Computational study of thermal changes during the non-invasive neuro-electrostimulation of the nerve structures in the human neck modelling using finite element method

In the article methodology of FEM stimulation of thermal effects, caused by neck-region neuro-electrostimulation was shown. Algorithm of the voxel model conversion to the 3-D objects represented as the complex of the STL-files was described. The evaluation of the temperature in the biological tissues is based on the association of the partial thermal changes, caused by the harmonics components of the pulsed neuro-electrostimulation signal. Features of the thermal changes in the neck region were considered for the neuro-electrostimulation by means of the current pulse field formed in the "SYMPATHOCOR-01" device. Results have shown that for modulation frequencies in range 45-55 Hz, duration of the partial pulses 25-30 us, current pulse amplitude less than 13 mA, the neuro-electrostimulation does not cause thermal changes higher than 0.1 K. Copyright © 2017 by SCITEPRESS – Science and Technology Publications, Lda. All rights reserved

Brain and Human Body Modeling

This open access book describes modern applications of computational human modeling with specific emphasis in the areas of neurology and neuroelectromagnetics, depression and cancer treatments, radio-frequency studies and wireless communications. Special consideration is also given to the use of human modeling to the computational assessment of relevant regulatory and safety requirements. Readers working on applications that may expose human subjects to electromagnetic radiation will benefit from this book’s coverage of the latest developments in computational modelling and human phantom development to assess a given technology’s safety and efficacy in a timely manner. Describes construction and application of computational human models including anatomically detailed and subject specific models; Explains new practices in computational human modeling for neuroelectromagnetics, electromagnetic safety, and exposure evaluations; Includes a survey of modern applications for which computational human models are critical; Describes cellular-level interactions between the human body and electromagnetic fields

Brain and Human Body Modeling

This open access book describes modern applications of computational human modeling with specific emphasis in the areas of neurology and neuroelectromagnetics, depression and cancer treatments, radio-frequency studies and wireless communications. Special consideration is also given to the use of human modeling to the computational assessment of relevant regulatory and safety requirements. Readers working on applications that may expose human subjects to electromagnetic radiation will benefit from this book’s coverage of the latest developments in computational modelling and human phantom development to assess a given technology’s safety and efficacy in a timely manner. Describes construction and application of computational human models including anatomically detailed and subject specific models; Explains new practices in computational human modeling for neuroelectromagnetics, electromagnetic safety, and exposure evaluations; Includes a survey of modern applications for which computational human models are critical; Describes cellular-level interactions between the human body and electromagnetic fields

Brain and Human Body Modeling 2020

​This open access book describes modern applications of computational human modeling in an effort to advance neurology, cancer treatment, and radio-frequency studies including regulatory, safety, and wireless communication fields. Readers working on any application that may expose human subjects to electromagnetic radiation will benefit from this book’s coverage of the latest models and techniques available to assess a given technology’s safety and efficacy in a timely and efficient manner. Describes computational human body phantom construction and application; Explains new practices in computational human body modeling for electromagnetic safety and exposure evaluations; Includes a survey of modern applications for which computational human phantoms are critical

Occupational exposure to electromagnetic fields: risk assessment of operators performing Transcranial Magnetic Stimulation (TMS) treatments

The assessment of the risk from occupational exposure to electromagnetic fields (EMF) has attracted the attention of those involved in safety in the workplace, in particular after the updating of European legislation, with the publication for EMFs, of Directive 2013/35/EU1 of the European Parliament and of the Council, which made the risk assessment mandatory for this type of physical agents. The issue is made even more relevant by the proliferation of industrial and health applications using EMF even of considerable intensity. However, the rapid technological development has not always been accompanied by adequate growth in the culture of prevention and safety. Many devices expose both operators and persons of the general public to significant risks, but often, these risks are not adequately reported by the manufacturer, nor mentioned in the instruction manual, as would be expressly required by the harmonized standards. In this general framework is placed this Ph.D. research project, whose aim is to analyze possible conditions of risk in the workplace, considering only the environment where the EMF sources potentially expose the operator to risk. The research project involves a joint collaboration between two Institutions: the National Institute for Insurance against Accidents at Work - INAIL and of course Sapienza University of Rome. The project is developed in a multidisciplinary manner, providing experimental and numerical investigations to achieve the required goals, also considering the literature review and comparison for a more realistic analysis of the risk, in terms of human exposure to EMF. The work is based on a multiphysics approach to obtain a complete evaluation of the risk in the workplace, with the prospective to improve the current approach in the assessment of the risk and eventually suggest some indications to the operator for better use of the device under test. Therefore, the starting point has been a review of the workplaces to identify any gaps and critical issues in relation to the risk assessment and therefore for which it is considered necessary to deepen the protectionist issues. A literature analysis of the state of the art on the risk in the workplace is first carried out. This has been followed by numerical and accurate modeling of the device under test as well as the workers in a real reproduced work condition of exposure. Of paramount importance is the understanding of all the parameters that can affect the distribution of the induced EM quantities, which are essential for the risk assessment and the verification of compliance with the regulations system. To do this, it was necessary to study human exposure in-depth, also using different human body models available for dosimetric analysis on dedicated software. All the research has traveled on two parallel tracks, on the one hand, the need to fill the scientific gaps in the research area of exposure assessment of workers and on the other one to take into account the regulatory aspects, essential for a correct evaluation of professional exposure. Therefore, as a last step of the overall work, a possible new protocol of risk assessment analysis is proposed to move forward on the improvement of safety and security in the workplace

A Subject-Specific Multiscale Model of Transcranial Magnetic Stimulation

Transcranial magnetic stimulation (TMS) is a neuromodulation technique used to treat a variety of neurological disorders. While many types of neuromodulation therapy are invasive, TMS is an attractive alternative because it is noninvasive and has a very strong safety record. However, clinical use of TMS has preceded a thorough scientific understanding: its mechanisms of action remain elusive, and the spatial extent of modulation is not well understood. We created a subject-specific, multiscale computational model to gain insights into the physiological response during motor cortex TMS. Specifically, we developed an approach that integrates three main components: 1) a high-resolution anatomical MR image of the whole head with diffusion weighted MRI data; 2) a subject-specific, electromagnetic, non-homogeneous, anisotropic, finite element model of the whole head with a novel time-dependent solver; 3) a population of multicompartmental pyramidal cell neuron models. We validated the model predictions by comparing them to motor evoked potentials (MEPs) immediately following single-pulse TMS of the human motor cortex. This modeling approach contains several novel components, which in turn allowed us to gain greater insights into the interactions of TMS with the brain. Using this approach we found that electric field magnitudes within gray matter and white matter vary substantially with coil orientation. Our results suggest that 1) without a time-dependent, subject-specific, non-homogeneous, anisotropic model, loci of stimulation cannot be accurately predicted; 2) loci of stimulation depend upon biophysical properties and morphologies of pyramidal cells in both gray and white matter relative to the induced electric field. These results indicate that the extent of neuromodulation is more widespread than originally thought. Through medical imaging and computational modeling, we provide insights into the effects of TMS at a multiscale level, which would be unachievable by either method alone. Finally, our approach is amenable to clinical implementation. As a result, it could provide the means by which TMS parameters can be prescribed for treatment and a foundation for improving coil design

Beyond language: The unspoken sensory-motor representation of the tongue in non-primates, non-human and human primates

The English idiom “on the tip of my tongue” commonly acknowledges that something is known, but it cannot be immediately brought to mind. This phrase accurately describes sensorimotor functions of the tongue, which are fundamental for many tongue-related behaviors (e.g., speech), but often neglected by scientific research. Here, we review a wide range of studies conducted on non-primates, non-human and human primates with the aim of providing a comprehensive description of the cortical representation of the tongue's somatosensory inputs and motor outputs across different phylogenetic domains. First, we summarize how the properties of passive non-noxious mechanical stimuli are encoded in the putative somatosensory tongue area, which has a conserved location in the ventral portion of the somatosensory cortex across mammals. Second, we review how complex self-generated actions involving the tongue are represented in more anterior regions of the putative somato-motor tongue area. Finally, we describe multisensory response properties of the primate and non-primate tongue area by also defining how the cytoarchitecture of this area is affected by experience and deafferentation

Electrostimulation Contingencies and Attention, Electrocortical Activity and Neurofeedback

There is a growing body of evidence for diverse ways of modulating neuronal processing to improve cognitive performance. These include brain-based feedback, self-regulation techniques such as EEG-neurofeedback, and stimulation strategies, alone or in combination. The thesis goal was to determine whether a combined strategy would have advantages for normal cognitive function; specifically operant control of EEG activity in combination with transcutaneous electro-acustimulation. In experiment one the association between transcutaneous electroacustimulation (EA) and improved perceptual sensitivity was demonstrated with a visual GO/NOGO attention task (Chen et al, 2011). Furthermore reduced commission errors were related to an electrocortical motor inhibition component during and after alternating high and low frequency EA, whereas habituation in the control group with sham stimulation was related to different independent components. Experiment two applied frequency-domain ICA to detect changes in EEG power spectra from the eyes-closed to the eyes-open state (Chen et al, 2012). A multiple step approach was provided for analysing the spatiotemporal dynamics of default mode and resting state networks of cerebral EEG sources, preferable to conventional scalp EEG data analysis. Five regions were defined, compatible with fMRI studies. In experiment three the EA approach of Exp I was combined with sensorimotor rhythm (SMR) neurofeedback. SMR training improved perceptual sensitivity, an effect not found in a noncontingent feedback group. However, non-significant benefits resulted from EA. With ICA spectral power analysis changes in frontal beta power were associated with contingent SMR training. Possible long-term effects on an attention network in the resting EEG were also found after SMR training, compared with mock SMR training. In conclusion, this thesis has supplied novel evidence for significant cognitive and electrocortical effects of neurofeedback training and transcutaneous electro-acustimulation in healthy humans. Possible implications of these findings and suggestions for future research are considered