Seat Position Research Articles

The Influence of Occupant Characteristics, Seat Positioning, and Pre-Crash Maneuvers on Front Passenger Safety Performance.

Crash avoidance vehicle maneuvers are known to influence occupant posture and kinematics which consequently may influence injury risks in the event of a crash. In this work, a generic buck vehicle finite element (FE) model was developed which included the vehicle interior and the front passenger airbag (PAB). Seat position and occupant characteristics including anthropometry, sex, and age were varied in a design of experiments. Two pre-crash maneuvers representing 1) a generic 1g braking and 2) turning-and-braking scenarios were simulated. Rigid-body human models with active joints (GHBMCsi-pre models) obtained by morphing a 50th male model to selected anthropometries were used in pre-crash simulations. The kinematics data of belted GHBMCsi-pre models at the end of the pre-crash phase were transferred using a developed switch algorithm to the corresponding morphed GHBMC occupant simplified (OS) models to predict occupant injury risks. During both pre-crash maneuvers, the occupant's head and thorax moved forward towards the dashboard. Therefore, the head and thorax contacted the PAB earlier, leading to lower head accelerations when the pre-crash phase was considered. Overall, it was concluded that pre-crash braking decreased the severity of injury sustained by the passenger. Seat track position and seat recline angle showed the highest influence on the head injury criteria (HIC). The brain injury criteria (BrIC), and neck injury criteria (Nij) were most sensitive to pre-crash maneuver type, seat recline angle, and occupant size.

Seating and Mobility Concerns of Adults with Duchenne Muscular Dystrophy

Background: Appropriate wheelchair and seating systems are key to allow for the participation of people with Duchenne Muscular Dystrophy. There is little research that focuses on their long-term seating issues and what topics they want studied. Methods: This mixed-method study with adults with Duchenne used an Internet-based survey about wheelchair mobility and discomfort, followed by in-depth interviews. Unanticipated remarks in the interviews led to a second survey regarding the effects of cold weather on wheelchair driving. Descriptive and qualitative analyses were performed. Results: Thirty-seven individuals completed the original survey: 78% used a powered wheelchair, 58% were uncomfortable in their wheelchair, and 94% felt the need to change their seating position. In-depth interviews (N = 9) revealed three themes: seating and pain management, caregiver cooperation, and temperature sensitivity. Almost all (8/9) interviewees explained that cold was a barrier to their participation. In the second survey (N = 13), 11 reported that cold affected their driving, with 10 remarking that it prevented them from participating in daily life activities and 11 stating that the effects of cold on wheelchair driving should be studied. Conclusions: It is essential to ask end-users to identify key issues to ensure the relevance of research to people with disabilities.

Voiding sonography: Technical description of a novel ultrasound method for assessment of micturition in women

AbstractVoiding sonography (VS) is a novel non‐invasive method that can be used to assess micturition in real time. When performed in a functional seated position and combined with free uroflowmetry, detailed evaluation of voiding can be conducted. VS presents advantages over current invasive assessment methods such as urodynamics. This methodological paper describes the rationale; advantages and disadvantages of VS; participant preparation; technique; a practical approach to obtain the video/image (including transducer placement to achieve an assessment of voiding with minimal obstruction of urine flow); recommended machine and transducer specifications; and the potential usefulness of ultrasound measurements. These measurements might provide information regarding the function of the pelvic floor muscle and urethral dynamics during voiding. Measures assessed with VS can also provide information regarding urine storage. In summary, VS is a new method to assess female voiding. Future work should evaluate the potential utility of the method to evaluate characteristics and mechanisms for voiding dysfunction in females with a variety of relevant clinical conditions. Use of VS as a screening tool before and after surgical or non‐surgical treatment intervention may also be a future consideration to assess progress and provide feedback to clinicians and patients.

Evaluation of Child Anthropometries in Relation to Modern Vehicle Seat and Booster Dimensions.

This study compared modern vehicle and booster geometries with relevant child anthropometries. Vehicle geometries (seat length, seat pan height, shoulder belt outlet height, and roof height) were obtained for 275 center and outboard rear seating positions of US vehicles (MY 2009-2022). Measurements of 85 US boosters (pan height and pan length) and anthropometries of 80 US children between 4-14yo (seated height, thigh length, leg length, and seated shoulder height) were also collected. Comparisons were made between vehicles, boosters, and child anthropometries. Average vehicle seat lengths exceeded child thigh lengths (+9.5cm). Only 16.4% of seating positions had seat lengths less than the child thigh length mean+1SD. Even for children at least 145cm, only 18.8% had thigh lengths greater than the average vehicle seat length. Child thigh lengths were more comparable with average booster seat pan lengths for all multi-mode and high-back designs (-2.0cm) and low-back boosters (+3.1cm). The average observed booster pan height (9.9cm) would help most children achieve seated shoulder heights similar to the Hybrid III 5th percentile Female ATD. Compared to vehicle seats, booster geometries were more compatible with child thigh lengths and assist children in achieving seated shoulder heights more comparable to the vehicle restraint system. This emphasizes the continued need for shorter vehicle seat cushion lengths for these occupants and the need to educate caregivers and promote booster recommendations which highlight the importance of achieving proper belt fit and avoiding slouched postures, even for children greater than 8 years and/or 145cm.

Evaluation of Ventilation Strategies to Mitigate Airborne Infection Risk in a Dental School: A Three-Dimensional CFD Analysis of Airflow Patterns and Ventilation Efficiency

Infection prevention and control is a crucial element in providing a safe environment for dental clinics and reducing airborne infections risks during dental procedures. In response to the prevailing COVID-19 situations, the clinical space in the dental school was operated with ventilation strategies, increasing air exchanges and incorporating supply and return air arrangement based on seating positions. This study evaluated airflow patterns to examine personal exposure to airborne infection risk under these strategies. The three-dimensional computational fluid dynamics technique using computational fluid dynamics (CFD) analysis was performed in 50 multi-units of the dental school of the university in Bangkok, Thailand. The results revealed substantial improvements in indoor ventilation. Improvement of airflow patterns and directions surpassed conventional design of the pre-existing building’s system and helped reduce airborne contaminant concentrations. The further discussion of occupant-based design in dental schools is needed to optimize ventilation systems and engineering controls concerning indoor airborne infections.

Rear passenger restraint in frontal NCAP tests compared to the right-front passenger

Objective This study compared kinematic and biomechanic responses of the 5th female Hybrid III in the right-rear and right-front passenger seats in frontal NCAP tests with 2015–16 MY vehicles. It focused on the lap-shoulder belt restraint of the rear passenger. Methods Eleven frontal NCAP tests were conducted by NHTSA at 56 km/h with a lap-shoulder belted 5th Hybrid III dummy in the right-rear and right-front seats. The right-front passenger had pretensioning and load limiting belts and advanced airbags with inflatable knee bolster. The rear passenger had seatbelts without pretensioning or load limiting. The kinematic and biomechanical responses of the 5th Hybrid III dummy in the rear and front were analyzed. The tests included onboard video cameras covering the rear and front passenger. Lap and shoulder belt loads were measured. The responses were compared for the two seating positions and restraint systems. Results Only one of 11 vehicles had favorable restraint of the right-rear passenger. All vehicles passed criteria for the right-front passenger. The right-rear passenger HIC15 was 888 ± 314 (779 IARV) significantly higher than 242 ± 72 in the right-front passenger (t = 6.36, p < 0.001). The right rear Nij was 1.16 ± 0.19 (1.00 IARV) significantly higher than 0.46 ± 0.11 in the right-front (t = 9.18, p < 0.001) and the rear chest deflection was 46.1 ± 9.8 mm (42 mm IARV) significantly higher than 20.8 ± 5.6 mm in the right-front (t = 7.12, p < 0.001). The shoulder belt load was 8,771 ± 2,088 N on the right-rear passenger significantly higher than 3,564 ± 911 N on the right-front (t = 7.28, p < 0.001). Three of the 11 crash tests involved submarining by the right-rear passenger at 76.0 ± 7.2 ms. Two tests with submarining involved the seatbelt buckle lifting by shoulder belt load pulling the lap belt onto the abdomen. One test involved compressing the front of the seat cushion with the H-point dropping, the pelvis rotating rearward and the lap belt sliding onto the abdomen. Conclusions Restraining loads on the rear passenger were significantly higher than on the right-front passenger in 2015–16 MY vehicle NCAP tests. The HIC15 was 3.7-times higher in the rear passenger than the front. The Nij was 2.5-times higher and chest deflection was 2.2-times higher. The dummy responses were significantly higher in the rear seat compared to the front seat because of greater restraining loads, submarining and a hardware failure in NCAP tests. The lack of pretensioning, load limiting and airbags involved higher injury risks in the rear passenger compared to the right-front passenger.

Evacuation from Cramped Interiors with Aisle Seats: Uncertainty Induced by the Random Choice of Initial Positions

Considering evacuation from cramped interiors with aisle seats, the initial seating positions of pedestrians represent a non-negligible source of variance in total evacuation time. By means of Pathfinder simulations, this uncertainty is quantitatively investigated for a train and lecture hall geometry with homogeneous and heterogeneous groups of agents. Furthermore, an energy-inspired description of the occupation configuration is introduced that enables a proper numerical representation of the configuration space of the initial seating positions.

Development of a feed-forward audio-visual notification system for reducing motion sickness in autonomous vehicles

To mitigate motion sickness occurring in seat positions where driving conditions cannot be predicted due to the changed interior structure of autonomous vehicles, a feed-forward audio-visual notification system was developed. The design, implemented in the driving environment, provides information through ambient light and notifying sound by predicting signal processing information, including steering angle and turn signals, to address the audio-visual impact of changes in the vehicle's direction, speed, and acceleration with feed-forward alerts. The correlation model between psychological and physiological responses was developed through measurements such as MSQ, MISC, EEG, fNIRS, and HRV during driving, quantifying the degree of motion sickness and improvement situations. The effect of visual variation by ambient light and the customized effect of notifying sound were combined to compare and analyze the degree of motion sickness reduction following the installation of the notification system.

Prone transpsoas lateral interbody fusion with retractor-mounted camera and heads-up display: illustrative case.

The prone transpsoas (PTP) technique involves the performance of a lateral lumbar interbody fusion with the patient prone. One challenge encountered in the early experience with the PTP technique is that with the patient in the prone position rather than the lateral decubitus position, the surgeon is often forced to raise the bed significantly and perform the interbody work in a hunched and seated position with their neck extended and shoulders abducted. The authors report on the use of a sterile retractor-mounted camera during PTP that allows for the surgery to be performed with surgical anatomy visualized on a heads-up display. The PTP procedure is performed without significant modification from standard practice. After the self-retaining retractor is inserted, a sterile retractor-mounted camera can be introduced down one of the blades of the self-retaining retractor, preferably the dorsally situated blade to avoid camera line-of-sight issues with dependent irrigation or bleeding. The surgical field can now be visualized on a high-definition monitor, allowing the surgeon to stand at the patient's side instead of sitting. A sterile retractor-mounted camera with a heads-up display is a novel way to address ergonomic challenges as well as improve educational opportunities in the operating room. https://thejns.org/doi/10.3171/CASE24318.

Pediatric occupant-to-occupant interaction responses in side impact conditions using Q-dummy and child human body models

Objective Road safety of children has improved considerably over the past decade; however, there is still much scope to better protect these occupants. Ensuring adequate protection of children seated in the rear seats requires a greater understanding of how children are injured in side crashes. The purpose of this study was to enhance the knowledge of children’s potential injuries in side impact collisions by the investigation of two different child sizes seated in different positions in the rear seats. The injury metrics associated with the occupant-to-occupant or occupant-to-child restraint system interaction was also identified. Methods Finite Elements Method simulations were performed using a validated simplified vehicle model with fully deformable side components. Dynamic virtual tests according to the Euro NCAP Child Occupant Protection Protocol were performed considering three different scenarios in terms of occupants´ distribution in the rear seats. Simulations were conducted with dummy and human body models. The injury metrics associated with near-side and far-side positions and the occupant-to-occupant interaction were analyzed. Results The 10-year-old child seated in the far-side position presented higher injury values, especially in the head due to the contact with the adjacent child or child restraint occupying the near-side seating position. Similar responses were observed in human body and dummies models in terms of head and neck injury values. However, human body models showed an increase in the chest measurements. Conclusions This study highlighted that the potential injuries of a child seated on the rear seats in a side impact crash are likely to be increased by the presence of an adjacent seat occupant, especially when larger children were seated in the far-side seating location or a CRS was installed in the near-side seating position. Results offer insight into the occupant-to-occupant interaction and occupants’ size as relevant factors to improve children safety under side impact conditions.

A hybrid simulation approach to predicting noise in restaurants

High levels of noise are a well-known source of occupant discomfort in dining environments, and noise ranks highly among the most common customer complaints in restaurant reviews. Prior work has focused on measuring existing restaurant soundscapes and attempting to predict acoustic performance; however, current techniques are still limited in accuracy for restaurants with time-varying occupancy and complex layouts. This presentation demonstrates a novel approach to predicting ambient noise in restaurants via a hybrid simulation framework. Acoustical computations for a given restaurant space are performed in a room acoustics model, while a discrete event simulation (DES) model is used to simulate the arrival patterns of patrons and their conversational behaviors. Predictions from the room acoustics model inform the DES model, allowing for noise level predictions at each seat position. Results from the prediction model are validated against measurements in a case study restaurant. Further development of this framework may support the practical assessment of design interventions in any restaurant while also accounting for time-varying patterns of occupancy.

How attentive is a student in class? A concentration evaluation method based on head Euler angle

How attentive is a student in class? It is an interesting and challenging question in the field of education research. In this paper, a concentration evaluation method based on head Euler angle is proposed. First, a fine large-small-interval video sampling strategy is advocated and concepts of dynamic threshold and action amplitude coefficient are defined, which are fused together to get the head up rate. Second, head front-facing rate is computed through analyzing the yaw angle, which is obtained from a proposed spatial physical model of camera and student seat position. Third, for any given time period, class concentration of a student is derived by fusing and normalizing the head up rate and head front-facing rate based on Euclidean-distance. Finally, accuracy experiments are conducted, where the proposed method achieves an average accuracy of 89.8% compared with the average score from the questionnaire given by 22 reviewers. Also, robust experiments on several head pose estimation models are facilitated, which achieves an average accuracy of 98.43% on recorded video dataset, indicates insensitivity to the head pose estimation model used for data collection and verifies that the proposed method is independent on any specific head pose estimation model. The experimental results show that the proposed method is accurate, effective and robust for the concentration evaluation in class.

3D-ARM-Gaze: a public dataset of 3D Arm Reaching Movements with Gaze information in virtual reality

3D-ARM-Gaze is a public dataset designed to provide natural arm movements together with visual and gaze information when reaching objects in a wide reachable space from a precisely controlled, comfortably seated posture. Participants were involved in picking and placing objects in various positions and orientations in a virtual environment, whereby a specific procedure maximized the workspace explored while ensuring a consistent seated posture by guiding participants to a predetermined neutral posture via visual feedback from the trunk and shoulders. These experimental settings enabled to capture natural arm movements with high median success rates (>98% objects reached) and minimal compensatory movements. The dataset regroups more than 2.5 million samples recorded from 20 healthy participants performing 14 000 single pick-and-place movements (700 per participant). While initially designed to explore novel prosthesis control strategies based on natural eye-hand and arm coordination, this dataset will also be useful to researchers interested in core sensorimotor control, humanoid robotics, human-robot interactions, as well as for the development and testing of associated solutions in gaze-guided computer vision.

Numerical Study of Solid–Gas Two-Phase Flow and Erosion Distribution in Glass Fiber-Reinforced Polymer Ball Valves

The use of glass fiber-reinforced polymer (GFRP) composites in fluid transport systems can effectively reduce corrosion damage caused by corrosive media. However, collisions between solid particles and the surfaces of ball valve flow passages can cause erosion damage and lead to safety issues. The two-phase flow and erosion characteristics of ball valves manufactured from resin-based fiber-reinforced composite materials were studied under different openings and particle sizes using the CFD-DPM method. The results indicate that both smaller and larger relative openings are prone to erosion damage at the thin edges of the valve ball. As the relative opening increases, the average erosion amount in the flow passage first increases and then decreases. The maximum average erosion amount is 0.0051 kg/m2·s when the relative opening is Cv = 40. At Cv = 40, erosion damage in the flow channel mainly occurs at the bottom of the inlet flow channel and the valve seat position. With increasing particle size, both the average and maximum erosion amounts in the flow channel increase. Larger particle sizes in the inlet flow channel significantly raise the erosion rate nearby, while at other locations, larger particle sizes mainly increase the erosion rate in the same area. During the use of GFRP valves, it is important to avoid introducing large-sized particles into the medium. Keeping the valve’s relative opening greater than 40 and using more erosion-resistant materials for the valve seat can effectively reduce the erosion of the composite ball valve and extend its service life.

A hybrid simulation approach to predicting noise in restaurants

High levels of noise are a well-known source of occupant discomfort in dining environments, and noise ranks highly among the most common customer complaints in restaurant reviews. Prior work has focused on measuring existing restaurant soundscapes and attempting to predict acoustic performance; however, current techniques are still limited in accuracy for restaurants with time-varying occupancy and complex layouts. This presentation demonstrates a novel approach to predicting ambient noise in restaurants via a hybrid simulation framework. Acoustical computations for a given restaurant space are performed in a room acoustics model, while a discrete event simulation (DES) model is used to simulate the arrival patterns of patrons and their conversational behaviors. Predictions from the room acoustics model inform the DES model, allowing for noise level predictions at each seat position. Results from the prediction model are validated against measurements in a case study restaurant. Further development of this framework may support the practical assessment of design interventions in any restaurant while also accounting for time-varying patterns of occupancy.

Ergonomic Design of Noseless Bicycle Saddle using UPVC/Silica-Aerogel

Introduction: During cycling most of the people suffer from perineal pain due to the pressure acting on the perineal area by the nose of the seat. Also Unsupported sitting on the saddle in a forward bending posture for longer time induce low back pain (LBP) among cyclists. So this paper presents the design of noseless bicycle seat with backrest using UPVC/Silica-Aerogel. Methods: This seat is designed as per the anthropometric dimensions of human body. Various parameters such as Lumbar position, seat tilt angle, seat position, backrest angle, seat height, backrest height, seat and backrest width are considered and the optimal value is determined while designing. The material chosen for the base of seat is UPVC/Silica- Aerogel composite and the cushioning material is chosen as polyurethene foam. The design is executed in 3D modelling software and validated using FEA package. Results: The maximum stresses induced in the newly proposed material UPVC/Silica-Aerogel (4.41MPa) is lesser than its yield strength (59 MPa). The maximum anterior stress of noseless seat is found out to be 24.5 kPa which is lower than that of the saddle with nose (41 kPa). Conclusion: As the anterior stress of noseless seat is lesser, the perineal pressure of cyclists is greatly reduced and this decreases the health problems associated with the perineal pressure. Also the backrest of the seatpan enhances the supporting of back muscles and reduces LBP among cyclists.

In silico analysis of the patient-specific acetabular cup anteversion safe zone

IntroductionVarious computer-assisted surgical systems claim to improve the accuracy of cup placement in total hip arthroplasties after assessing spinopelvic mobility to prevent prosthetic impingement. However, no study has yet analyzed the extent of the patient-specific cup anteversion safe zones. HypothesisWe hypothesized that most patients have a safe zone >10 °, except those with abnormal spinopelvic mobility, who have a much narrower safe zone. Materials and methodsWe simulated the risks of prosthetic impingement using the planned cup anteversion. The consecutive cohort included 341 patients who underwent total hip arthroplasty. Our primary endpoint was the patient-specific impingement-free zone for cup anteversion, which was then divided into four subgroups: 0 °, 1 ° to 5 °, 6 ° to 10 °, and >10 °. This data was then secondarily analyzed for abnormal spinopelvic mobility (the difference in the spinopelvic tilt [ΔSPT] from a standing to a flexed seated position >20 °). ResultsThe mean anteversion safe zone was 22.8 ° with 82.4% (281/341) of patients with a zone strictly >10 °. The mean safe zone was 8.9 ° (+/− 9 °) in patients with an ΔSPT ≥20 ° (18.2%), with 37.1% of these patients having a zone of 0 °, 16.13% a zone between 1 ° and 5 °, 8.06% a zone between 6 ° and 10 ° and 38.71% a zone >10 °. The mean safe zone was 25.9 ° (+/− 9 °) in patients with an ΔSPT <20 ° (81.8%), and the proportion of cases in each zone was 2.51%, 1.08%, 4.3%, and 92.11%, respectively (p < 0.001). ConclusionThe safe zone for anteversion appears to be fairly wide in most patients. However, identifying patients at risk of abnormal spinopelvic mobility seems necessary to identify the two-thirds of patients with a narrow safe zone. Level of evidenceIV; retrospective study

Classroom Management Problems Faced by English Education Students at Faculty of Teacher Training and Education University of Mataram Undertaking the Campus Teaching Program

This study addresses the challenges English Education students face in developing relationships, motivation, and engaging instruction in English classes. The research design is descriptive qualitative research, and the data collection methods include observation sheets, interviews, and document analysis. The study participants are five students who participated in the Kampus Mengajar or Campus Teaching (KM) program at University of Mataram and seek to identify the problems they encounter in classroom management, how they solve them, and how well they manage their classrooms. The result of both observation and interview founded that there are included six problems faced by KM-5 students during teaching practice i.e., (1) Naughty students, (2) Underestimate the teacher, (3) Hyper active students, (4) Passive students in learning activities, (5) Crowded classes and (6) Bored students. The efforts given by the KM students in dealing with the problems are building good teacher-student relationships, making the lesson more attractive, giving a small gift to catch students' attention, giving word motivation, changing students' seat positions, and making some games related to the topic discussion. The results highlight the need for further support and development opportunities for student teachers to enhance their classroom management skills and teaching practice.

MỐI LIÊN HỆ GIỮA VỊ TRÍ CHỖ NGỒI TRONG LỚP HỌC VỚI KẾT QUẢ HỌC TẬP MÔN HỌC “MẠNG MÁY TÍNH”

The paper investigates the correlation between seating positions in the classroom and academic performance in the subject of Computer Networks, specifically focusing on students from the Faculty of Information Technology at Thai Nguyen University of Information and Communication Technology. The research methodology employed scenarios, situations, interview questions, and real experimental cases involving 500 students. These students were assigned different seating arrangements in classrooms throughout the course, from the beginning to the end. Through specific input data, the study quantitatively assessed the relatively accurate research outcomes, based on the final exam results. The research results, comparisons, and practical evaluations indicate that seating positions are related to students' academic performance. Specifically, students achieving grades of C or higher are predominantly found in the front and middle rows, while those with grades below C are in the remaining rows

Vehicle Seat Adjustment System based on Body Image Recognition

A vehicle seat adjustment system based on body image recognition is designed. The system uses body image recognition algorithms to calculate the physique parameters of passengers, and automatically adjusts the vehicle seat position. Through on-site testing, the matching rate between the automatically adjusted vehicle seat position and passenger body shape reaches 98.1%, which can effectively improve the convenience and comfort of the vehicle.