Working Group 3 (WG3) – EMF dosimetry – in silico tools & measurements
Leader: Niels Kuster, IT’IS Foundation, Zurich, Switzerland
concerting the research on EMF computational (in silico) and measurement dosimetry.
– understand and control the underlying physical, technical, and relevant biological (tissue) parameters during medical procedures and experimental studies
– develop and/or improve validated multi-physics, multi-scale simulation tools and functionalized anatomical models
– develop and/or improve dosimetric measurement equipment and exposure equipment
– provide the technical support to WG1 and WG2
EMF dosimetry is an essential part of all scientific studies on EMF biological and health effects. Underlying physical, technical, and relevant biological (tissue) parameters must be properly understood and controlled during experimental investigations, and, consequently, during medical procedures. This WG provides the technical support to WG1 and WG2.
Computational tools in EMF dosimetry have previously concentrated on modelling and simulations on the macroscopic level. This is still essential for all parts of the experimental and application system design, thus the computational analyses will be applied to the EMF generating devices, EM wave propagation through various media, and EMF distribution in various media, especially in the targeted tissue. However, research topics 1 and 2 require accurate characterization of the interactions of EMF with non-isotropic tissue models embedded in complex anatomies at all levels. This includes: 1) EMF macro-dosimetry, i.e., thorough understanding and control of the induced fields at the macroscopic level; 2) EMF micro-dosimetry, i.e., the development of simulation models to describe the induced-field distribution at the subcellular level, thereby enabling the studying of interaction mechanisms of EMF with the biology; 3) neural tissue models, i.e., models for studying the coupling of the externally applied or induced fields with the non-isotropic neuron network. Accordingly, this topic includes both the development of novel and improvement of currently available tools for in silico studies of biological interactions with EMFs. In silico models require accurate characterization of tissues with respect to their dielectric parameters. Considering the shortcomings of the present databases, regarding their validity with respect to frequency and temperature range, proper tissue- and application-specific values have yet to be obtained experimentally. Thus, this topic includes the development of measurement instrumentation, methods, and procedures, for validation of the predicted theoretical or in silico values, and for obtaining the accurate input parameters needed for theoretical or numerical analyses.
EMF macro-dosimetry can now exploit both numerical and experimental tools, providing accurate information on the distribution of the EMF induced in the biological target. Experimental dosimetry is a necessary tool for validating numerical codes, as well as for testing EM exposure systems and EM applicators under reference conditions. Numerical dosimetry, once validated, allows performing thorough investigations on induced field distribution in complex targets (e.g. by exploiting the availability of high-resolution digital anatomical models). Therefore, EMF macro-dosimetry can be considered as a necessary and powerful tool throughout the research topics defined in this proposal.
The tools to be developed or adapted from existing ones include:
– Validated multi-physics, multi-scale simulation tools optimized for simulations involving living tissue: These tools must be able to integrate physiology and biology on many levels (organism, systems, organs, tissues, cells, subcellular structures, biomolecules), their interactions, and the coupling with EMFs. To handle the necessary complexity, the underlying solvers – EM, neural- and molecular-dynamics, etc. – must be efficient, high-performance-computing enabled, and optimized for the needs of computational life sciences (i.e., with support for anatomical models, living tissue, and inclusion of biological measurement information).
– Dosimetric measurement equipment: The equipment is needed to perform accurate macro- and micro-scale measurements to characterize treatment and exposure equipment. Such measurements are also critical for the validation of simulation tools and models.
– Functionalized anatomical models: In view of the important impact of the inhomogeneity (on many scales) of the human body on the local EM field strengths and induced effects, detailed anatomical models are crucial for assessment of exposure in regards to personalized treatment, equipment development, or mechanism exploration. In the case of personalized treatment, it can even be necessary to generate patient-specific models that are enriched with tissue parameters (dielectric properties and perfusion information, potentially personalized) and functionalized, e.g., with integration of dynamical neuron models, vasculature and thermoregulation information, and tissue growth/damage models.
– Exposure equipment: This equipment is required to generate well-controlled conditions for experiments. Exposure can target humans, animals, and tissue or cell cultures. Tight control over the frequency, waveform, field strength, deposited energy, and temperature is crucial.