Jak zní naše tělo - měření a interpretace biosignálů lidského těla

Abstract

This bachelor’s thesis focuses on the conversion of biosignals into the audible spectrum for the purpose of their subsequent acoustic reproduction. The main challenge in processing biological signals is their very low frequency, which lies below the threshold of human hearing. For this reason, an artificial shift of the signal’s frequency spectrum is required. In the developed software application, this goal is achieved by applying amplitude modulation to a signal resampled to 44100~Hz, which represents the standard sampling frequency in digital audio. Preset digital filters also enable the raw signal to be filtered of unwanted motion artifacts and power line noise (50~Hz). For this purpose, both finite-impulse-response (FIR) and infinite-impulse-response (IIR) filters were implemented, with Butterworth and Chebyshev approximations used for the IIR filters. The resulting program thus provides the user with a comprehensive tool for frequency filtering and frequency shifting of biosignals for the purpose of generating audio output.