Signal Separation Using a Mathematical Model of Physiological Signals for the Measurement of Heart Pulse Wave Propagation With Array Radar

Takuya Sakamoto

doi:10.1109/access.2020.3026539

Abstract

The arterial pulse wave, which propagates along the artery, is an important indicator of various cardiovascular diseases. By measuring the displacement at multiple parts of the human body, pulse wave velocity can be estimated from the pulse transit time. This paper proposes a technique for signal separation using an antenna array, so that pulse wave propagation can be measured in a non-contact manner. The body displacements due to the pulse wave at different body parts are highly correlated, and cannot be accurately separated using techniques that assume independent or uncorrelated signals. The proposed method formulates the signal separation as an optimization problem, based on a mathematical model of the arterial pulse wave. The objective function in the optimization comprises four terms that are derived based on a small-displacement approximation, unimodal impulse response approximation, and a causality condition. The optimization process was implemented using a genetic algorithm. The effectiveness of the proposed method is demonstrated through numerical simulations and experiments.

Highlights

According to reports from the National Center for Health Statistics of the Centers for Disease Control and Prevention in the United States, the number of adults diagnosed with heart disease was 30.3 million in 2018 [1]
We introduce a simplified model of pulse wave propagation; the displacements caused by the pulse wave are assumed to have similar waveforms with a time delay corresponding to the pulse transit time
In this study, we proposed a signal processing technique for non-contact measurement of the pulse wave propagating along the artery using an array radar system

Summary

Introduction

According to reports from the National Center for Health Statistics of the Centers for Disease Control and Prevention in the United States, the number of adults diagnosed with heart disease was 30.3 million in 2018 [1]. That accounts for 12.1% of all adults, resulting in more than 600 000 deaths/year, making heart disease the leading cause of death in the United States. Constant monitoring of health status is important for the prevention and treatment of heart disease. Some signs of heart disease can be detected from pulse wave propagation along the arteries caused by the pulsation of the heart. Pulse wave velocity (PWV), which is the velocity of the pulse wave, is related to blood pressure and vascular stiffness, and is important for early detection of signs of heart disease such as hypertension, arteriosclerosis, and myocardial infarction. PWV can be calculated by wearing multiple cuffs on the four limbs, The associate editor coordinating the review of this manuscript and approving it for publication was Liangtian Wan

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Conclusion