The signal processing chain for the HR estimation is shown in Figure 1. First, the electric potentials created by the heart are measured, amplified and digitized. After, an algorithm commonly termed as a QRS complex detector, or simply QRS detector, searches the ECG signal, and identifies all the recognizable QRS complexes. Last, the positions of the QRS complexes are used to estimate the HR of the measured subject.
The signal processing chain used for the heart rate estimation
Even though in this chapter we will concentrate chiefly on the last stage - the HR estimation - it is important to understand characteristics of data we are going to process. Therefore, in this section we will provide a brief overview of all the above-mentioned signal processing stages. Namely, we will comment on heart activity, ECG signal measurement, QRS complex detection, current state of the art of a robust HR estimation, and also on the Bayesian framework that we are going to use in the design our HR estimator.