IEEE Trans Biomed Eng. 2020 Nov;67(11):3173-3184. doi: 10.1109/TBME.2020.2979249. Epub 2020 Mar 9.
We attempt to reconstruct brachial arterial pressure (BAP) waves from finger arterial pressure waves measured using the vascular unloading technique without arm-cuff calibration. A novel method called two-level optimization (TOP) strategy is proposed as follows.
We first derive a simplified transfer function (TF) based on a tube-load model with only two parameters to be estimated, a coefficient B and a time delay ∆t. Then, at level one, two minimization problems are formulated to estimate the optimal coefficient B and time delay ∆t. Then, we can derive an optimal TF h(t). However, this derivation requires true (or reference) BAP waves. Therefore, at level two, we apply multiple linear regression (MLR) to further model the relationship between the derived optimal parameters and subjects' physiologic parameters. Hence, eventually, one can estimate coefficient B and time delay ∆t from subject's physiologic parameters to derive the MLR-based TF h(t) for the BAP reconstruction.
Twenty-one volunteers were recruited for the data collection. The mean ± standard deviation of the root mean square errors between the reference BAP waves and the BAP waves reconstructed by h(t), h(t), and a generalized transfer function (GTF) were 3.46 ± 1.42 mmHg, 3.61 ± 2.28 mmHg, and 6.80 ± 3.73 mmHg (significantly larger with p < 0.01), respectively.
The proposed method can be considered as a semi-individualized TF which reconstructs significantly better BAP waves than a GTF.
The proposed TOP strategy can potentially be useful in more general reconstruction of proximal BP waves.
尝试在不使用臂带校准的情况下，从使用血管减压技术测量的指动脉压力波中重建肱动脉压力（BAP）波。提出了一种称为两级优化（TOP）策略的新方法，如下所示。
我们首先基于仅需估计两个参数的管载模型推导出简化传递函数（TF），一个系数 B 和一个时间延迟 ∆t。然后，在一级，我们制定了两个最小化问题来估计最优系数 B 和时间延迟 ∆t。然后，我们可以推导出最优 TF h(t)。然而，这种推导需要真实（或参考）BAP 波。因此，在二级，我们应用多元线性回归（MLR）进一步建模推导的最优参数与受试者生理参数之间的关系。因此，最终，可以从受试者生理参数估计系数 B 和时间延迟 ∆t，以推导出用于 BAP 重建的基于 MLR 的 TF h(t)。
共招募了 21 名志愿者进行数据采集。参考 BAP 波与 h(t)、h(t)和广义传递函数（GTF）重建的 BAP 波之间的均方根误差的平均值 ± 标准差分别为 3.46 ± 1.42 mmHg、3.61 ± 2.28 mmHg 和 6.80 ± 3.73 mmHg（显著更大，p < 0.01）。
所提出的方法可以被认为是一种半个性化 TF，它可以比 GTF 更好地重建 BAP 波。
所提出的 TOP 策略可能在更一般的近端 BP 波重建中有用。
