基于 RR 间期检测、小波变换与优化游程编码的 ECG 信号有损压缩

摘要

传输或存储大量心电图（ECG）记录的代价高昂，在按传输数据量计费的电信信道上尤其如此。远程医疗的发展使 ECG 信号压缩变得更为必要。压缩的目标是在保持 ECG 信号特征的前提下缩减数据规模。本文提出一种基于三维格式转换的 ECG 信号压缩新策略：先识别出 RR 间期，据此把信号切分为若干心动周期，再执行截取与对齐处理；随后采用三维离散小波变换（DWT）削减相邻体素之间的相关性。此外，本文还提出了一种新的无损压缩技术——优化游程编码（RLE），以进一步提高压缩比（CR）。所提策略在心律失常数据库的多类 ECG 记录上进行了验证。与近年发表的若干工作相比，本算法在 CR 与均方根差百分比（PRD）两项指标上均表现更优。

Abstract

It is expensive to transmit or store significant amounts of electrocardiogram (ECG) records, particularly when using telecommunications channels that charge according to the volume of transferred data. The advancement of telemedicine renders compressing ECG signals even more necessary. Compression aims to reduce the size of data while maintaining the features of ECG signals. This paper presents a novel strategy for compressing ECG signals based on 3D format conversion. After identifying the RR intervals, we divide the signal into cardiac cycles and proceed with the cut and align process. A 3D discrete wavelet transform (DWT) is employed to minimize the correlation existing between two adjacent voxels. Moreover, an optimized run-length encoding (RLE), a novel lossless compression technique, has been proposed to increase the compression ratio (CR). The proposed strategy is applied to different types of ECG records of the Arryyhmia database. This algorithm demonstrates improved performance in terms of CR and percentage root-mean-square difference (PRD) compared to several recently published works.