Biomedical Engineering Reference
In-Depth Information
Chapter 7
Electromagnetic Effects of IR-UWB
Implant Communication
Abstract With the increased use of Impulse Radio-Ultra-Wideband (IR-UWB)
devices within or at close proximity to the human body, it is of utmost importance
to analyze the electromagnetic effects caused by those devices. As human tissue is
exposed to the electromagnetic signals emitted from IR-UWB devices, they absorb
a certain amount of transmitted power and convert it into heat. This phenomenon
causes a temperature increase in the human tissue. The heating effect of the human
tissue is significant for high-frequency and high-bandwidth signals, such as the IR-
UWB signals. The temperature increase of the tissue material should be regulated
in order to prevent any adverse effects caused by the exposure to electromagnetic
signals. Specific Absorption Rate (SAR) and Specific Absorption (SA) provide a
good indication of the amount of power absorbed by the himan tissues. This
chapter presents the SAR, SA and temperature variation of the human body caused
by IR-UWB signals. An IR-UWB based Wireless Capsule Endoscopy (WCE) that
operates inside the human abdomen is used as the main application for this study.
This analysis compares the compliance of the IR-UWB based WCE devices with
international safety regulations. A voxel model of the human body consisting
of human tissue simulating materials is used for this simulation-based study.
The tissue properties, such as relative permittivity, are characterized according to
the incident signal frequency and age of the tissue sample during simulations. The
SAR and SA variations are analyzed using the Finite Integration Technique (FIT)
as the discretization model.
Keywords SAR/SA
Wireless capsule endoscopy
Head implant
Electro-
magnetic effects
Temperature increase
Bio-heat equation
IR-UWB
7.1 Introduction
Wireless communication for implantable sensor devices has drawn the attention of
researchers in recent years due to the several advantages it possesses, such as
minimizing
restrictions
in
daily
activities,
facilitating
less
invasive
surgical
