As Vehicle-to-Everything (V2X) communication technologies gain prominence, ensuring human safety from radiofrequency (RF) electromagnetic fields (EMF) becomes paramount. This study critically examines human RF exposure in the context of ITS-5.9 GHz V2X connectivity, employing a combination of numerical dosimetry simulations and targeted experimental measurements. The focus extends across Road-Side Units (RSUs), On-Board Units (OBUs), and, notably, the advanced vehicular technologies within a Tesla Model S, which includes Bluetooth, Long Term Evolution (LTE) modules, and millimeter-wave (mmWave) radar systems. Key findings indicate that RF exposure levels for RSUs and OBUs, as well as from Tesla’s integrated technologies, consistently remain below the International Commission on Non-Ionizing Radiation Protection (ICNIRP) exposure guidelines by a significant margin. Specifically, the maximum exposure level around RSUs was observed to be 10 times lower than ICNIRP reference level, and Tesla’s mmWave radar exposure did not exceed 0.29 W/m2, well below the threshold of 10 W/m2 set for the general public. This comprehensive analysis not only corroborates the effectiveness of numerical dosimetry in accurately predicting RF exposure but also underscores the compliance of current V2X communication technologies with exposure guidelines, thereby facilitating the protective advancement of intelligent transportation systems against potential health risks.
MULTIFILE
Background: Magnetic resonance imaging (MRI) is being used extensively in the search for pathoanatomical factors contributing to low back pain (LBP) such as Modic changes (MC). However, it remains unclear whether clinical findings can identify patients with MC. The purpose of this explorative study was to assess the predictive value of six clinical tests and three questionnaires commonly used with patients with low-back pain (LBP) on the presence of Modic changes (MC).Methods: A retrospective cohort study was performed using data from Dutch military personnel in the period between April 2013 and July 2016. Questionnaires included the Roland Morris Disability Questionnaire, Numeric Pain Rating Scale, and Pain Self-Efficacy Questionnaire. The clinical examination included (i) range of motion, (ii) presence of pain during flexion and extension, (iii) Prone Instability Test, and (iv) straight leg raise. Backward stepwise regression was used to estimate predictive value for the presence of MC and the type of MC. The exploration of clinical tests was performed by univariable logistic regression models.Results: Two hundred eighty-six patients were allocated for the study, and 112 cases with medical records and MRI scans were available; 60 cases with MC and 52 without MC. Age was significantly higher in the MC group. The univariate regression analysis showed a significantly increased odds ratio for pain during flexion movement (2.57 [95% confidence interval (CI): 1.08-6.08]) in the group with MC. Multivariable logistic regression of all clinical symptoms and signs showed no significant association for any of the variables. The diagnostic value of the clinical tests expressed by sensitivity, specificity, positive predictive, and negative predictive values showed, for all the combinations, a low area under the curve (AUC) score, ranging from 0.41 to 0.53. Single-test sensitivity was the highest for pain in flexion: 60% (95% CI: 48.3-70.4).Conclusion: No model to predict the presence of MC, based on clinical tests, could be demonstrated. It is therefore not likely that LBP patients with MC are very different from other LBP patients and that they form a specific subgroup. However, the study only explored a limited number of clinical findings and it is possible that larger samples allowing for more variables would conclude differently.
DOCUMENT
Background: A new selective preventive spinal immobilization (PSI) protocol was introduced in the Netherlands. This may have led to an increase in non-immobilized spinal fractures (NISFs) and consequently adverse patient outcomes. Aim: A pilot study was conducted to describe the adverse patient outcomes in NISF of the PSI protocol change and assess the feasibility of a larger effect study. Methods: Retrospective comparative cohort pilot study including records of trauma patients with a presumed spinal injury who were presented at the emergency department of a level 2 trauma center by the emergency medical service (EMS). The pre-period 2013-2014 (strict PSI protocol), was compared to the post-period 2017-2018 (selective PSI protocol). Primary outcomes were the percentage of records with a NISF who had an adverse patient outcome such as neurological injuries and mortality before and after the protocol change. Secondary outcomes were the sample size calculation for a larger study and the feasibility of data collection. Results: 1,147 records were included; 442 pre-period, and 705 post-period. The NISF-prevalence was 10% (95% CI 7-16, n = 19) and 8% (95% CI 6-11, n = 33), respectively. In both periods, no neurological injuries or mortality due to NISF were found, by which calculating a sample size is impossible. Data collection showed to be feasible. Conclusions: No neurological injuries or mortality due to NISF were found in a strict and a selective PSI protocol. Therefore, a larger study is discouraged. Future studies should focus on which patients really profit from PSI and which patients do not.
DOCUMENT
