ABSTRACT
Digital signal processing is a tool that is used not only in classic engineering but also in a range of multidisciplinary applications. To understand the benefits that a particular signal processing method offers, the researchers must be aware of the theory underlying the method, as well as the limitations thereof. A classical electrocardiograph (ECG) is an analog signal. It is continuous in time, meaning that it is defined at any instant in time. On the other hand, most computers are digital machines that do not have an infinitesimally small resolution. Digital computers are fundamentally based on discrete or discontinuous numbers and cannot process a signal that is continuous in time or continuous in amplitude. While analog signals are appropriate for ECG signals written on millimeter paper, digitalization offers many possibilities to all aspects of medical data analysis, from electronic wristbands that record sleep patterns to the most sophisticated diagnostic devices.
