Fundamentals, Recent Advances, and Future Challenges in Bioimpedance Devices for Healthcare Applications
Figure 3
Bioimpedance models: (a) single-dispersion RC model, (b) single-dispersion Cole model, (c) double dispersion Cole model, (d) one resistor and two CPEs, (e) three resistors and three CPEs, and (f) one resistor and two CPEs, in series. and are the extracellular and intracellular resistances, respectively; C is the membrane capacitance; s is the complex variable in the Laplace domain; R∞ is the resistance at infinite frequency; CPE symbolizes a constant phase element; R1, R2 are the resistance increase due to the first and second dispersions, respectively; α1, α2, and α3 are the order of the fractional components associated with the first, second, and third dispersions, respectively; and C1, C2, and C3 are capacitances related to the first, second, and third dispersions, respectively.