A Low-Latency, Low-Power FPGA Implementation of ECG Signal Characterization Using Hermite Polynomials

Madhav P Desai,Abraham Otero,Ruzica Jevtic,Gabriel Caffarena,David G Márquez

doi:10.3390/electronics10192324

Madhav P Desai, Abraham Otero + Show 3 more

Open Access

https://doi.org/10.3390/electronics10192324

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Abstract

Automatic ECG signal characterization is of critical importance in patient monitoring and diagnosis. This process is computationally intensive, and low-power, online (real-time) solutions to this problem are of great interest. In this paper, we present a novel, dedicated hardware implementation of the ECG signal processing chain based on Hermite functions, aiming for real-time processing. Starting from 12-bit ADC samples of the ECG signal, the hardware implements filtering, peak and QRS detection, and least-squares Hermite polynomial fit on heartbeats. This hardware module can be used to compress ECG data or to perform beat classification. The hardware implementation has been validated on a Field Programmable Gate Array (FPGA). The implementation is generated using an algorithm-to-hardware compiler tool-chain and the resulting hardware is characterized using a low-cost off-the-shelf FPGA card. The single-beat best-fit computation latency when using six Hermite basis polynomials is under 1 s with a throughput of 3 beats/s and with an average power dissipation around 28 mW, demonstrating true real-time applicability.

Highlights

Cardiovascular disease is the number one cause of death worldwide [1]
The work in [25] is a HW/SW co-design where the QRS complex extraction is implemented in an Field Programmable Gate Array (FPGA) and is based on geometrical properties of a two-dimensional phase-space portrait of the ECG signal, while the beat classification is performed by Open Source ECG analysis software
We presented the design of an FPGA-based system able to perform real-time ECG characterization through Hermite polynomials

Summary

Introduction

Cardiovascular disease is the number one cause of death worldwide [1]. An electrocardiogram (ECG) registers the electrical activity of a heart, and it stands as a valuable diagnostic tool. The Q, R and S waves are normally studied together as the QRS complex. The P wave represents the moment when the auricles contract to send blood to the ventricles, and at the end of the PR segment, the ventricle is full. During the QRS complex, the ventricle expels their contents and are fully emptied at the end of the ST segment. The T wave indicates that the heart is at rest

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