**2. Materials and Methods**

The primary goal of this research was to check the effectiveness of the HR algorithm during typical human-computer interaction (HCI) scenarios. Thus, we evaluated four signal extraction methods and implemented three different HR estimation algorithms. We evaluated the effectiveness of selected algorithms using recorded video sequences of participants performing various HCI tasks. The implementation of the proposed methods can be easily adapted to running in real-time framework, however implementation details are not included in this paper.
