Local-Spatiotemporal Change Monitoring in Extracellular Fluid by Time-Variation-Constraint Sparse Bayesian Learning Implemented Into Frequency-Difference Electrical Impedance Tomography (tvcSBL-fdEIT)
Local-Spatiotemporal Change Monitoring in Extracellular Fluid by Time-Variation-Constraint Sparse Bayesian Learning Implemented Into Frequency-Difference Electrical Impedance Tomography (tvcSBL-fdEIT)
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DOI：
10.1109/tim.2022.3220282
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发表时间：
2023
影响因子：
5.6
通讯作者：
Ryoma Ogawa;Shinsuke Akita;M. Takei
中科院分区：
文献类型：
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作者：
Ryoma Ogawa;Shinsuke Akita;M. Takei
局部时空变化（LSTC）的频差电导率分布$\Delta \sigma $在细胞外液（ECF）已被监测在皮下脂肪组织（SAT），以评估腿部水肿的时变约束稀疏贝叶斯学习实施到频差电阻抗断层扫描（tvc SBL- fd EIT）。tvc SBL-fd EIT具有三个步骤-步骤1：分块列向量（BCV）的公式化，步骤2：通过时间变化约束的SAT分离，以及步骤3：通过超参数学习的时间相关性提取。tvc SBL- fd EIT应用于监测15名受试者的小牛沿着，并采用长时间站立和腿部抬高的实验方案。通过生物电阻抗分析（BIA），分离的SAT中的空间平均电导率$\langle \Delta \sigma \rangle ^{\mathrm {SAT}}$与常规阻抗$z^{\mathrm {BIA}}$具有强正相关性（相关系数为0.715美元;$n$ = 15和$p），在长时间站立时下降，而$\langle \Delta \sigma \rangle ^{\mathrm {SAT}}$在腿抬高时增加。$\Delta \sigma $的频率依赖性与ECF中钠离子浓度的LSTC相关，而$\Delta \sigma $的局部最大值位置与大隐静脉（GSV）位置相关。最后，在不稳定背景场下，数值分析了该算法的优越性。
Local-spatiotemporal change (LSTC) of frequency-difference conductivity distribution $\Delta \sigma $ in extracellular fluid (ECF) has been monitored in subcutaneous adipose tissue (SAT) to evaluate leg edema by time-variation-constraint sparse Bayesian learning implemented into frequency-difference electrical impedance tomography (tvc SBL- fd EIT). The tvc SBL- fd EIT has three steps—Step 1: formulation of blocked column vector (BCV), Step 2: SAT separation by time variation constraint, and Step 3: temporal correlation extraction by hyperparameter learning. The tvc SBL- fd EIT was applied to the monitoring of 15 subjects’ calves along with an experimental protocol of prolonged standing and leg elevation. The spatial-mean conductivity $\langle \Delta \sigma \rangle ^{\mathrm {SAT}}$ in the separated SAT has a strong positive correlation with conventional impedance $z^{\mathrm {BIA}}$ by a bioelectrical impedance analysis (BIA) (a correlation coefficient $0.715; $n$ = 15 and $p ), which is decreased during the prolonged standing, while $\langle \Delta \sigma \rangle ^{\mathrm {SAT}}$ is increased during the leg elevation. The frequency dependence of $\Delta \sigma $ is associated with LSTC of sodium ion concentration in ECF, while the local maximum position of $\Delta \sigma $ is associated with great saphenous vein (GSV) position. Moreover, the superiority of the proposed algorithm is numerically evaluated under the unstable-background fields.