摘要
提出一种高压缩比、高保真度的ＤＣＴ（离散余弦变换）压缩ＥＣＧ（心电图）数据的方法。ＥＣＧ波形中变化梯度大的部分（如ＱＲＳ波段）是导致信号能量铺展于大部分ＤＣＴ分量上的主要因素。鉴此，我们通过插值处理将其扩展成变化梯度小的波形，从而促使信号能量集中地分布于低频ＤＣＴ分量上，实现只需保留更少的ＤＣＴ分量，舍弃更多的ＤＣＴ分量，提高ＥＣＧ数据压缩比。本方法对ＭＩＴ的ＥＣＧ数据，在两种采样速率（５００Ｈｚ和２５０Ｈｚ）下进行了处理，数据处理结果显示，在百分比均方根误差（ＰＲＤ）为Ｉ～４％，相关系数（ｃｃ）为０．９５～０．９９７时，ＣＲ（压缩比）达到９～１７。另外，对原始的有噪ＥＣＧ数据，本方法还具有良好的去噪声性能。
method of ECG data compression via DCT was presented with high compression ratio(CR) and high fidelity. Since segments of ECG waveforms with large gradient changes werethe main contributing factor of signal energy divergence over the most of DCT coefficients.Authors extended the segments by interpolating and transforming into ones with small gradi-ent changes, so that the signal energy might bts. By preserving a smaller number of DCT co-efficients and neglecting a larger number of DCT ones, we could obtain a high data compres-sion ratio. The method was applied to compression of MIT ECG data, obtaining results withPRD (Percentage RMS Difference)= l￣4%,CC(Correlation Coefficient)=0.95￣0.997 andCR=9￣17.8. Besides, the mothed also has the advantages of removing noise of the originaldata and smoothing the reconstructed waveforms.
出处
《中国生物医学工程学报》
CAS
CSCD
北大核心
1995年第4期332-338,共7页
Chinese Journal of Biomedical Engineering
基金
国家自然科学基金
关键词
数据压缩
离散余弦变换
心电图
Data Compression
ECG
DCT
Interpolation
extending waveform
