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ITALIAN NATIONAL RESEARCH COUNCILInstitute for Applied Physics"Nello Carrara" - Florence (Italy) |
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Overview |
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Applications |
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Server documentation |
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Credits |
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References |
Numerical dosimetry, for instance, (the discipline devoted to calculate, by means of numerical algorithms, current densities and specific absorption rates (SARs) in tissues and organs of individuals exposed to EM fields) deals with digitized 2D or 3D human models each element of which (pixel in 2D and voxel in 3D models) has to be recognized as being constituted by a given, well defined tissue and thus must have assigned unique dielectric properties, consisting of a pair of values, one for the relative permittivity and one for the electrical conductivity at each frequency of interest.
This application is aimed to calculate the dielectric properties
of human body tissues in the frequency range from 10 Hz to 100 GHz
using the parametric model and the parameter values developed by
C.Gabriel and collegues (see Credits and
References below).
It is based on a client-server approach.
The server program runs in background on a central system and
is responsible for the management of the parameter database (14
parameters for each defined tissue) and for the calculation of the
dielectric properties of requested tissues at requested frequencies.
These properties comprise the relative permittivity, the electrical
conductivity and a few significant derived quantities: the loss tangent,
the wavelength and the penetration or "skin" depth.
The client program is executed by the user on a remote system
connected to the server by a Local or a Wide Area Network supporting the
TCP/IP protocol; the client program implements the user interface and
translates user requests into commands for the server; it also has to deal
with reception and display of the requested data.
The main advantage of the client/server approach consists in the
centralized management of the tissue parameters, allowing
new tissues to be defined or parameter values to be changed
without having to redistribute software to the users.
The users, on their sides, get also rid of the need to implement
the code for the calculation of the dielectric properties from the
parameter values.
The availability of the server documentation
makes it possible, for users who need it and can afford it, to develop
their own applications devoted to specific tasks or platforms.
The reverse of the medal obviously is the need of a TCP/IP link between
the client and the server.
This application has been prepared at IFAC-CNR (ex IROE-CNR) as a side project among the activities of the research line devoted to "Protection against exposures to low-frequency, radiofrequency and microwave electromagnetic fields". It would not have been possible without the huge work of C.Gabriel and collegues at the Brooks Air Force Base (USA), who developed the parametric model for the calculation of the dielectric properties of body tissues we use here (see References below).
At IFAC-CNR, the following people took part in the project:
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