L’évolution des normes face au développement des objets de santé connectés

A lot of connected objects can be sold on the Internet and in some general stores. These products can be used in a health environment; they can help to promote a healthy lifestyle. But they do not always have a well determined legal status, that is established to protect the patients or the healthcare professionals. The connected objects can support innovation. They can become an essential help for the patients and the healthcare professionals, nevertheless they can be at the origin of physical injuries, if they are badly used.     

Work potential of road accident survivors with post-traumatic stress disorder

Work potential in adult survivors of road accidents with and without post-traumatic stress disorder (PTSD) was examined at a mean of 8.6 months (SD = 3.77) post-accident. All participants were working prior to their accident. Results showed that survivors with PTSD had significantly less work potential post-accident than survivors without PTSD. Specific barriers to employability for survivors with PTSD identified by this study included high levels of depression, reduced time-management ability, and an over-concern or anxiety with physical injuries. Respondents with PTSD, however, reported significantly greater extrinsic motivation to work than those without PTSD. Early intervention and referral to occupational rehabilitation programs that: (1) help address these barriers to employability and stimulate the existing motivation to return to work, and (2) work alongside clinical treatment programs, may assist in the reduction of poor work outcomes that people with PTSD following road accidents often experience.     

A technology to measure multiple driving behaviors without self-report or participant reactivity

An in-vehicle information system (IVIS) was used to videotape drivers (N = 61) without their knowledge while driving 22 miles in normal traffic. The drivers were told that they were participating in a study of direction following and map reading. Two data-coding procedures were used to analyze videotapes. Safety-related behaviors were counted during consecutive 15-s intervals of a driving trial, and the occurrence of certain safety-related behaviors was assessed under critical conditions. These two methods of data coding were assessed for practicality, reliability, and sensitivity. Interobserver agreement for the five different driving behaviors ranged from 85% to 95%. Within-subject variability in safe driving was more pronounced among younger drivers and decreased as a function of age. Contrary to previous research that has relied on self-reports, driver risk taking did not vary significantly as a function of gender. These results are used to illustrate the capabilities of the technology introduced here to design and evaluate behavior-analytic interventions to increase safe driving.     

Cross-generational acceptance of and interest in advanced vehicle technologies: A nationwide survey

The number of older drivers on the roadways is increasing; at the same time, technology in the automotive environment is rapidly evolving. To investigate the potential impact of these converging changes, this study used a cross-generational approach to compare driver attitudes toward advanced automotive technologies. Approximately 1000 drivers between the ages of 18 and 85 located across the United States responded to a survey about their opinions regarding general technology, advanced in-vehicle technology, and near-horizon connected vehicle systems. Participant responses were categorized using a generational construct, sorting responses not only by age but by shared life experiences (e.g. economic circumstances, involvement in wartime activities, cultural movements, etc.). The oldest generation (the “Silent” generation) exhibited the least interest in and comfort with advanced technology, although they owned and used advanced in-vehicle technology at approximately the same rates as the two middle generations. The youngest generation (the “Millennial” generation) was most likely to be interested in and comfortable with technology, but was least likely to own vehicles with advanced technology. All participants expressed interest in safety-related connected vehicle systems, but less so in infotainment applications. Reservations regarding data security and system cost were shared across generations. These findings are framed in the context of an aging population with unique driving and vehicle needs, and provide information that may assist both with vehicle technology design aspects and the proposed large-scale implementation of connected vehicle systems, including considerations for seniors and emphasis on safety systems and data security.     

Do sport modes cause behavioral adaptation?

A key question in transportation research is whether drivers show behavioral adaptation, that is, slower or faster driving, when new technology is introduced into the vehicle. This study investigates behavioral adaptation in response to the sport mode, a technology that alters the vehicle’s auditory, throttle-mapping, power-steering, and chassis settings. Based on the literature, it can be hypothesized that the sport mode increases perceived sportiness and encourages faster driving. Oppositely, the sport mode may increase drivers’ perceived danger, homeostatically causing them to drive more slowly. These hypotheses were tested using an instrumented vehicle on a test track. Thirty-one drivers were asked to drive as they normally would with different sport mode settings: Baseline, Modified Throttle Mapping (MTM), Artificial Engine Sound enhancement (AESe), MTM and AESe combined (MTM-AESe), and MTM, AESe combined with four-wheel steering, increased damping, and decreased power steering (MTM-AESe-4WS). Post-trial questionnaires showed increased perceived sportiness but no differences in perceived danger for the three MTM conditions compared to Baseline. Furthermore, compared to Baseline, MTM led to higher vehicle accelerations and, with a smaller effect size, a higher time-percentage of driving above the 110 km/h speed limit, but not higher cornering speeds. The AESe condition did not significantly affect perceived sportiness, perceived danger, and driving speed compared to Baseline. These findings suggest that behavioral adaptation is a functional and opportunistic phenomenon rather than mediated by perceived sportiness or perceived danger.     

Interplay between acoustic/phonetic and semantic processes during spoken sentence comprehension: an ERP study

When listening to speech in everyday-life situations, our cognitive system must often cope with signal instabilities such as sudden breaks, mispronunciations, interfering noises or reverberations potentially causing disruptions at the acoustic/phonetic interface and preventing efficient lexical access and semantic integration. The physiological mechanisms allowing listeners to react instantaneously to such fast and unexpected perturbations in order to maintain intelligibility of the delivered message are still partly unknown. The present electroencephalography (EEG) study aimed at investigating the cortical responses to real-time detection of a sudden acoustic/phonetic change occurring in connected speech and how these mechanisms interfere with semantic integration. Participants listened to sentences in which final words could contain signal reversals along the temporal dimension (time-reversed speech) of varying durations and could have either a low- or high-cloze probability within sentence context. Results revealed that early detection of the acoustic/phonetic change elicited a fronto-central negativity shortly after the onset of the manipulation that matched the spatio-temporal features of the Mismatch Negativity (MMN) recorded in the same participants during an oddball paradigm. Time reversal also affected late event-related potentials (ERPs) reflecting semantic expectancies (N400) differently when words were predictable or not from the sentence context. These findings are discussed in the context of brain signatures to transient acoustic/phonetic variations in speech. They contribute to a better understanding of natural speech comprehension as they show that acoustic/phonetic information and semantic knowledge strongly interact under adverse conditions.     

Investigating driver reactions to movements of autonomous vehicle in permitted right turn through driving simulator experiments

Traffic safety has always been a hot topic for human-driven (HDV) and autonomous vehicles (AV) mixed flow. The conflict between permitted right-turn vehicles (PRT) and opposing through vehicles (TH) at signalized intersections (left-handed traffic) is extraordinarily critical. AVs with aggressive behaviors are able to accept short gap time without losing safety. However, such a turning maneuver may lead to dangerous feelings and cause unexpected reactions of approaching drivers. This study aims to investigate and model drivers’ reactions in TH movements to PRT AVs considering the trust degree of drivers to AVs. Questionnaire surveys and driving simulator experiments were conducted for 41 participants. Results reveal that the right turn timing of PRT AV will significantly influence drivers’ reactions. Basically, TH drivers will brake with a high probability under the situation of small expected post encroachment time (PET). It is also found that female drivers and drivers with low trust in AVs are more vigilant to PRT AVs than other drivers. Based on this finding a two-layer model for reproducing TH drivers’ reactions to PRT AVs is proposed. The first layer is to determine the braking decision and the second layer is to calculate the parameters of braking behaviors (brake lag, braking time, and speed drop). The significance and coefficients variables in these models proved that the trust in AV will influence drivers’ decisions and braking behaviors (brake lag and braking time). The more the drivers trust AVs, the smaller the expected PET to AVs they can accept for passing without braking, and the more gently they will brake (longer brake lag and shorter braking time) due to the cutting in of PRT AVs. This effect will become significant after drivers have experienced several interactions with AVs.     

Experimental evidence supporting simpler Action Point paradigms for car-following

The Action Point theory is one of the paradigms that can be applied to understand and reproduce car-following behaviour. Several different approaches to this theory have been proposed, some more simple and others more complex. In particular, the reference point in this field is still the paradigm from Wiedemann, which requires the identification of four action-point thresholds. In this paper we review Action Point theories in order to highlight similarities and differences and to ascertain whether all the thresholds proposed by Wiedemann actually bind the driving behaviour. Based on a large-scale experiment in which car-following data were collected, we identified all candidate action points assuming that the more complex (four-threshold) theory holds. Then we tested these points with respect to the large data set of available observations, in order to check whether actual actions are performed at the points. The results show that very often simpler approaches better match the observed data and that in order to explain car-following behaviour it is sufficient in most cases to refer to two thresholds. The results obtained by real-world observation were also tested in virtual environments (two different kinds of driving simulators) and were confirmed.     

The impact of motor vehicle injury on distress: Moderators and trajectories over time

Research reveals that motor vehicle injuries (MVIs) can result in severe and debilitating psychological distress. Yet, not every person who has sustained a MVI suffers psychologically. It appears that risk of distress varies by demographic and psychosocial characteristics. The present study aimed to explore the trajectories of post-MVI distress and the effect of pre-MVI psychological functioning on post-MVI distress. Hierarchical linear modeling was used to explore the longitudinal dataset from the Canadian National Population Health Survey. Participants were assessed up to nine years post-MVI. Post-MVI distress increased over time. Men experienced greater overall distress than women and a greater increase in distress over time. Pre-MVI distress predicted post-MVI distress. This relationship was strongest for those with greater pre-MVI alcohol consumption. At low levels of pre-MVI distress, greater pre-MVI alcohol consumption was related to lower post-MVI distress, but at high levels of pre-MVI distress, greater pre-MVI alcohol consumption predicted increased post-MVI distress. Those with partners experienced less distress than the unpartnered. This study supports the general findings of other post-MVI and post-trauma studies, although the current study’s main and interaction effects reveal more complex and nuanced relationships among variables in their prediction of post-MVI psychological distress.     

Audiovisual time-to-collision estimation for accelerating vehicles: The acoustic signature of electric vehicles impairs pedestrians' judgments

To avoid collisions, pedestrians intending to cross a road need to accurately estimate the time-to-collision (TTC) of an approaching vehicle. For TTC estimation, auditory information can be considered particularly relevant when the approaching vehicle accelerates. The sound of vehicles with internal combustion engine (ICEVs) provides characteristic auditory information about the acceleration state (increasing rotational speed and engine load). However, for electric vehicles (EVs), the acoustic signature during acceleration is less salient. Although the auditory detection of EVs has been studied extensively, there is no research on potential effects of the altered acoustic signature of EVs on TTC estimation. To close this gap, we compared TTC estimates for ICEVs and for EVs with and without activated acoustic vehicle alerting system (AVAS). We implemented a novel interactive audiovisual virtual-reality system for studying the human perception of approaching vehicles. Using acoustic recordings of real vehicles as source signals, the dynamic spatial sound field corresponding to a vehicle approaching in an urban setting is generated based on physical modeling of the sound propagation between vehicle and pedestrian (listener) and is presented via sound field synthesis (higher-order Ambisonics). In addition to the auditory simulations, the scene was visually presented on a head-mounted display with head tracking. Participants estimated the TTC of vehicles that either approached at a constant speed or accelerated positively. In conditions with constant speed, TTC estimates for EVs with and without AVAS were similar to those for ICEVs. In contrast, for accelerating vehicles, there was a substantial effect of the vehicle type on the TTC estimates. For the EVs, the mean TTC estimates showed a significant overestimation. Thus, subjects on average perceived the time of arrival of the EV at their position as longer than it actually was. The extent of overestimation increased with acceleration and presented TTC. This pattern is similar to a first-order TTC estimation representing a failure to consider the acceleration, which is consistently reported in the literature for visual-only presentations of accelerating objects. In comparison, the overestimation of TTC was largely reduced for the accelerating ICEVs. The AVAS somewhat improved the TTC estimates for the accelerating EVs, but without reaching the same level of accuracy as for the ICEVs. In real traffic scenarios, overestimations of the TTC of approaching vehicles might lead to risky road-crossing decisions. Therefore, our finding that pedestrians are significantly less able to use the acoustic information emitted by accelerating EVs for their TTC judgments, compared to accelerating ICEVs, has important implications for road safety and for the design of AVAS technologies.