Bioimpedance Resistance Indices and Cell Membrane Capacitance Used to Assess Disease Status and Cell Membrane Integrity in Children with Nephrotic Syndrome

Figure 1

Model representing the electrical properties of body tissue [21]. R corresponds to the electrical resistance offered by the extracellular water (ECW) and likewise R from the intracellular water (ICW). C represents (at the body level) cell membrane capacitance of the double-layered cell membrane, i.e., the cell’s ability to uphold a charge difference between the two sides of the membrane. The BIS device applies an alternating current (AC) and measures the combined impedance. Due to C, the impedance will depend on the frequency of the electrical current, because high-frequency currents pass the cell membrane with less opposition than low-frequency currents. R and R are measured in Ohm (Ω), while C is measured in nanofarad (nF).