Knowledge of spatial and temporal trends in the environmental exposure to radiofrequency electromagnetic fields (RF-EMF) is a key prerequisite for RF-EMF risk assessment studies attempting to establish a link between RF-EMF and potential effects on human health as well as on fauna and flora. In this paper, we determined the validity of RF exposure modelling based on inner-area kriging interpolation of measurements on the surrounding streets. The results vary depending on area size and shape and structural factors; a Spearman coefficient of 0.8 and a relative error of less than 3.5 dB are achieved on a data set featuring a closed measurement ring around a decently sized area (1 km2, with an average minimum distance of the encircled area to the ring of less than 100 m), containing mainly low, detached buildings. In larger areas, additional inner-area sampling is advised, lowering the average minimum distance between sampled and interpolated locations to 100 m, to achieve the same level of accuracy. https://doi.org/10.1016/j.envint.2016.06.006 LinkedIn: https://www.linkedin.com/in/john-bolte-0856134/
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A low-cost sensornode is introduced to monitor the 5G EMF exposure in the Netherlands for the four FR1 frequency bands. The sensornode is validated with in-lab measurements both with CW signals as for QAM signals and perform for both cases and for all frequency bands an error less than 1 dB for a dynamic range of 40 dB. This sensor is a follow up of the earlier version of our previously developed sensor and have substantial improvements in terms of linearity, error, and stability.
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Aim: Optimise a set of exposure factors, with the lowest effective dose, to delineate spinal curvature with the modified Cobb method in a full spine using computed radiography (CR) for a 5-year-old paediatric anthropomorphic phantom.Methods: Images were acquired by varying a set of parameters: positions (antero-posterior (AP), posteroanterior (PA) and lateral), kilo-voltage peak (kVp) (66-90), source-to-image distance (SID) (150 to 200cm), broad focus and the use of a grid (grid in/out) to analyse the impact on E and image quality(IQ). IQ was analysed applying two approaches: objective [contrast-to-noise-ratio/(CNR] and perceptual, using 5 observers. Monte-Carlo modelling was used for dose estimation. Cohen’s Kappa coefficient was used to calculate inter-observer-variability. The angle was measured using Cobb’s method on lateralprojections under different imaging conditions.Results: PA promoted the lowest effective dose (0.013 mSv) compared to AP (0.048 mSv) and lateral (0.025 mSv). The exposure parameters that allowed lower dose were 200cm SID, 90 kVp, broad focus and grid out for paediatrics using an Agfa CR system. Thirty-seven images were assessed for IQ andthirty-two were classified adequate. Cobb angle measurements varied between 16°±2.9 and 19.9°±0.9.Conclusion: Cobb angle measurements can be performed using the lowest dose with a low contrast-tonoise ratio. The variation on measurements for this was ±2.9° and this is within the range of acceptable clinical error without impact on clinical diagnosis. Further work is recommended on improvement tothe sample size and a more robust perceptual IQ assessment protocol for observers.
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BACKGROUND AND PURPOSE: The MyotonPRO is a portable device that measures muscle tone and biomechanical muscle properties objectively. MyotonPRO has already proven to be effective in measuring muscle properties in healthy and diseased populations. However, to the best of our knowledge, it has never been tested in individuals suffering from paratonia, a form of hypertonia frequently accompanying dementia. The aims of the present study were to (1) compare muscle tone, elasticity, and stiffness between 3 different subpopulations of young and old healthy adults and individuals with paratonia, and (2) investigate the intra- and interrater reproducibility of MyotonPRO measurements of the biceps brachii (BB) muscle in each subpopulation.METHODS: MyotonPRO measurements of muscle tone, elasticity, and dynamic stiffness were carried out by 2 investigators on 2 different days over the BB muscles of 54 participants (18 healthy young adults, 20 healthy older adults, and 16 older individuals with paratonia). Muscle properties were compared between subpopulations using ANOVA/Welch and post hoc tests. Reliability (intraclass correlation coefficient) and agreement parameters (standard error of measurement and the minimal detectable change) were calculated.RESULTS: Statistically significant differences between subpopulations were found in all parameters, except for stiffness between healthy elderly and individuals with paratonia. In the healthy subpopulations, (a) intrarater reliability was very high and intrarater agreement was good between 2 consecutive series, (b) between days intrarater reliability was low to high and intrarater agreement was variable, (c) interrater reliability was high to very high and interrater agreement was good. In individuals with paratonia, (a) intrarater reliability was moderate to high and agreement was variable between series, (b) between days intrarater reliability was poor to moderate and agreement was poor, (c) interrater reliability ranged from low to high with poor agreement.CONCLUSIONS: MyotonPRO measurements of the BB muscle showed good reproducibility in both healthy subpopulations, particularly for measurements performed within the same day. In individuals with paratonia, reliability and agreement were substantially lower. MyotonPRO can be used in clinical assessment and research. However, in individuals with paratonia, careful interpretation of results is required. Research in a larger sample of persons with paratonia at different stages of disease severity is recommended.
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This work provides a feasibility study on estimating the 3-D locations of several thousand miniaturized free-floating sensor platforms. The localization is performed on basis of sparse ultrasound range measurements between sensor platforms and without the use of beacons. We show that this task can be viewed as a specific type of pose graph optimization. The main challenge is robustly estimating an initial pose graph, that models the locations of sensor platforms. For this, we introduce a novel graph growing strategy that uses random sample consensus in alternation with non-linear refinement. The theoretical properties of our sensor cloud localization method are analyzed and its robustness is investigated using simulations. These simulations are based on inlier-outlier measurement models and focus on the application of subterranean 3-D mapping of liquid environments, such as pipe infrastructures and oil wells.
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This paper is concerned with the governance of geodetic deformation measurements. If we want to know if and how fast a country, or parts of it, are subsiding or rising, who decides that it should be measured and how is the methodology determined? What interests are at stake? How is the proper use and innovation of geodetic methods guaranteed? To be able to answer such and similar questions, a prelude to a taxonomy of governance arrangements for geodetic deformation measurements is presented. Relevant aspects of activities to measure deformations are incorporated into a system to describe governance arrangements. By interviewing nine experts in the field of geodetic deformation measurements in the Netherlands, the activities of companies, institutions and other structures that are concerned with geodetic deformation measurements were analysed, which provided the information to build a system that provides the basis for a taxonomy, which needs further validation in future research.
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This study introduces the first steps of an on-going project and examines the suitability of biometric measurements for the analysis of dining experiences in combination with self-reports by 25 participants.
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Objectives: Improving foot orthoses (FOs) in patients with rheumatoid arthritis (RA) by using in-shoe plantar pressure measurements seems promising. The objectives of this study were to evaluate (1) the outcome on plantar pressure distribution of FOs that were adapted using in-shoe plantar pressure measurements according to a protocol and (2) the protocol feasibility. Methods: Forty-five RA patients with foot problems were included in this observational proof-of concept study. FOs were custom-made by a podiatrist according to usual care. Regions of Interest (ROIs) for plantar pressure reduction were selected. According to a protocol, usual care FOs were evaluated using in-shoe plantar pressure measurements and, if necessary, adapted. Plantar pressure–time integrals at the ROIs were compared between the following conditions: (1) no-FO versus usual care FO and (2) usual care FO versus adapted FO. Semi-structured interviews were held with patients and podiatrists to evaluate the feasibility of the protocol. Results: Adapted FOs were developed in 70% of the patients. In these patients, usual care FOs showed a mean 9% reduction in pressure–time integral at forefoot ROIs compared to no-FOs (p = 0.01). FO adaptation led to an additional mean 3% reduction in pressure–time integral (p = 0.05). The protocol was considered feasible by patients. Podiatrists considered the protocol more useful to achieve individual rather than general treatment goals. A final protocol was proposed. Conclusions: Using in-shoe plantar pressure measurements for adapting foot orthoses for patients with RA leads to a small additional plantar pressure reduction in the forefoot. Further research on the clinical relevance of this outcome is required.
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Health symptoms may be influenced, supported, or even controlled via a lighting control system which includes personal lighting conditions and personal factors (health characteristics). In order to be effective, this lighting control system requires both continuous information on the lighting and health conditions at the individual level. A new practical method to determine these continuous personal lighting conditions has been developed: location-bound estimations (LBE). This method was validated in the field in two case studies; comparisons were made between the LBE and location-bound measurements (LBM) in case study 1 and between the LBE and person-bound measurements (PBM) in case study 2. Overall, the relative deviation between the LBE and LBM was less than 15%, whereas the relative deviation between the LBE and PBM was 32.9% in the best-case situation. The relative deviation depends on inaccuracies in both methods (i.e., LBE and PBM) and needs further research. Adding more input parameters to the predictive model (LBE) will improve the accuracy of the LBE. The proposed first approach of the LBE is not without limitations; however, it is expected that this practical method will be a pragmatic approach of inserting personal lighting conditions into lighting control systems.
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Performance feedback and supervision are essential to the adoption of evidence-based interventions with high treatment integrity in child and youth care organizations. Little is known about the use of treatment integrity measurements in these organizations. For this study, 12 interventions for children and young people in the Netherlands with externalizing behavioral problems were selected. For each intervention, an expert, two supervisors, and two therapists were approached for an interview. In total, 54 semi-structured interviews were conducted. The results show that almost all interventions used treatment integrity instruments (N = 11, 91.7%). Only two used measurements for both QA procedures (certification and recertification) and supervision purposes. Therapists regard treatment integrity measurements as valuable when they are used for multiple purposes and feedback is provided. The results of this study suggest the feasibility of the use of measurements for multiple purposes. Collaborative action is required to develop instruments that effectively contribute to continuous improvement.
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