发表机构
Virginia Commonwealth University; Nile University（弗吉尼亚联邦大学; 尼罗大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
提出BeatFlow-ECG，一种条件整流流模型，利用PPG和IMU信号重建单通道心电图，在PPG-DaLiA和WESAD上优于现有基线，实现高相关性和低误差。
AI 中文摘要
在临床环境之外的连续心脏监测需要既信息丰富又便于日常采集的信号。心电图（ECG）提供关于心脏节律和波形形态的丰富信息，而可穿戴光电容积脉搏波（PPG）更容易连续获取，但仅是一种间接的心血管测量，且对运动高度敏感。我们提出BeatFlow-ECG，一种条件整流流模型，用于从同步的PPG和惯性测量中重建单通道心电图。BeatFlow-ECG将重建建模为从噪声到心电图的条件传输，采用带有Transformer瓶颈和显式流时间条件的卷积编码器-解码器。运动信息通过IMU衍生的条件特征、运动相关损失加权和从易到难的训练课程来整合。我们在PPG-DaLiA和WESAD上采用留一受试者协议评估模型。BeatFlow-ECG在所有报告的波形和心跳时序指标中，相比评估的确定性、对抗性和基于扩散的基线取得了最佳结果，Pearson相关系数分别为0.983和0.986，R峰F1分数分别为0.946和0.955。与条件DDPM-1D相比，L1误差在PPG-DaLiA上从0.085降至0.062，在WESAD上从0.074降至0.055。对PPG-DaLiA的额外分析显示，在固定的R峰相对波形区域中相关性更高，并且在低、中、高运动子集上重建误差更低。
英文摘要
Continuous cardiac monitoring outside clinical settings requires signals that are both informative and practical to collect during daily life. Electrocardiography (ECG) provides rich information about cardiac rhythm and waveform morphology, while wearable photoplethysmography (PPG) is easier to acquire continuously but is only an indirect cardiovascular measurement and is highly sensitive to motion. We present BeatFlow-ECG, a conditional rectified-flow model for reconstructing single-channel ECG from synchronized PPG and inertial measurements. BeatFlow-ECG models reconstruction as conditional transport from noise to ECG using a convolutional encoder-decoder with a transformer bottleneck and explicit flow-time conditioning. Motion information is incorporated through IMU-derived conditioning features, motion-dependent loss weighting, and an easy-to-hard training curriculum. We evaluate the model under leave-one-subject-out protocols on PPG-DaLiA and WESAD. BeatFlow-ECG achieves the best results among the evaluated deterministic, adversarial, and diffusion-based baselines across all reported waveform and beat-timing metrics, with Pearson correlations of 0.983 and 0.986 and R-peak F1 scores of 0.946 and 0.955, respectively. Compared with Conditional DDPM-1D, L1 error decreases from 0.085 to 0.062 on PPG-DaLiA and from 0.074 to 0.055 on WESAD. Additional analyses on PPG-DaLiA show higher correlation in fixed R-peak-relative waveform regions and lower reconstruction error across low-, medium-, and high-motion subsets.
Comments27 pages. Preprint. Under review
