Study of blood supply to functional brain areas under memory load based on bioimpedance technology

Abstract

The cerebral blood supply is crucial for normal brain function. This paper aims to detect and describe alterations in blood supply within functional brain regions during working memory (WM), utilizing bioimpedance technology. Methods: We propose a bioimpedance-based method to detect blood supply to functional brain regions. We introduce the impedance systolic wave height and the impedance rise time to characterize cerebral blood flow (CBF) and small artery vasodilation velocity in functional regions. Lastly, we explore blood supply to frontal lobe regions by utilizing changes in impedance parameters under WM loads. Results: Under low WM load, frontal lobe impedance systolic wave height increased by 0.0051–0.0084 Ω, CBF increased by 14.42–22.24 %, impedance rise time decreased by 0.0332–0.0441 s, and small artery vasodilation velocity increased by 9.80–14.36 %. Under high WM load, the impedance systolic wave height increased by 0.0062–0.0104 Ω, CBF increased by 18.62–30.98 %, impedance rise time decreased by 0.0370–0.0597 s, and small artery vasodilation velocity increased by 12.17–19.42 %. Differences in blood supply between the bilateral frontal lobes due to different WM loads and division of labor between brain regions. Conclusion: The bioimpedance technique is effective in detecting blood supply changes in functional brain regions and quantifying CBF and small artery vasodilation velocity by impedance systolic wave height and impedance rise time, which reveal the differences in blood supply in functional brain regions. The method proposed in this paper provides more information for the study of blood supply in functional brain regions and lays the foundation for further research on bioimpedance detection of brain function.