Information Technology Reference
In-Depth Information
Chapter 9
Optimized Positioning of ECG Electrodes
for WSN Applications
Ivan Tomašić and Roman Trobec
9.1
Introduction
Electrocardiography has its foundations in the recording of the electrical activity of
the heart over time, using electrodes placed on the skin. Two electrodes measure the
electrical potential differences on the body surface induced by the electrical currents
through the heart muscle and surrounding conductive tissues. The method is simple
and noninvasive and, therefore, widely used for diagnostic purposes in cardiology.
The initial breakthrough in recording the electrical activity of the heart came from
Willem Einthoven at the beginning of the twentieth century. He was the first to
identify the various deflections, assigning to them the letters P, Q, R, S, and T, and
described the electrocardiographic features of a number of cardiovascular disor-
ders. In 1924, he was awarded the Nobel Prize in Medicine for his discovery. Since
Einthoven's time there have been many advances in electrocardiography. Over the
years, 12-lead ECG (electrocardiogram) became the gold standard, with its diag-
nostic foundation recognized by most cardiologists.
The conventional 12-lead ECG is obtained from ten electrodes placed strategically
on the patient's body. A combination of signals measured between certain electrodes,
with the introduction of a reference potential point, enables the heart to be “observed”
in horizontal and vertical planes from different “view” angles. A systematic and
intuitive interpretation of the measured results is possible, and is often supported by
automatic rule-based diagnostics.
The limited communication bandwidth in body wireless sensor networks
(BWSNs) motivates the optimization of electrocardiographic recording in terms of
the number of body electrodes. Minimization of the required distance between
Search WWH ::
Custom Search