VOL. 10, NO. 20, NOVEMBER 2015 ISSN 1819-6608
ARPN Journal of Engineering and Applied Sciences
© 2006-2015 Asian Research Publishing Network (ARPN). All rights reserved.
www.arpnjournals.com
9839
ARRHYTHMIA DETECTION BASED ON HERMITE POLYNOMIAL
EXPANSION AND MULTILAYER PERCEPTRON ON SYSTEM-ON-CHIP
IMPLEMENTATION
Amin Hashim
1
, Rabia Bakhteri
2
and Yuan Wen Hau
3
1,2
Faculty of Electrical Engineering, Universiti Teknologi Malaysia, Skudai, Johor, Malaysia
3
IJN-UTM Cardiovascular Engineering Centre, Faculty of Biosciences and Medical Engineering, Universiti Teknologi
Malaysia, Skudai, Johor, Malaysia
E-Mail:cik.amin@gmail.com
ABSTRACT
As the number of health issues caused by heart problems is on the rise worldwide, the need for an efficient and
portable device for detecting heart arrhythmia is needed. This work proposes a Premature Ventricular Contraction detection
system, which is one of the most common arrhythmia, based on Hermite Polynomial Expansion and Artificial Neural
Network Algorithm. The algorithm is implemented as a System-On-Chip on Altera DE2-115 FPGA board to form a
portable, lightweight and cost effective biomedical embedded system to serve for arrhythmia screening and monitoring
purposes. The complete Premature Ventricular Contraction classification computation includes pre-processing,
segmentation, morphological information extraction based on Hermite Polynomial Expansion and classification based on
artificial Neural Network algorithm. The MIT-BIH Database containing 48 patients’ ECG records was used for training
and testing purposes and Multilayer Perceptron training is performed using back propagation algorithm. Results show that
the algorithm can detect the PVC arrhythmia for 48 different patients with 92.1% accuracy.
Keywords: artificial neural network, electrocardiography, FPGA, hermite polynomial expansion, multilayer perceptron.
INTRODUCTION
The heart is the most important organ in the
human body and it beats non-stop throughout the human
lifespan. Its main function is to supply oxygen and
nutrients throughout the body. Cardiovascular diseases
(CVD) are heart related diseases and they are the leading
cause of death worldwide. According to World Health
Organization estimate, in the year 2012, 17.5 million
people died from CVD, representing 31% of all global
deaths (Dinc, 2013). Electrocardiography is the process of
monitoring the electrical activity that is primarily used to
diagnose heart disease. A study done in (De Backquer,
1998) shows that the CVDs that caused mortality have
high correlation with arrhythmia found in the patient’s
electrocardiogram (ECG) record. Therefore, a highly
accurate screening device is important to detect arrhythmia
for early treatment, thus reducing the risk of death due to
CVD.
Premature Ventricular (PVC) heartbeat is the
most common arrhythmia. Framingham Heart Study
reported that risk of mortality, cardiac death and
myocardial infarction is double when associated with PVC
(Ng, 2006), (Bikkina, 1992). PVC can be recognized by its
irregular rhythm, absence of P wave and wide QRS
complex shape. If PVC happens more than three times, it
is named as Ventricular Tachycardia that later might
evolve to Ventricular Fibrillation that is a fatal rhythm
(Reid, 1924). Thus it is important to monitor and detect
PVC at early stage.
The electrocardiogram is a widely accepted tool
used to detect abnormal heart rhythms and as the first
indicator to investigate cardiac disorder, such as the cause
of chest pain. It records the electrical activity of heart by
attaching electrodes to the patient limbs.
However, the ECG signals are irregular in nature
and occur randomly at different time intervals during the
day. Thus the need of continuous monitoring of the ECG
signal is desired, which by nature is complex to
comprehend. Moreover, there is a possibility of the analyst
missing vital information through manual analysis which
can be crucial in determining the nature of the disease. To
reduce the medical practitioner’s workload, a highly
accurate algorithm for computerized arrhythmia detection
proposed by researchers.
To design a portable, lightweight heart
monitoring device that can detect arrhythmia accurately,
the most suitable implementation is as a System-On-Chip
(SOC). The prototype of SOC can be designed on Field
Programmable Gate Array (FPGA) where the more
compute intensive computation modules can be designed
in hardware while other process blocks are implemented
on software. This would greatly reduce the computational
clock cycle needed to perform the task, thus it might
reduce the computational time tremendously compared to
general purpose embedded processor (Nambiar, 2012).
RELATED WORK
There are many general computations involved in
detecting the arrhythmia in ECG. The first is
preprocessing stage to remove noise, normalize the signal
and prepare the data so that it contains only useful
information. The second stage is feature extraction, which
is to extract the ECG feature so that it can be classified
accordingly. Feature extraction algorithm such as Hermite
Polynomial Expansion (Lagerholm, 2000), Wavelet
transform (Pachauri, 2009), Peak Valley Detection (Al-
Aloui, 1986), Statistical analysis based on heart rate
variability (Mohammadzadeh, 2006) and many more can