对ecg信号进行预处理，并检测ecg的r波，并进行特征提取，并在图中进行标注-On ecg signal preprocessing and detection of r ecg wave, and feature extraction, and marked on the drawing

对ecg信号进行预处理，并检测ecg的pqrs波，并进行特征提取，并在图中进行标注-On ecg signal preprocessing and detection of pqrs ecg wave, and feature extraction, and marked on the drawing