Search

Taiwan currently faces an aging population and an increased mortality rate caused by cardiovascular disease. Therefore, preventing cardiovascular disease and constantly tracking people's physiological conditions are very important. Photoplethysmography (PPG) can be used to instantaneously monitor and measure the physiological information of each person. Compared with using electrocardiography, measurement using PPG is less expensive and more convenient. However, PPG has high susceptibility to motion artifacts. To analyze the physiological information in PPG signals with higher accuracy, the negative effects of motion artifacts on PPG signals must first be eliminated. In this study, the independent components of PPG signals were separated by independent component analyses (i.e., of the PPG noises and signals) to separate raw signals from motion artifacts. Subsequently, the PPG signals contained in the independent components were selected and the frequency spectrum was used to analyze the locations of the PPG signal components. Next, to eliminate motion artifacts, a multi-bandpass filter that the raw signals could pass through was specifically designed for this study. In our experiment, motion artifacts were created using two types of finger movements: random finger shaking and rapid finger shaking. In this study, research results included the waveforms of the filtered PPG signals in the frequency and time domains, independent ingredients after the separation of independent components, and the measurements of the heart rate. [ABSTRACT FROM AUTHOR]

Taiwan currently faces an aging population and a rise in mortality rate caused by cardiovascular disease. Therefore, the prevention of cardiovascular disease and the constant tracking of physiological information are crucial. Photoplethysmography (PPG) is used to instantaneously measure and monitor a person's physiological information. Compared with electrocardiography, PPG measurements are more convenient and less expensive. However, PPG is more susceptible to the effects of motion artifacts. To accurately analyze the physiological information contained in PPG signals, the negative effects of motion artifacts on PPG signals must first be eliminated. In this study, independent component analysis was employed to separate independent components (i.e., PPG signals and noise) from raw signals with motion artifacts. Subsequently, independent components containing PPG signals were selected and the locations of the PPG signal components in the frequency spectrum were analyzed. Next, the raw signals were passed through a multi-bandpass filter specifically designed for this study to eliminate motion artifacts. Motion artifacts were created for an experiment using two types of finger movements: vertical and horizontal finger movements. From the independent component analysis of the independent components, the waveforms of the filtered PPG signals in the time and frequency domains were acquired, which were then compared with the results of heartbeat measurement. [ABSTRACT FROM AUTHOR]