Cerebral Blood Flow Autoregulation Measurement via Bioimpedance Technology

Background: Cerebral blood flow (CBF) auto-regulation function is essential for evaluating CBF status. This article provides an evaluation method of CBF using bioimpedance. Method: A mathematical model of cerebral vascular compliance is established to analyze the effect of autoregulation ability changes on the impedance of CBF. The synchronization signals of impedance and blood pressure are measured, and the peak phase shift is extracted to evaluate the cerebral blood autoregulation function. Results: The experiment results show that the peak phase shift can express the cerebral autoregulation change process. The frontal and occipital region's peak phase shift changes are 10.32%-37.6% and 11.18%-36.86%, respectively. Significant: The proposed approach could build the relationship between CBF autoregulation and impedance, and this method is noninvasive, continuous, and easy to execute. This study provides a basis for the health assessment of the CBF system using bioimpedance.