CPSC2020
Full name: The 3rd China Physiological Signal Challenge 2020

# Introduction

Abnormality of cardiac conduction system can induce arrhythmia. Abnormal heart rhythm can lead to other cardiac diseases and complications, and can be life-threatening [1]. There are various types of arrhythmias and each type is associated with a pattern, and as such, it is possible to be identified. Arrhythmias can be classified into two major categories. The first category consists of arrhythmias formed by a single irregular heartbeat in electrocardiogram (ECG), herein called morphological arrhythmia, while another category consists of arrhythmias formed by a set of irregular heartbeats in ECG, herein called rhythmic arrhythmias [2]. Dynamic electrocardiogram (DCG), like ECG Holter, provides an important way to monitor the incidences of arrhythmias in daily life, facilitating the doctors to check a total number and distribution of arrhythmias in a long time and thus to provide the required therapy to prevent further problems.
The 3rd China Physiological Signal Challenge 2020 (CPSC 2020) aims to encourage the development of algorithms for searching for premature ventricular contraction (PVC) and supraventricular premature beat (SPB) from 24-hour dynamic single-lead ECG recordings usually with low signal quality and/or abnormal rhythm waveforms. Similar the previous works and efforts of the CPSC 2018 [3] and CPSC 2019 [4], accurate locating of abnormal heartbeats is another critical issue put forward here for further discussion.
ECG signal provides an important role in non-invasively monitoring and clinical diagnosis for cardiovascular disease (CVD). Arrhythmia detection is one of the ultimate goals of routine ECG monitoring, and PVC and SPB are the two most common arrhythmias. Increase in these beats may be a precursor to stroke or sudden cardiac death [5]. Although their detection methods have been severely tracked throughout the last several decades, accurate and robust detections are still challenging in noisy or low-signal quality environment, especially for daily monitored ECG waveforms. It is true that many of the developed PVC and SPB detection algorithms can achieve high accuracy (over 96% in sensitivity and positive predictivity) when tested over the standard ECG databases such as the MIT-BIH Arrhythmia Database or AHA Database [6]. However, these algorithms may fail when used in the noisy environment. Especially, even the basic QRS detection can be invalid in the low signal quality ECG analysis [7]. A recent study confirmed that none of the common QRS detection algorithms can obtain 80% detection accuracy when tested in a dynamic noisy ECG database. In this year’s challenge, we provide a new ECG database containing long-term noisy ECG recordings from clinical arrhythmia patients, to encourage the participants to develop more efficient and robust algorithms for PVC and SPB detection.

# Challenge Data

Training data consists of 10 single-lead ECG recordings collected from arrhythmia patients, each of the recording last for about 24 hours (shown in Table 1). Table 1 also indicates the patient if he/she is an atrial fibrillation (AF) patient. Test set contains similar ECG recordings, which is unavailable to public and will remain private for the purpose of scoring for the duration of Challenge and for some period afterwards. All data were collected by a unified wearable ECG device with a sampling frequency of 400 Hz, and provided in MATLAB format (each including three *.mat file: one is ECG data and another two are the corresponding PVC and SPB annotation files, respectively).

Detailed information of training data.

|Recordings	| AF patient ?	|Length (h)	|\# N beats	|\# V beats	|\# S beats	|\# Total beats|
|-----|-----|-----|-----|-----|-----|-----|
|A01	|No	|25.89	|109,062	|0	|24	|109,086|
|A02	|Yes|	22.83	|98,936|	4,554|	0	|103,490|
|A03	|Yes|	24.70	|137,249|	382|	0|	137,631|
|A04	|No	|24.51|	77,812	|19,024|	3,466|	100,302|
|A05	|No|	23.57|	94,614	|1|	25|	94,640|
|A06	|No|	24.59|	77,621|	0|	6	|77,627|
|A07	|No	|23.11|	73,325	|15,150	|3,481	|91,956|
|A08	|Yes|	25.46|	115,518|	2,793|	0|	118,311|
|A09	|No|	25.84|	88,229|	2|	1,462|	89,693|
|A10	|No	|23.64|	72,821|	169|	9,071|	82,061|

# Reference
[1] S. L. Oh, E. Y. Ng, R. San Tan, and U. R. Acharya, "Automated diagnosis of arrhythmia using combination of CNN and LSTM techniques with variable length heart beats," Computers in biology and medicine, vol. 102, pp. 278-287, 2018.
[2] E. J. D. S. Luz, W. R. Schwartz, G. Cámara-Chávez, and D. Menotti, "ECG-based heartbeat classification for arrhythmia detection: A survey," Computer methods and programs in biomedicine, vol. 127, pp. 144-164, 2016.
[3] F. Liu, C. Liu, L. Zhao, X. Zhang, X. Wu, X. Xu, Y. Liu, C. Ma, S. Wei, Z. He, J. Li, and E. Y. K. Ng, "An open access database for evaluating the algorithms of electrocardiogram rhythm and morphology abnormality detection," Journal of Medical Imaging and Health Informatics, vol. 8, pp. 1368-1373, 2018.
[4] H. Gao, C. Liu, X. Wang, L. Zhao, Q. Shen, E. Y. K. Ng, and J. Li, "An Open-Access ECG Database for Algorithm Evaluation of QRS Detection and Heart Rate Estimation," Journal of Medical Imaging and Health Informatics, vol. 9, pp. 1853-1858, 2019.
[5] J. Oster, J. Behar, O. Sayadi, S. Nemati, A. E. Johnson, and G. D. Clifford, "Semisupervised ECG ventricular beat classification with novelty detection based on switching Kalman filters," IEEE Transactions on Biomedical Engineering, vol. 62, pp. 2125-2134, 2015.
[6] A. L. Goldberger, L. A. Amaral, L. Glass, J. M. Hausdorff, P. C. Ivanov, R. G. Mark, J. E. Mietus, G. B. Moody, C. Peng, and H. E. Stanley, "PhysioBank, PhysioToolkit, and PhysioNet: components of a new research resource for complex physiologic signals," Circulation, vol. 101, pp. e215-e220, 2000.
[7] F. Liu, C. Liu, X. Jiang, Z. Zhang, Y. Zhang, J. Li, and S. Wei, "Performance analysis of ten common QRS detectors on different ECG application cases," Journal of Healthcare Engineering, vol. 2018, pp. 9050812(1)-9050812(8), 2018.
[8] ANSI/AAMI EC57, "1998 / (R) 2008-Testing and reporting performance results of cardiac rhythm and ST segment measurement algorithms", Arlington, VA, USA, 2008.