A kind of monitoring device (for example, ECG monitors or Holter monitors) uses electrocardiograph (40) and ECG quality controllers (50). In operation, electrocardiograph (40) exports electrocardiogram according to one or more ECG Leads (30) in the case where electrocardiograph (40) is connected to (one or more) ECG Lead 30 (for example, based on electrode or based on patch/paddle). In response to the connection of electrocardiograph (40) and (one or more) ECG Lead (30), ECG quality controllers (50) control electrocardiogram segmentation on the basis of (such as, continuous ECG records are divided the segmentation for being divided into the specified duration) to the high frequency noise levels of individual ECG Lead (30) (such as, the degree of muscle artifact in electrocardiogram and/or the degree of electrode movement artifact) and low-frequency noise level (for example, degree of the baseline drift of electrocardiogram) independent evaluation.
