IEEE Trans Biomed Eng. 2019 Jan;66(1):187-198. doi: 10.1109/TBME.2018.2821182. Epub 2018 Mar 30.
In this paper, a method for assessment of quadratic phase coupling (QPC) between respiration and heart rate variability (HRV) is presented.
First, a method for QPC detection is proposed named real wavelet biphase (RWB). Then, a method for QPC quantification is proposed based on the normalized wavelet biamplitude (NWB). A simulation study has been conducted to test the reliability of RWB to identify QPC, even in the presence of constant delays between interacting oscillations, and to discriminate it from quadratic phase uncoupling. Significant QPC was assessed based on surrogate data analysis. Then, quadratic cardiorespiratory couplings were studied during a tilt-table test protocol of 17 young healthy subjects.
Simulation study showed that RWB is able to detect even weak QPC with delays in the range of [Formula: see text] s, which are usual in the autonomic nervous system (ANS) control of heart rate. Results from the database revealed a significant reduction ([Formula: see text]) of NWB between respiration and both low and high frequencies of HRV in head-up tilt position compared to early supine.
The proposed technique detects and quantifies robustly QPC and is able to track the coupling between respiration and various HRV components during ANS changes.
The proposed method can help to assess alternations of nonlinear cardiorespiratory interactions related to ANS dysfunction and physiological regulation of HRV in cardiovascular diseases.
本文提出了一种评估呼吸与心率变异性（HRV）之间二次相位耦合（QPC）的方法。
首先，提出了一种名为实波双相（RWB）的 QPC 检测方法。然后，提出了一种基于归一化小波双幅值（NWB）的 QPC 量化方法。进行了一项模拟研究，以测试 RWB 识别 QPC 的可靠性，即使在相互作用的振荡之间存在恒定的延迟，以及将其与二次相位去耦区分开来。基于替代数据分析评估了显著的 QPC。然后，在 17 名年轻健康受试者的倾斜台测试方案中研究了二次心肺耦合。
模拟研究表明，RWB 能够检测到具有 [公式：见文本] s 范围内延迟的微弱 QPC，这在自主神经系统（ANS）对心率的控制中很常见。来自数据库的结果表明，与早期仰卧位相比，头高位倾斜时，NWB 在呼吸与 HRV 的低频和高频之间显著降低（[公式：见文本]）。
所提出的技术能够稳健地检测和量化 QPC，并能够在自主神经系统变化期间跟踪呼吸与各种 HRV 分量之间的耦合。
该方法可用于评估与自主神经功能障碍和心血管疾病中 HRV 的生理调节相关的非线性心肺相互作用的变化。
