Institute of Biomedical Technologies, Auckland University of Technology, Auckland, 1010, New Zealand.
Cardiovasc Eng Technol. 2023 Dec;14(6):810-826. doi: 10.1007/s13239-023-00689-9. Epub 2023 Oct 17.
Bio-impedance analysis (BIA) has been widely investigated for hemodynamic monitoring. However, previous works rarely modelled two synchronously pulsatile arteries (representing the radial and ulnar arteries) in the wrist/forearm model. This work aims to clarify and quantify the influences of two pulsatile arteries on BIA.
First, two blood-filled arteries were structured in a 3D wrist segment using the finite element method (FEM). Afterwards, an easy-to-produce two-arteries artificial wrist was fabricated with two components: gelatine-based surrounding tissue phantom and saline blood phantom. A syringe driver was utilised to constrict the arteries, and the impedance signals were measured using a Multi-frequency Impedance Analyser (MFIA).
Both simulation and experimental results demonstrated the non-negligible influences of the ulnar artery on the overall BIA, inducing unwanted resistance changes to the acquired signals from the radial artery. The phantom experiments revealed the summation of the individual resistance changes caused by a single pulsatile artery was approximately equal to the measured resistance change caused by two synchronously pulsatile arteries, confirming the measured impedance signal at the wrist contains the pulsatile information from both arteries.
This work is the first simulation and phantom investigation into two synchronously pulsatile arteries under BIA in the distal forearm, providing a better insight and understanding in the morphology of measured impedance signals. Future research can accordingly select either a small spacing 4-spot electrode configuration for a single artery sensing or a band electrode configuration for overall pulsatile arteries sensing. A more accurate estimation of blood volume change and pulse wave analysis (PWA) could help to develop cuffless blood pressure measurement (BPM).
生物阻抗分析（BIA）已广泛应用于血流动力学监测。然而，以前的工作很少在腕部/前臂模型中同时建模两条搏动动脉（代表桡动脉和尺动脉）。本研究旨在阐明和量化两条搏动动脉对 BIA 的影响。
首先，使用有限元方法（FEM）在 3D 腕部模型中构建了两条充满血液的动脉。然后，使用两个组件制造了易于生产的具有两条动脉的人工腕部：基于明胶的周围组织模拟体和盐水血液模拟体。使用注射器驱动器收缩动脉，并使用多频阻抗分析仪（MFIA）测量阻抗信号。
模拟和实验结果均表明尺动脉对整体 BIA 有不可忽略的影响，导致从桡动脉获得的信号产生不必要的电阻变化。幻影实验表明，单个搏动动脉引起的个体电阻变化之和约等于两个同时搏动动脉引起的测量电阻变化，证实了在腕部测量的阻抗信号包含来自两条动脉的搏动信息。
这是首次在远端前臂的 BIA 下对两条同时搏动动脉进行模拟和幻影研究，为测量阻抗信号的形态提供了更好的洞察力和理解。未来的研究可以相应地选择用于单个动脉感应的小间距 4 点电极配置或用于整体搏动动脉感应的带电极配置。更准确地估计血容量变化和脉搏波分析（PWA）有助于开发无袖带血压测量（BPM）。
