A strong anti-noise segmentation algorithm based on variational mode decomposition and multi-wavelet for wearable heart sound acquisition system

Abstract

Wearable devices have now been widely used in the acquisition and measurement of heart sound signals with good effect. However, the wearable heart sound acquisition system (WHSAS) will face more noise compared with the traditional system, such as Gaussian white noise, powerline interference, colored noise, motion artifact noise, and lung sound noise, because users often wear these devices for running, walking, jumping or various strong noise occasions. In a strong noisy environment, WHSAS needs a high-precision segmentation algorithm. This paper proposes a segmentation algorithm based on Variational Mode Decomposition (VMD) and multi-wavelet. In the algorithm, various noises are layered and filtered out using VMD. The cleaner signal is fed into multi-wavelet to construct a time–frequency matrix. Then, the principal component analysis method is applied to reduce the dimension of the matrix. After extracting the high order Shannon envelope and Teager energy envelope of the heart sound, we accurately segment the signals. In this paper, the algorithm is verified through our developing WHSAS. The results demonstrate that the proposed algorithm can achieve high-precision segmentation of the heart sound under a mixed noise condition.

Non-Contact Heart Sound Measurement Using Independent Component Analysis

“…Although several studies have shown the automated diagnosis of cardiovascular diseases by analyzing measured heart sounds [3][4][5], these measurement methods usually involve physical restraint such as auscultation by a physician. While a few studies have shown wearable devices for heart sound monitoring [6,7], these devices have disadvantages such as discomfort due to constant wear and the need for intermittent charging. A microphone device such as a smartphone or a smart speaker placed around the user could monitor their heart sounds daily and provide an effective non-contact method to measure heart sounds.…”