Phonocardiography and Photoplethysmography With Simple Arduino Setups to Support Interdisciplinary STEM Education

Small computer board platforms, such as Arduino, Raspberry Pi, and micro: bit are very common, cheap, and useful tools to teach modern technology, coding, and experimenting in different disciplines at various levels. Due to the huge available information on websites, it is very easy to find a solution for almost any job and problem, therefore one may not be motivated to work out an own version, to study carefully, to understand the principles in-depth and to be creative. This is also one of the reasons why so high proportion of the examples employ technically inadequate methods, misleading concepts. These are rather serious problems concerning high-quality science, technology, engineering and mathematics (STEM) education. Although technology and available tools change rapidly, the basic principles remain the same, therefore education should focus on a better understanding of these. On the other hand, it is very important for the future's engineers, developers, and professionals to follow the correct methods, to be reliable, creative, and open to the more and more common interdisciplinary methodology. In this paper, we demonstrate this approach by investigating exciting interdisciplinary phonocardiography and photoplethysmography experiments and related electronics, data acquisition, and signal processing. In our work, we focus on the understanding and applying the correct methods, provide a detailed analysis of common pitfalls and leave room also for additional work. Students and teachers, lecturers can learn what to consider, pick what they find useful for their projects. It is also important to note, that the principles are valid for much other instrumentation and information processing jobs as well.