Method for Bioimpedance Assessment of Superficial Head Tissue Microcirculation

Assessment of microcirculation status during surgical interventions is of significant interest for monitoring tissue perfusion and controlling the effectiveness of systemic hemodynamics. This study investigated the applicability of the electrical impedance method for the quantitative assessment of changes in the blood supply to superficial head tissues during cardiac surgeries. Impedance signal recording was performed synchronously with laser Doppler flowmetry, allowing for the comparison of parameter dynamics reflecting microcirculatory processes. Analysis of a set of impedance parameters reflecting the amplitude and temporal characteristics of the pulse signal revealed consistent changes with microvascular indicators obtained by laser Doppler flowmetry. The most pronounced changes in impedance parameters were observed during transitions between key physiological states-induction of anesthesia, initiation of cardiopulmonary bypass, and its termination. This indicates the informativeness of the electrical impedance method for assessing the dynamics of scalp perfusion. The obtained results demonstrate its potential for non-invasive, continuous, and safe monitoring of microcirculation in superficial tissues in the operating room. This approach can be considered as an additional tool for comprehensive assessment of microcirculatory changes and improving the accuracy of tissue perfusion monitoring during cardiac surgeries.