The 4th-order Chebyshev II filter improved photoplethysmogram signal quality more effectively than 8 other types of filters across 10 different orders.
Observational (n=219)
No
Does the 4th-order Chebyshev II filter improve the signal quality of short PPG signals compared to other filter types?
The 4th-order Chebyshev II filter is the optimal digital filter for improving the signal quality of short photoplethysmogram (PPG) recordings, facilitating better cardiovascular monitoring in wearable devices.
Abstract A photoplethysmogram (PPG) contains a wealth of cardiovascular system information, and with the development of wearable technology, it has become the basic technique for evaluating cardiovascular health and detecting diseases. However, due to the varying environments in which wearable devices are used and, consequently, their varying susceptibility to noise interference, effective processing of PPG signals is challenging. Thus, the aim of this study was to determine the optimal filter and filter order to be used for PPG signal processing to make the systolic and diastolic waves more salient in the filtered PPG signal using the skewness quality index. Nine types of filters with 10 different orders were used to filter 219 (2.1s) short PPG signals. The signals were divided into three categories by PPG experts according to their noise levels: excellent, acceptable, or unfit. Results show that the Chebyshev II filter can improve the PPG signal quality more effectively than other types of filters and that the optimal order for the Chebyshev II filter is the 4 th order.
Liang et al. (Tue,) conducted a observational in Photoplethysmogram (PPG) signal processing (n=219). Chebyshev II filter (4th order) vs. 8 other filter types (including Butterworth, Chebyshev I, Elliptic, Wavelet, etc.) with 10 different orders was evaluated on Skewness Signal Quality Index (SSQI). The 4th-order Chebyshev II filter improved photoplethysmogram signal quality more effectively than 8 other types of filters across 10 different orders.