Investigation and reduction methods of specific absorption
rate for biomedical applications: A survey
S. Jemima Priyadarshini
D. Jude Hemanth
ECE Department, Karunya University,
D. Jude Hemanth, ECE Department,
Karunya University, India.
Specific Absorption Rate (SAR) is an inevitable parameter to be considered for vari-
ous RF dosimetry evaluations in the field of biomedical engineering. There is a much
concern in exposure studies as they have a significant impact on the social and health
issues in the recent global community. SAR measures the absorption of electromag-
netic radiation of RF from devices in an exposure area. The significance of SAR
parameter has been awakened in broad areas of technology and even considered in
the design of radiating structures from biomedical devices such as MRI to also
popular mobile phones. Researchers have explicated the constant interaction of
electromagnetic field interactions with biological systems. The advancements in tech-
nology pose a grave concern about the impact on human health. This paper intends to
undertake an extensive survey of the various current investigations done with SAR in
different scenarios with possible radiating structures and also focus on exposure areas
on the human body. The SAR depends on estimation parameters that are analyzed
and discussed. Further, the paper will analyze comparatively the facets of implied
Methodologies in SAR computation. The parametric evaluation of SAR paves the
way for a requirement reduction of SAR parameter. The paper discusses current
reduction methodologies and its primary advantages and details possible setbacks.
The analysis indicates a requirement of the specific radiation structure for a particular
area of exposure of concern, followed by a need of ideal reduction methodology.
base station (BS), finite difference time domain (FDTD), method of moments (MOM), radio frequency
(RF), specific absorption rate (SAR)
SAR is a vital parameter for safety concerns to human expo-
sure analysis. The Specific Absorption Rate is a process of
detailed analysis and considered as one of the pioneering
areas of research in exposure studies. Specific Absorption
Rate measures rate of the amount of absorption of energy
when there is an exposure of the human body to the radio
frequency. SAR represents power absorbed by the mass
tissue. The unit of SAR is Watts per Kilogram (W/Kg).
Where jEj is the magnitude of Electric Field, r is the
conductivity of the tissue and q mass density of the tissue
SAR analysis entails three primary steps:
An investigation of the scenario with SAR parameters.
The estimation Technique with computational methods.
To reduce the SAR parameters on different levels.
SAR Investigation is a domain that mandates a source and an
exposure area. The source is usually a radiating structure
directed towards a vital part of a human body that is vulnera-
ble to severe biological effects of constant exposure. Kim
emphasized the biological to epidemiological implica-
tions of a single device such as cell phones. The hazardous
estimation of radio frequency was studied. Muzaffar
Fazlul et al.
investigated the SAR with a human head and
suggested the safety aspects for usage of handheld devices.
Int J RF Microw Comput Aided Eng. 2018;28:e21211.
2017 Wiley Periodicals, Inc.
Received: 25 July 2017
Revised: 21 November 2017
Accepted: 22 November 2017