Bezkontaktní měření vitálních funkcí pomocí CW Radaru a Raspberry Pi

This bachelor thesis is a response to a project to create a non-contact monitoring system of human emotions. The thesis deals with the first part of this project, the non-contact measurement of heart rate and respiratory rate using CW Doppler Radar. In the introduction, the thesis is about the problematics of monitoring vital signs. It compares what devices are used today and what complications are associated with them. The chapter on radars discusses their principle of operation. It is specifically about radars using the Doppler effect. The Doppler effect is explained in one of the subchapters. Finally, the most important types of transmitted waves for this thesis are introduced – continuous, frequency-modulated continuous and pulse, which use the Doppler effect to detect the speed or position of the observed object. The next chapter of the theoretical part of the thesis is the vital functions. The chapter briefly describes the functioning of both the circulatory and respiratory systems. Subchapters elaborate these processes and describe what movements occur during their functioning. The penultimate part of the theory describes the Raspberry Pi 4 model B minicomputer, its origin and topology. To complete the information about its universal use, some operating systems that can be installed on it, such as Ubuntu, Manjaro, OctoPi and others, are briefly listed. Due to the technical limitations that accompany the size of this minicomputer, ways in which its performance can be increased are listed at the end of the chapter. The last theoretical part is the introduction of the 24GHz CW Radar – OPS242-A from Omnipresense. This part of the thesis explains the communication of the radar with the computer, how to set its parameters and lists its technical specifications. The practical part deals mainly with the implementation of the algorithm that allows to measure heart rate and respiration rate. In addition, it also describes how to set the radar parameters. Within the description of the algorithm, individual functions are described with code samples. The complete source code can be found at the end of the paper in the appendices. The output of this work is then presented in the results, what was achieved and what complications were encountered in its processing. The last chapter is the conclusion, where the work is summarized and further possibilities for future work are presented.