FPGA-Based Real-Time ECG Classification System Using Quantized Inception-ResNeXt Neural Network and CWT Approximation

Tiancheng Cao, Wei Soon Ng, Wang Ling Goh, Yuan Gao, Hen-Wei Huang

Abstract: This article presents a software–hardware codesigned field-programmable gate array (FPGA)-based real-time electrocardiogram (ECG) classification system that combines methodological and practical innovations to achieve state-of-the-art performance with an ultracompact model. On the software side, we introduce a hardware-adaptive, configurable quantization-aware training (QAT) framework that enables layerwise precision assignment and flexible quantization, ensuring that the trained model is highly accurate and hardware-friendly even at ultralow bit widths. On the hardware side, we propose a resource-efficient FPGA accelerator featuring a streaming architecture and a cosine-approximated continuous wavelet transform (CWT) module, optimized for low-power and real-time inference. Implemented in an FPGA, we demonstrate that a six-layer Inception-ResNeXt (IRN) network can achieve 99.5% inference accuracy on the MIT-BIH ECG dataset with 200-mW dynamic power and 0.0767-mJ/inference energy efficiency.