Decomposed switch mode signal assisted approach for estimating heart rate from PPG
摘要
Heart rate (HR) measurement is essential for assessing physical fitness and diagnosing various diseases. Photoplethysmogram (PPG) is a convenient method for HR estimation due to its simplicity. However, PPG signals recorded from the wrist are highly susceptible to motion artifacts. Traditional noise cancellation techniques, such as adaptive filtering, are sensitive to the reference signal choice. This paper presents a novel approach using switch-mode decomposed gyroscopic and accelerometer signals as reference inputs for a three-stage Least Mean Square (LMS) filter-based noise cancellation system.
MethodsThe signal decomposition is done using Multivariate Variational Mode Decomposition (MVMD), allowing more flexible noise handling. By using decomposed modes as noise references, this method enables separate treatment of different motion artifact components by adjusting the LMS filter parameters, which is not feasible with raw accelerometer or gyroscope data.
ResultsThe proposed method was tested on a publicly available PPG dataset with recordings from 24 subjects. The method achieved an Average Absolute Error (AAE) of 2.3, a Standard Deviation of Absolute Error of 2.05, and an Average Relative Error of 4.43%.
ConclusionThe novel aspect of this proposed scheme is the use of switch mode decomposed reference inputs to the three-stage LMS filter along with a new peak tracking algorithm. The MVMD decomposition technique and three-stage filtering enable us to denoise the PPG signal effectively and achieve an AAE of 2.3, at least 13.86% better than the previous best method.