SIAM Journal on Applied Mathematics, Volume 80, Issue 1, Page 499-520, January 2020.
In electrical impedance tomography (EIT), multiple electrodes are attached around an imaging domain such as the human thorax to inject currents and measure induced boundary voltages. Using the measured boundary voltage data, cross-sectional images of an internal conductivity distribution are reconstructed. Taking advantage of its fast temporal resolution, time-difference EIT can be used for image-based monitoring of physiological functions such as lung ventilation and cardiac blood flow. Among numerous data collection protocols, we assume current injections and voltage measurements between adjacent pairs of electrodes. The measured voltage difference between the $j$th electrode pair subject to the current injection between the $k$th electrode pair, for example, changes with time and its time-series is called a voltage channel in this paper. Investigating shapes of voltage channels, a new technique called source consistency EIT (scEIT) is proposed to extract voltage channel data originating from a physiological function or source of interest. The proposed scEIT technique suggests each voltage channel can be expressed up to a scale factor and offset value from a single shape-reference voltage channel when there exists only one time-varying source. When multiple physiological sources exist to concurrently produce correspondingly different conductivity changes, measured voltage channels are influenced by all of the sources. Using the scEIT method, each voltage channel can be expressed as a weighted sum of multiple shape-reference voltage channels of the sources. The proposed scEIT technique is verified through numerical simulations and animal experiments. Future experimental studies of applying the scEIT technique to in vivo human experiments are proposed.

中文翻译：

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源一致性电阻抗层析成像

SIAM应用数学杂志，第80卷，第1期，第499-520页，2020年1月。
在电阻抗层析成像（EIT）中，多个电极连接在成像区域（例如人体胸部）周围，以注入电流并测量感应的边界电压。使用测得的边界电压数据，可以重建内部电导率分布的横截面图像。利用其快速的时间分辨率，时差EIT可用于基于图像的生理功能监测，例如肺通气和心脏血流。在众多数据收集协议中，我们假设相邻电极对之间的电流注入和电压测量。在第k个电极对之间的第j个电极对之间测量的电压差，例如，随时间变化，其时间序列在本文中称为电压通道。为了研究电压通道的形状，提出了一种称为源一致性EIT（scEIT）的新技术来提取源自生理功能或目标源的电压通道数据。提出的scEIT技术建议，当仅存在一个时变源时，每个电压通道都可以表示成比例因子和单个形状参考电压通道的偏移值。当存在多个生理源同时产生相应不同的电导率变化时，所有电压源都会影响所测量的电压通道。使用scEIT方法，每个电压通道可以表示为电源的多个形状参考电压通道的加权和。通过数值模拟和动物实验验证了所提出的scEIT技术。