitive electrode position for a BIS measurement as well as a MatLab simulation of the optimal frequency range. Both simulations and results are presented in this article and shall contribute to increase the accuracy and significance of BIS thoracic measurements.