Zurich, Switzerland

Schmid & Partner Engineering AG

Zurich, Switzerland
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Agency: European Commission | Branch: FP7 | Program: CP-FP | Phase: ENV.2009. | Award Amount: 3.92M | Year: 2009

Public exposure to electromagnetic fields in the radio frequency spectrum has increased dramatically in the last two decades. Although research has mainly focused on the exposure and health risk evaluations of cellular networks and mobile phones in recent years, studies on the effects of the pervasive and prolonged EMF exposure on human health due to the exponential growth of wireless network device usage in homes, offices and schools are lacking. The proposed project SEAWIND aims (1) to provide a comprehensive assessment of the incident field exposure in typical living scenarios such as in homes, offices and classrooms by installed wireless local area networks (WLAN or WiFi) or wireless metropolitan area networks (WMAN or WiMAX), body-mounted and body-worn wireless personal area networks (WPAN) and WLAN devices, and specific wireless applications in industry, e.g., novel RFID logistic applications; (2) to numerically determine the induced fields in the human body using a set of models representing the human population; and (3) to screen potential biological sensitivities at the molecular, developmental and functional levels in cells. The necessary technology will also be developed to accurately assess the exposures for device compliance testing and to accurately assess in situ exposures. The comprehensive risk assessment will be based on the findings of this project, addressing the specificity of the exposure of wireless networks combined with the current body of literature on biological interactions of EMF covering the entire radio-frequency spectrum. A comparison to other exposures such as cellular mobile devices, base stations, TV, Radio, etc will also be included.

Agency: European Commission | Branch: FP7 | Program: CP-FP | Phase: ENV.2011.1.2.2-2 | Award Amount: 4.58M | Year: 2011

Based on epidemiological evidence supporting an ssociation between residential exposure to extremely low frequency magnetic fields (ELF MF) and childhood leukaemia, ELF MF have been classified as possibly carcinogenic to humans. The proposed project aims to scrutinize the underlying biophysical mechanisms and to clarify a possible causal relationship between ELF MF exposure and cancer, especially childhood leukaemia. This will be achieved by 1) developing and applying novel experimental and computational techniques to close knowledge gaps in the exposure assessment to ELF MF and 2) applying advanced biological in vitro, ex vivo and in vivo models and techniques under well-defined exposure conditions to test likely interaction mechanisms. The selected experimental approach is based on epidemiological evidence and current knowledge about the molecular processes underlying acute leukaemia in children. It aims to investigate the possible impact of ELF-MF exposure: 1) on the epigenetic dynamics associated with hematopoietic cell lineage commitment and differentiation; epigenetic signatures will be monitored genome-wide, and mechanisms underlying eventual misprogramming will be addressed in gene promoter models; 2) on the alteration of signalling processes in cells; 3) on the induction of possible cytotoxic effects on CD8 positive T cells; and 4) on the genesis or evolution of childhood leukaemia by generating genetically modified advanced animal models. Advanced biophysical simulations with efficient numerical solvers combined with the latest tissue and cellular models will be implemented to support the bioexperiments. A risk assessment will be performed at the end based on studies conducted within the project and correlated to recent studies conducted outside the consortium by adapting and applying procedures as outlined by the International Agency for Research on Cancer (IARC) Monographs on the Evaluation of Carcinogenic Risks to Humans.

Li C.-H.,ETH Zurich | Douglas M.,ETH Zurich | Ofli E.,Schmid & Partner Engineering AG | Derat B.,Field Imaging | And 3 more authors.
IEEE Transactions on Antennas and Propagation | Year: 2012

The influence of the user's hand holding a mobile phone to the ear on the peak spatial-average Specific Absorption Rate (psSAR) averaged over any 1 g and 10 g of tissue in the head is investigated. This study is motivated by recent reports that found substantial increases in psSAR by the presence of the hand in some cases. Current measurement standards prescribe the measurement of SAR in a head phantom without a hand present. The mechanisms of interaction between the hand and mobile phone models are studied. Simulations and measurements at 900 and 1800 MHz have been conducted to complement the understanding of the hand grip parameters leading to higher SAR in the head. Numerical simulations were conducted on four mobile phone models, and parameters such as the palm-phone distance and hand position were varied. Measurements of 46 commercial mobile phones were made, and the maximum psSAR with different hand positions and palm-phone distances was recorded. Both simulations and measurements have found increases in the psSAR in the head of at least 2.5 dB due to the presence of the hand. Furthermore, the psSAR is sensitive to the hand grip, i.e., the variations can exceed 3 dB. © 2011 IEEE.

Kuhn S.,ETH Zurich | Kuster N.,ETH Zurich | Kochali B.,Schmid & Partner Engineering AG
IEEE International Symposium on Electromagnetic Compatibility | Year: 2014

We present a medical resonance imaging (MRI) B1-field polarisation mapping system based on active electro-optical H-field probes. The active electro-optical field probes have a bandwidth ranging from 10 MHz to 6 GHz with a sensitivity of < -110dB(A/m)/√Hz at 128MHz. The miniature size of the probe elements (2×2 mm2) provides a high spatial resolution. The electrical isolation using fiber-optics enables the system to be used in the harsh electro-magnetic environment of an MRI system and eliminates any feedback on the RF transmit coil under test. The developed measurement system has been tailored to the B1-field measurement application with a specific control and postprocessing software and allows for traceable B-field calibration with an absolute measurement uncertainty of better than ±1 dB. The relative measurement uncertainties in terms of the axial ratio and the relative phase of the B1x and B1y (polarisation ellipse parameter) are better than 0.4 dB and 3%, respectively. © 2014 The Institute of Electronics, Information and Communication Engineer.

Gosselin M.-C.,Foundation for Research on Information Technologies in Society itIs | Gosselin M.-C.,ETH Zurich | Neufeld E.,Foundation for Research on Information Technologies in Society itIs | Moser H.,Foundation for Research on Information Technologies in Society itIs | And 12 more authors.
Physics in Medicine and Biology | Year: 2014

The Virtual Family computational whole-body anatomical human models were originally developed for electromagnetic (EM) exposure evaluations, in particular to study how absorption of radiofrequency radiation from external sources depends on anatomy. However, the models immediately garnered much broader interest and are now applied by over 300 research groups, many from medical applications research fields. In a first step, the Virtual Family was expanded to the Virtual Population to provide considerably broader population coverage with the inclusion of models of both sexes ranging in age from 5 to 84years old. Although these models have proven to be invaluable for EM dosimetry, it became evident that significantly enhanced models are needed for reliable effectiveness and safety evaluations of diagnostic and therapeutic applications, including medical implants safety. This paper describes the research and development performed to obtain anatomical models that meet the requirements necessary for medical implant safety assessment applications. These include implementation of quality control procedures, re-segmentation at higher resolution, more-consistent tissue assignments, enhanced surface processing and numerous anatomical refinements. Several tools were developed to enhance the functionality of the models, including discretization tools, posing tools to expand the posture space covered, and multiple morphing tools, e.g., to develop pathological models or variations of existing ones. A comprehensive tissue properties database was compiled to complement the library of models. The results are a set of anatomically independent, accurate, and detailed models with smooth, yet feature-rich and topologically conforming surfaces. The models are therefore suited for the creation of unstructured meshes, and the possible applications of the models are extended to a wider range of solvers and physics. The impact of these improvements is shown for the MRI exposure of an adult woman with an orthopedic spinal implant. Future developments include the functionalization of the models for specific physical and physiological modeling tasks. © 2014 Institute of Physics and Engineering in Medicine.

Toivanen J.I.,University of Jyväskylä | Stefanski T.P.,ETH Zurich | Kuster N.,ETH Zurich | Chavannes N.,Schmid & Partner Engineering AG
Progress In Electromagnetics Research M | Year: 2011

Three distinctively different implementations of convolutional perfectly matched layer for the FDTD method on CUDA enabled graphics processing units are presented. All implementations store ad- ditional variables only inside the convolutional perfectly matched lay- ers, and the computational speeds scale according to the thickness of these layers. The merits of the different approaches are discussed, and a comparison of computational performance is made using complex real-life benchmarks.

Chen X.-L.,Foundation for Research on Information Technologies in Society ITIS | Benkler S.,Schmid & Partner Engineering AG | Chavannes N.,Schmid & Partner Engineering AG | De Santis V.,Foundation for Research on Information Technologies in Society ITIS | And 5 more authors.
Bioelectromagnetics | Year: 2013

Compliance with the established exposure limits for the electric field (E-field) induced in the human brain due to low-frequency magnetic field (B-field) induction is demonstrated by numerical dosimetry. The objective of this study is to investigate the dependency of dosimetric compliance assessments on the applied methodology and segmentations. The dependency of the discretization uncertainty (i.e., staircasing and field singularity) on the spatially averaged peak E-field values is first determined using canonical and anatomical models. Because spatial averaging with a grid size of 0.5mm or smaller sufficiently reduces the impact of artifacts regardless of tissue size, it is a superior approach to other proposed methods such as the 99th percentile or smearing of conductivity contrast. Through a canonical model, it is demonstrated that under the same uniform B-field exposure condition, the peak spatially averaged E-fields in a heterogeneous model can be significantly underestimated by a homogeneous model. The frequency scaling technique is found to introduce substantial error if the relative change in tissue conductivity is significant in the investigated frequency range. Lastly, the peak induced E-fields in the brain tissues of five high-resolution anatomically realistic models exposed to a uniform B-field at ICNIRP and IEEE reference levels in the frequency range of 10Hz to 100kHz show that the reference levels are not always compliant with the basic restrictions. Based on the results of this study, a revision is recommended for the guidelines/standards to achieve technically sound exposure limits that can be applied without ambiguity. © 2013 Wiley Periodicals, Inc.

Chen X.L.,Schmid & Partner Engineering AG | De Santis V.,ITIS Foundation | Chavannes N.,Schmid & Partner Engineering AG | Kuster N.,ITIS Foundation
cccc2012 Asia-Pacific Symposium on Electromagnetic Compatibility, APEMC 2012 - Proceedings | Year: 2012

The study of magnetic stimulation of the human brain has been an on-going research topic since the 1980s. To achieve a better understanding of the cerebral stimulation, it is necessary to estimate the spatial distribution and peak magnitude of the induced electric field in the brain. By utilizing a high resolution anatomical model and a numerical technique based on quasi-static approximation, this study provides a state-of-the-art estimation of the in situ electric field distribution in an adult brain when undergoing transcranial magnetic stimulation. Coil designs such as figure-8 and 4-leaf-clover are employed in the analysis. It is demonstrated that the brain regions which are more likely to be stimulated by the respective coil design can be better estimated by employing a realistic anatomical model than a homogeneous model. It is revealed that the location of the maximum in situ electric field does not necessarily coincide with the location of the maximum magnetic flux (directly below the coil). Instead, the site of stimulation is significantly influenced by the design of the coil and the coil position. © 2012 IEEE.

Kelsh M.A.,Exponent, Inc. | Shum M.,Exponent, Inc. | Sheppard A.R.,Asher Sheppard Consulting | McNeely M.,Exponent, Inc. | And 6 more authors.
Journal of Exposure Science and Environmental Epidemiology | Year: 2011

Epidemiologic studies of mobile phone users have relied on self reporting or billing records to assess exposure. Herein, we report quantitative measurements of mobile-phone power output as a function of phone technology, environmental terrain, and handset design. Radiofrequency (RF) output data were collected using software-modified phones that recorded power control settings, coupled with a mobile system that recorded and analyzed RF fields measured in a phantom head placed in a vehicle. Data collected from three distinct routes (urban, suburban, and rural) were summarized as averages of peak levels and overall averages of RF power output, and were analyzed using analysis of variance methods. Technology was the strongest predictor of RF power output. The older analog technology produced the highest RF levels, whereas CDMA had the lowest, with GSM and TDMA showing similar intermediate levels. We observed generally higher RF power output in rural areas. There was good correlation between average power control settings in the software-modified phones and power measurements in the phantoms. Our findings suggest that phone technology, and to a lesser extent, degree of urbanization, are the two stronger influences on RF power output. Software-modified phones should be useful for improving epidemiologic exposure assessment.

Schmid & Partner Engineering AG | Date: 2016-02-23

Measuring instruments for the acquisition of monodimensional or multidimensional measured values, and related software for the acquisition of monodimensional or multidimensional measured values; software for building multidimensional objects, simulating physical quantities, optimizing physical values and viewing objects and physical values. Development of measuring instruments for the acquisition of monodimensional or multidimensional measured values, and development of related software for the acquisition of monodimensional or multidimensional measured values; development, installation and maintenance of software for building multidimensional objects, simulating physical quantities, optimizing physical values and viewing objects and physical values.

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