Quantitative Evaluation of Burn Injuries Based on Electrical Impedance Spectroscopy of Blood with a Seven-Parameter Equivalent Circuit

A quantitative and rapid burn injury detection method has been proposed based on the electrical impedance spectroscopy (EIS) of blood with a seven-parameter equivalent circuit. The degree of burn injury is estimated from the electrical impedance characteristics of blood with different volume proportions of red blood cells (RBCs) and heated red blood cells (HRBCs). A quantitative relationship between the volume portion H(HCT) of HRBCs and the electrical impedance characteristics of blood has been demonstrated. A seven -parameter equivalent circuit is employed to quantify the relationship from the perspective of electricity. Additionally, the traditional Hanai equation has been modified to verify the experimental results. Results show that the imaginary part of impedance Z(Imt) under the characteristic frequency (f(c)) has a linear relationship with H(HCT) which could be described by Z(Imt) = −2.56H(HCT) − 2.01 with a correlation coefficient of 0.96. Moreover, the relationship between the plasma resistance R(p) and H(HCT) is obtained as R(p) = −7.2H(HCT) + 3.91 with a correlation coefficient of 0.96 from the seven -parameter equivalent circuit. This study shows the feasibility of EIS in the quantitative detection of burn injury by the quantitative parameters Z(Imt) and R(p), which might be meaningful for the follow-up clinical treatment for burn injury.