This work aims to investigate the feasibility of employing multi-frequency bioimpedance analysis for hemodynamic assessment. Towards this, we aim to explore one of its implementations, electrical impedance spectroscopy (EIS), for estimating changes in radial artery diameter due to blood flow. Following from our previous investigations, here, we use a commercial device—the Quadra^® Impedance Spectroscopy device—for impedance measurements of the forearm of three subjects under normal conditions and occluding the artery with a cuff. This was performed simultaneously with ultrasound measurements as a reference. The impedance spectra were measured over time, yielding waveforms reflecting changes due to blood flow. Contributions from the fat/muscle domains were accounted for using the occluded impedance response, resulting in arterial impedance. A modified relationship was approximated to calculate the diameter from the arterial impedance, which showed a similarity with ultrasound measurements. Comparison with the ultrasound measurements revealed differences in phase and amplitude, primarily due to the approximated relationship between impedance and diameter and neglecting the impedance phase analysis. This work shows the potential of EIS, with improvements, towards estimating blood flow-induced variation in arteries. Further analysis and improvements could help place this technology in mainstream clinical practice for hemodynamic monitoring.

中文翻译：

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研究电阻抗谱以估计人前臂中血流引起的变化。

这项工作旨在研究采用多频生物阻抗分析进行血液动力学评估的可行性。为此，我们旨在探索其实现之一，即电阻抗光谱（EIS），用于估计由于血液流动而引起的radial动脉直径的变化。从我们以前的调查之后，在这里，我们使用了商用设备的夸^®阻抗光谱仪-用于在正常情况下测量三名受试者的前臂的阻抗，并用袖带阻塞动脉。这与超声测量同时进行。随时间测量阻抗谱，产生反映血流变化的波形。来自脂肪/肌肉区域的贡献使用闭塞的阻抗反应来解释，从而导致动脉阻抗。近似的修改关系可从动脉阻抗计算直径，这与超声测量结果相似。与超声测量结果的比较表明，相位和幅度存在差异，这主要是由于阻抗和直径之间的近似关系，而忽略了阻抗相位分析。这项工作显示了EIS的潜力，并且经过改进，可以估算出由血流引起的动脉变异。进一步的分析和改进可以帮助将该技术应用于血液动力学监测的主流临床实践。