Ternary LDPC Error Correction for Arrhythmia Classification in Wireless Wearable Electrocardiogram Sensors
Ternary LDPC Error Correction for Arrhythmia Classification in Wireless Wearable Electrocardiogram Sensors
复制标题
用于无线可穿戴心电图传感器中心律失常分类的三态 LDPC 纠错
DOI：
10.1109/tcsi.2021.3096755
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Tang, Wei
中科院分区：
文献类型：
--
作者：
Liu, Yanfang;Tang, Xiaochen;Mitchell, David G.;Tang, Wei
本文提出了一种用于无线心电传感器的三值低密度奇偶校验（LDPC）纠错系统，以提高心律失常分类的准确性。该分类系统是基于三进制增量调制的比特流和旋转线性核支持向量机，它识别室上性异位搏动（SVEB）和室性异位搏动（VEB）超过正常心跳。我们使用具有概率参数的三进制对称信道来建模错误，并通过级联两个分量子矩阵来构造具有不同码率的各种三进制LDPC码，以形成具有准循环结构的奇偶校验矩阵，从而便于硬件设计。特别地，提出了一种硬件友好的LDPC编码器电路，其利用高度结构化的奇偶校验矩阵来使用累加器和查找表执行奇偶符号的串行生成。编码器电路在FPGA上实现，并使用32 nm CMOS工艺在ASIC上综合。仿真结果表明，在存在错误的情况下，三值LDPC码可以显著提高分类精度。例如，在传感器输出比特流中错误概率高达21%的情况下，所提出的纠错系统的分类准确度保持在99%以上。
This paper presents a ternary low-density parity-check (LDPC) error correction system for wireless electrocardiogram sensors to improve the accuracy of arrhythmia classification. The classification system is based on ternary Delta-modulated bitstreams and rotation linear kernel support vector machines, which identifies the supraventricular ectopic beat (SVEB) and the ventricular ectopic beat (VEB) over the normal heartbeats. We model errors using a ternary symmetric channel with probability parameterand construct a variety of ternary LDPC codes with different coding rates by concatenating two-component sub-matrices to form a parity-check matrix with a quasi-cyclic structure that facilitates the hardware design. In particular, a hardware-friendly LDPC encoder circuit is proposed that leverages the highly structured parity-check matrix to perform serial generation of the parity symbols using an accumulator and a look-up table. The encoder circuits are implemented on FPGA and synthesized on ASIC using a 32 nm CMOS process. Simulation results show that the ternary LDPC codes can significantly improve classification accuracy in the presence of errors. For example, with an error probability of up to 21% in the sensor output bitstreams, the classification accuracy remains above 99% with the proposed error correction system.