Measurement and modelling of x-direction apparent mass of the seated human body-cushioned seat system.

PubMed

Stein, George Juraj; Múcka, Peter; Chmúrny, Rudolf; Hinz, Barbara; Blüthner, Ralph

2007-01-01

For modelling purposes and for evaluation of driver's seat performance in the vertical direction various mechano-mathematical models of the seated human body have been developed and standardized by the ISO. No such models exist hitherto for human body sitting in an upright position in a cushioned seat upper part, used in industrial environment, where the fore-and-aft vibrations play an important role. The interaction with the steering wheel has to be taken into consideration, as well as, the position of the human body upper torso with respect to the cushioned seat back as observed in real driving conditions. This complex problem has to be simplified first to arrive at manageable simpler models, which still reflect the main problem features. In a laboratory study accelerations and forces in x-direction were measured at the seat base during whole-body vibration in the fore-and-aft direction (random signal in the frequency range between 0.3 and 30 Hz, vibration magnitudes 0.28, 0.96, and 2.03 ms(-2) unweighted rms). Thirteen male subjects with body masses between 62.2 and 103.6 kg were chosen for the tests. They sat on a cushioned driver seat with hands on a support and backrest contact in the lumbar region only. Based on these laboratory measurements a linear model of the system-seated human body and cushioned seat in the fore-and-aft direction has been developed. The model accounts for the reaction from the steering wheel. Model parameters have been identified for each subject-measured apparent mass values (modulus and phase). The developed model structure and the averaged parameters can be used for further bio-dynamical research in this field.

An analytic model of the in-line and cross-axis apparent mass of the seated human body exposed to vertical vibration with and without a backrest

NASA Astrophysics Data System (ADS)

Zheng, Guangtai; Qiu, Yi; Griffin, Michael J.

2011-12-01

During vertical excitation of the seated human body there are vertical and fore-and-aft forces at the seat that are influenced by contact with a backrest, so it is desirable to take into account the effect of a backrest when developing models of the seated human body. Initially, a seven degree-of-freedom multi-body dynamic model was developed for the human body sitting with an upright posture unsupported by a backrest and exposed to vertical vibration. The model was optimized to fit the vertical apparent mass and the fore-and-aft cross-axis apparent mass measured on a seat. The model was then extended by the addition of vertical and fore-and-aft reaction forces to the upper lumbar spine to model the interaction between the human body and a backrest. By minimizing the least square error between experimental data and the analytical solution of the apparent masses on the seat and at the back, the human body model was able to represent both the vertical apparent mass and the fore-and-aft cross-axis apparent mass on the seat and at the back. Parameter sensitivity studies showed that the vertical apparent mass and the fore-and-aft cross-axis apparent mass on the seat and the backrest were all highly sensitive to the axial stiffness of the tissue beneath the pelvis. Pitch motion of the upper-body contributed to the vertical apparent mass and the fore-and-aft cross-axis apparent mass on the seat. The apparent mass at the back was more sensitive to the stiffness and damping of the lower back than the properties of the upper back.

Computer Code for the Determination of Ejection Seat/Man Aerodynamic Parameters.

DTIC Science & Technology

1980-08-28

ARMS, and LES (computer code -- .,. ,... ,, ..,.., .: . .. ... ,-." . ;.’ -- I- ta names) and Seat consisted of 4 panels SEAT, BACK, PADD , and SIDE. An... general application of Eq. (I) is for blunt bodies at hypersonic speed, because accuracy of this equation becomes better at higher Mach number. Therefore...pressure coefficient is set equal to zero on those portions of the body that are invisible to a distant observer who views the body from the direction

Seating Considerations for Spaceflight: The Human to Machine Interface

NASA Technical Reports Server (NTRS)

Gohmert, Dustin M.

2011-01-01

Seating is one of the most critical components to be considered during design of a spacecraft. Since seats are the final interface between the occupant and the vehicle wherein all launch and landing operations are performed, significant effort must be spent to ensure proper integration of the human to the spacecraft. The importance of seating can be divided into two categories: seat layout and seat design. The layout of the seats drives the overall cabin configuration - from displays and controls, to windows, to stowage, to egress paths. Since the layout of the seats is such a critical design parameter within the crew compartment, it is one of the first design challenges that must be completed in the critical path of the spacecraft design. In consideration of seat layout in the vehicle, it is important for the designers to account for often intangible factors such as safety, operability, contingency performance, crew rescue. Seat layout will lead to definition of the quantity, shape, and posture of the seats. The seats of the craft must restrain and protect the occupant in all seated phases of flight, while allowing for nominal mission performance. In design of a spacecraft seat, the general posture of the occupant and the landing loads to be encountered are the greatest drivers of overall design. Variances, such as upright versus recumbent postures will dictate fit of the seat to the occupant and drive the total envelope of the seat around the occupant. Seat design revolves around applying sound principles of seated occupant protection coupled with the unique environments driven by the seat layout, landing loads, and operational and emergency scenarios.

The relationship between sitting posture and seated-related upper quadrant musculoskeletal pain in computing South African adolescents: A prospective study.

PubMed

Brink, Yolandi; Louw, Quinette; Grimmer, Karen; Jordaan, Esmè

2015-12-01

There is evidence that consistent sitting for prolonged periods is associated with upper quadrant musculoskeletal pain (UQMP). It is unclear whether postural alignment is a significant risk factor. The aim of the prospective study (2010-2011) was to ascertain if three-dimensional sitting postural angles, measured in a real-life school computer classroom setting, predict seated-related UQMP. Asymptomatic Grade 10 high-school students, aged 15-17 years, undertaking Computer Application Technology, were eligible to participate. Using the 3D Posture Analysis Tool, sitting posture was measured while students used desk-top computers. Posture was reported as five upper quadrant angles (Head flexion, Neck flexion; Craniocervical angle, Trunk flexion and Head lateral bending). The Computer Usage Questionnaire measured seated-related UQMP and hours of computer use. The Beck Depression Inventory and the Multidimensional Anxiety Scale for Children assessed psychosocial factors. Sitting posture, computer use and psychosocial factors were measured at baseline. UQMP was measured at six months and one-year follow-up. 211, 190 and 153 students participated at baseline, six months and one-year follow-up respectively. 34.2% students complained of seated-related UQMP during the follow-up period. Increased head flexion (HF) predicted seated-related UQMP developing over time for a small group of students with pain scores greater than the 90th pain percentile, adjusted for age, gender, BMI, computer use and psychosocial factors (p = 0.003). The pain score increased 0.22 points per 1° increase in HF. Classroom ergonomics and postural hygiene should therefore focus on reducing large HF angles among computing adolescents. Copyright © 2015 Elsevier Ltd. All rights reserved.

Narrowing Your Seating Options.

ERIC Educational Resources Information Center

Vukovic, Vladimir

1998-01-01

Offers guidance on selecting appropriate seating furniture for outdoor facilities, arenas, auditoriums, and lecture rooms. Considerations such as beam mounting systems to facilitate laptop computer and campuswide networking use by students and chair durability and ergonomics are discussed as are tips for choosing a seating remanufacturing company.…

A biomechanical and physiological study of office seat and tablet device interaction.

PubMed

Weston, Eric; Le, Peter; Marras, William S

2017-07-01

Twenty subjects performed typing tasks on a desktop computer and touch-screen tablet in two chairs for an hour each, and the effects of chair, device, and their interactions on each dependent measure were recorded. Biomechanical measures of muscle force, spinal load, and posture were examined, while discomfort was measured via heart rate variability (HRV) and subjective reports. HRV was sensitive enough to differentiate between chair and device interactions. Biomechanically, a lack of seat back mobility forced individuals to maintain an upright seating posture with increased extensor muscle forces and increased spinal compression. Effects were exacerbated by forward flexion upon interaction with a tablet device or by slouching. Office chairs should be designed with both the human and workplace task in mind and allow for reclined postures to off-load the spine. The degree of recline should be limited, however, to prevent decreased lumbar lordosis resulting from posterior hip rotation in highly reclined postures. Copyright © 2017 Elsevier Ltd. All rights reserved.

Descriptive study of electromagnetic wave distribution for various seating positions: using digital textbooks.

PubMed

Seomun, GyeongAe; Kim, YoungHwan; Lee, Jung-Ah; Jeong, KwangHoon; Park, Seon-A; Kim, Miran; Noh, Wonjung

2014-04-01

To better understand environmental electromagnetic wave exposure during the use of digital textbooks by elementary school students, we measured numeric values of the electromagnetic fields produced by tablet personal computers (TPCs). Specifically, we examined the distribution of the electromagnetic waves for various students' seating positions in an elementary school that uses digital textbooks. Electric and magnetic fields from TPCs were measured using the HI-3603 Visual Display Terminal/ Very Low Frequency (VDT/VLF) radiation measurement system. Electromagnetic field values from TPCs measured at a student's seat and at a teacher's computer were deemed not harmful to health. However, electromagnetic field values varied based on the distance between students, other electronic devices such as a desktop computers, and student posture while using a TPC. Based on these results, it is necessary to guide students to observe proper posture and to arrange seats at an appropriate distance in the classroom.

Seating Considerations for Spaceflight: The Human to Machine Interface

NASA Astrophysics Data System (ADS)

Gohmert, D. M.

2012-01-01

Seating is one of the most critical components to be considered during design of a spacecraft. Since seats are the final interface between the occupant and the vehicle wherein all launch and landing operations are performed, significant effort must be spent to ensure proper integration of the human to the spacecraft. The importance of seating can be divided into two categories: seat layout and seat design. The layout of the seats drives the overall cabin configuration - from displays and controls, to windows, to stowage, to egress paths. Since the layout of the seats is such a critical design parameter within the crew compartment, it is one of the first design challenges that must be completed in the critical path of the spacecraft design. In consideration of seat layout in the vehicle, it is important for the designers to account for often intangible factors such as safety, operability, contingency performance, and crew rescue. Seat layout will lead to definition of the quantity, shape, and posture of the seats. The seats of the craft must restrain and protect the occupant in all seated phases of flight, while allowing for nominal mission performance. In design of a spacecraft seat, the general posture of the occupant and the landing loads to be encountered are the greatest drivers of overall design. Variances, such as upright versus recumbent postures will dictate fit of the seat to the occupant and drive the total envelope of the seat around the occupant. Seat design revolves around applying sound principles of seated occupant protection coupled with the unique environments driven by the seat layout, landing loads, and operational and emergency scenarios.

Potential method for relieving fatigue in radiologists

NASA Astrophysics Data System (ADS)

Krupinski, Elizabeth A.

2013-03-01

Radiologists moved to an environment in which they read digital images off of computer displays instead of film images off of light boxes. With film and light boxes they typically would read for about an hour (seated) and then take a break while the film librarian changed the images on the view box. With digital viewing off computers they tend to sit all day in front of the computers with far fewer breaks and opportunity to stand up and move around than with film. There is concern that this lack of activity not only contributes to back, shoulder and neck discomfort, but also contributes to increased fatigue which has been shown to impact reader performance. The goal of this study was to determine if there are differences in physiologic vital signs (heart rate and blood pressure) of radiologists as a function of whether they read images while seated or while standing up. Five subjects had their blood pressure and heart rate measured while seated and while standing reading cases in the normal clinical setting. For all three measures there was a statistically significant (p < 0.0001) difference between seated and standing measures with seated being lower than standing. The higher heart rate and blood pressure with standing suggests that the radiologists are more active in this position and thus potentially more attentive than while seated. This study will be followed up to determine impact on diagnostic performance of standing vs seated as well as subjective ratings of wakefulness and mood.

A split-crank bicycle ergometer uses servomotors to provide programmable pedal forces for studies in human biomechanics.

PubMed

Van der Loos, H F Machiel; Worthen-Chaudhari, Lise; Schwandt, Douglas; Bevly, David M; Kautz, Steven A

2010-08-01

This paper presents a novel computer-controlled bicycle ergometer, the TiltCycle, for use in human biomechanics studies of locomotion. The TiltCycle has a tilting (reclining) seat and backboard, a split pedal crankshaft to isolate the left and right loads to the feet of the pedaler, and two belt-driven, computer-controlled motors to provide assistance or resistance loads independently to each crank. Sensors measure the kinematics and force production of the legs to calculate work performed, and the system allows for goniometric and electromyography signals to be recorded. The technical description presented includes the mechanical design, low-level software and control algorithms, system identification and validation test results.

Human Factors Assessment of Vibration Effects on Visual Performance During Launch

NASA Technical Reports Server (NTRS)

Holden, Kritina

2009-01-01

The Human Factors Assessment of Vibration Effects on Visual Performance During Launch (Visual Performance) investigation will determine visual performance limits during operational vibration and g-loads on the Space Shuttle, specifically through the determination of minimum readable font size during ascent using planned Orion display formats. Research Summary: The aim of the Human Factors Assessment of Vibration Effects on Visual Performance during Launch (Visual Performance) investigation is to provide supplementary data to that collected by the Thrust Oscillation Seat Detailed Technical Objective (DTO) 695 (Crew Seat DTO) which will measure seat acceleration and vibration from one flight deck and two middeck seats during ascent. While the Crew Seat DTO data alone are important in terms of providing a measure of vibration and g-loading, human performance data are required to fully interpret the operational consequences of the vibration values collected during Space Shuttle ascent. During launch, crewmembers will be requested to view placards with varying font sizes and indicate the minimum readable size. In combination with the Crew Seat DTO, the Visual Performance investigation will: Provide flight-validated evidence that will be used to establish vibration limits for visual performance during combined vibration and linear g-loading. o Provide flight data as inputs to ongoing ground-based simulations, which will further validate crew visual performance under vibration loading in a controlled environment. o Provide vibration and performance metrics to help validate procedures for ground tests and analyses of seats, suits, displays and controls, and human-in-the-loop performance.

Human body modeling method to simulate the biodynamic characteristics of spine in vivo with different sitting postures.

PubMed

Dong, Rui-Chun; Guo, Li-Xin

2017-11-01

The aim of this study is to model the computational model of seated whole human body including skeleton, muscle, viscera, ligament, intervertebral disc, and skin to predict effect of the factors (sitting postures, muscle and skin, buttocks, viscera, arms, gravity, and boundary conditions) on the biodynamic characteristics of spine. Two finite element models of seated whole body and a large number of finite element models of different ligamentous motion segments were developed and validated. Static, modal, and transient dynamic analyses were performed. The predicted vertical resonant frequency of seated body model was in the range of vertical natural frequency of 4 to 7 Hz. Muscle, buttocks, viscera, and the boundary conditions of buttocks have influence on the vertical resonant frequency of spine. Muscle played a very important role in biodynamic response of spine. Compared with the vertical posture, the posture of lean forward or backward led to an increase in stress on anterior or lateral posterior of lumbar intervertebral discs. This indicated that keeping correct posture could reduce the injury of vibration on lumbar intervertebral disc under whole-body vibration. The driving posture not only reduced the load of spine but also increased the resonant frequency of spine. Copyright © 2017 John Wiley & Sons, Ltd.

75 FR 4509 - Uniform Criteria for State Observational Surveys of Seat Belt Use

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-28

... establishing the criteria for designing and conducting State seat belt use observational surveys, procedures for obtaining NHTSA approval of survey designs, and a new form for reporting seat belt use rates to.... Assignment of Observation Times D. Observation Procedures E. Quality Control F. Computation of Estimates III...

An online means of testing asymmetries in seating preference reveals a bias for airplanes and theaters.

PubMed

Nicholls, Michael E R; Thomas, Nicole A; Loetscher, Tobias

2013-08-01

The aim of this study was to investigate asymmetrical interactions between humans and their environment using online seat booking sites. Functional differences between the cerebral hemispheres affect the choices people make. For example, when asked to imagine going to a cinema, people preferentially select seats to the right We investigated whether this experimental research generalizes to online booking sites for aircraft and theaters. Occupancy rates for seats taken on the left and right sides were assessed for 100 airline flights with 12,762 available seats and 37 theater performances with 34,456 seats. On the basis of previous research, a rightward bias was predicted for aircraft and theaters. For aircraft, contrary to expectation, occupancy rate was higher for left- compared with right-side seats. For theaters, a rightward bias was observed when the theater was less than half full.The bias was not affected by the orientation of the map. For aircraft, the leftward preference could be attributable to a rightward turning bias or a "feeling" that the port seats are closer to the exit, even though they are not. For theaters, the data demonstrate that the rightward preference observed in earlier studies exists only when the theater is relatively empty. Asymmetrical seating may play an important role in the efficient assimilation of information from the environment, and this role should take this into account when designing effective human-environment interfaces.The online method of assessing seating used in the current study provides an informative and potentially powerful means of assessing asymmetries in human perception and action.

Evaluation of wheelchair drop seat crashworthiness.

PubMed

Bertocci, G; Ha, D; van Roosmalen, L; Karg, P; Deemer, E

2001-05-01

Wheelchair seating crash performance is critical to protecting wheelchair users who remain seated in their wheelchairs during transportation. Relying upon computer simulation and sled testing seat loads associated with a 20 g/48 kph (20 g/30 mph) frontal impact and 50th percentile male occupant were estimated to develop test criteria. Using a static test setup we evaluated the performance of various types of commercially available drop seats against the loading test criteria. Five different types of drop seats (two specimens each) constructed of various materials (i.e. plastics, plywood, metal) were evaluated. Two types of drop seats (three of the total 10 specimens) met the 16650 N (3750 lb) frontal impact test criteria. While additional validation of the test protocol is necessary, this study suggests that some drop seat designs may be incapable of withstanding crash level loads.

75 FR 68664 - Federal Motor Vehicle Safety Standards; Child Restraint Systems; Booster Seat Effectiveness...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-08

... early graduation from booster seats to lap and shoulder belts. Estimates are computed by double-pair... 3-4-year-olds there is evidence of increased risk of injury when restrained in booster seats rather.... Among 4-8-year-olds there is strong evidence of increased risk of injury when restrained by lap and...

NASA experiments on the B-720 structure and seats

NASA Astrophysics Data System (ADS)

Alfaro-Bou, E.

1986-01-01

Two experiments onboard a remotely piloted transport aircraft that was crashed on landing are discussed. The structural experiment deals with the location and distribution of the instrumentation throughout the airplane structure. In the seat experiment, the development and testing of an energy absorbing seat are discussed. The objective of the structural experiment was to obtain a data base of structural crash loads for use in the advancement of crashworthy technology of materials (such as composites) in structural design and for use in the comparison between computer and experimental results. The objective of the seat experiment was to compare the performance of an energy absorbing transport seat and a standard seat when subjected to similar crash pulses. Details are given on the location of instrumentation, on the dynamic seat test pulse and headward acceleration limits.

Lateral bias in theatre-seat choice.

PubMed

Harms, Victoria; Reese, Miriam; Elias, Lorin J

2014-01-01

Examples of behavioural asymmetries are common in the range of human behaviour; even when faced with a symmetrical environment people demonstrate reliable asymmetries in behaviours like gesturing, cradling, and even seating. One such asymmetry is the observation that participants tend to choose seats to the right of the screen when asked to select their preferred seating location in a movie theatre. However, these results are based on seat selection using a seating chart rather than examining real seat choice behaviour in the theatre context. This study investigated the real-world seating patterns of theatre patrons during actual film screenings. Analysis of bias scores calculated using photographs of theatre patrons revealed a significant bias to choose seats on the right side of the theatre. These findings are consistent with the prior research in the area and confirm that the seating bias observed when seats are selected from a chart accurately reflects real-world seating behaviour.

Determination of crash test pulses and their application to aircraft seat analysis

NASA Technical Reports Server (NTRS)

Alfaro-Bou, E.; Williams, M. S.; Fasanella, E. L.

1981-01-01

Deceleration time histories (crash pulses) from a series of twelve light aircraft crash tests conducted at NASA Langley Research Center (LaRC) were analyzed to provide data for seat and airframe design for crashworthiness. Two vertical drop tests at 12.8 m/s (42 ft/s) and 36 G peak deceleration (simulating one of the vertical light aircraft crash pulses) were made using an energy absorbing light aircraft seat prototype. Vertical pelvis acceleration measured in a 50 percentile dummy in the energy absorbing seat were found to be 45% lower than those obtained from the same dummy in a typical light aircraft seat. A hybrid mathematical seat-occupant model was developed using the DYCAST nonlinear finite element computer code and was used to analyze a vertical drop test of the energy absorbing seat. Seat and occupant accelerations predicted by the DYCAST model compared quite favorably with experimental values.

Evaluation of lumbar vertebra injury risk to the seated human body when exposed to vertical vibration

NASA Astrophysics Data System (ADS)

Ayari, H.; Thomas, M.; Doré, S.; Serrus, O.

2009-03-01

The objective of this research is to numerically determine the levels of vibration not to exceed accordingly to the corresponding dynamic stresses in the lumbar rachis when exposed to whole-body vibrations in order to identify the risk of adverse health effect to which professional heavy equipment drivers are particularly prone. A parametric finite element model of the lumbar rachis is generated in order to compute the modal parameters, the dynamic stresses and forces under harmonic excitations in a seated posture. The stress analysis reveals that the areas exposed to the highest fracture risk are the cancellous bone of the vertebral body as well as the vertebral endplate when vertical vibrations are transmitted from a seat to the lumbar spine of a driver. An injury risk factor has been developed in order to estimate the risk of adverse health effect arising from mechanical vibrations. It is shown that the injury risk factor increases with the age and consequently that the excitation amplitude must be limited to lower levels when age increases.

NASA Standards Inform Comfortable Car Seats

NASA Technical Reports Server (NTRS)

2014-01-01

NASA developed standards, which included the neutral body posture (NBP), to specify ways to design flight systems that support human health and safety. Nissan Motor Company, with US offices in Franklin, Tennessee, turned to NASA's NBP research for the development of a new driver's seat. The 2013 Altima now features the new seat, and the company plans to incorporate the seats in upcoming vehicles.

Effects of deceleration and rate of deceleration on live seated human subjects

DOT National Transportation Integrated Search

1977-10-01

This report describes the testing of live, seated human subjects to determine : the maximum deceleration and associated rate of change of deceleration (jerk) at : which the majority of potential users of automated guideway transportation (ACT) : syst...

Design Control Systems of Human Machine Interface in the NTVS-2894 Seat Grinder Machine to Increase the Productivity

NASA Astrophysics Data System (ADS)

Ardi, S.; Ardyansyah, D.

2018-02-01

In the Manufacturing of automotive spare parts, increased sales of vehicles is resulted in increased demand for production of engine valve of the customer. To meet customer demand, we carry out improvement and overhaul of the NTVS-2894 seat grinder machine on a machining line. NTVS-2894 seat grinder machine has been decreased machine productivity, the amount of trouble, and the amount of downtime. To overcome these problems on overhaul the NTVS-2984 seat grinder machine include mechanical and programs, is to do the design and manufacture of HMI (Human Machine Interface) GP-4501T program. Because of the time prior to the overhaul, NTVS-2894 seat grinder machine does not have a backup HMI (Human Machine Interface) program. The goal of the design and manufacture in this program is to improve the achievement of production, and allows an operator to operate beside it easier to troubleshoot the NTVS-2894 seat grinder machine thereby reducing downtime on the NTVS-2894 seat grinder machine. The results after the design are HMI program successfully made it back, machine productivity increased by 34.8%, the amount of trouble, and downtime decreased 40% decrease from 3,160 minutes to 1,700 minutes. The implication of our design, it could facilitate the operator in operating machine and the technician easer to maintain and do the troubleshooting the machine problems.

A review of the analytical simulation of aircraft crash dynamics

NASA Technical Reports Server (NTRS)

Fasanella, Edwin L.; Carden, Huey D.; Boitnott, Richard L.; Hayduk, Robert J.

1990-01-01

A large number of full scale tests of general aviation aircraft, helicopters, and one unique air-to-ground controlled impact of a transport aircraft were performed. Additionally, research was also conducted on seat dynamic performance, load-limiting seats, load limiting subfloor designs, and emergency-locator-transmitters (ELTs). Computer programs were developed to provide designers with methods for predicting accelerations, velocities, and displacements of collapsing structure and for estimating the human response to crash loads. The results of full scale aircraft and component tests were used to verify and guide the development of analytical simulation tools and to demonstrate impact load attenuating concepts. Analytical simulation of metal and composite aircraft crash dynamics are addressed. Finite element models are examined to determine their degree of corroboration by experimental data and to reveal deficiencies requiring further development.

The NASA Ames integral aircraft passenger seat concept - A human engineering approach

NASA Technical Reports Server (NTRS)

Kubokawa, C. C.

1974-01-01

A new NASA Ames concept for an aircraft passenger seat has been under research and development since 1968. It includes many human-factor features that will provide protection to the passenger from vibration, jostle, and high impact. It is comfortable and safer than any of the seats presently in use. An in-depth design, fabrication, and impact analysis was conducted in order to design a seat that will maximize passenger protection in high g impacts (20 g horizontal -Gx, 36 g vertical +Gz, 16 g lateral Gy). The method for absorbing impact energy was accomplished with a combination of stretching stainless steel cables, thread breaking of stitches, hydraulic mechanism and the special Temper Form cushions. The restraint system for the seat consisted of a lap belt and shoulder harness inertia reel combination.

Biodynamic Assessment of the THOR-K Manikin

DTIC Science & Technology

2013-09-01

finite element model, and for optimization of occupant seating systems and restraint system design for the MPCV and USAF aircraft ejection seats and...had the same rigid backrest, a rigid seat pan, a rigid footrest and leg support panel, but also provided side supports that restrict the motion of the... Ejection Seat (Technical Report AFRL-HE-WP-SR-2000-0002). Wright-Patterson AFB OH: Human Effectiveness Directorate, Air Force Research Laboratory

The influence of car-seat design on its character experience.

PubMed

Kamp, Irene

2012-03-01

Producing higher efficiency cars with less and lighter materials but without compromising safety, comfort and driving pleasure might give a competitive advantage. In this light, at BMW a new light weight car-seat concept was developed based on the human body contour. A possibility to increase the comfort is using a seat which elicits positive tactile experiences. However, limited information is available on seat characteristics and tactile experiences. Therefore, this study describes the contour of three different car-seat designs, including a light weight seat, and the recorded corresponding emotion and tactile experience of 21 persons sitting in the seats. Results show that the new light weight car-seat concept rated well on experienced relaxedness, even with the lack of a side support. The most important findings are that hard seats with rather high side supports are rated sporty and seats that are softer are rated more luxurious. Copyright © 2011 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Effects of UAV Supervisory Control on F-18 Formation Flight Performance in a Simulator Environment

DTIC Science & Technology

2013-03-01

words) Continual advances in technology, along with increased cockpit workload— particularly the shift from two- seat to single- seat fighters to save...INTENTIONALLY LEFT BLANK v ABSTRACT Continual advances in technology, along with increased cockpit workload— particularly the shift from two- seat to...single- seat fighters to save money and reduce risk to life—push the limits of human mental capacity. Additionally, there is interest within the

Development and Validation of the Total HUman Model for Safety (THUMS) Toward Further Understanding of Occupant Injury Mechanisms in Precrash and During Crash.

PubMed

Iwamoto, Masami; Nakahira, Yuko; Kimpara, Hideyuki

2015-01-01

Active safety devices such as automatic emergency brake (AEB) and precrash seat belt have the potential to accomplish further reduction in the number of the fatalities due to automotive accidents. However, their effectiveness should be investigated by more accurate estimations of their interaction with human bodies. Computational human body models are suitable for investigation, especially considering muscular tone effects on occupant motions and injury outcomes. However, the conventional modeling approaches such as multibody models and detailed finite element (FE) models have advantages and disadvantages in computational costs and injury predictions considering muscular tone effects. The objective of this study is to develop and validate a human body FE model with whole body muscles, which can be used for the detailed investigation of interaction between human bodies and vehicular structures including some safety devices precrash and during a crash with relatively low computational costs. In this study, we developed a human body FE model called THUMS (Total HUman Model for Safety) with a body size of 50th percentile adult male (AM50) and a sitting posture. The model has anatomical structures of bones, ligaments, muscles, brain, and internal organs. The total number of elements is 281,260, which would realize relatively low computational costs. Deformable material models were assigned to all body parts. The muscle-tendon complexes were modeled by truss elements with Hill-type muscle material and seat belt elements with tension-only material. The THUMS was validated against 35 series of cadaver or volunteer test data on frontal, lateral, and rear impacts. Model validations for 15 series of cadaver test data associated with frontal impacts are presented in this article. The THUMS with a vehicle sled model was applied to investigate effects of muscle activations on occupant kinematics and injury outcomes in specific frontal impact situations with AEB. In the validations using 5 series of cadaver test data, force-time curves predicted by the THUMS were quantitatively evaluated using correlation and analysis (CORA), which showed good or acceptable agreement with cadaver test data in most cases. The investigation of muscular effects showed that muscle activation levels and timing had significant effects on occupant kinematics and injury outcomes. Although further studies on accident injury reconstruction are needed, the THUMS has the potential for predictions of occupant kinematics and injury outcomes considering muscular tone effects with relatively low computational costs.

Designing for aircraft structural crashworthiness

NASA Technical Reports Server (NTRS)

Thomson, R. G.; Caiafa, C.

1981-01-01

This report describes structural aviation crash dynamics research activities being conducted on general aviation aircraft and transport aircraft. The report includes experimental and analytical correlations of load-limiting subfloor and seat configurations tested dynamically in vertical drop tests and in a horizontal sled deceleration facility. Computer predictions using a finite-element nonlinear computer program, DYCAST, of the acceleration time-histories of these innovative seat and subfloor structures are presented. Proposed application of these computer techniques, and the nonlinear lumped mass computer program KRASH, to transport aircraft crash dynamics is discussed. A proposed FAA full-scale crash test of a fully instrumented radio controlled transport airplane is also described.

The anthropometric match between high school learners of the Cape Metropole area, Western Cape, South Africa and their computer workstation at school.

PubMed

van Niekerk, Sjan-Mari; Louw, Quinette Abigail; Grimmer-Somers, Karen; Harvey, Justin; Hendry, Kevan John

2013-05-01

Descriptive study. The objective of this study was to present anthropometric data from high school students in Cape Metropole area, Western Cape, South Africa that are relevant for chair design and whether the dimensions of computer laboratory chairs currently used in high schools match linear anthropometrics of high-school students. Summary of Background Data. Learner-chair mismatch is proposed as a cause of poor postural alignment and spinal pain in adolescents. A learner-chair mismatch is defined as the incompatibility between the dimensions of a chair and the anthropometric dimensions of the learner. Currently, there is no published research to ascertain whether the furniture dimensions in school computer laboratories match the anthropometrics of the students. This may contribute to the high prevalence of adolescent spinal pain. The sample consisted of 689 learners, 13-18 years old. The following body dimensions were measured: stature, popliteal height, buttock-to-popliteal length and hip width. These measurements were matched with the corresponding chair seat dimensions: height, depth and width. Popliteal and seat height mismatch was defined when the seat height is either >95% or <88% of the popliteal height. Buttock-popliteal length and seat depth mismatch was defined when the seat depth is either >95% or <80% of the buttock-popliteal length. Seat width mismatch is defined where the seat width should be at least 10% and at the most 30% larger than hip width. An 89% of learners did not match the seat. Five percent of learners matched the chair depth, the majority was found to be too big. In contrast, 65% of the learners matched the chair width dimension. A substantial mismatch was found. The school chairs failed standard ergonomics recommendations for the design of furniture to fit the user. This study supports the conclusion that there is no one-size-fits-all solution. There is an urgent need for chairs that are of different sizes or that are adjustable. Copyright © 2012 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Measurement and modelling of the y-direction apparent mass of sitting human body-cushioned seat system

NASA Astrophysics Data System (ADS)

Stein, George Juraj; Múčka, Peter; Hinz, Barbara; Blüthner, Ralph

2009-04-01

Laboratory tests were conducted using 13 male subjects seated on a cushioned commercial vehicle driver's seat. The hands gripped a mock-up steering wheel and the subjects were in contact with the lumbar region of the backrest. The accelerations and forces in the y-direction were measured during random lateral whole-body vibration with a frequency range between 0.25 and 30 Hz, vibration magnitudes 0.30, 0.98, and 1.92 m s -2 (unweighted root mean square (rms)). Based on these laboratory measurements, a linear multi-degree-of-freedom (mdof) model of the seated human body and cushioned seat in the lateral direction ( y-axis) was developed. Model parameters were identified from averaged measured apparent mass values (modulus and phase) for the three excitation magnitudes mentioned. A preferred model structure was selected from four 3-dof models analysed. The mean subject parameters were identified. In addition, identification of each subject's apparent mass model parameters was performed. The results are compared with previous studies. The developed model structure and the identified parameters can be used for further biodynamical research in seating dynamics.

Railroad Tie Responses to Directly Applied Rail Seat Loading in Ballasted Tracks : A Computational Study.

DOT National Transportation Integrated Search

2012-04-17

This paper describes work in-progress that applies the : finite element (FE) method in predicting the responses of : individual railroad crossties to rail seat pressure loading in a : ballasted track. Both wood and prestressed concrete crossties : ar...

Energy absorption capability of foam-based composite materials and their applications as seat cushions in aircraft crashworthiness

NASA Astrophysics Data System (ADS)

Kh. Beheshti, Hamid

This study is focusing on the application of foam materials in aviation. These materials are being used for acoustic purposes, as padding in the finished interior panels of the aircraft, and as seat cushions. Foams are mostly used in seating applications. Since seat cushion is directly interacting with the body of occupant, it has to be ergonomically comfortable beside of absorbing the energy during the impact. All the seats and seat cushions have to pass regulations defined by Federal Aviation Administration (FAA). In fact, all airplane companies are required to certify the subcomponents of aircrafts before installing them on the main structure, fuselage. Current Federal Aviation Administration Regulations require a dynamic sled test of the entire seat system for certifying the seat cushions. This dynamic testing is required also for replacing the deteriorated cushions with new cushions. This involves a costly and time-consuming certification process. AGATE group has suggested a procedure based on quasi-static testing in order to certify new seat cushions without conducting full-scale dynamic sled testing. AGATE subcomponent methodology involves static tests of the energy-absorbing foam cushions and design validation by conducting a full-scale dynamic seat test. Microscopic and macroscopic studies are necessary to provide a complete understanding about performance of foams during the crash. Much investigation has been done by different sources to obtain the reliable modeling in terms of demonstration of mechanical behavior of foams. However, rate sensitivity of foams needs more attention. A mathematical hybrid dynamic model for the cushion underneath of the human body will be taken into consideration in this research. Analytical and finite element codes such as MADYMO and LS-DYNA codes have the potential to greatly speed up the crashworthy design process, to help certify seats and aircraft to dynamic crash loads, to predict seat and occupant response to impact with the probability of injury, and to evaluate numerous crash scenarios not economically feasible with full-scale crash testing. Therefore, these codes are being used to find the accurate response of spinal load during the impact of model including human body, seat cushion and seat under different acceleration pulses. (Abstract shortened by UMI.)

78 FR 40823 - Reports, Forms, and Record Keeping Requirements

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-08

... at time of approval. Title: National Survey of Principal Drivers of Vehicles with a Rear Seat Belt... from both groups and information on their passengers seat belt usage habits, as well as the... use computer-assisted telephone interviewing to reduce interview length and minimize recording errors...

Identification of human-generated forces on wheelchairs during total-body extensor thrusts.

PubMed

Hong, Seong-Wook; Patrangenaru, Vlad; Singhose, William; Sprigle, Stephen

2006-10-01

Involuntary extensor thrust experienced by wheelchair users with neurological disorders may cause injuries via impact with the wheelchair, lead to the occupant sliding out of the seat, and also damage the wheelchair. The concept of a dynamic seat, which allows movement of a seat with respect to the wheelchair frame, has been suggested as a potential solution to provide greater freedom and safety. Knowledge of the human-generated motion and forces during unconstrained extensor thrust events is of great importance in developing more comfortable and effective dynamic seats. The objective of this study was to develop a method to identify human-generated motions and forces during extensor thrust events. This information can be used to design the triggering system for a dynamic seat. An experimental system was developed to automatically track the motions of the wheelchair user using a video camera and also measure the forces at the footrest. An inverse dynamic approach was employed along with a three-link human body model and the experimental data to predict the human-generated forces. Two kinds of experiments were performed: the first experiment validated the proposed model and the second experiment showed the effects of the extensor thrust speed, the footrest angle, and the seatback angle. The proposed method was tested using a sensitivity analysis, from which a performance index was deduced to help indicate the robust region of the force identification. A system to determine human-generated motions and forces during unconstrained extensor thrusts was developed. Through experiments and simulations, the effectiveness and reliability of the developed system was established.

Development and validation of rear impact computer simulation model of an adult manual transit wheelchair with a seated occupant.

PubMed

Salipur, Zdravko; Bertocci, Gina

2010-01-01

It has been shown that ANSI WC19 transit wheelchairs that are crashworthy in frontal impact exhibit catastrophic failures in rear impact and may not be able to provide stable seating support and thus occupant protection for the wheelchair occupant. Thus far only limited sled test and computer simulation data have been available to study rear impact wheelchair safety. Computer modeling can be used as an economic and comprehensive tool to gain critical knowledge regarding wheelchair integrity and occupant safety. This study describes the development and validation of a computer model simulating an adult wheelchair-seated occupant subjected to a rear impact event. The model was developed in MADYMO and validated rigorously using the results of three similar sled tests conducted to specifications provided in the draft ISO/TC 173 standard. Outcomes from the model can provide critical wheelchair loading information to wheelchair and tiedown manufacturers, resulting in safer wheelchair designs for rear impact conditions. (c) 2009 IPEM. Published by Elsevier Ltd. All rights reserved.

Descriptive Study of Electromagnetic Wave Distribution for Various Seating Positions: Using Digital Textbooks

ERIC Educational Resources Information Center

Seomun, GyeongAe; Kim, YoungHwan; Lee, Jung-Ah; Jeong, KwangHoon; Park, Seon-A; Kim, Miran; Noh, Wonjung

2014-01-01

To better understand environmental electromagnetic wave exposure during the use of digital textbooks by elementary school students, we measured numeric values of the electromagnetic fields produced by tablet personal computers (TPCs). Specifically, we examined the distribution of the electromagnetic waves for various students' seating positions in…

Boeing CST-100 Starliner Seat Test

NASA Image and Video Library

2017-02-21

Engineers working with Boeing's CST-100 Starliner test the spacecraft's seat design in Mesa, Arizona, focusing on how the spacecraft seats would protect an astronaut's head, neck and spine during the 240-mile descent from the International Space Station. The company incorporated test dummies for a detailed analysis of impacts on a crew returning to earth. The human-sized dummies were equipped with sensitive instrumentation and secured in the seats for 30 drop tests at varying heights, angles, velocities and seat orientations in order to mimic actual landing conditions. High-speed cameras captured the footage for further analysis. The Starliner spacecraft is being developed in partnership with NASA's Commercial Crew Program.

[A cyborg is only human].

PubMed

Schermer, Maartje H N

2013-01-01

New biomedical technologies make it possible to replace parts of the human body or to substitute its functions. Examples include artificial joints, eye lenses and arterial stents. Newer technologies use electronics and software, for example in brain-computer interfaces such as retinal implants and the exoskeleton MindWalker. Gradually we are creating cyborgs: hybrids of man and machine. This raises the question: are cyborgs still humans? It is argued that they are. First, because employing technology is a typically human characteristic. Second, because in western thought the human mind, and not the body, is considered to be the seat of personhood. However, it has been argued by phenomenological philosophers that the body is more than just an object but is also a subject, important for human identity. From this perspective, we can appreciate that a bionic body does not make one less human, but it does influence the experience of being human.

Physiological Motion Axis for the Seat of a Dynamic Office Chair.

PubMed

Kuster, Roman Peter; Bauer, Christoph Markus; Oetiker, Sarah; Kool, Jan

2016-09-01

The aim of this study was to determine and verify the optimal location of the motion axis (MA) for the seat of a dynamic office chair. A dynamic seat that supports pelvic motion may improve physical well-being and decrease the risk of sitting-associated disorders. However, office work requires an undisturbed view on the work task, which means a stable position of the upper trunk and head. Current dynamic office chairs do not fulfill this need. Consequently, a dynamic seat was adapted to the physiological kinematics of the human spine. Three-dimensional motion tracking in free sitting helped determine the physiological MA of the spine in the frontal plane. Three dynamic seats with physiological, lower, and higher MA were compared in stable upper body posture (thorax inclination) and seat support of pelvic motion (dynamic fitting accuracy). Spinal kinematics during sitting and walking were compared. The physiological MA was at the level of the 11th thoracic vertebra, causing minimal thorax inclination and high dynamic fitting accuracy. Spinal motion in active sitting and walking was similar. The physiological MA of the seat allows considerable lateral flexion of the spine similar to walking with a stable upper body posture and a high seat support of pelvic motion. The physiological MA enables lateral flexion of the spine, similar to walking, without affecting stable upper body posture, thus allowing active sitting while focusing on work. © 2016, Human Factors and Ergonomics Society.

Three experiments to support the design of lightweight comfortable vehicle seats.

PubMed

Vink, P; Franz, M; Kamp, I; Zenk, R

2012-01-01

Seats need to be more lightweight for airplanes, cars, busses and even trains to contribute to a better environment and to reduce energy consumption. However, a reduction in comfort due to weight reduction is not preferable, which opens a new area of research: improving comfort with a minimum of material or with lightweight materials and systems. In this paper three experiments are performed to test the effects of light weight seats and parts of a seat on comfort. The first experiment shows that a new developed light weight massage system improves comfort and reduces muscle activity. The second experiment shows that the automatic seat adjustment without motors improves the comfort as well. The third experiment showed that a light weight seat following closely the human body contour is experienced on many aspects in the same way as current more heavy seats. More research and models will be needed in this ergonomic field which needs more attention.

STS-36 Pilot Casper reaches for laptop computer on OV-104's flight deck

NASA Image and Video Library

1990-03-03

STS036-03-027 (3 March 1990) --- STS-36 Pilot John H. Casper reaches for the shuttle portable onboard computer (SPOC), a laptop computer, while at the pilots station on the forward flight deck of Atlantis, Orbiter Vehicle (OV) 104. Casper, seated in the pilot’s seat, lifts the SPOC from the forward window ledge. Appearing around him are forward crew compartment windows, the head up display (HUD), the flight mirror assembly, and a checklist attached to control panel O3. Casper and four other astronauts spent four days, 10 hours and 19 minutes aboard the spacecraft for a Department of Defense (DOD) devoted mission.

Human Tolerance to Rapidly Applied Accelerations: A Summary of the Literature

NASA Technical Reports Server (NTRS)

Eiband, A. Martin

1959-01-01

The literature is surveyed to determine human tolerance to rapidly applied accelerations. Pertinent human and animal experiments applicable to space flight and to crash impact forces are analyzed and discussed. These data are compared and presented on the basis of a trapezoidal pulse. The effects of body restraint and of acceleration direction, onset rate, and plateau duration on the maximum tolerable and survivable rapidly applied accelerations are shown. Results of the survey indicate that adequate torso and extremity restraint is the primary variable in tolerance to rapidly applied accelerations. The harness, or restraint system, must be arranged to transmit the major portion of the accelerating force directly to the pelvic structure and not via the vertebral column. When the conditions of adequate restraint have been met, then the other variables, direction, magnitude, and onset rate of rapidly applied accelerations, govern maximum tolerance and injury limits. The results also indicate that adequately stressed aft-faced passenger seats offer maximum complete body support with minimum objectionable harnessing. Such a seat, whether designed for 20-, 30-, or 40-G dynamic loading, would include lap strap, chest (axillary) strap, and winged-back seat to increase headward and lateral G protection, full-height integral head rest, arm rests (load-bearing) with recessed hand-holds and provisions to prevent arms from slipping either laterally or beyond the seat back, and leg support to keep the legs from being wedged under the seat. For crew members and others whose duties require forward-facing seats, maximum complete body support requires lap, shoulder, and thigh straps, lap-belt tie-down strap, and full-height seat back with integral head support.

Aircraft Cabin Turbulence Warning Experiment

NASA Technical Reports Server (NTRS)

Bogue, Rodney K.; Larcher, Kenneth

2006-01-01

New turbulence prediction technology offers the potential for advance warning of impending turbulence encounters, thereby allowing necessary cabin preparation time prior to the encounter. The amount of time required for passengers and flight attendants to be securely seated (that is, seated with seat belts fastened) currently is not known. To determine secured seating-based warning times, a consortium of aircraft safety organizations have conducted an experiment involving a series of timed secured seating trials. This demonstrative experiment, conducted on October 1, 2, and 3, 2002, used a full-scale B-747 wide-body aircraft simulator, human passenger subjects, and supporting staff from six airlines. Active line-qualified flight attendants from three airlines participated in the trials. Definitive results have been obtained to provide secured seating-based warning times for the developers of turbulence warning technology

Multi-body dynamics modelling of seated human body under exposure to whole-body vibration.

PubMed

Yoshimura, Takuya; Nakai, Kazuma; Tamaoki, Gen

2005-07-01

In vehicle systems occupational drivers might expose themselves to vibration for a long time. This may cause illness of the spine such as chronic lumbago or low back pain. Therefore, it is necessary to evaluate the influence of vibration to the spinal column and to make up appropriate guidelines or counter plans. In ISO2631-1 or ISO2631-5 assessment of vibration effects to human in the view of adverse-health effect was already presented. However, it is necessary to carry out further research to understand the effect of vibration to human body to examine their validity and to prepare for the future revision. This paper shows the detail measurement of human response to vibration, and the modelling of the seated human body for the assessment of the vibration risk. The vibration transmissibilities from the seat surface to the spinal column and to the head are measured during the exposure to vertical excitation. The modal paramters of seated subject are extracted in order to understand the dominant natural modes. For the evaluation of adverse-health effect the multi-body modelling of the spinal column is introduced. A simplified model having 10 DOFs is counstructed so that the transmissibilities of the model fit to those of experiment. The transient response analysis is illustrated when a half-sine input is applied. The relative displacements of vertebrae are evaluated, which can be a basis for the assessment of vibration risk. It is suggested that the multi-body dynamic model is used to evaluate the vibration effect to the spinal column for seated subjects.

Survey of NASA research on crash dynamics

NASA Technical Reports Server (NTRS)

Thomson, R. G.; Carden, H. D.; Hayduk, R. J.

1984-01-01

Ten years of structural crash dynamics research activities conducted on general aviation aircraft by the National Aeronautics and Space Administration (NASA) are described. Thirty-two full-scale crash tests were performed at Langley Research Center, and pertinent data on airframe and seat behavior were obtained. Concurrent with the experimental program, analytical methods were developed to help predict structural behavior during impact. The effects of flight parameters at impact on cabin deceleration pulses at the seat/occupant interface, experimental and analytical correlation of data on load-limiting subfloor and seat configurations, airplane section test results for computer modeling validation, and data from emergency-locator-transmitter (ELT) investigations to determine probable cause of false alarms and nonactivations are assessed. Computer programs which provide designers with analytical methods for predicting accelerations, velocities, and displacements of collapsing structures are also discussed.

Quantifying the effects of on-the-fly changes of seating configuration on the stability of a manual wheelchair.

PubMed

Thomas, Louise; Borisoff, Jaimie; Sparrey, Carolyn J

2017-07-01

In general, manual wheelchairs are designed with a fixed frame, which is not optimal for every situation. Adjustable on the fly seating allow users to rapidly adapt their wheelchair configuration to suit different tasks. These changes move the center of gravity (CoG) of the system, altering the wheelchair stability and maneuverability. To assess these changes, a computer simulation of a manual wheelchair was created with adjustable seat, backrest, rear axle position and user position, and validated with experimental testing. The stability of the wheelchair was most affected by the position of the rear axle, but adjustments to the backrest and seat angles also result in stability improvements that could be used when wheeling in the community. These findings describe the most influential parameters for wheelchair stability and maneuverability, as well as provide quantitative guidelines for the use of manual wheelchairs with on the fly adjustable seats.

Measurement of whole-body human centers of gravity and moments of inertia.

PubMed

Albery, C B; Schultz, R B; Bjorn, V S

1998-06-01

With the inclusion of women in combat aircraft, the question of safe ejection seat operation has been raised. The potential expanded population of combat pilots would include both smaller and larger ejection seat occupants, which could significantly affect seat performance. The method developed to measure human whole-body CG and MOI used a scale, a knife edge balance, and an inverted torsional pendulum. Subjects' moments of inertia were measured along six different axes. The inertia tensor was calculated from these values, and principal moments of inertia were then derived. Thirty-eight antropometric measurements were also taken for each subject to provide a means for direct correlation of inertial properties to body dimensions and for modeling purposes. Data collected in this study has been used to validate whole-body mass properties predictions. In addition, data will be used to improve Air Force and Navy ejection seat trajectory models for the expanded population.

Crashworthy Seats Would Afford Superior Protection

NASA Technical Reports Server (NTRS)

Gohmert, Dustin

2009-01-01

Seats to prevent or limit crash injuries to astronauts aboard the crew vehicle of the Orion spacecraft are undergoing development. The design of these seats incorporates and goes beyond crash-protection concepts embodied in prior spacecraft and racing-car seats to afford superior protection against impacts. Although the seats are designed to support astronauts in a recumbent, quasi-fetal posture that would likely not be suitable for non-spacecraft applications, parts of the design could be adapted to military and some civilian aircraft seats and to racing car seats to increase levels of protection. The main problem in designing any crashworthy seat is to provide full support of the occupant against anticipated crash and emergency-landing loads so as to safely limit motion, along any axis, of any part of the occupant s body relative to (1) any other part of the occupant s body, (2) the spacecraft or other vehicle, and (3) the seat itself. In the original Orion spacecraft application and in other applications that could easily be envisioned, the problem is complicated by severe limits on space available for the seat, a requirement to enable rapid egress by the occupant after a crash, and a requirement to provide for fitting of the seat to a wide range of sizes and shapes of a human body covered by a crash suit, space suit, or other protective garment. The problem is further complicated by other Orion-application-specific requirements that must be omitted here for the sake of brevity. To accommodate the wide range of crewmember body lengths within the limits on available space in the original Orion application, the design provides for taller crewmembers to pull their legs back closer toward their chests, while shorter crewmembers can allow their legs to stretch out further. The range of hip-support seat adjustments needed to effect this accommodation, as derived from NASA s Human Systems Integration Standard, was found to define a parabolic path along which the knees must be positioned. For a given occupant, the specific position along the path depends on the distance from the heel to the back of the knee. The application of the concept of parabolic adjustment of the hip-support structure caused the seat pan to also take on a parabolic shape, yielding the unanticipated additional benefit that the seat pan fits the occupant s buttocks and thighs more nearly conformally than do seat pans of prior design. This more nearly conformal fit effectively eliminates a void between the occupant s body and the seat pan, thereby helping to prevent what, in prior seat designs, was shifting of the occupant s body into that void during an impact.

Comparison of simulator fidelity model predictions with in-simulator evaluation data

NASA Technical Reports Server (NTRS)

Parrish, R. V.; Mckissick, B. T.; Ashworth, B. R.

1983-01-01

A full factorial in simulator experiment of a single axis, multiloop, compensatory pitch tracking task is described. The experiment was conducted to provide data to validate extensions to an analytic, closed loop model of a real time digital simulation facility. The results of the experiment encompassing various simulation fidelity factors, such as visual delay, digital integration algorithms, computer iteration rates, control loading bandwidths and proprioceptive cues, and g-seat kinesthetic cues, are compared with predictions obtained from the analytic model incorporating an optimal control model of the human pilot. The in-simulator results demonstrate more sensitivity to the g-seat and to the control loader conditions than were predicted by the model. However, the model predictions are generally upheld, although the predicted magnitudes of the states and of the error terms are sometimes off considerably. Of particular concern is the large sensitivity difference for one control loader condition, as well as the model/in-simulator mismatch in the magnitude of the plant states when the other states match.

Impact of scaling and body movement on contaminant transport in airliner cabins

NASA Astrophysics Data System (ADS)

Mazumdar, Sagnik; Poussou, Stephane B.; Lin, Chao-Hsin; Isukapalli, Sastry S.; Plesniak, Michael W.; Chen, Qingyan

2011-10-01

Studies of contaminant transport have been conducted using small-scale models. This investigation used validated Computational Fluid Dynamics (CFD) to examine if a small-scale water model could reveal the same contaminant transport characteristics as a full-scale airliner cabin. But due to similarity problems and the difficulty of scaling the geometry, a perfect scale up from a small water model to an actual air model was found to be impossible. The study also found that the seats and passengers tended to obstruct the lateral transport of the contaminants and confine their spread to the aisle of the cabin. The movement of a crew member or a passenger could carry a contaminant in its wake to as many rows as the crew member or passenger passed. This could be the reason why a SARS infected passenger could infect fellow passengers who were seated seven rows away. To accurately simulate the contaminant transport, the shape of the moving body should be a human-like model.

A study of cervical spine kinematics and joint capsule strain in rear impacts using a human FE model.

PubMed

Kitagawa, Yuichi; Yasuki, Tsuyoshi; Hasegawa, Junji

2006-11-01

Many efforts have been made to understand the mechanism of whiplash injury. Recently, the cervical facet joint capsules have been focused on as a potential site of injury. An experimental approach has been taken to analyze the vertebral motion and to estimate joint capsule stretch that was thought to be a potential cause of pain. The purpose of this study is to analyze the kinematics of the cervical facet joint using a human FE model in order to better understand the injury mechanism. The Total Human Model for Safety (THUMS) was used to visually analyze the local and global kinematics of the spine. Soft tissues in the neck were newly modeled and introduced into THUMS for estimating the loading level in rear impacts. The model was first validated against human test data in the literature by comparing vertebrae motion as well as head and neck responses. Joint capsule strain was estimated from a maximum principal strain output from the elements representing the capsule tissues. A rear-end collision was then simulated using THUMS and a prototype seat model, assuming a delta-V of 25 km/h. The trajectory of the vertebrae was analyzed in a local coordinate system defined along the joint surface. Strain growth in the joint capsules was explained, as related to contact events between the occupant and the seat. A new seat concept was proposed to help lessen the loading level to the neck soft tissues. The foam material of the seat back was softened, the initial gap behind the head was reduced and the head restraint was stiffened for firm support. The lower seat back frame was also reinforced to withstand the impact severity at the given delta-V. Another rear impact simulation was conducted using the new seat concept model to examine the effectiveness of the new concept. The joint capsule strain was found to be relatively lower with the new seat concept. The study also discusses the influence of seat parameters to the vertebral motion and the resultant strain in the joint capsules. The meaning of the contact timing of the head to the head restraint was examined based on the results in terms of correlation with injury indicators such as NIC and the joint capsule strain.

Development of Accomodation Models for Soldiers in Vehicles: Driver

DTIC Science & Technology

2014-09-01

human needs and performance. A small section of this standard addresses the design of vehicle seats and the layout of the driver workstation...drivers and passengers (squad). The study was designed to focus on tactical vehicle (truck) designs with fixed driver heel points and H30 values...fore-aft and vertically, along with adjusting the seat back angle, to obtain a comfortable driving position. The Soldier’s posture and seat adjustments

Dynamic Characteristics and Human Perception of Vibration Aboard a Military Propeller Aircraft

DTIC Science & Technology

2007-09-01

a significant reduction in the X-axis seat pan vibration as compared to the original operational seat cushion at the blade passage frequency ( BPF ...system characteristics at higher frequencies. A body region perception survey suggested that the subjects were most sensitive to the BPF component of...perception of the exposure. Current human exposure guidelines may not optimally reflect these relationships for assessing higher frequency propeller

Establishing the Biodynamics Data Resource (BDR): Human Volunteer Impact Acceleration Research Data in the BDR

DTIC Science & Technology

2009-10-01

accelerations (+Z) were applied to HRVs in the supine position to mimic the acceleration of an ejection seat , while runs simulating aircraft crashes were...Naval Biodynamics Laboratory, 1985). The vertical testing provided a more authentic ejection seat simulation than was achievable using axial...impact acceleration exposures with hundreds of human research volunteers. The resulting volumes of kinematic and physiological data serve as a

Evaluation of the influence of velocity on dynamic passenger loads during a frontal minibus impact against an obstacle

NASA Astrophysics Data System (ADS)

Prochowski, L.; Dębowski, A.; Żuchowski, A.; Zielonka, K.

2016-09-01

The safety of people travelling by minibus is a very complex issue, in which the decisive role is played by load-bearing vehicle structure, passenger seats, and personal protection means. In order to maximize the number of people transported, the seats are spaced very closely to each other and this may pose a hazard to the passengers. Based on an analysis of experimental test results, a computer model representing a system composed of a minibus floor segment, seats, and dummies was built. For the analysis, seats integrated with seat belts were adopted. A seat of this type was based on a high-rigidity frame necessary to bear, inter alia, the strong force exerted (during a collision) by passenger's torso on the shoulder seat belt and transmitted to the upper seat belt anchorage point on the seat backrest. Within this work, the frontal minibus impact against an obstacle with velocities ranging from 20 km/h to 70 km/h was considered. The analysis covered the motion of, and dynamic loads on, a test dummy representing a 50th percentile adult male (Hybrid III dummy). Within the analysis, realizations of dynamic loads caused by inertial forces and reactions exerted by a three-point seat belt were taken into account. Special attention was paid to the extreme values of the loads that acted on dummy's head, neck, and torso when the head hit the backrest of the preceding seat in the culminating phase of the vehicle impact against an obstacle. The values of biomechanical indicators HIC, ThAC, Nij , and FAC and of the joint injury risk indicator were calculated.

Energy-absorbing car seat designs for reducing whiplash.

PubMed

Himmetoglu, S; Acar, M; Bouazza-Marouf, K; Taylor, A J

2008-12-01

This study presents an investigation of anti-whiplash features that can be implemented in a car seat to reduce whiplash injuries in the case of a rear impact. The main emphasis is on achieving a seat design with good energy absorption properties. A biofidelic 50th percentile male multi-body human model for rear impact is developed to evaluate the performance of car seat design concepts. The model is validated using the responses of 7 volunteers from the Japanese Automobile Research Institute (JARI) sled tests, which were performed at an impact speed of 8 kph with a rigid seat and without head restraint and seatbelt. A generic multi-body car seat model is also developed to implement various seatback and recliner properties, anti-whiplash devices, and head restraints. Using the same driving posture and the rigid seat in the JARI sled tests as the basic configuration, several anti-whiplash seats are designed to allow different types of motion for the seatback and seat-pan. The anti-whiplash car seat design concepts limit neck internal motion successfully until the head-to-head restraint contact occurs and they exhibit low NIC(max) values (7 m(2)/s(2) on average). They are also effective in reducing neck compression forces and T1 forward accelerations. In principle, these car seat design concepts employ controlled recliner rotation and seat-pan displacement to limit the formation of S-shape. This is accomplished by using anti-whiplash devices that absorb the crash energy in such a way that an optimum protection is provided at different severities. The results indicate that the energy absorbing car seat design concepts all demonstrate good whiplash-reducing performances at the IIWPG standard pulse. Especially in higher severity rear impacts, two of the car seat design concepts reduce the ramping of the occupant considerably.

Biomechanical considerations for assessing interactions of children and small occupants with inflatable seat belts.

PubMed

Rouhana, Stephen W; Sundararajan, Srinivasan; Board, Derek; Prasad, Priya; Rupp, Jonathan D; Miller, Carl S; Jeffreys, Thomas A; Schneider, Lawrence W

2013-11-01

NHTSA estimates that more than half of the lives saved (168,524) in car crashes between 1960 and 2002 were due to the use of seat belts. Nevertheless, while seat belts are vital to occupant crash protection, safety researchers continue efforts to further enhance the capability of seat belts in reducing injury and fatality risk in automotive crashes. Examples of seat belt design concepts that have been investigated by researchers include inflatable, 4-point, and reverse geometry seat belts. In 2011, Ford Motor Company introduced the first rear seat inflatable seat belts into production vehicles. A series of tests with child and small female-sized Anthropomorphic Test Devices (ATD) and small, elderly female Post Mortem Human Subjects (PMHS) was performed to evaluate interactions of prototype inflatable seat belts with the chest, upper torso, head and neck of children and small occupants, from infants to young adolescents. Tests simulating a 6-year-old child asleep in a booster seat, with its head lying directly on its shoulder on top of the inflatable seat belt, were considered by engineering judgment, to represent a worst case scenario for interaction of an inflating seat belt with the head and neck of a child and/or small occupant. All evaluations resulted in ATD responses below Injury Assessment Reference Values reported by Mertz et al. (2003). In addition, the tests of the PMHS subjects resulted in no injuries from interaction of the inflating seat belt with the heads, necks, and chests of the subjects. Given the results from the ATD and PMHS tests, it was concluded that the injury risk to children and small occupants from deployment of inflatable seat belt systems is low.

SPREADSHEET-BASED PROGRAM FOR ERGONOMIC ADJUSTMENT OF NOTEBOOK COMPUTER AND WORKSTATION SETTINGS.

PubMed

Nanthavanij, Suebsak; Prae-Arporn, Kanlayanee; Chanjirawittaya, Sorajak; Paripoonyo, Satirajit; Rodloy, Somsak

2015-06-01

This paper discusses a computer program, ErgoNBC, which provides suggestions regarding the ergonomic settings of a notebook computer (NBC), workstation components, and selected accessories in order to help computer users to assume an appropriate work posture during the NBC work. From the users' body height, NBC and workstation component data, ErgoNBC computes the recommended tilt angle of NBC base unit, NBC screen angle, distance between the user and NBC, seat height and work surface height. If necessary, the NBC base support, seat cushion and footrest, including their settings, are recommended. An experiment involving twenty-four university students was conducted to evaluate the recommendations provided by ErgoNBC. The Rapid Upper Limb Assessment (RULA) technique was used to analyze their work postures both before and after implementing the Ergo NBC's recommendations. The results clearly showed that ErgoNBC could significantly help to improve the subjects' work postures.

Energy absorption of seated occupants exposed to horizontal vibration and role of back support condition.

PubMed

Rakheja, Subhash; Mandapuram, Santosh; Dong, Ren G

2008-12-01

Absorbed power characteristics of seated human subjects under fore-aft (x-axis) and lateral (y-axis) vibration are investigated through measurements of dynamic interactions at the two driving-points formed by the body and the seat pan, and upper body and the backrest. The experiments involved: (i) three back support conditions (no back support, and back supported against a vertical and an inclined backrest); (ii) three seat pan heights (425, 390 and 350 mm); and three magnitudes (0.25, 0.5 and 1.0 m/s2 rms acceleration) of band limited random excitations in 0.5-10 Hz frequency range, applied independently along the x- and y- axes. The force responses, measured at the seat pan and the backrest are applied to characterize total energy transfer reflected on the seat pan and the backrest. The mean responses suggest strong contributions due to back support, and direction and magnitude of vibration. In the absence of a back support, the seat pan responses dominated in lower frequency bands centered at 0.63 and 1.25 Hz under both directions of motion. Most significant interactions of the upper body against the back support was observed under fore-aft vibration. The addition of back support caused the seat pan response to converge to a single primary peak near a higher frequency of 4 Hz under x- axis, with only little effect on the y-axis responses. The back support serves as an additional source of vibration to the occupant and an important constraint to limit the fore-aft movement of the upper body and thus relatively higher energy transfer under. The mean responses were further explored to examine the Wd frequency-weighting used for assessing exposure to horizontal vibration. The results show that the current weighting is suited for assessing the vibration exposure of human subjects seated only without a back support.

Modeling 3-D Slope Stability of Coastal Bluffs Using 3-D Ground-Water Flow, Southwestern Seattle, Washington

USGS Publications Warehouse

Brien, Dianne L.; Reid, Mark E.

2007-01-01

Landslides are a common problem on coastal bluffs throughout the world. Along the coastal bluffs of the Puget Sound in Seattle, Washington, landslides range from small, shallow failures to large, deep-seated landslides. Landslides of all types can pose hazards to human lives and property, but deep-seated landslides are of significant concern because their large areal extent can cause extensive property damage. Although many geomorphic processes shape the coastal bluffs of Seattle, we focus on large (greater than 3,000 m3), deepseated, rotational landslides that occur on the steep bluffs along Puget Sound. Many of these larger failures occur in advance outwash deposits of the Vashon Drift (Qva); some failures extend into the underlying Lawton Clay Member of the Vashon Drift (Qvlc). The slope stability of coastal bluffs is controlled by the interplay of three-dimensional (3-D) variations in gravitational stress, strength, and pore-water pressure. We assess 3-D slope-stability using SCOOPS (Reid and others, 2000), a computer program that allows us to search a high-resolution digital-elevation model (DEM) to quantify the relative stability of all parts of the landscape by computing the stability and volume of thousands of potential spherical failures. SCOOPS incorporates topography, 3-D strength variations, and 3-D pore pressures. Initially, we use our 3-D analysis methods to examine the effects of topography and geology by using heterogeneous material properties, as defined by stratigraphy, without pore pressures. In this scenario, the least-stable areas are located on the steepest slopes, commonly in Qva or Qvlc. However, these locations do not agree well with observations of deep-seated landslides. Historically, both shallow colluvial landslides and deep-seated landslides have been observed near the contact between Qva and Qvlc, and commonly occur in Qva. The low hydraulic conductivity of Qvlc impedes ground-water flow, resulting in elevated pore pressures at the base of Qva, thereby increasing the potential for landslides. Our analysis simulates the ground-water flow using the results of a 3-D ground-water flow model, MODFLOW-2000 (Harbaugh and others, 2000), to generate a 3-D pore-pressure field. Areas of elevated pore pressure reflect the influence of a perched ground-water table in Qva, as well as ground-water convergence in the coastal re-entrants. We obtain a realistic model of deep-seated landsliding by combining 3-D pore pressures with heterogeneous strength properties. The results show the least-stable areas where pore pressures are locally elevated in Qva. We compare our results with records of past landslides. The predicted leaststable areas include two historically active deep-seated landslides and areas adjacent to these landslides.

Application of ideal pressure distribution in development process of automobile seats.

PubMed

Kilincsoy, U; Wagner, A; Vink, P; Bubb, H

2016-07-19

In designing a car seat the ideal pressure distribution is important as it is the largest contact surface between the human and the car. Because of obstacles hindering a more general application of the ideal pressure distribution in seating design, multidimensional measuring techniques are necessary with extensive user tests. The objective of this study is to apply and integrate the knowledge about the ideal pressure distribution in the seat design process for a car manufacturer in an efficient way. Ideal pressure distribution was combined with pressure measurement, in this case pressure mats. In order to integrate this theoretical knowledge of seating comfort in the seat development process for a car manufacturer a special user interface was defined and developed. The mapping of the measured pressure distribution in real-time and accurately scaled to actual seats during test setups directly lead to design implications for seat design even during the test situation. Detailed analysis of the subject's feedback was correlated with objective measurements of the subject's pressure distribution in real time. Therefore existing seating characteristics were taken into account as well. A user interface can incorporate theoretical and validated 'state of the art' models of comfort. Consequently, this information can reduce extensive testing and lead to more detailed results in a shorter time period.

Reference PMHS Sled Tests to Assess Submarining.

PubMed

Uriot, Jérôme; Potier, Pascal; Baudrit, Pascal; Trosseille, Xavier; Petit, Philippe; Richard, Olivier; Compigne, Sabine; Masuda, Mitsutoshi; Douard, Richard

2015-11-01

Sled tests focused on pelvis behavior and submarining can be found in the literature. However, they were performed either with rigid seats or with commercial seats. The objective of this study was to get reference tests to assess the submarining ability of dummies in more realistic conditions than on rigid seat, but still in a repeatable and reproducible setup. For this purpose, a semi-rigid seat was developed, which mimics the behavior of real seats, although it is made of rigid plates and springs that are easy to reproduce and simulate with an FE model. In total, eight PMHS sled tests were performed on this semirigid seat to get data in two different configurations: first in a front seat configuration that was designed to prevent submarining, then in a rear seat configuration with adjusted spring stiffness to generate submarining. All subjects sustained extensive rib fractures from the shoulder belt loading. No pelvis fractures and no submarining were observed in the front seat configuration, but two subjects sustained lumbar vertebrae fractures. In the rear seat configuration, all subjects sustained pelvic fractures and demonstrated submarining. Corridors were constructed for the external forces and the PMHS kinematics. They are provided in this paper as new reference tests to assess the biofidelity of human surrogates in different configurations that either result in submarining or do not. In future, it is intended to analyze further seat and restraint system configurations to be able to define a submarining predictor.

Strategies to increase the use of child safety seats : an assessment of current knowledge

DOT National Transportation Integrated Search

1986-12-01

This analytic literature research reports on characteristics of child-safety-seat (CSS) users and nonusers, and on the efficacy of approaches to increasing CSS use. It concentrates on human factors issues in CSS use, excluding technical studies on de...

Effect of Standing or Walking at a Workstation on Cognitive Function: A Randomized Counterbalanced Trial.

PubMed

Bantoft, Christina; Summers, Mathew J; Tranent, Peter J; Palmer, Matthew A; Cooley, P Dean; Pedersen, Scott J

2016-02-01

In the present study, we examined the effect of working while seated, while standing, or while walking on measures of short-term memory, working memory, selective and sustained attention, and information-processing speed. The advent of computer-based technology has revolutionized the adult workplace, such that average adult full-time employees spend the majority of their working day seated. Prolonged sitting is associated with increasing obesity and chronic health conditions in children and adults. One possible intervention to reduce the negative health impacts of the modern office environment involves modifying the workplace to increase incidental activity and exercise during the workday. Although modifications, such as sit-stand desks, have been shown to improve physiological function, there is mixed information regarding the impact of such office modification on individual cognitive performance and thereby the efficiency of the work environment. In a fully counterbalanced randomized control trial, we assessed the cognitive performance of 45 undergraduate students for up to a 1-hr period in each condition. The results indicate that there is no significant change in the measures used to assess cognitive performance associated with working while seated, while standing, or while walking at low intensity. These results indicate that cognitive performance is not degraded with short-term use of alternate workstations. © 2015, Human Factors and Ergonomics Society.

The transmission of vertical vibration through seats: Influence of the characteristics of the human body

NASA Astrophysics Data System (ADS)

Toward, Martin G. R.; Griffin, Michael J.

2011-12-01

The transmission of vibration through a seat depends on the impedance of the seat and the apparent mass of the seat occupant. This study was designed to determine how factors affecting the apparent mass of the body (age, gender, physical characteristics, backrest contact, and magnitude of vibration) affect seat transmissibility. The transmission of vertical vibration through a car seat was measured with 80 adults (41 males and 39 females aged 18-65) at frequencies between 0.6 and 20 Hz with two backrest conditions (no backrest and backrest), and with three magnitudes of random vibration (0.5, 1.0, and 1.5 m s -2 rms). Linear regression models were used to study the effects of subject physical characteristics (age, gender, and anthropometry) and features of their apparent mass (resonance frequency, apparent mass at resonance and at 12 Hz) on the measured seat transmissibility. The strongest predictor of both the frequency of the principal resonance in seat transmissibility and the seat transmissibility at resonance was subject age, with other factors having only marginal effects. The transmissibility of the seat at 12 Hz depended on subject age, body mass index, and gender. Although subject weight was strongly associated with apparent mass, weight was not strongly associated with seat transmissibility. The resonance frequency of the seat decreased with increases in the magnitude of the vibration excitation and increased when subjects made contact with the backrest. Inter-subject variability in the resonance frequency and transmissibility at resonance was less with greater vibration excitation, but was largely unaffected by backrest contact. A lumped parameter seat-person model showed that changes in seat transmissibility with age can be predicted from changes in apparent mass with age, and that the dynamic stiffness of the seat appeared to increase with increased loading so as to compensate for increases in subject apparent mass associated with increased sitting weight.

Thermal comfort of seats as visualized by infrared thermography.

PubMed

Sales, Rosemary Bom Conselho; Pereira, Romeu Rodrigues; Aguilar, Maria Teresa Paulino; Cardoso, Antônio Valadão

2017-07-01

Published studies that deal with the question of how the temperature of chair seats influences human activities are few, but the studies considering such a factor, a function of the type of material, could contribute to improvements in the design of chairs. This study evaluates seat temperatures of 8 types of chairs made of different materials. The parts of the furniture that people come into contact with, and the thermal response of the material to heating and cooling have been evaluated. Infrared thermography was used for this, as it is a non-contact technique that does not present any type of risk in the measurement of temperatures. Seats made of synthetic leather (leatherette), wood and polyester fabric were found to have the highest temperatures, and the plywood seat showed the lowest. The study has also revealed that thermography can contribute to studies of thermal comfort of chair seats in addition to determining the most suitable material. Copyright © 2017 Elsevier Ltd. All rights reserved.

A prospective study for the detection of vascular injury in adult and pediatric patients with cervicothoracic seat belt signs.

PubMed

Rozycki, Grace S; Tremblay, Lorraine; Feliciano, David V; Tchorz, Kathryn; Hattaway, Aaron; Fountain, Jack; Pettitt, Barbara J

2002-04-01

A delayed diagnosis of injury to cervicothoracic vessels from blunt trauma may cause significant adverse sequelae. The association of a cervicothoracic seat belt sign with such an injury is unknown. Algorithms were prospectively studied for the detection of occult vascular injury in patients with cervicothoracic seat belt signs. Patients with neck seat belt signs underwent arteriography or computed tomographic angiography (CTA). Those with thoracic seat belt signs underwent aortography/arteriography if a ruptured thoracic aorta or injury to a great vessel was suspected or a neurovascular abnormality was present. During a 17-month period, 797 patients were admitted to the trauma service secondary to motor vehicle crashes. One hundred thirty-one (16.4%) had cervical or thoracic seat belt signs. Four (3%) of the patients had carotid artery injuries, the presence of which was strongly associated with a Glasgow Coma Scale score < 14, an Injury Severity Score > 16 (p < 0.0001), and the presence of a clavicle and/or first rib fracture (p < 0.0037). Of the remaining patients, 17 had thoracic trauma. There were no vascular injuries in the children and only one had thoracic trauma. The algorithms are safe and accurate for the detection of cervicothoracic vascular injury in adult and pediatric patients with seat belt signs. The cervicothoracic seat belt mark and an abnormal physical examination are an effective combination in screening for cervicothoracic vascular injury.

Power absorbed during whole-body vertical vibration: Effects of sitting posture, backrest, and footrest

NASA Astrophysics Data System (ADS)

Nawayseh, Naser; Griffin, Michael J.

2010-07-01

Previous studies have quantified the power absorbed in the seated human body during exposure to vibration but have not investigated the effects of body posture or the power absorbed at the back and the feet. This study investigated the effects of support for the feet and back and the magnitude of vibration on the power absorbed during whole-body vertical vibration. Twelve subjects were exposed to four magnitudes (0.125, 0.25, 0.625, and 1.25 m s -2 rms) of random vertical vibration (0.25-20 Hz) while sitting on a rigid seat in four postures (feet hanging, maximum thigh contact, average thigh contact, and minimum thigh contact) both with and without a rigid vertical backrest. Force and acceleration were measured at the seat, the feet, and the backrest to calculate the power absorbed at these three locations. At all three interfaces (seat, feet, and back) the absorbed power increased in proportion to the square of the magnitude of vibration, with most power absorbed from vibration at the seat. Supporting the back with the backrest decreased the power absorbed at the seat at low frequencies but increased the power absorbed at high frequencies. Supporting the feet with the footrest reduced the total absorbed power at the seat, with greater reductions with higher footrests. It is concluded that contact between the thighs and the seat increases the power absorbed at the seat whereas a backrest can either increase or decrease the power absorbed at the seat.

Towards a truly mobile auditory brain-computer interface: exploring the P300 to take away.

PubMed

De Vos, Maarten; Gandras, Katharina; Debener, Stefan

2014-01-01

In a previous study we presented a low-cost, small, and wireless 14-channel EEG system suitable for field recordings (Debener et al., 2012, psychophysiology). In the present follow-up study we investigated whether a single-trial P300 response can be reliably measured with this system, while subjects freely walk outdoors. Twenty healthy participants performed a three-class auditory oddball task, which included rare target and non-target distractor stimuli presented with equal probabilities of 16%. Data were recorded in a seated (control condition) and in a walking condition, both of which were realized outdoors. A significantly larger P300 event-related potential amplitude was evident for targets compared to distractors (p<.001), but no significant interaction with recording condition emerged. P300 single-trial analysis was performed with regularized stepwise linear discriminant analysis and revealed above chance-level classification accuracies for most participants (19 out of 20 for the seated, 16 out of 20 for the walking condition), with mean classification accuracies of 71% (seated) and 64% (walking). Moreover, the resulting information transfer rates for the seated and walking conditions were comparable to a recently published laboratory auditory brain-computer interface (BCI) study. This leads us to conclude that a truly mobile auditory BCI system is feasible. © 2013.

Dynamic forces over the interface between a seated human body and a rigid seat during vertical whole-body vibration.

PubMed

Liu, Chi; Qiu, Yi; Griffin, Michael J

2017-08-16

Biodynamic responses of the seated human body are usually measured and modelled assuming a single point of vibration excitation. With vertical vibration excitation, this study investigated how forces are distributed over the body-seat interface. Vertical and fore-and-aft forces were measured beneath the ischial tuberosities, middle thighs, and front thighs of 14 subjects sitting on a rigid flat seat in three postures with different thigh contact while exposed to random vertical vibration at three magnitudes. Measures of apparent mass were calculated from transfer functions between the vertical acceleration of the seat and the vertical or fore-and-aft forces measured at the three locations, and the sum of these forces. When sitting normally or sitting with a high footrest, vertical forces at the ischial tuberosities dominated the vertical apparent mass. With feet unsupported to give increased thigh contact, vertical forces at the front thighs were dominant around 8Hz. Around 3-7Hz, fore-and-aft forces at the middle thighs dominated the fore-and-aft cross-axis apparent mass. Around 8-10Hz, fore-and-aft forces were dominant at the ischial tuberosities with feet supported but at the front thighs with feet unsupported. All apparent masses were nonlinear: as the vibration magnitude increased the resonance frequencies decreased. With feet unsupported, the nonlinearity in the apparent mass was greater at the front thighs than at the ischial tuberosities. It is concluded that when the thighs are supported on a seat it is not appropriate to assume the body has a single point of vibration excitation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Reliability of assessing postural control during seated balancing using a physical human-robot interaction.

PubMed

Ramadan, Ahmed; Cholewicki, Jacek; Radcliffe, Clark J; Popovich, John M; Reeves, N Peter; Choi, Jongeun

2017-11-07

This study evaluated the within- and between-visit reliability of a seated balance test for quantifying trunk motor control using input-output data. Thirty healthy subjects performed a seated balance test under three conditions: eyes open (EO), eyes closed (EC), and eyes closed with vibration to the lumbar muscles (VIB). Each subject performed three trials of each condition on three different visits. The seated balance test utilized a torque-controlled robotic seat, which together with a sitting subject resulted in a physical human-robot interaction (pHRI) (two degrees-of-freedom with upper and lower body rotations). Subjects balanced the pHRI by controlling trunk rotation in response to pseudorandom torque perturbations applied to the seat in the coronal plane. Performance error was expressed as the root mean square (RMSE) of deviations from the upright position in the time domain and as the mean bandpass signal energy (E mb ) in the frequency domain. Intra-class correlation coefficients (ICC) quantified the between-visit reliability of both RMSE and E mb . The empirical transfer function estimates (ETFE) from the perturbation input to each of the two rotational outputs were calculated. Coefficients of multiple correlation (CMC) quantified the within- and between-visit reliability of the averaged ETFE. ICCs of RMSE and E mb for all conditions were ≥0.84. The mean within- and between-visit CMCs were all ≥0.96 for the lower body rotation and ≥0.89 for the upper body rotation. Therefore, our seated balance test consisting of pHRI to assess coronal plane trunk motor control is reliable. Copyright © 2017 Elsevier Ltd. All rights reserved.

Apparent mass of the human body in the vertical direction: Effect of a footrest and a steering wheel

NASA Astrophysics Data System (ADS)

Toward, M. G. R.; Griffin, M. J.

2010-04-01

The apparent mass of the seated human body influences the vibration transmitted through a car seat. The apparent mass of the body is known to be influenced by sitting posture but the influence of the position of the hands and the feet is not well understood. This study was designed to quantify the influence of steering wheel location and the position of a footrest on the vertical apparent mass of the human body. The influences of the forces applied by the hands to a steering wheel and by the feet to a footrest were also investigated. Twelve subjects were exposed to whole-body vertical random vibration (1.0 m s -2 rms over the frequency range 0.13-40.0 Hz) while supported by a rigid seat with a backrest reclined to 15°. The apparent mass of the body was measured with five horizontal positions and three vertical positions of a steering wheel and also with hands in the lap, and with five horizontal positions of a footrest. The influence of five forward forces (0, 50, 100, 150, 200 N) applied separately to the 'steering wheel' and the footrest were also investigated as well as a 'no backrest' condition. With their hands in their laps, subjects exhibited a resonance around 6.7 Hz, compared to 4.8 Hz when sitting upright with no backrest. In the same posture holding a steering wheel, the mass supported on the seat surface decreased and there was an additional resonance at 4 Hz. Moving the steering wheel away from the body reduced the apparent mass at the primary resonance frequency and increased the apparent mass around the 4 Hz resonance. As the feet moved forward, the mass supported on the seat surface decreased, indicating that the backrest and footrest supported a greater proportion of the subject weight. Applying force to either the steering wheel or the footrest reduced the apparent mass at resonance and decreased the mass supported on the seat surface. It is concluded that the positions and contact conditions of the hands and the feet affect the biodynamic response of the body in a car driving posture. As the biodynamic response influences the vibration transmitted through seats, these factors should be considered in dynamic models of vehicle seating.

EVALUATING EXTREMELY LOW FREQUENCY MAGNETIC FIELDS IN THE REAR SEATS OF THE ELECTRIC VEHICLES.

PubMed

Lin, Jun; Lu, Meng; Wu, Tong; Yang, Lei; Wu, Tongning

2018-03-23

In the electric vehicles (EVs), children can sit on a safety seat installed in the rear seats. Owing to their smaller physical dimensions, their heads, generally, are closer to the underfloor electrical systems where the magnetic field (MF) exposure is the greatest. In this study, the magnetic flux density (B) was measured in the rear seats of 10 different EVs, for different driving sessions. We used the measurement results from different heights corresponding to the locations of the heads of an adult and an infant to calculate the induced electric field (E-field) strength using anatomical human models. The results revealed that measured B fields in the rear seats were far below the reference levels by the International Commission on Non-Ionizing Radiation Protection. Although small children may be exposed to higher MF strength, induced E-field strengths were much lower than that of adults due to their particular physical dimensions.

Modeling the Impact of Space Suit Components and Anthropometry on the Center of Mass of a Seated Crewmember

NASA Technical Reports Server (NTRS)

Rajulu, Sudhakar; Blackledge, Christopher; Ferrer, Mike; Margerum, Sarah

2009-01-01

The designers of the Orion Crew Exploration Vehicle (CEV) utilize an intensive simulation program in order to predict the launch and landing characteristics of the Crew Impact Attenuation System (CIAS). The CIAS is the energy absorbing strut concept that dampens loads to levels sustainable by the crew during landing and consists of the crew module seat pallet that accommodates four to six seated astronauts. An important parameter required for proper dynamic modeling of the CIAS is knowledge of the suited center of mass (COM) variations within the crew population. Significant center of mass variations across suited crew configurations would amplify the inertial effects of the pallet and potentially create unacceptable crew loading during launch and landing. Established suited, whole-body, and posture-based mass properties were not available due to the uncertainty of the final CEV seat posture and suit hardware configurations. While unsuited segmental center of mass values can be obtained via regression equations from previous studies, building them into a model that was posture dependent with custom anthropometry and integrated suit components proved cumbersome and time consuming. Therefore, the objective of this study was to quantify the effects of posture, suit components, and the expected range of anthropometry on the center of mass of a seated individual. Several elements are required for the COM calculation of a suited human in a seated position: anthropometry; body segment mass; suit component mass; suit component location relative to the body; and joint angles defining the seated posture. Anthropometry and body segment masses used in this study were taken from a selection of three-dimensional human body models, called boundary manikins, which were developed in a previous project. These boundary manikins represent the critical anthropometric dimension extremes for the anticipated astronaut population. Six male manikins and 6 female manikins, representing a subset of the possible maximum and minimum sized crewmembers, were segmented using point-cloud software to create 17 major body segments. The general approach used to calculate the human mass properties was to utilize center of volume outputs from the software for each body segment and apply a homogeneous density function to determine segment mass 3-D coordinates. Suit components, based on the current consensus regarding predicted suit configuration values, were treated as point masses and were positioned using vector mathematics along the body segments based on anthropometry and COM position. A custom MATLAB script then articulates the body segment and suit positions into a selected seated configuration, using joint angles that characterize a standard seated position and a CEV specific seated position. Additional MATLAB(r) scripts are finally used to calculate the composite COM positions in 3-D space for all 12 manikins in both suited and unsuited conditions for both seated configurations. The analysis focused on two aspects: (1) to quantify how much the whole body COM varied from the smallest to largest subject and (2) the impacts of the suit components on the overall COM in each seat configuration. The location across all boundary manikins of the anterior- posterior COM varied by approximately 7cm, the vertical COM varied by approximately 9-10cm, and the mediolateral COM varied by approximately 1.2 cm from the midline sagittal plane for both seat configurations. This variation was surprisingly large given the relative proportionality of the mass distribution of the human body. The suit components caused an anterior shift of the total COM by approximately 2 cm and a shift to the right along the mediolateral axis of 0.4 cm for both seat configurations. When the seat configuration is in the standard posture, the suited vertical COM shifts inferiorly by up to 1 cm whereas in the CEV posture the vertical COM has no appreciable change. These general differences were due the high proportion of suit mass located in the boots and lower legs and their corresponding distance from the body COM as well as the prevalence of suit components on the right side of the body.

Seatbelt and seatback control for occupant protection in frontal automotive collisions

NASA Astrophysics Data System (ADS)

Mott, Michael; Sun, Zhen; Rajamani, Rajesh

2013-10-01

This paper investigates the potential benefits of an imminent collision prediction system for improving occupant protection in a frontal automotive crash. Knowledge of an impending unavoidable crash is assumed to be known 100 ms before the crash occurs. A three dof human occupant model is developed using a Lagrangian approach to represent occupant translation with respect to seat, torso rotation and neck rotation. The performance of traditional elastic seat belts is compared with that of an analytically calculated seat belt law in which the force values are calculated in real-time so as to just prevent collision with car interior. Simulations verify that the analytical seat belt force calculation results in less force on occupant for the same level of safety. Furthermore, results show that knowledge of a future collision can be used to pre-tension seat belts but can provide no additional benefits, if seat belts are the only means for active occupant protection. However, if seat tilt-back can be deployed using an on-off mechanism, such predictive knowledge of a future collision can provide significantly improved occupant protection in terms of preventing occupant collision with car interior.

Biomechanics of 4-point seat belt systems in frontal impacts.

PubMed

Rouhana, Stephen W; Bedewi, Paul G; Kankanala, Sundeep V; Prasad, Priya; Zwolinski, Joseph J; Meduvsky, Alex G; Rupp, Jonathan D; Jeffreys, Thomas A; Schneider, Lawrence W

2003-01-01

The biomechanical behavior of 4-point seat belt systems was investigated through MADYMO modeling, dummy tests and post mortem human subject tests. This study was conducted to assess the effect of 4-point seat belts on the risk of thoracic injury in frontal impacts, to evaluate the ability to prevent submarining under the lap belt using 4-point seat belts, and to examine whether 4-point belts may induce injuries not typically observed with 3-point seat belts. The performance of two types of 4-point seat belts was compared with that of a pretensioned, load-limited, 3-point seat belt. A 3-point belt with an extra shoulder belt that "crisscrossed" the chest (X4) appeared to add constraint to the torso and increased chest deflection and injury risk. Harness style shoulder belts (V4) loaded the body in a different biomechanical manner than 3-point and X4 belts. The V4 belt appeared to shift load to the clavicles and pelvis and to reduce traction of the shoulder belt across the chest, resulting in a reduction in chest deflection by a factor of two. This is associated with a 5 to 500-fold reduction in thoracic injury risk, depending on whether one assumes 4-point belts apply concentrated or distributed load. In four of six post mortem human subjects restrained by V4 belts during 40 km/h sled tests, chest compression was zero or negative and rib fractures were nearly eliminated. Submarining was not observed in any test with post mortem human subjects. Though lumbar, sacral and pelvic injuries were noted, they are believed to be due to the artificial restraint environment (no knee bolsters, instrument panels, steering systems or airbags). While they show significant potential to reduce thoracic injury risk, there are still many issues to be resolved before 4-point belts can be considered for production vehicles. These issues include, among others, potential effects on hard and soft neck tissues, of interaction with inboard shoulder belts in farside impacts and potential effects on the fetus of latch/buckle junctions at the centerline of pregnant occupants. Work continues at Ford Motor Company to resolve these issues.

Application of a bus seat buffer to mitigate frontal crash effects

NASA Astrophysics Data System (ADS)

Stanisławek, Sebastian; Dziewulski, Paweł; Sławiński, Grzegorz

2018-01-01

The paper considers the problem of coach occupant safety during crash events. The authors present a simple low-cost seat buffer concept which may mitigate the effects of frontal impact. The method of computer simulation was chosen to solve the problem efficiently. The Finite Element Method (FEM) implemented in the LS-DYNA commercial code was used. The testing procedure was based on European Commission regulations, under which vehicles move at a defined speed. Simulations have shown that seat occupants suffer serious trauma during a crash, with the head experiencing relatively high acceleration, thus resulting in an HIC36 of 1490. The installation of a protective buffer mounted on the upper part of the seat reduced the HIC36 to only 510. However, in its current form it does not meet the requirements of the regulations. Further modifications to the overlay shape and structure are essential in order to better improve the deceleration of passengers' bodies. Moreover, a detailed model of seats and their anchorage should be taken into account. A more flexible structure should provide more positive and more accurate results.

Impact Testing and Simulation of a Crashworthy Composite Fuselage Section with Energy-Absorbing Seats and Dummies

NASA Technical Reports Server (NTRS)

Fasanella, Edwin L.; Jackson, Karen E.

2002-01-01

A 25-ft/s vertical drop test of a composite fuselage section was conducted with two energy-absorbing seats occupied by anthropomorphic dummies to evaluate the crashworthy features of the fuselage section and to determine its interaction with the seats and dummies. The 5-ft. diameter fuselage section consists of a stiff structural floor and an energy-absorbing subfloor constructed of Rohacel foam blocks. The experimental data from this test were analyzed and correlated with predictions from a crash simulation developed using the nonlinear, explicit transient dynamic computer code, MSC.Dytran. The anthropomorphic dummies were simulated using the Articulated Total Body (ATB) code, which is integrated into MSC.Dytran.

Impact Testing and Simulation of a Crashworthy Composite Fuselage Section with Energy-Absorbing Seats and Dummies

NASA Technical Reports Server (NTRS)

Fasanella, Edwin L.; Jackson, Karen E.

2002-01-01

A 25-ft/s vertical drop test of a composite fuselage section was conducted with two energy-absorbing seats occupied by anthropomorphic dummies to evaluate the crashworthy features of the fuselage section and to determine its interaction with the seats and dummies. The 5-ft diameter fuselage section consists of a stiff structural floor and an energy-absorbing subfloor constructed of Rohacel foam blocks. The experimental data from this test were analyzed and correlated with predictions from a crash simulation developed using the nonlinear, explicit transient dynamic computer code, MSC.Dytran. The anthropomorphic dummies were simulated using the Articulated Total Body (ATB) code, which is integrated into MSC.Dytran.

STS-28 Columbia, OV-102, Pilot Richards at forward flight deck pilots station

NASA Technical Reports Server (NTRS)

1989-01-01

Pilot Richard N. Richards, sitting at forward flight deck pilots station controls, looks back to aft flight deck during STS-28, a Department of Defense (DOD) dedicated mission. Control panels F7 and F8 and portable laptop computer propped on panel F4 appear in front of Richards. Behind him are the pilots seat seat back and head rest. A stuffed toy animal is positioned on C1 panel.

Occupant Kinematics in Simulated Autonomous Driving Vehicle Collisions: Influence of Seating Position, Direction and Angle.

PubMed

Kitagawa, Yuichi; Hayashi, Shigeki; Yamada, Katsunori; Gotoh, Mitsuaki

2017-11-01

This two-part study analyzed occupant kinematics in simulated collisions of future automated driving vehicles in terms of seating configuration. In part one, a frontal collision was simulated with four occupants with the front seats reversed. The left front seat occupant was unbelted while the others were belted. In part two of the study, occupant restraint was examined in various seating configurations using a single seat model with a three-point seatbelt. The seat direction with respect to impact was considered as forward, rearward, and lateral facing in 45 degree increments. The effect of seat recline was also studied in the forward-facing and rear-facing cases by assuming three positions: driving position, resting position and relaxed position. Occupants were represented by human body finite element models. The results of part one showed that the front seat (rear-facing) occupants were restrained by the seatback, resulting in T1 forward displacement less than 100 mm; the rear seat occupants were restrained by the seatbelt resulting larger T1 forward displacement more than 500 mm. The results of the part two showed the directional dependence of occupant restraint. Greater T1 displacements were observed when the occupant faced lateral or front oblique. However, the seatbelt provided some restraint in all directions considered. The seatback generated contact force to the occupant when it was in the impact direction, including the lateral directions. The relaxed position allowed increased excursion compared to the driving position when the occupant faced rearward, but the magnitude of this increase was lower with lower impact speed.

Biomechanical responses of PMHS in moderate-speed rear impacts and development of response targets for evaluating the internal and external biofidelity of ATDS.

PubMed

Kang, Yun-Seok; Bolte, John H; Moorhouse, Kevin; Donnelly, Bruce; Herriott, Rodney; Mallory, Ann

2012-10-01

The objectives of this study were to obtain biomechanical responses of post mortem human subjects (PMHS) by subjecting them to two moderate-speed rear impact sled test conditions (8.5g, 17 km/h; 10.5g, 24 km/h) while positioned in an experimental seat system, and to create biomechanical targets for internal and external biofidelity evaluation of rear impact ATDs. The experimental seat was designed to measure external loads on the head restraint (4 load cells), seat back (6 load cells), and seat pan (4 load cells) such that subject dynamic interaction with the seat could be evaluated. This seat system was capable of simulating the dynamic characteristics of modern vehicle seat backs by considering the moment-rotation properties of a typical passenger vehicle, thus providing a more realistic test environment than using a rigid seat with a non-rotating seat back as done in previous studies. Instrumentation used to measure biomechanical responses of the PMHS included both accelerometers and angular rate sensors (ARS). A total of fourteen sled tests using eight PMHS (males 175.8 ± 6.2 cm of stature and 78.4 ± 7.2 kg of weight) provided data sets of seven PMHS for both test conditions. The biomechanical responses are described at both speeds, and cervical spine injuries are documented. Biomechanical targets are also created for internal and external biofidelity evaluation of rear impact anthropomorphic test devices (ATDs).

Comparative Assessment of Torso and Seat Mounted Restraint Systems using Manikins on the Vertical Deceleration Tower

DTIC Science & Technology

2017-03-01

experimental effort involving a series of +z-axis impact tests was conducted on the 711th Human Performance Wing’s Vertical Deceleration Tower (VDT...parameters) and a JSF-styled ejection seat configuration (combined non -baseline test parameters) produced similar biodynamic response parameters for the LOIS...Photography .............................................................................. 12 6.0 EXPERIMENTAL DESIGN

Neuro-Cognitive Assessment, Symptoms of Attention Deficit and Hyperactivity Disorder, and Soldier Performance during 68W Advanced Individual Training

DTIC Science & Technology

2007-10-01

Disorder ( ADHD ). When distinctions are made, they are clearly identified by type: inattentive or hyperactive-impulsive. A third grouping of symptoms...and emergency medical training, followed by nine weeks of classroom lecture, interactive computer training, and life-sized patient simulation, to...his seat in the classroom or in other situations in which remaining seated is expected. Often runs about or climbs in situations when it is

STS-26 Commander Hauck in fixed based (FB) shuttle mission simulator (SMS)

NASA Technical Reports Server (NTRS)

1988-01-01

STS-26 Discovery, Orbiter Vehicle (OV) 103, Commander Frederick H. Hauck, wearing comunications kit assembly headset, checks control panel data while seated in the commanders seat on forward flight deck. A flight data file (FDF) notebook rests on his lap. A portable computer (laptop) is positioned on the center console. The STS-26 crew is training in the fixed base (FB) shuttle mission simulator (SMS) located in JSC Mission Simulation and Training Facility Bldg 5.

Study of materials performance model for aircraft interiors

NASA Technical Reports Server (NTRS)

Leary, K.; Skratt, J.

1980-01-01

A demonstration version of an aircraft interior materials computer data library was developed and contains information on selected materials applicable to aircraft seats and wall panels, including materials for the following: panel face sheets, bond plies, honeycomb, foam, decorative film systems, seat cushions, adhesives, cushion reinforcements, fire blocking layers, slipcovers, decorative fabrics and thermoplastic parts. The information obtained for each material pertains to the material's performance in a fire scenario, selected material properties and several measures of processability.

Tutorial Guide: Computer Aided Structural Modeling (CASM). Version 1.01, Release Date - February 1990

DTIC Science & Technology

1990-09-01

seats Dining room Parking garage (1 story) Kitchen Required: Prepare a list of live loads for the project. Live load reductions are to be taken for all...Corridor (main) 100 Office: Lobbies 100 Assembly: Mouable seats 100 Dining rooms 100 Garages (passenger cars) 50 Kitchens (non domestic) 150a AI...rooms 100 Garages (passenger cars) 50 Kitchens (non domestic) 150a a. Variable design load. Increase may be necessary. Notes Uniformly distributed live

Ergonomics in the electronic library.

PubMed Central

Thibodeau, P L; Melamut, S J

1995-01-01

New technologies are changing the face of information services and how those services are delivered. Libraries spend a great deal of time planning the hardware and software implementations of electronic information services, but the human factors are often overlooked. Computers and electronic tools have changed the nature of many librarians' daily work, creating new problems, including stress, fatigue, and cumulative trauma disorders. Ergonomic issues need to be considered when designing or redesigning facilities for electronic resources and services. Libraries can prevent some of the common problems that appear in the digital workplace by paying attention to basic ergonomic issues when designing workstations and work areas. Proper monitor placement, lighting, workstation setup, and seating prevent many of the common occupational problems associated with computers. Staff training will further reduce the likelihood of ergonomic problems in the electronic workplace. PMID:7581189

Influence of support conditions on vertical whole-body vibration of the seated human body.

PubMed

M-Pranesh, Anand; Rakheja, Subhash; Demont, Richard

2010-01-01

The vibration transmission to the lumbar and thoracic segments of seated human subjects exposed to whole body vibration of a vehicular nature have been mostly characterised without the back and hand supports, which is not representative of general driving conditions. This non-invasive experimental study investigated the transmission of vertical seat vibration to selected vertebrae and the head along the vertical and fore-aft axes of twelve male human subjects seated on a rigid seat and exposed to random vertical excitation in the 0.5-20 Hz range. The measurements were performed under four different sitting postures involving combinations of back support conditions and hands positions, and three difference magnitudes of vertical vibration (0.25, 0.5 and 1.0 m/s(2) rms acceleration). The results showed significant errors induced by sensor misalignment and skin effects, which required appropriate correction methodologies. The averaged corrected responses revealed that the back support attenuates vibration in the vertical axis to all the body locations while increasing the fore-aft transmissibility at the C7 and T5. The hands position generally has a relatively smaller effect, showing some influences on the C7 and L5 vibration. Sitting without a back support resulted in very low magnitude fore-aft vibration at T5, which was substantially higher with a back support, suggestive of a probable change in the body's vibration mode. The effect of back support was observed to be very small on the horizontal vibration of the lower thoracic and lumbar regions. The results suggest that distinctly different target body-segment biodynamic functions need to be defined for different support conditions in order to represent the unique contribution of the specific support condition. These datasets may then be useful for the development of biodynamic models.

G-cueing microcontroller (a microprocessor application in simulators)

NASA Technical Reports Server (NTRS)

Horattas, C. G.

1980-01-01

A g cueing microcontroller is described which consists of a tandem pair of microprocessors, dedicated to the task of simulating pilot sensed cues caused by gravity effects. This task includes execution of a g cueing model which drives actuators that alter the configuration of the pilot's seat. The g cueing microcontroller receives acceleration commands from the aerodynamics model in the main computer and creates the stimuli that produce physical acceleration effects of the aircraft seat on the pilots anatomy. One of the two microprocessors is a fixed instruction processor that performs all control and interface functions. The other, a specially designed bipolar bit slice microprocessor, is a microprogrammable processor dedicated to all arithmetic operations. The two processors communicate with each other by a shared memory. The g cueing microcontroller contains its own dedicated I/O conversion modules for interface with the seat actuators and controls, and a DMA controller for interfacing with the simulation computer. Any application which can be microcoded within the available memory, the available real time and the available I/O channels, could be implemented in the same controller.

Evaluation of wheelchair back support crashworthiness: combination wheelchair back support surfaces and attachment hardware.

PubMed

Ha, D; Bertocci, G; Deemer, E; van Roosmalen, L; Karg, P

2000-01-01

Automotive seats are tested for compliance with federal motor vehicle safety standards (FMVSS) to assure safety during impact. Many wheelchair users rely upon their wheelchairs to serve as vehicle seats. However, the crashworthiness of these wheelchairs during impact is often unknown. This study evaluated the crashworthiness of five combinations of wheelchair back support surfaces and attachment hardware using a static test procedure simulating crash loading conditions. The crashworthiness was tested by applying a simulated rearward load to each seat-back system. The magnitude of the applied load was established through computer simulation and biodynamic calculations. None of the five tested wheelchair back supports withstood the simulated crash loads. All failures were associated with attachment hardware.

Investigation of the transmission of fore and aft vibration through the human body.

PubMed

Demić, Miroslav; Lukić, Jovanka

2009-07-01

Understanding the behavior of human body under the influence of vibration is of great importance for the optimal motor vehicle system design. Therefore, great efforts are being done in order to discover as many information about the influence of vibration on human body as possible. So far the references show that the major scientific attention has been paid to vertical vibration, although intensive research has been performed lately on the other sorts of excitation. In this paper, the results of the investigation of behavior of human body, in seated position, under the influence of random fore and aft vibration are shown. The investigation is performed by the use of an electro-hydraulic simulator, on a group of 30 healthy male occupants. Experiments are performed in order to give results to improve human body modeling in driving conditions. Excitation amplitudes (1.75 and 2.25 m/s(2) rms) and seat backrest conditions (with and without inclination) were varied. Data results are analyzed by partial coherence and transfer functions. Analyses have been performed and results are given in detail. The results obtained have shown that the human body under the influence of random excitations behaves as a non-linear system and its response depends on spatial position. Obtained results give necessary data to define structure and parameters of human biodynamic model with respect to different excitation and seat backrest position.

Effects of standing on typing task performance and upper limb discomfort, vascular and muscular indicators.

PubMed

Fedorowich, Larissa M; Côté, Julie N

2018-10-01

Standing is a popular alternative to traditionally seated computer work. However, no studies have described how standing impacts both upper body muscular and vascular outcomes during a computer typing task. Twenty healthy adults completed two 90-min simulated work sessions, seated or standing. Upper limb discomfort, electromyography (EMG) from eight upper body muscles, typing performance and neck/shoulder and forearm blood flow were collected. Results showed significantly less upper body discomfort and higher typing speed during standing. Lower Trapezius EMG amplitude was higher during standing, but this postural difference decreased with time (interaction effect), and its variability was 68% higher during standing compared to sitting. There were no effects on blood flow. Results suggest that standing computer work may engage shoulder girdle stabilizers while reducing discomfort and improving performance. Studies are needed to identify how standing affects more complex computer tasks over longer work bouts in symptomatic workers. Copyright © 2018 Elsevier Ltd. All rights reserved.

The influence of vibration on seated human drowsiness

PubMed Central

AZIZAN, Amzar; FARD, Mohammad; AZARI, Michael F.; BENEDIKTSDÓTTIR, Bryndís; ARNARDÓTTIR, Erna Sif; JAZAR, Reza; MAEDA, Setsuo

2016-01-01

Although much is known about human body vibration discomfort, there is little research data on the effects of vibration on vehicle occupant drowsiness. A laboratory experimental setup has been developed. Vibration was applied to the volunteers sitting on the vehicle seat mounted on the vibration platform. Seated volunteers were exposed to a Gaussian random vibration, with 1–15 Hz frequency bandwidth at 0.2 ms−2 r.m.s., for 20-minutes. Two drowsiness measurement methods were used, Psychomotor Vigilance Test (PVT) and Karolinska Sleepiness Scale (KSS). Significant changes in PVT (p<0.05) and KSS (p<0.05) were detected in all eighteen volunteers. Furthermore, a moderate correlation (r>0.4) was observed between objective measurement (PVT) and subjective measurement (KSS). The results suggest that exposure to vibration even for 20-minutes can cause significant drowsiness impairing psychomotor performance. This finding has important implications for road safety. PMID:26829971

Characterization of the frequency and muscle responses of the lumbar and thoracic spines of seated volunteers during sinusoidal whole body vibration.

PubMed

Baig, Hassam A; Dorman, Daniel B; Bulka, Ben A; Shivers, Bethany L; Chancey, Valeta C; Winkelstein, Beth A

2014-10-01

Whole body vibration has been postulated to contribute to the onset of back pain. However, little is known about the relationship between vibration exposure, the biomechanical response, and the physiological responses of the seated human. The aim of this study was to measure the frequency and corresponding muscle responses of seated male volunteers during whole body vibration exposures along the vertical and anteroposterior directions to define the transmissibility and associated muscle activation responses for relevant whole body vibration exposures. Seated human male volunteers underwent separate whole body vibration exposures in the vertical (Z-direction) and anteroposterior (X-direction) directions using sinusoidal sweeps ranging from 2 to 18 Hz, with a constant amplitude of 0.4 g. For each vibration exposure, the accelerations and displacements of the seat and lumbar and thoracic spines were recorded. In addition, muscle activity in the lumbar and thoracic spines was recorded using electromyography (EMG) and surface electrodes in the lumbar and thoracic region. Transmissibility was determined, and peak transmissibility, displacement, and muscle activity were compared in each of the lumbar and thoracic regions. The peak transmissibility for vertical vibrations occurred at 4 Hz for both the lumbar (1.55 ± 0.34) and thoracic (1.49 ± 0.21) regions. For X-directed seat vibrations, the transmissibility ratio in both spinal regions was highest at 2 Hz but never exceeded a value of 1. The peak muscle response in both spinal regions occurred at frequencies corresponding to the peak transmissibility, regardless of the direction of imposed seat vibration: 4 Hz for the Z-direction and 2-3 Hz for the X-direction. In both vibration directions, spinal displacements occurred primarily in the direction of seat vibration, with little off-axis motion. The occurrence of peak muscle responses at frequencies of peak transmissibility suggests that such frequencies may induce greater muscle activity, leading to muscle fatigue, which could be a contributing mechanism of back pain.

Simulation of adaptive semi-active magnetorheological seat damper for vehicle occupant blast protection

NASA Astrophysics Data System (ADS)

Yoo, Jin-Hyeong; Murugan, Muthuvel; Wereley, Norman M.

2013-04-01

This study investigates a lumped-parameter human body model which includes lower leg in seated posture within a quarter-car model for blast injury assessment simulation. To simulate the shock acceleration of the vehicle, mine blast analysis was conducted on a generic land vehicle crew compartment (sand box) structure. For the purpose of simulating human body dynamics with non-linear parameters, a physical model of a lumped-parameter human body within a quarter car model was implemented using multi-body dynamic simulation software. For implementing the control scheme, a skyhook algorithm was made to work with the multi-body dynamic model by running a co-simulation with the control scheme software plug-in. The injury criteria and tolerance levels for the biomechanical effects are discussed for each of the identified vulnerable body regions, such as the relative head displacement and the neck bending moment. The desired objective of this analytical model development is to study the performance of adaptive semi-active magnetorheological damper that can be used for vehicle-occupant protection technology enhancements to the seat design in a mine-resistant military vehicle.

Adaptive magnetorheological seat suspension for shock mitigation

NASA Astrophysics Data System (ADS)

Singh, Harinder Jit

This research focuses on theoretical and experimental analysis of an adaptive seat suspension employing magnetorheological energy absorber with the objective of minimizing injury potential to seated occupant of different weights subjected to broader crash intensities. The research was segmented into three tasks: (1) development of magnetorheological energy absorber, (2) biodynamic modeling of a seated occupant, and (3) control schemes for shock mitigation. A linear stroking semi-active magnetorheological energy absorber (MREA) was designed, fabricated and tested for intense impact conditions with piston velocities up to 8 m/s. MREA design was optimized on the basis of Bingham-plastic model (BPM model) in order to maximize the energy absorption capabilities at high impact velocities. Computational fluid dynamics and magnetic FE analysis were conducted to validate MREA performance. Subsequently, low-speed cyclic testing (0-2 Hz subjected to 0-5.5 A) and high-speed drop testing (0-4.5 m/s at 0 A) were conducted for quantitative comparison with the numerical simulations. Later, a nonlinear four degrees-of-freedom biodynamic model representing a seated 50th percentile male occupant was developed on the basis of experiments conducted on Hybrid II 50th percentile male anthropomorphic test device. The response of proposed biodynamic model was compared quantitatively against two different biodynamic models from the literature that are heavily implemented for obtaining biodynamic response under impact conditions. The proposed biodynamic model accurately predicts peak magnitude, overall shape and the duration of the biodynamic transient response, with minimal phase shift. The biodynamic model was further validated against 16 impact tests conducted on horizontal accelerator facility at NAVAIR for two different shock intensities. Compliance effects of human body were also investigated on the performance of adaptive seat suspension by comparing the proposed biodynamic model response with that of a rigid body response. Finally, three different control schemes were analyzed for maximizing shock attenuation using semi-active magnetorheological energy absorber. High-speed drop experiments were conducted by dropping two rigid payloads of 240 and 340 lb mass from heights of 35 and 60 inch to simulate different impact intensities. First control scheme called constant stroking load control offered inflexible stroking load irrespective of varying impact severity or occupant weight. The other two control schemes: terminal trajectory control and optimal control adapted stroking load as per the shock intensity. The control schemes were compared on the basis of their adaptability and ease of implementation. These tools can serve as the basis for future research and development of state-of-the-art crashworthy seat suspension designs that further enhance occupant protection compared to limited performance of existing passive crashworthy concepts.

Postural stability of sitting women.

PubMed

Nag, Pranab K; Vyas, Heer; Nag, Anjali; Pal, Swati

2013-01-01

The study examined the utility of stabilometric dimensions and explored whether the changes in sitting postures were manifested in functional measures of postural control. Eleven women participated in the study, which used 11 chair sitting postures: arms on laps or arms right angled; armrest at a height of 17, 20 and 23 cm; with or without backrest; slouch or straight back; legs right angled at knees or crossed legs. The backrest and armrest shifted 16.3% of body weight from a seat pan. The characteristics of stabilometric dimensions evaluated the influence of seat components and sitting behaviour on postural balance. The study attempted to evaluate stability and its application in human-seat interface design.

23 CFR 1340.9 - Computation of estimates.

Code of Federal Regulations, 2014 CFR

2014-04-01

... OBSERVATIONAL SURVEYS OF SEAT BELT USE Survey Design Requirements § 1340.9 Computation of estimates. (a) Data... design and any subsequent adjustments. (e) Sampling weight adjustments for observation sites with no... section, the nonresponse rate for the entire survey shall not exceed 10 percent for the ratio of the total...

23 CFR 1340.9 - Computation of estimates.

Code of Federal Regulations, 2012 CFR

2012-04-01

... OBSERVATIONAL SURVEYS OF SEAT BELT USE Survey Design Requirements § 1340.9 Computation of estimates. (a) Data... design and any subsequent adjustments. (e) Sampling weight adjustments for observation sites with no... section, the nonresponse rate for the entire survey shall not exceed 10 percent for the ratio of the total...

23 CFR 1340.9 - Computation of estimates.

Code of Federal Regulations, 2013 CFR

2013-04-01

... OBSERVATIONAL SURVEYS OF SEAT BELT USE Survey Design Requirements § 1340.9 Computation of estimates. (a) Data... design and any subsequent adjustments. (e) Sampling weight adjustments for observation sites with no... section, the nonresponse rate for the entire survey shall not exceed 10 percent for the ratio of the total...

The Classroom, Board Room, Chat Room, and Court Room: School Computers at the Crossroads.

ERIC Educational Resources Information Center

Stewart, Michael

2000-01-01

In schools' efforts to maximize technology's benefits, ethical considerations have often taken a back seat. Computer misuse is growing exponentially and assuming many forms: unauthorized data access, hacking, piracy, information theft, fraud, virus creation, harassment, defamation, and discrimination. Integrated-learning activities will help…

Report: EPA’s Contract Oversight and Controls Over Personal Computers Need Improvement

EPA Pesticide Factsheets

Report #11-P-0705, September 26, 2011. EPA paid the CTS contractor a total of $489,734 over an 11-month period for 3,343 seats—a standard seat includes a leased computer with accessories and technical support—not ordered by the Agency during the period.

The energy expenditure of using a "walk-and-work" desk for office workers with obesity.

PubMed

Levine, James A; Miller, Jennifer M

2007-09-01

For many people, most of the working day is spent sitting in front of a computer screen. Approaches for obesity treatment and prevention are being sought to increase workplace physical activity because low levels of physical activity are associated with obesity. Our hypothesis was that a vertical workstation that allows an obese individual to work while walking would be associated with significant and substantial increases in energy expenditure over seated work. The vertical workstation is a workstation that allows an office worker to use a standard personal computer while walking on a treadmill at a self-selected velocity. 15 sedentary individuals with obesity (14 women, one man; 43 (7.5) years, 86 (9.6) kg; body mass index 32 (2.6) kg/m(2)) underwent measurements of energy expenditure at rest, seated working in an office chair, standing and while walking at a self-selected speed using the vertical workstation. Body composition was measured using dual x ray absorptiometry. The mean (SD) energy expenditure while seated at work in an office chair was 72 (10) kcal/h, whereas the energy expenditure while walking and working at a self-selected velocity of 1.1 (0.4) mph was 191 (29) kcal/h. The mean (SD) increase in energy expenditure for walking-and-working over sitting was 119 (25) kcal/h. If sitting computer-time were replaced by walking-and-working, energy expenditure could increase by 100 kcal/h. Thus, if obese individuals were to replace time spent sitting at the computer with walking computer time by 2-3 h/day, and if other components of energy balance were constant, a weight loss of 20-30 kg/year could occur.

Seats of Productivity.

ERIC Educational Resources Information Center

Kennedy, Mike

2003-01-01

Discusses key factors to consider when selecting furniture for offices and other administrative areas, including flexibility, ergonomics, aesthetics, and cost. Includes a sidebar on dealing with bulky wiring at computer workstations. (EV)

KENNEDY SPACE CENTER, FLA. - Boeing workers perform a 3D digital scan of the actuator on the table. At left is Dan Clark. At right are Alden Pitard (seated at computer) and John Macke, from Boeing, St. Louis. . There are two actuators per engine on the Shuttle, one for pitch motion and one for yaw motion. The Space Shuttle Main Engine hydraulic servoactuators are used to gimbal the main engine.

NASA Image and Video Library

2003-09-03

KENNEDY SPACE CENTER, FLA. - Boeing workers perform a 3D digital scan of the actuator on the table. At left is Dan Clark. At right are Alden Pitard (seated at computer) and John Macke, from Boeing, St. Louis. . There are two actuators per engine on the Shuttle, one for pitch motion and one for yaw motion. The Space Shuttle Main Engine hydraulic servoactuators are used to gimbal the main engine.

Workplace Design

NASA Technical Reports Server (NTRS)

1984-01-01

The Anthropometric Source Book was developed based on Johnson Space Center project of anthropometry, the study of the size, shape and motion characteristics of the human body. Designed primarily for use by NASA, the military services and aerospace contractors, the book was also intended to help non-aerospace engineers, architects, and others engaged in design of clothing, equipment and workplaces. An example of its use by Eastman Kodak Company is the company's application of the data to design efficient, productive and comfortable workplaces for employees in the Rochester, NY processing laboratories. The sourcebook was used to determine such dimensions as leg space, work surface height and thickness, employee reach distances, proper height for computer terminal screen, seat height and knee space.

Research on an Active Seat Belt System

NASA Astrophysics Data System (ADS)

Kawashima, Takeshi

In a car crash, permanent injury can be avoided if deformation of an occupant's rib cage is maintained within the allowable value. In order to realize this condition, the occupant's seat belt tension must be instantaneously adjusted by a feedback control system. In this study, a seat belt tension control system based on the active shock control system is proposed. The semi-active control law used is derived from the sliding mode control method. One advantage of this proposed system is that it does not require a large power actuator because the seat belt tension is controlled by a brake mechanism. The effectiveness is confirmed by numerical simulation using general parameters of a human thorax and a passenger car in a collision scenario with a wall at a velocity of 100 km/h. The feasibility is then confirmed with a control experiment using a scale model of about 1/10 scale. The relative displacement of the thorax model approaches the allowable value smoothly along the control reference and settles near this value. Thus, the proposed seat belt tension control system design is established.

Analysis of Potential Deep-Seated Landslide in Hekeng Watershed by Environment Indices

NASA Astrophysics Data System (ADS)

Hsieh, C. J.; Chompuchan, C.

2014-12-01

Landslides are a major natural disaster in Taiwan relevant to the human life. After the catastrophic Xiaolin landslide during Typhoon Morakot in August 2009 caused around 400 casualties, the deep-seated landslide has become a serious issue. This study explored the potential deep-seated landslide in Hekeng watershed extracted from SPOT-5 imageries. The empirical topographic correction was applied to minimize effect of the mountain shaded area due to the difference of sun elevation and terrain angle. Consequently the multi-temporal environmental indices, i.e., modified Normalized Difference Vegetation Index (mNDVI) and modified Normalized Difference Water Index (mNDWI) were corrected. Seasonal vegetation cover and surface moisture change were analyzed incorporate with a slope which obtain from DEM data. The result showed that the distribution of potential deep-seated landslide vulnerable area mainly located at headstream watershed. It could be explained that the headstream watershed has less human interference, therefore the environmental indices interpreted those area as deep soil layer and dense vegetation coverage. However, the upstream canal could suffer from the long-term erosion and possibly cause slope toe collapse. In addition, the western watershed is the afforestation zone whereas the eastern watershed is natural forest zone with higher development ratio. The upslope forest management of eastern and western watershed should be discussed variously.

Mapping the zone of eye-height utility for seated and standing observers

NASA Technical Reports Server (NTRS)

Wraga, M.; Proffitt, D. R.; Kaiser, M. K. (Principal Investigator)

2000-01-01

In a series of experiments, we delimited a region within the vertical axis of space in which eye height (EH) information is used maximally to scale object heights, referred to as the "zone of eye height utility" (Wraga, 1999b Journal of Experimental Psychology, Human Perception and Performance 25 518-530). To test the lower limit of the zone, linear perspective (on the floor) was varied via introduction of a false perspective (FP) gradient while all sources of EH information except linear perspective were held constant. For seated (experiment 1a) observers, the FP gradient produced overestimations of height for rectangular objects up to 0.15 EH tall. This value was taken to be just outside the lower limit of the zone. This finding was replicated in a virtual environment, for both seated (experiment 1b) and standing (experiment 2) observers. For the upper limit of the zone, EH information itself was manipulated by lowering observers' center of projection in a virtual scene. Lowering the effective EH of standing (experiment 3) and seated (experiment 4) observers produced corresponding overestimations of height for objects up to about 2.5 EH. This zone of approximately 0.20-2.5 EH suggests that the human visual system weights size information differentially, depending on its efficacy.

Seat belt use, counseling and motor-vehicle injury during pregnancy: results from a multi-state population-based survey.

PubMed

Sirin, Hulya; Weiss, Harold B; Sauber-Schatz, Erin K; Dunning, Kari

2007-09-01

Motor-vehicle injuries are the leading cause of death and hospitalized trauma during pregnancy. The study objectives were to report the prevalence of seat belt counseling by prenatal care providers during pregnancy, seat belt use during the last trimester, and self-reported motor-vehicle injury during pregnancy. Differences were examined by age, race and education. A cross-sectional study design using self-reported 22 state data from the Centers for Disease Control and Prevention's 2001 Pregnancy Risk Assessment Monitoring System (PRAMS) were used (n = 37,081). Estimates were computed using logistic regression from weighted counts. On average, reported prenatal care provider counseling for seat belt use occurred in 48.7% (38.2-58.8%) of prenatal visits. Women most likely to report being counseled were aged 20-29, non-White, Hispanic ethnicity, and less educated. Women 30 years of age or greater and that had a greater than high school education were more likely to report always wearing seat belts in the last trimester. On average, 2.3% (1.2-4.7%) of respondents reported being hurt in a "car accident" during pregnancy. Women less than 20 years old (3.0%), Black (3.9%), and less educated (3.2%) were the most likely to report being hurt in a crash during pregnancy. Based on PRAMS, it is estimated that about 92,500 pregnant women are hurt annually in motor-vehicle crashes in the United States. Despite this reported risk and the proven efficacy of restraint use, most pregnant women do not report being counseled about seat belt use during prenatal visits. Limitations of PRAMS methodology make it difficult to determine the association of prenatal counseling with seat belt use.

Through the Bugscope

ERIC Educational Resources Information Center

Hadley, Kathryn; Korb, Michele

2007-01-01

The projection screen in the dimly lit auditorium was ready and an online chat window was open on the computer screen. Computer experts and entomologists were ready on the other end. One by one, students filled up the rows of seats eagerly anticipating what was going to happen next. Each student was asked to close their eyes. Ms. Hadley asked…

Soldier-Computer Interface

DTIC Science & Technology

2015-01-27

placed on the user by the required tasks. Design areas that are of concern include seating , input and output device location and design , ambient...software, hardware, and workspace design for the test function of operability that influence operator performance in a computer-based system. 15...PRESENTATION ................... 23 APPENDIX A. SAMPLE DESIGN CHECKLISTS ...................................... A-1 B. SAMPLE TASK CHECKLISTS

Repeatability, reproducibility, and validity of a new method for characterizing lumbar support in automotive seating.

PubMed

Kolich, Mike

2009-04-01

This article describes a new and more repeatable, reproducible, and valid test method for characterizing lumbar support in automotive seating. Lumbar support is important because it affects occupant accommodation and perceptions of seat comfort. Assessing only the lumbar mechanism--particularly in terms of travel--is inadequate because it does not consider the effects of trim and foam. The Society of Automotive Engineers' next-generation H-Point machine and associated loading protocol were used as the basis for the new test. The method was found to satisfy minimum gage repeatability and reproducibility requirements. Validity was demonstrated through a regression model that revealed 93.9% of the variance in subjective ratings of poor uncomfortable lumbar support can be explained by two objective indicators: (1) lumbar support prominence in the full-off position and (2) effective travel. The method can be used to differentiate between seats offering two-way adjustable lumbar support. The best two-way adjustable lumbar seat systems are those that couple little to no lumbar support in the starting or off position (i.e., they are nonintrusive) with a considerable amount of effective or perceptible travel. The automotive industry has long needed a way to address the fact that consumers want more lumbar support than their seats currently supply. This contribution offers a method to objectify an important aspect of automotive seating comfort-namely, lumbar support. This should help human factors professionals produce, but not necessarily guarantee, better consumer ratings.

An on-the-road experiment into the thermal comfort of car seats.

PubMed

Cengiz, Tülin Gündüz; Babalik, Fatih C

2007-05-01

This paper presents an evaluation of thermal comfort in an extended road trial study. Automobile seats play an important role in improving the thermal comfort. In the assessment of thermal comfort in autos, in general subjective and objective measurements are used. Testing on the road is very difficult but real traffic conditions affect the comfort level directly, as well as the driver's experience to real conditions. Thus, for such cases real traffic situations should not be neglected in the evaluation of comfort. The aim of this study was to carry out, on an extended road trial study, an evaluation of thermal comfort using human subjects. In the experiments used, the 100% polyester seat cover had three different cover materials, which were velvet, jacquard and micro fiber. All experiments were carried out on a sunny day with ten participants over 1h. They were carried out at air temperatures of 25 degrees C in a Fiat Marea 2004, which had an automatic climate function. Skin temperature at eight points and skin wettedness at two points on the human body were measured during the trials. Participants were required to complete a questionnaire of 15 questions, every 5 min. It can be concluded that there was negligible difference in participants' reported thermal sensation between the three seats. According to objective measurement results, all seat cover materials have the same degree of thermal comfort. On the road the participants feel warmer around their waist than any other area of the body. It was suggested that the effects of real traffic conditions must be accounted for in comfort predictions.

Human Interactive Triboelectric Nanogenerator as a Self-Powered Smart Seat.

PubMed

Chandrasekhar, Arunkumar; Alluri, Nagamalleswara Rao; Saravanakumar, Balasubramaniam; Selvarajan, Sophia; Kim, Sang-Jae

2016-04-20

A lightweight, flexible, cost-effective, and robust, single-electrode-based Smart Seat-Triboelectric Nanogenerator (SS-TENG) is introduced as a promising eco-friendly approach for harvesting energy from the living environment, for use in integrated self-powered systems. An effective method for harvesting biomechanical energy from human motion such as walking, running, and sitting, utilizing widely adaptable everyday contact materials (newspaper, denim, polyethylene covers, and bus cards) is demonstrated. The working mechanism of the SS-TENG is based on the generation and transfer of triboelectric charge carriers between the active layer and user-friendly contact materials. The performance of SS-TENG (52 V and 5.2 μA for a multiunit SS-TENG) is systematically studied and demonstrated in a range of applications including a self-powered passenger seat number indicator and a STOP-indicator using LEDs, using a simple logical circuit. Harvested energy is used as a direct power source to drive 60 blue and green commercially available LEDs and a monochrome LCD. This feasibility study confirms that triboelectric nanogenerators are a suitable technology for energy harvesting from human motion during transportation, which could be used to operate a variety of wireless devices, GPS systems, electronic devices, and other sensors during travel.

Effect of human movement on airborne disease transmission in an airplane cabin: study using numerical modeling and quantitative risk analysis.

PubMed

Han, Zhuyang; To, Gin Nam Sze; Fu, Sau Chung; Chao, Christopher Yu-Hang; Weng, Wenguo; Huang, Quanyi

2014-08-06

Airborne transmission of respiratory infectious disease in indoor environment (e.g. airplane cabin, conference room, hospital, isolated room and inpatient ward) may cause outbreaks of infectious diseases, which may lead to many infection cases and significantly influences on the public health. This issue has received more and more attentions from academics. This work investigates the influence of human movement on the airborne transmission of respiratory infectious diseases in an airplane cabin by using an accurate human model in numerical simulation and comparing the influences of different human movement behaviors on disease transmission. The Eulerian-Lagrangian approach is adopted to simulate the dispersion and deposition of the expiratory aerosols. The dose-response model is used to assess the infection risks of the occupants. The likelihood analysis is performed as a hypothesis test on the input parameters and different human movement pattern assumptions. An in-flight SARS outbreak case is used for investigation. A moving person with different moving speeds is simulated to represent the movement behaviors. A digital human model was used to represent the detailed profile of the occupants, which was obtained by scanning a real thermal manikin using the 3D laser scanning system. The analysis results indicate that human movement can strengthen the downward transport of the aerosols, significantly reduce the overall deposition and removal rate of the suspended aerosols and increase the average infection risk in the cabin. The likelihood estimation result shows that the risk assessment results better fit the outcome of the outbreak case when the movements of the seated passengers are considered. The intake fraction of the moving person is significantly higher than most of the seated passengers. The infection risk distribution in the airplane cabin highly depends on the movement behaviors of the passengers and the index patient. The walking activities of the crew members and the seated passengers can significantly increase their personal infection risks. Taking the influence of the movement of the seated passengers and the index patient into consideration is necessary and important. For future studies, investigations on the behaviors characteristics of the passengers during flight will be useful and helpful for infection control.

Modeling occupants in far-side impacts.

PubMed

Douglas, Clay; Fildes, Brian; Gibson, Tom

2011-10-01

Far-side impacts are not part of any regulated NCAP, FMVSS, or similar test regime despite accounting for 43 percent of the seriously injured persons and 30 percent of the harm in U.S. side impact crashes. Furthermore, injuries to the head and thorax account for over half of the serious injuries sustained by occupants in far-side crashes. Despite this, there is no regulated or well-accepted anthropomorphic test device (ATD) or computer model available to investigate far-side impacts. As such, this presents an opportunity to assess a computer model that can be used to measure the effect of varying restraint parameters on occupant biomechanics in far-side impacts. This study sets out to demonstrate the modified TASS human facet model's (MOTHMO) capabilities in modeling whole-body response in far-side impacts. MOTHMO's dynamic response was compared to that of postmortem human subjects (PMHS), WorldSID, and Thor-NT in a series of far-side sled tests. The advantages, disadvantages, and differences of using MOTHMO compared to ATDs were highlighted and described in terms of model design and instrumentation. Potential applications and improvements for MOTHMO were also recommended. The results showed that MOTHMO is capable of replicating the seat belt-to-shoulder complex interaction, pelvis impacts, head displacement, neck and shoulder belt loading from inboard mounted belts, and impacts from multiple directions. Overall, the model performed better than Thor-NT and at least as well as WorldSID when compared to PMHS results. Though WorldSID and Thor-NT ATDs were capable of reproducing many of these impact loads, measuring the seat belt-to-shoulder complex interaction and thoracic deflection at multiple sites and directions was less accurately handled. This study demonstrated that MOTHMO is capable of modeling whole-body response in far-side impacts. Furthermore, MOTHMO can be used as a virtual design tool to explore the effect of varying restraint parameters on occupant kinematics in far-side crash configurations.

Emergency department transport rates of children from the scene of motor vehicle collisions: do booster seats make a difference?

PubMed

House, Darlene R; Huffman, Gretchen; Walthall, Jennifer D H

2012-11-01

Motor vehicle collisions (MVCs) are the leading cause of death and disability among children older than 1 year. Many states currently mandate all children between the ages of 4 and 8 years be restrained in booster seats. The implementation of a booster-seat law is generally thought to decrease the occurrence of injury to children. We hypothesized that appropriate restraint with booster seats would also cause a decrease in emergency department (ED) visits compared with children who were unrestrained. This is an important measure as ED visits are a surrogate marker for injury. The main purpose of this study was to look at the rate of ED visits between children in booster seats compared with those in other or no restraint systems involved in MVCs. Injury severity was compared across restraint types as a secondary outcome of booster-seat use after the implementation of a state law. A prospective observational study was performed including all children 4 to 8 years old involved in MVCs to which emergency medical services was dispatched. Ambulance services used a novel on-scene computer charting system for all MVC-related encounters to collect age, sex, child-restraint system, Glasgow Coma Scale score, injuries, and final disposition. One hundred fifty-nine children were studied with 58 children (35.6%) in booster seats, 73 children in seatbelts alone (45.2%), and 28 children (19.1%) in no restraint system. 76 children (47.7%), 74 by emergency medical services and 2 by private vehicle, were transported to the ED with no significant difference between restraint use (P = 0.534). Utilization of a restraint system did not significantly impact MVC injury severity. However, of those children who either died (n = 2) or had an on-scene decreased Glasgow Coma Scale score (n = 6), 75% (6/8) were not restrained in a booster seat. The use of booster-seat restraints does not appear to be associated with whether a child will be transported to the ED for trauma evaluation.

Driver kinematic and muscle responses in braking events with standard and reversible pre-tensioned restraints: validation data for human models.

PubMed

Osth, Jonas; Olafsdóttir, Jóna Marín; Davidsson, Johan; Brolin, Karin

2013-11-01

The objectives of this study are to generate validation data for human models intended for simulation of occupant kinematics in a pre-crash phase, and to evaluate the effect of an integrated safety system on driver kinematics and muscle responses. Eleven male and nine female volunteers, driving a passenger car on ordinary roads, performed maximum voluntary braking; they were also subjected to autonomous braking events with both standard and reversible pre-tensioned restraints. Kinematic data was acquired through film analysis, and surface electromyography (EMG) was recorded bilaterally for muscles in the neck, the upper extremities, and lumbar region. Maximum voluntary contractions (MVCs) were carried out in a driving posture for normalization of the EMG. Seat belt positions, interaction forces, and seat indentions were measured. During normal driving, all muscle activity was below 5% of MVC for females and 9% for males. The range of activity during steady state braking for males and females was 13-44% in the cervical and lumbar extensors, while antagonistic muscles showed a co-contraction of 2.3-19%. Seat belt pre-tension affects both the kinematic and muscle responses of drivers. In autonomous braking with standard restraints, muscle activation occurred in response to the inertial load. With pre-tensioned seat belts, EMG onset occurred earlier; between 71 ms and 176 ms after belt pre-tension. The EMG onset times decreased with repeated trials and were shorter for females than for males. With the results from this study, further improvement and validation of human models that incorporate active musculature will be made possible.

An in situ study of the habits of users that affect office chair design and testing.

PubMed

Benden, Mark E; Fink, Rainer; Congleton, Jerome

2011-02-01

The purpose of this study was to perform an in situ assessment of office seating habits that influence chair testing and design. Many chair testing parameters were derived decades ago when the average weight of people within the United States was dramatically lower and the office work tasks less computer based. For the study, 51 participants were randomly selected from Brazos Valley, Texas, businesses to participate in 8-hr assessments of office seating habits. Overall results were compared with current chair testing and design assumptions. Data were collected through written survey and through data logging of seat and back contact pressure and duration with the use of the X-SENSOR pressure mapping device and software. Additionally, I day per participant of caster roll distance was recorded with the use of a caster mounted digital encoder. Participants were grouped by body mass index (BMI) and weight (BMI <35 and weight < 102 kg or BMI >35 and weight >102 kg). It was determined that a significant difference did exist between the groups in mean seat time per shift (p < .001), back cycles per shift (p < .002), seat cycles per shift (p < .01), and caster distance rolled per shift (p < .001). Several key parameters and assumptions of current chair test methods and design specifications may no longer be valid for the upper quartile of weight range of the current U.S. population. The data collected in this study will enable engineers to determine whether revision of design standards for testing office seating for both normal weight and extremely obese workers is indicated.

Effect of Esophagus Position on Surgical Difficulty and Postoperative Morbidities After Thoracoscopic Esophagectomy.

PubMed

Yoshida, Naoya; Baba, Yoshifumi; Shigaki, Hironobu; Shiraishi, Shinya; Harada, Kazuto; Watanabe, Masayuki; Iwatsuki, Masaaki; Kurashige, Junji; Sakamoto, Yasuo; Miyamoto, Yuji; Ishimoto, Takatsugu; Kosumi, Keisuke; Tokunaga, Ryuma; Yamashita, Yasuyuki; Baba, Hideo

2016-01-01

The objective include thoracoscopic esophagectomy for the deep-seated (left-sided) esophagus has several technical difficulties, which may affects the intraoperative or postoperative outcomes. However, no previous studies have focused on the correlation between the position of the esophagus and short-term outcome after thoracoscopic esophagectomy. Of 470 esophagectomies between April 2005 and April 2015 in Kumamoto University Hospital, 112 patients who underwent thoracoscopic esophagectomy for esophageal cancer were examined. The position of the esophagus was divided into 2 types: deep-seated esophagus or another type based on computed tomographic images in the supine position. In results, the deep-seated esophagus was associated with a longer operation time in the thorax and high incidence of severe morbidity of Clavien-Dindo classification ≥IIIb, pneumonia, and any pulmonary morbidity. The deep-seated esophagus was also an independent risk factor for severe morbidity (hazard ratio [HR] = 5.37, 95% CI: 1.307-22.03; P = 0.020), pneumonia (HR = 9.23, 95% CI: 2.150-39.60; P = 0.003), and any pulmonary morbidity (HR = 10.3, 95% CI: 2.714-38.78; P < 0.001). In conclusion, the position of the esophagus had a strong influence on the difficulty of thoracoscopic esophagectomy and the incidence of postoperative morbidities. Surgeons would be well advised to keep a careful watch perioperatively for patients with a deep-seated esophagus. Copyright © 2016 Elsevier Inc. All rights reserved.

Factors Influencing Occupant-To-Seat Belt Interaction in Far-Side Crashes

PubMed Central

Douglas, C.A.; Fildes, B.N.; Gibson, T.J.; Boström, O.; Pintar, F.A.

2007-01-01

Seat belt interaction with a far-side occupant’s shoulder and thorax is critical to governing excursion towards the struck-side of the vehicle in side impact. In this study, occupant-to-belt interaction was simulated using a modified MADYMO human model and finite element belts. Quasi-static tests with volunteers and dynamic sled tests with PMHS and WorldSID were used for model validation and comparison. Parameter studies were then undertaken to quantify the effect of impact direction, seat belt geometry and pretension on occupant-to-seat belt interaction. Results suggest that lowering the D-ring and increasing pretension reduces the likelihood of the belt slipping off the shoulder. Anthropometry was also shown to influence restraint provided by the shoulder belt. Furthermore, the belt may slip off the occupant’s shoulder at impact angles greater than 40 degrees from frontal when no pretension is used. However, the addition of pretension allowed the shoulder to engage the belt in all impacts from 30 to 90 degrees. PMID:18184500

Biomechanical considerations for abdominal loading by seat belt pretensioners.

PubMed

Rouhana, Stephen W; El-Jawahri, Raed E; Laituri, Tony R

2010-11-01

While seat belts are the most effective safety technology in vehicles today, there are continual efforts in the industry to improve their ability to reduce the risk of injury. In this paper, seat belt pretensioners and current trends towards more powerful systems were reviewed and analyzed. These more powerful systems may be, among other things, systems that develop higher belt forces, systems that remove slack from belt webbing at higher retraction speeds, or both. The analysis started with validation of the Ford Human Body Finite Element Model for use in evaluation of abdominal belt loading by pretensioners. The model was then used to show that those studies, done with lap-only belts, can be used to establish injury metrics for tests done with lap-shoulder belts. Then, previously-performed PMHS studies were used to develop AIS 2+ and AIS 3+ injury risk curves for abdominal interaction with seat belts via logistic regression and reliability analysis with interval censoring. Finally, some considerations were developed for a possible laboratory test to evaluate higher-powered pretensioners.

Human factors evaluation of the HL-20 full-scale model

NASA Astrophysics Data System (ADS)

Willshire, Kelli F.; Simonsen, Lisa C.; Willshire, William L., Jr.

1993-09-01

The human factors testing of the HL-20 personnel launch system full-scale model was conducted in both the vertical and horizontal positions at NASA Langley Research Center. Three main areas of testing were considered: an anthropometric fit evaluation, the ingress and egress of a 10-person crew, and pilot viewing. The subjects, ranging from the 5th to 95th percentile size, had sufficient clearance in the model, with the exception of the last two rows of seats and the cockpit area. Adjustable seat heights and/or placement of the seats farther forward would provide more headroom. In the horizontal position, the model's seat placement and aisle width allowed a quick and orderly 10-person egress for the no-keel (a structural support running the length on the aisle), 6-in.-high keel, and 12-in.-high keel conditions. Egress times were less than 20 s. For the vertical position, the model's long cylindrical shape with the ladder in the ceiling allowed a quick and orderly egress with average times less than 30 s. Ingress and egress procedures were demonstrated using shuttle partial-pressure suits. The reduced mobility experienced while wearing the suits did increase egress times, although they still remained acceptable. The window arrangement for pilot viewing was found to be reasonably acceptable, although slight modifications, such as an increased downward view, is desirable.

Musculoskeletal symptoms in workers of a Telecom Company.

PubMed

Antunes, Evelise Dias; de Araújo, Célia Regina Alves; Abage, Zilda

2012-01-01

Millions of people work with computers every day. Human work provides a means of comfort and ease to perform the tasks, favoring incorrect postures. Among the employees of a telecom company, it appears that all make use of computer, remaining in a seated position leading in musculoskeletal symptoms. This is a quantitative study, conducted in a telecom company in the city of Curitiba. Were interviewed 27 analysts who work in engineering department, who agreed to participate and receive guidelines regarding sitting posture. This study, consisted of a structured questionnaire and the Nordic Musculoskeletal Questionnaire with musculoskeletal symptoms indicators. After answering the questionnaire, the subjects were guided through the folder on correct posture and positioning front the computer. Of employees 74% were male, and 100% of the employees are the computer's user, remaining in the sitting posture during working day. Concerning the break time, 74% reported that they frequently do it. Been the average working day is 8 hours. Regarding the frequency of musculoskeletal symptoms, 70% of employees reported some symptoms during the last 12 months but only one came to be sick leave. It is necessary to an analysis of the work situation, evaluating and correcting inadequacies of securities and the risks inherent in function, making prevention.

Development of a Methodology to Gather Seated Anthropometry in a Microgravity Environment

NASA Technical Reports Server (NTRS)

Rajulu, Sudhakar; Young, Karen; Mesloh, Miranda

2009-01-01

The Constellation Program's Crew Exploration Vehicle (CEV) is required to accommodate the full population range of crewmembers according to the anthropometry requirements stated in the Human-Systems Integration Requirement (HSIR) document (CxP70024). Seated height is one of many critical dimensions of importance to the CEV designers in determining the optimum seat configuration in the vehicle. Changes in seated height may have a large impact to the design, accommodation, and safety of the crewmembers. Seated height can change due to elongation of the spine when crewmembers are exposed to microgravity. Spinal elongation is the straightening of the natural curvature of the spine and the expansion of inter-vertebral disks. This straightening occurs due to fluid shifts in the body and the lack of compressive forces on the spinal vertebrae. Previous studies have shown that as the natural curvature of the spine straightens, an increase in overall height of 3% of stature occurs which has been the basis of the current HSIR requirements. However due to variations in the torso/leg ratio and impact of soft tissue, data is nonexistent as to how spinal elongation specifically affects the measurement of seated height. In order to obtain this data, an experiment was designed to collect spinal elongation data while in a seated posture in microgravity. The purpose of this study was to provide quantitative data that represents the amount of change that occurs in seated height due to spinal elongation in microgravity environments. Given the schedule and budget constraints of ISS and Shuttle missions and the uniqueness of the problem, a methodology had to be developed to ensure that the seated height measurements were accurately collected. Therefore, simulated microgravity evaluations were conducted to test the methodology and procedures of the experiment. This evaluation obtained seat pan pressure and seated height data to a) ensure that the lap restraint provided sufficient restraint to eliminate any gap between the subject s gluteal surface and the seat pan and b) to document any necessary design and procedural changes needed due to the microgravity environment. The methodology and setup used during the simulated microgravity evaluations was replicable to the proposed methodology and setup for in-space missions. A flight-like Shuttle seat, pressure sensors, anthropometer, and existing hardware was used to measure seated height and contact area while experiencing microgravity. The outlying buttock and thigh surface contact areas were collected to determine if the subjects were in contact with the seat pan, while a measurer recorded their seated height with an anthropometer. The Anthropometry and Biomechanics Facility (ABF) completed data collection from three microgravity flights to assess the restraint methods and techniques to be used for the in-flight procedures performed by the crewmembers in orbit. The first flight demonstrated that the restraint system on the seat, used in a nominal configuration, did not sufficiently restrain a person in the seat. The results showed the subjects were not in full contact with the seat pan, resulting in inaccurate sitting height data. Thus, a second flight was conducted to test different restraint system options. The results showed that by 1) changing the restraint system from the nominal 3-points of the 5-point harness, which is used for crewmembers when fully suited with emergency equipment, and 2) rerouting the lap straps around the joint of the backrest, where the backrest and seat pan are joined, resulted in the optimal method to restrain a subject. This rerouting method allowed for the anchor location to change and pull the subjects back into the seat instead of being anchored at the side of the subjects thighs. The results from the third flight validated the final restraint system, which resulted in a verified methodology for collecting seated anthropometry to ultimately determine the amount of spil elongation in a microgravity environment.

Computer Models of Proteins

NASA Technical Reports Server (NTRS)

2000-01-01

Dr. Marc Pusey (seated) and Dr. Craig Kundrot use computers to analyze x-ray maps and generate three-dimensional models of protein structures. With this information, scientists at Marshall Space Flight Center can learn how proteins are made and how they work. The computer screen depicts a proten structure as a ball-and-stick model. Other models depict the actual volume occupied by the atoms, or the ribbon-like structures that are crucial to a protein's function.

Vehicular Causation Factors and Conceptual Design Modifications to Reduce Aortic Strain in Numerically Reconstructed Real World Nearside Lateral Automotive Crashes

PubMed Central

Yang, King H.

2015-01-01

Aortic injury (AI) leading to disruption of the aorta is an uncommon but highly lethal consequence of trauma in modern society. Most recent estimates range from 7,500 to 8,000 cases per year from a variety of causes. It is observed that more than 80% of occupants who suffer an aortic injury die at the scene due to exsanguination into the chest cavity. It is evident that effective means of substantially improving the outcome of motor vehicle crash-induced AIs is by preventing the injury in the first place. In the current study, 16 design of computer experiments (DOCE) were carried out with varying levels of principal direction of force (PDOF), impact velocity, impact height, and impact position of the bullet vehicle combined with occupant seating positions in the case vehicle to determine the effects of these factors on aortic injury. Further, a combination of real world crash data reported in the Crash Injury Research and Engineering Network (CIREN) database, Finite Element (FE) vehicle models, and the Wayne State Human Body Model-II (WSHBM-II) indicates that occupant seating position, impact height, and PDOF, in that order play, a primary role in aortic injury. PMID:26448781

Experimental studies for determining human discomfort response to vertical sinusoidal vibration

NASA Technical Reports Server (NTRS)

Dempsey, T. K.; Leatherwood, J. D.

1975-01-01

A study was conducted to investigate several problems related to methodology and design of experiments to obtain human comfort response to vertical sinusoidal vibration. Specifically, the studies were directed to the determination of (1) the adequacy of frequency averaging of vibration data to obtain discomfort predictors, (2) the effect of practice on subject ratings, (3) the effect of the demographic factors of age, sex, and weight, and (4) the relative importance of seat and floor vibrations in the determination of measurement and criteria specification location. Results indicate that accurate prediction of discomfort requires knowledge of both the acceleration level and frequency content of the vibration stimuli. More importantly, the prediction of discomfort was shown to be equally good based upon either floor accelerations or seat accelerations. Furthermore, it was demonstrated that the discomfort levels in different seats resulting from similar vibratory imputs were equal. Therefore, it was recommended that criteria specifications and acceleration measurements be made at the floor location. The results also indicated that practice did not systematically influence discomfort responses nor did the demographic factors of age, weight, and sex contribute to the discomfort response variation.

Integral flange design program. [procedure for computing stresses

NASA Technical Reports Server (NTRS)

Wilson, J. F.

1974-01-01

An automated interactive flange design program utilizing an electronic desk top calculator is presented. The program calculates the operating and seating stresses for circular flanges of the integral or optional type subjected to internal pressure. The required input information is documented. The program provides an automated procedure for computing stresses in selected flange geometries for comparison to the allowable code values.

THE PRODUCTION AND EVALUATION OF THREE COMPUTER-BASED ECONOMICS GAMES FOR THE SIXTH GRADE. FINAL REPORT.

ERIC Educational Resources Information Center

WING, RICHARD L.; AND OTHERS

THE PURPOSE OF THE EXPERIMENT WAS TO PRODUCE AND EVALUATE 3 COMPUTER-BASED ECONOMICS GAMES AS A METHOD OF INDIVIDUALIZING INSTRUCTION FOR GRADE 6 STUDENTS. 26 EXPERIMENTAL SUBJECTS PLAYED 2 ECONOMICS GAMES, WHILE A CONTROL GROUP RECEIVED CONVENTIONAL INSTRUCTION ON SIMILAR MATERIAL. IN THE SUMERIAN GAME, STUDENTS SEATED AT THE TYPEWRITER TERMINALS…

Computational fluid dynamics modeling of transport and deposition of pesticides in an aircraft cabin

PubMed Central

Isukapalli, Sastry S.; Mazumdar, Sagnik; George, Pradeep; Wei, Binnian; Jones, Byron; Weisel, Clifford P.

2015-01-01

Spraying of pesticides in aircraft cabins is required by some countries as part of a disinsection process to kill insects that pose a public health threat. However, public health concerns remain regarding exposures of cabin crew and passengers to pesticides in aircraft cabins. While large scale field measurements of pesticide residues and air concentrations in aircraft cabins scenarios are expensive and time consuming, Computational Fluid Dynamics (CFD) models provide an effective alternative for characterizing concentration distributions and exposures. This study involved CFD modeling of a twin-aisle 11 row cabin mockup with heated manikins, mimicking a part of a fully occupied Boeing 767 cabin. The model was applied to study the flow and deposition of pesticides under representative scenarios with different spraying patterns (sideways and overhead) and cabin air exchange rates (low and high). Corresponding spraying experiments were conducted in the cabin mockup, and pesticide deposition samples were collected at the manikin’s lap and seat top for a limited set of five seats. The CFD model performed well for scenarios corresponding to high air exchange rates, captured the concentration profiles for middle seats under low air exchange rates, and underestimated the concentrations at window seats under low air exchange rates. Additionally, both the CFD and experimental measurements showed no major variation in deposition characteristics between sideways and overhead spraying. The CFD model can estimate concentration fields and deposition profiles at very high resolutions, which can be used for characterizing the overall variability in air concentrations and surface loadings. Additionally, these model results can also provide a realistic range of surface and air concentrations of pesticides in the cabin that can be used to estimate potential exposures of cabin crew and passengers to these pesticides. PMID:25642134

Human Robotic Study at Houghton Crater - virtual reality study from NASA Ames (FFC) Future Fight

NASA Technical Reports Server (NTRS)

2002-01-01

Human Robotic Study at Houghton Crater - virtual reality study from NASA Ames (FFC) Future Fight Central simulator tower L-R: Dr Geoffrey Briggs; Jen Jasper (seated); Dr Jan Akins and Mr. Tony Gross, Ames

Variation between seated and standing/walking postures among male and female call centre operators.

PubMed

Toomingas, Allan; Forsman, Mikael; Mathiassen, Svend Erik; Heiden, Marina; Nilsson, Tohr

2012-03-02

The dose and time-pattern of sitting has been suggested in public health research to be an important determinant of risk for developing a number of diseases, including cardiovascular disorders and diabetes. The aim of the present study was to assess the time-pattern of seated and standing/walking postures amongst male and female call centre operators, on the basis of whole-shift posture recordings, analysed and described by a number of novel variables describing posture variation. Seated vs. standing/walking was recorded using dichotomous inclinometers throughout an entire work shift for 43 male and 97 female call centre operators at 16 call centres. Data were analysed using an extensive set of variables describing occurrence of and switches between seated and standing/walking, posture similarity across the day, and compliance with standard recommendations for computer work. The majority of the operators, both male and female, spent more than 80% of the shift in a seated posture with an average of 10.4 switches/hour between seated and standing/walking or vice versa. Females spent, on average, 11% of the day in periods of sustained sitting longer than 1 hour; males 4.6% (p = 0.013). Only 38% and 11% of the operators complied with standard recommendations of getting an uninterrupted break from seated posture of at least 5 or 10 minutes, respectively, within each hour of work. Two thirds of all investigated variables showed coefficients of variation between subjects above 0.5. Since work tasks and contractual break schedules were observed to be essentially similar across operators and across days, this indicates that sedentary behaviours differed substantially between individuals. The extensive occurrence of uninterrupted seated work indicates that efforts should be made at call centres - and probably in other settings in the office sector - to introduce more physical variation in terms of standing/walking periods during the work day. We suggest the metrics used in this study for quantifying variation in sedentary behaviour to be of interest even for other dichotomous exposures relevant to occupational and public health, for instance physical activity/inactivity.

An efficient workflow to accurately compute groundwater recharge for the study of rainfall-triggered deep-seated landslides, application to the Séchilienne unstable slope (western Alps)

NASA Astrophysics Data System (ADS)

Vallet, A.; Bertrand, C.; Fabbri, O.; Mudry, J.

2015-01-01

Pore water pressure build-up by recharge of underground hydrosystems is one of the main triggering factors of deep-seated landslides. In most deep-seated landslides, pore water pressure data are not available since piezometers, if any, have a very short lifespan because of slope movements. As a consequence, indirect parameters, such as the calculated recharge, are the only data which enable understanding landslide hydrodynamic behaviour. However, in landslide studies, methods and recharge-area parameters used to determine the groundwater recharge are rarely detailed. In this study, the groundwater recharge is estimated with a soil-water balance based on characterisation of evapotranspiration and parameters characterising the recharge area (soil available water capacity, runoff and vegetation coefficient). A workflow to compute daily groundwater recharge is developed. This workflow requires the records of precipitation, air temperature, relative humidity, solar radiation and wind speed within or close to the landslide area. The determination of the parameters of the recharge area is based on a spatial analysis requiring field observations and spatial data sets (digital elevation models, aerial photographs and geological maps). This study demonstrates that the performance of the correlation with landslide displacement velocity data is significantly improved using the recharge estimated with the proposed workflow. The coefficient of determination obtained with the recharge estimated with the proposed workflow is 78% higher on average than that obtained with precipitation, and is 38% higher on average than that obtained with recharge computed with a commonly used simplification in landslide studies (recharge = precipitation minus non-calibrated evapotranspiration method).

Design and milling manufacture of polyurethane custom contoured cushions for wheelchair users.

PubMed

da Silva, Fabio Pinto; Beretta, Elisa Marangon; Prestes, Rafael Cavalli; Kindlein Junior, Wilson

2011-01-01

The design of custom contoured cushions manufactured in flexible polyurethane foams is an option to improve positioning and comfort for people with disabilities that spend most of the day seated in the same position. These surfaces increase the contact area between the seat and the user. This fact contributes to minimise the local pressures that can generate problems like decubitus ulcers. The present research aims at establishing development routes for custom cushion production to wheelchair users. This study also contributes to the investigation of Computer Numerical Control (CNC) machining of flexible polyurethane foams. The proposed route to obtain the customised seat began with acquiring the user's contour in adequate posture through plaster cast. To collect the surface geometry, the cast was three-dimensionally scanned and manipulated in CAD/CAM software. CNC milling parameters such as tools, spindle speeds and feed rates to machine flexible polyurethane foams were tested. These parameters were analysed regarding the surface quality. The best parameters were then tested in a customised seat. The possible dimensional changes generated during foam cutting were analysed through 3D scanning. Also, the customised seat pressure and temperature distribution was tested. The best parameters found for foams with a density of 50kg/cm(3) were high spindle speeds (24000 rpm) and feed rates between 2400-4000mm/min. Those parameters did not generate significant deformities in the machined cushions. The custom contoured cushion satisfactorily increased the contact area between wheelchair and user, as it distributed pressure and heat evenly. Through this study it was possible to define routes for the development and manufacturing of customised seats using direct CNC milling in flexible polyurethane foams. It also showed that custom contoured cushions efficiently distribute pressure and temperature, which is believed to minimise tissue lesions such as pressure ulcers.

Study of the counting efficiency of a WBC setup by using a computational 3D human body library in sitting position based on polygonal mesh surfaces.

PubMed

Fonseca, T C Ferreira; Bogaerts, R; Lebacq, A L; Mihailescu, C L; Vanhavere, F

2014-04-01

A realistic computational 3D human body library, called MaMP and FeMP (Male and Female Mesh Phantoms), based on polygonal mesh surface geometry, has been created to be used for numerical calibration of the whole body counter (WBC) system of the nuclear power plant (NPP) in Doel, Belgium. The main objective was to create flexible computational models varying in gender, body height, and mass for studying the morphology-induced variation of the detector counting efficiency (CE) and reducing the measurement uncertainties. First, the counting room and an HPGe detector were modeled using MCNPX (Monte Carlo radiation transport code). The validation of the model was carried out for different sample-detector geometries with point sources and a physical phantom. Second, CE values were calculated for a total of 36 different mesh phantoms in a seated position using the validated Monte Carlo model. This paper reports on the validation process of the in vivo whole body system and the CE calculated for different body heights and weights. The results reveal that the CE is strongly dependent on the individual body shape, size, and gender and may vary by a factor of 1.5 to 3 depending on the morphology aspects of the individual to be measured.

Effects of body height, notebook computer size, and workstation height on recommended adjustments for proper work posture when operating a notebook computer.

PubMed

Nanthavanij, Suebsak; Jalil, Sakib; Ammarapala, Veeris

2008-12-01

Factors which are likely to affect recommended workstation and notebook computer (NBC) adjustments to obtain ergonomic work posture during NBC operation are investigated. They are: (1) body height, (2) NBC size, and (3) workstation height (i.e., seat and work surface heights). Six recommended adjustments which are evaluated include: (1) footrest height, (2) seat support height, (3) NBC base support height, (4) distance between the user's body and NBC (or user-NBC distance), (5) tilt angle of NBC base, and (6) screen angle. It is found that body height has a significant effect on footrest height and user-NBC distance while NBC size has a significant effect on user-NBC distance, tilt angle of NBC base, and screen angle. Workstation height, on the other hand, does not show any effect on the six recommended adjustments. However, the results suggest that there are interactions between body height and NBC size, and between body height and workstation height when evaluating their effects on footrest height, tilt angle of NBC base, and screen angle.

Rail passenger equipment collision tests : analysis of occupant protection measurements

DOT National Transportation Integrated Search

2000-01-01

The Federal Railroad Administration has been conducting research : on occupant protection in train collisions. As part of this research, : computer simulations have been performed, passenger seats have been sled tested, and two full-scale collision t...

Some Aspects of the Investigation of Random Vibration Influence on Ride Comfort

NASA Astrophysics Data System (ADS)

DEMIĆ, M.; LUKIĆ, J.; MILIĆ, Ž.

2002-05-01

Contemporary vehicles must satisfy high ride comfort criteria. This paper attempts to develop criteria for ride comfort improvement. The highest loading levels have been found to be in the vertical direction and the lowest in lateral direction in passenger cars and trucks. These results have formed the basis for further laboratory and field investigations. An investigation of the human body behaviour under random vibrations is reported in this paper. The research included two phases; biodynamic research and ride comfort investigation. A group of 30 subjects was tested. The influence of broadband random vibrations on the human body was examined through the seat-to-head transmissibility function (STHT). Initially, vertical and fore and aft vibrations were considered. Multi-directional vibration was also investigated. In the biodynamic research, subjects were exposed to 0·55, 1·75 and 2·25 m/s2 r.m.s. vibration levels in the 0·5- 40 Hz frequency domain. The influence of sitting position on human body behaviour under two axial vibrations was also examined. Data analysis showed that the human body behaviour under two-directional random vibrations could not be approximated by superposition of one-directional random vibrations. Non-linearity of the seated human body in the vertical and fore and aft directions was observed. Seat-backrest angle also influenced STHT. In the second phase of experimental research, a new method for the assessment of the influence of narrowband random vibration on the human body was formulated and tested. It included determination of equivalent comfort curves in the vertical and fore and aft directions under one- and two-directional narrowband random vibrations. Equivalent comfort curves for durations of 2·5, 4 and 8 h were determined.

Human Kinematics During Non-Collinear Low Velocity Rear End Collisions

PubMed Central

McConnell, Whitman E.; Guzman, Herbert M.; Krenrich, Scott W.; Bomar, John B.; Harding, Richard M.; Raddin, James H.; Funk, James R.; Smith, Darrin A.

2003-01-01

Non-collinear low velocity rear end (LVRE) collision human kinematics have not previously been studied. Occupant head and neck motions during twenty similar non-collinear (15 and 30 degree angle) left rear end collisions were analyzed for five male test subjects alternately positioned in the left and right front seats of the struck vehicle. Displacement-time and acceleration data for occupant, seat, and vehicles were determined by 3D motion analyses and linear accelerometer outputs. The dynamics of the struck vehicle at 6.0 to 9.3 kph (3.8 to 5.8 mph) delta-V showed an initial period of yaw, even when the rear tires did not lose traction with the pavement. The brief yaw seen during the 15 degree impacts was accompanied by early relative rightward movement of the vehicle’s seat and seatback behind the stationary test subject: the subjects subsequently engaged the left region of the seatback and head restraint. A more pronounced yaw accompanied the loss of rear tire traction during the 30 degree tests, and resulted in occupant contact/loading further toward the left edge of the seat back and head restraint. For a given striking vehicle velocity, the impact severity in terms of head acceleration and changes in head velocity were significantly lower (p<0.05) at vehicle impact angles of 30 degrees compared with 15 degrees. Clinically, there were only minor short-term symptoms and no long-term symptoms observed in these angled impacts. PMID:12941242

Seat Interfaces for Aircrew Performance and Safety

DTIC Science & Technology

2010-01-01

Quantum -II Desktop System consists of a keyboard and hardware accessories (electrodes, cables, etc.), and interfaces with a desktop computer via software...segment. Resistance and reactance data was collected to estimate blood volume changes. The Quantum -II Desktop system collected continuous data of...Approved for public release; distribution unlimited. 88 ABW Cleared 03/13/2015; 88ABW-2015-1053. mockup also included a laptop computer , a

GPSS/360 computer models to simulate aircraft passenger emergency evacuations.

DOT National Transportation Integrated Search

1972-09-01

Live tests of emergency evacuation of transport aircraft are becoming increasingly expensive as the planes grow to a size seating hundreds of passengers. Repeated tests, to cope with random variations, increase these costs, as well as risks of injuri...

Blinded by Science.

ERIC Educational Resources Information Center

Snyder, Tom

1994-01-01

Huge infusion of technology is coming into education; nothing can stop it, because so much money is involved. With computer marketers in driver seat instead of teachers, schools risk being blinded by science. Vendors have coopted progressive education buzzwords, including "frontal teaching,""linear thinking," and "computer…

Descriptive analysis of combine cabin vibrations and their effect on the human body

NASA Astrophysics Data System (ADS)

Hostens, I.; Ramon, H.

2003-09-01

All on- and off-road vehicles are exposed to vibrations caused by unevenness of road or soil profile, moving elements within the machine or implements. A higher prevalence of low back pain is found in drivers of off-road machinery than in other drivers. In this study, significantly higher levels of low-frequency vibrations are found in the cabin of a combine, driving at high speed (20 km/h) on a concrete surface, compared to driving slower on field road. Comfort values indicate that injury can result from long-term driving on the field as well as on a concrete road. As seats with suspension systems are the main transmission paths of vibration towards the spine of the driver, their vibration attenuating characteristics play an important role in comfort assessment. The resonant frequency of seats with passive suspension system, used in agricultural machinery, lies in the low-frequency range most excited in agricultural machinery. A seat with air suspension is found to attenuate better frequencies above 4 Hz and provide more comfort to the driver than a seat with a mechanical suspension.

Biomechanical assessment of a rear-seat inflatable seatbelt in frontal impacts.

PubMed

Sundararajan, Srinivasan; Rouhana, Stephen W; Board, Derek; DeSmet, Ed; Prasad, Priya; Rupp, Jonathan D; Miller, Carl S; Schneider, Lawrence W

2011-11-01

This study evaluated the biomechanical performance of a rear-seat inflatable seatbelt system and compared it to that of a 3-point seatbelt system, which has a long history of good real-world performance. Frontal-impact sled tests were conducted with Hybrid III anthropomorphic test devices (ATDs) and with post mortem human subjects (PMHS) using both restraint systems and a generic rear-seat configuration. Results from these tests demonstrated: a) reduction in forward head excursion with the inflatable seatbelt system when compared to that of a 3-point seatbelt and; b) a reduction in ATD and PMHS peak chest deflections and the number of PMHS rib fractures with the inflatable seatbelt system and c) a reduction in PMHS cervical-spine injuries, due to the interaction of the chin with the inflated shoulder belt. These results suggest that an inflatable seatbelt system will offer additional benefits to some occupants in the rear seats. Further research is needed to assess the field effectiveness, customer comfort and acceptance and change in the belt usage rate with the inflatable seatbelt system.

FDTD calculations of specific energy absorption rate in a seated voxel model of the human body from 10 MHz to 3 GHz

NASA Astrophysics Data System (ADS)

Findlay, R. P.; Dimbylow, P. J.

2006-05-01

Finite-difference time-domain (FDTD) calculations have been performed to investigate the frequency dependence of the specific energy absorption rate (SAR) in a seated voxel model of the human body. The seated model was derived from NORMAN (NORmalized MAN), an anatomically realistic voxel phantom in the standing posture with arms to the side. Exposure conditions included both vertically and horizontally polarized plane wave electric fields between 10 MHz and 3 GHz. The resolution of the voxel model was 4 mm for frequencies up to 360 MHz and 2 mm for calculations in the higher frequency range. The reduction in voxel size permitted the calculation of SAR at these higher frequencies using the FDTD method. SAR values have been calculated for the seated adult phantom and scaled versions representing 10-, 5- and 1-year-old children under isolated and grounded conditions. These scaled models do not exactly reproduce the dimensions and anatomy of children, but represent good geometric information for a seated child. Results show that, when the field is vertically polarized, the sitting position causes a second, smaller resonance condition not seen in resonance curves for the phantom in the standing posture. This occurs at ~130 MHz for the adult model when grounded. Partial-body SAR calculations indicate that the upper and lower regions of the body have their own resonant frequency at ~120 MHz and ~160 MHz, respectively, when the grounded adult model is orientated in the sitting position. These combine to produce this second resonance peak in the whole-body averaged SAR values calculated. Two resonance peaks also occur for the sitting posture when the incident electric field is horizontally polarized. For the adult model, the peaks in the whole-body averaged SAR occur at ~180 and ~600 MHz. These peaks are due to resonance in the arms and feet, respectively. Layer absorption plots and colour images of SAR in individual voxels show the specific regions in which the seated human body absorbs the incident field. External electric field values required to produce the ICNIRP basic restrictions were derived from SAR calculations and compared with ICNIRP reference levels. This comparison shows that the reference levels provide a conservative estimate of the ICNIRP whole-body averaged SAR restriction, with the exception of the region above 1.4 GHz for the scaled 1-year-old model.

FDTD calculations of specific energy absorption rate in a seated voxel model of the human body from 10 MHz to 3 GHz.

PubMed

Findlay, R P; Dimbylow, P J

2006-05-07

Finite-difference time-domain (FDTD) calculations have been performed to investigate the frequency dependence of the specific energy absorption rate (SAR) in a seated voxel model of the human body. The seated model was derived from NORMAN (NORmalized MAN), an anatomically realistic voxel phantom in the standing posture with arms to the side. Exposure conditions included both vertically and horizontally polarized plane wave electric fields between 10 MHz and 3 GHz. The resolution of the voxel model was 4 mm for frequencies up to 360 MHz and 2 mm for calculations in the higher frequency range. The reduction in voxel size permitted the calculation of SAR at these higher frequencies using the FDTD method. SAR values have been calculated for the seated adult phantom and scaled versions representing 10-, 5- and 1-year-old children under isolated and grounded conditions. These scaled models do not exactly reproduce the dimensions and anatomy of children, but represent good geometric information for a seated child. Results show that, when the field is vertically polarized, the sitting position causes a second, smaller resonance condition not seen in resonance curves for the phantom in the standing posture. This occurs at approximately 130 MHz for the adult model when grounded. Partial-body SAR calculations indicate that the upper and lower regions of the body have their own resonant frequency at approximately 120 MHz and approximately 160 MHz, respectively, when the grounded adult model is orientated in the sitting position. These combine to produce this second resonance peak in the whole-body averaged SAR values calculated. Two resonance peaks also occur for the sitting posture when the incident electric field is horizontally polarized. For the adult model, the peaks in the whole-body averaged SAR occur at approximately 180 and approximately 600 MHz. These peaks are due to resonance in the arms and feet, respectively. Layer absorption plots and colour images of SAR in individual voxels show the specific regions in which the seated human body absorbs the incident field. External electric field values required to produce the ICNIRP basic restrictions were derived from SAR calculations and compared with ICNIRP reference levels. This comparison shows that the reference levels provide a conservative estimate of the ICNIRP whole-body averaged SAR restriction, with the exception of the region above 1.4 GHz for the scaled 1-year-old model.

A case of hemothorax following seat-belt injury with a bulla in the apex of the lung: a subtype of spontaneous hemopneumothorax.

PubMed

Kinoshita, Haruyuki; Akiyama, Naoko; Murao, Masaki; Yamauchi, Yosuke; Nakamura, Teruya; Sekiya, Naosumi; Toyota, Naoyuki; Miyagatani, Yasusuke

2015-05-01

We experienced a case of a subtype of spontaneous hemopneumothorax caused by external forces associated with a seat-belt injury. A female aged 39 years sustained a minor collision with an oncoming car while she was driving. Although pneumothorax was not detected, hemothorax and bleeding from the area surrounding the subclavian artery were observed on contrast-enhanced chest computed tomography (CT). After confirming continuous bleeding into the thoracic cavity after superselective arterial embolization, we performed emergency open surgery. We found a bulla in the apex of the lung, and the thoracic stump of the bulla was considered the source of bleeding. In this case, the direct cause of hemothorax was considered to be the external force associated with the seat-belt injury. When a bulla in the apex of the lung and continuous bleeding are both observed on CT, spontaneous hemopneumothorax should be suspected, necessitating open chest surgery in cases where pneumothorax is not observed.

Characterization of specific anti-Candida IgM, IgA and IgE: diagnostic value in deep-seated infections.

PubMed

Aubert, D; Puygauthier-Toubas, D; Leon, P; Pignon, B; Foudrinier, F; Marnef, F; Boulant, J; Pinon, J M

1996-01-01

The proposed serological diagnosis of systemic Candida infections is based on a microplate immunocapture technique detecting IgM, IgA and IgE anti-Candida antibodies. Activity is revealed with a suspension of human erythrocytes sensitized with somatic antigen of Candida albicans, and is quantified on an automated plate reader. The sera were obtained from patients with deep-seated (n = 56) and superficial (n = 193) candidosis. We compared this immunological method with a combination of indirect immunofluorescence and co-immunoelectrodiffusion. The immunocapture method was more sensitive (80.4% vs. 48.2% with indirect immunofluorescence and 58.9% with co-immunoelectrodiffusion), and often provided the diagnosis at an earlier stage, with clear therapeutic advantages. The IgA isotype was a particularly valuable marker of deep-seated Candida infections.

Tilting table for ergometer and for other biomedical devices

NASA Technical Reports Server (NTRS)

Gause, R. L.; Spier, R. A. (Inventor)

1973-01-01

The apparatus is for testing the human body in a variety of positions, ranging from the vertical to the supine, while exercising on an ergometer; and can also be used for angular positioning of other biomedical devices. It includes a floor plate and a hinged plate upon which to fix the ergometer, a back rest and a head rest attached at right angles to said hinged plate and behind the seat of the ergometer, dual hydraulic cylinders for raising and lowering the hinged plate through 90 deg by means of a self contained hydraulic system, with valve means for control and positive stops on the apparatus to prevent over travel. Tests can be made with the subject positioned on the seat of the ergometer, through the various angles, with a substantially normal body attitude relative to the seat and ergometer.

Microgravity

NASA Image and Video Library

2000-04-19

Dr. Marc Pusey (seated) and Dr. Craig Kundrot use computers to analyze x-ray maps and generate three-dimensional models of protein structures. With this information, scientists at Marshall Space Flight Center can learn how proteins are made and how they work. The computer screen depicts a proten structure as a ball-and-stick model. Other models depict the actual volume occupied by the atoms, or the ribbon-like structures that are crucial to a protein's function.

Pedal force determination respect to ride comfort

NASA Astrophysics Data System (ADS)

Mačužić, Slavica; Lukić, Jovanka; Glišović, Jasna; Miloradović, Danijela

2017-10-01

Automotive ergonomics is a set of knowledge which has a task to design a vehicle to make the passengers feel comfortable. Interior packaging represents an important stage in the vehicle design process, in order to enable the driver to every important aspect of movement. During the process of driving, the driver performs various movements of arms and legs, leading to a certain fatigue. Each seating position in the vehicle, contain certain boundary conditions, and for that reason it was necessary to examine how the seating position affects the driver possibilities. In this paper, the pedal forces were determined by application of Ramsis human model. Different human populations were taken into account. Correlation between subjects’ anthropometrics measures and the foot pedal force pedal was observed. Obtained results were significant input data for vehicle packaging.

MRI Reconstructions of Human Phrenic Nerve Anatomy and Computational Modeling of Cryoballoon Ablative Therapy.

PubMed

Goff, Ryan P; Spencer, Julianne H; Iaizzo, Paul A

2016-04-01

The primary goal of this computational modeling study was to better quantify the relative distance of the phrenic nerves to areas where cryoballoon ablations may be applied within the left atria. Phrenic nerve injury can be a significant complication of applied ablative therapies for treatment of drug refractory atrial fibrillation. To date, published reports suggest that such injuries may occur more frequently in cryoballoon ablations than in radiofrequency therapies. Ten human heart-lung blocs were prepared in an end-diastolic state, scanned with MRI, and analyzed using Mimics software as a means to make anatomical measurements. Next, generated computer models of ArticFront cryoballoons (23, 28 mm) were mated with reconstructed pulmonary vein ostias to determine relative distances between the phrenic nerves and projected balloon placements, simulating pulmonary vein isolation. The effects of deep seating balloons were also investigated. Interestingly, the relative anatomical differences in placement of 23 and 28 mm cryoballoons were quite small, e.g., the determined difference between mid spline distance to the phrenic nerves between the two cryoballoon sizes was only 1.7 ± 1.2 mm. Furthermore, the right phrenic nerves were commonly closer to the pulmonary veins than the left, and surprisingly tips of balloons were further from the nerves, yet balloon size choice did not significantly alter calculated distance to the nerves. Such computational modeling is considered as a useful tool for both clinicians and device designers to better understand these associated anatomies that, in turn, may lead to optimization of therapeutic treatments.

Mapping Prefrontal Cortex Functions in Human Infancy

ERIC Educational Resources Information Center

Grossmann, Tobias

2013-01-01

It has long been thought that the prefrontal cortex, as the seat of most higher brain functions, is functionally silent during most of infancy. This review highlights recent work concerned with the precise mapping (localization) of brain activation in human infants, providing evidence that prefrontal cortex exhibits functional activation much…

Computer simulation of an Aircraft Seat and Occupant(s) in a Crash Environment - Program SOM-LA/SOM-TA (User Manual)

DTIC Science & Technology

1991-05-01

INFORMATION 8 2.7.1 Rigid Seat Option 8 2.7.2 Simplified Energy-Absorbing Seal Option 8 2.7.3 Finite Elemrent Structural Analysis 8 3.0 PROGRAM OUTPUT DATA 10...62000. 0,0 0.0 00035000 244130- STFEL 000330].0 7 .120E-4 29.086 163000. 6. CFb 180000. 0. 𔃻 00034010 174000. 81000, 0.0 0.0 00035010 8 0 0.4347 0.3028...0.0 IRoiational damping in neck. (Ub .’c). IIUCEIFjI.__Qti: Dimensions of seaL model as shown in Figure A-8. _45Y 0 V14567 ’TT2 l-8-7-T345367 0 1

Computer Laboratory Workstation Dimensions: Scaling Down for Elementary School Children.

ERIC Educational Resources Information Center

Wilson, Janetta A.

1991-01-01

Discusses design of microcomputer workstations for children. Dimensions for seating and worksurface are suggested for ages 6-8 and 9-11, and these dimensions are compared to adult standards. Several drawings and tables are used to present the design specifications. (nine references) (MES)

[Numerical finite element modeling of custom car seat using computer aided design].

PubMed

Huang, Xuqi; Singare, Sekou

2014-02-01

A good cushion can not only provide the sitter with a high comfort, but also control the distribution of the hip pressure to reduce the incidence of diseases. The purpose of this study is to introduce a computer-aided design (CAD) modeling method of the buttocks-cushion using numerical finite element (FE) simulation to predict the pressure distribution on the buttocks-cushion interface. The buttock and the cushion model geometrics were acquired from a laser scanner, and the CAD software was used to create the solid model. The FE model of a true seated individual was developed using ANSYS software (ANSYS Inc, Canonsburg, PA). The model is divided into two parts, i.e. the cushion model made of foam and the buttock model represented by the pelvis covered with a soft tissue layer. Loading simulations consisted of imposing a vertical force of 520N on the pelvis, corresponding to the weight of the user upper extremity, and then solving iteratively the system.

Characterization of posture and comfort in laptop users in non-desk settings.

PubMed

Gold, J E; Driban, J B; Yingling, V R; Komaroff, E

2012-03-01

Laptop computers may be used in a variety of postures not coupled to the office workstation. Using passive motion analysis, this study examined mean joint angles during a short typing/editing task in college students (n=20), in up to seven positions. Comfort was assessed after task execution through a body map. For three required postures, joint angles in a prone posture were different than those while seated at a couch with feet either on floor or on ottoman. Specifically, the prone posture was characterized by comparatively non-neutral shoulders, elbows and wrists, and pronounced neck extension. Significantly greater intensity and more regions of discomfort were marked for the prone posture than for the seated postures. It is recommended that the prone posture only be assumed briefly during laptop use. Exposure to laptops outside of the office setting should be assessed in future epidemiologic studies of musculoskeletal complaints and computer use. Copyright © 2011 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Finite element models of the thigh-buttock complex for assessing static sitting discomfort and pressure sore risk: a literature review.

PubMed

Savonnet, Léo; Wang, Xuguang; Duprey, Sonia

2018-03-01

Being seated for long periods, while part of many leisure or occupational activities, can lead to discomfort, pain and sometimes health issues. The impact of prolonged sitting on the body has been widely studied in the literature, with a large number of human-body finite element models developed to simulate sitting and assess seat-induced discomfort or to investigate the biomechanical factors involved. Here, we review the finite element models developed to investigate sitting discomfort or risk of pressure sores. Our study examines finite element models from twenty-seven papers, seventeen dedicated to assessing seating discomfort and ten dedicated to investigating pressure ulcers caused by prolonged sitting. The models' mesh composition and material properties are found to differ widely. These models share a lack of validation and generally make little allowance for anthropometric diversity.

49 CFR 393.93 - Seats, seat belt assemblies, and seat belt assembly anchorages.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 5 2012-10-01 2012-10-01 false Seats, seat belt assemblies, and seat belt assembly anchorages. 393.93 Section 393.93 Transportation Other Regulations Relating to Transportation... § 393.93 Seats, seat belt assemblies, and seat belt assembly anchorages. (a) Buses—(1) Buses...

49 CFR 393.93 - Seats, seat belt assemblies, and seat belt assembly anchorages.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 5 2010-10-01 2010-10-01 false Seats, seat belt assemblies, and seat belt assembly anchorages. 393.93 Section 393.93 Transportation Other Regulations Relating to Transportation... § 393.93 Seats, seat belt assemblies, and seat belt assembly anchorages. (a) Buses—(1) Buses...

49 CFR 393.93 - Seats, seat belt assemblies, and seat belt assembly anchorages.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 5 2011-10-01 2011-10-01 false Seats, seat belt assemblies, and seat belt assembly anchorages. 393.93 Section 393.93 Transportation Other Regulations Relating to Transportation... § 393.93 Seats, seat belt assemblies, and seat belt assembly anchorages. (a) Buses—(1) Buses...

49 CFR 393.93 - Seats, seat belt assemblies, and seat belt assembly anchorages.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 5 2014-10-01 2014-10-01 false Seats, seat belt assemblies, and seat belt assembly anchorages. 393.93 Section 393.93 Transportation Other Regulations Relating to Transportation... § 393.93 Seats, seat belt assemblies, and seat belt assembly anchorages. (a) Buses—(1) Buses...

49 CFR 393.93 - Seats, seat belt assemblies, and seat belt assembly anchorages.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 5 2013-10-01 2013-10-01 false Seats, seat belt assemblies, and seat belt assembly anchorages. 393.93 Section 393.93 Transportation Other Regulations Relating to Transportation... § 393.93 Seats, seat belt assemblies, and seat belt assembly anchorages. (a) Buses—(1) Buses...

Construction of a mathematical model of the human body, taking the nonlinear rigidity of the spine into account

NASA Technical Reports Server (NTRS)

Glukharev, K. K.; Morozova, N. I.; Potemkin, B. A.; Solovyev, V. S.; Frolov, K. V.

1973-01-01

A mathematical model of the human body was constructed, under the action of harmonic vibrations, in the 2.5-7 Hz frequency range. In this frequency range, the model of the human body as a vibrating system, with concentrated parameters is considered. Vertical movements of the seat and vertical components of vibrations of the human body are investigated.

Demodulation Processes in Auditory Perception.

DTIC Science & Technology

1992-08-15

not provide a fused image that the listener can process binaurally . 5 A type of dichotic profile has been developed for this study in which the stimulus...the component frequencies between the two ears may allow the i listener to develop a better fused image to be processed i binaurally than in the...listener was seated facing a 3 monitor and computer keyboard (Radio Shack Color Computer II). Signals were presented binaurally via Sennheiser HD414SL

STS-41 Commander Richards uses DTO 1206 portable computer onboard OV-103

NASA Technical Reports Server (NTRS)

1990-01-01

STS-41 Commander Richard N. Richards, at pilots station, uses Detailed Test Objective (DTO) Space Station Cursor Control Device Evaluation MACINTOSH portable computer on the forward flight deck of Discovery, Orbiter Vehicle (OV) 103. Richards tests the roller ball cursor control device. Surrounding Richards are checklists, forward flight deck windows, his lightweight communications kit assembly headset, a beverage container (orange-mango drink), and the pilots seat back and headrest.

School Libraries: A Design Recipe for the Future.

ERIC Educational Resources Information Center

Myerberg, Henry

2002-01-01

Discusses design elements of a 21st century school library, including space, books and shelving, seats, tables, technology (computers, scanners, projectors), building materials (wood, metal, plastic, paint, glass, fibers), and light and color. A sidebar describes the L!BRARY initiative to creatively design, professionally staff, and…

Take a Seat.

ERIC Educational Resources Information Center

Grant, Deborah R.

1999-01-01

Examines the factors involved in purchasing school furnishings that will help ensure its long-time use, safety, and ability to resist abuse. Cost and safety factors discussed include resisting trendy colors to reduce cost in furniture matching, managing computer and office wiring for safety, considering ergonomics in the purchasing decision, and…

Supporting Mobile Collaborative Activities through Scaffolded Flexible Grouping

ERIC Educational Resources Information Center

Boticki, Ivica; Looi, Chee-Kit; Wong, Lung-Hsiang

2011-01-01

Within the field of Mobile Computer-Supported Collaborative Learning (mCSCL), we are interested in exploring the space of collaborative activities that enable students to practice communication, negotiation and decision-making skills. Collaboration is via learning activities that circumvent the constraints of fixed seating or locations of…

The application of SEAT values for predicting how compliant seats with backrests influence vibration discomfort.

PubMed

Basri, Bazil; Griffin, Michael J

2014-11-01

The extent to which a seat can provide useful attenuation of vehicle vibration depends on three factors: the characteristics of the vehicle motion, the vibration transmissibility of the seat, and the sensitivity of the body to vibration. The 'seat effective amplitude transmissibility' (i.e., SEAT value) reflects how these three factors vary with the frequency and the direction of vibration so as to predict the vibration isolation efficiency of a seat. The SEAT value is mostly used to select seat cushions or seat suspensions based on the transmission of vertical vibration to the principal supporting surface of a seat. This study investigated the accuracy of SEAT values in predicting how seats with backrests influence the discomfort caused by multiple-input vibration. Twelve male subjects participated in a four-part experiment to determine equivalent comfort contours, the relative discomfort, the location of discomfort, and seat transmissibility with three foam seats and a rigid reference seat at 14 frequencies of vibration in the range 1-20 Hz at magnitudes of vibration from 0.2 to 1.6 ms(-2) r.m.s. The 'measured seat dynamic discomfort' (MSDD) was calculated for each foam seat from the ratio of the vibration acceleration required to cause similar discomfort with the foam seat and with the rigid reference seat. Using the frequency weightings in current standards, the SEAT values of each seat were calculated from the ratio of overall ride values with the foam seat to the overall ride values with the rigid reference seat, and compared to the corresponding MSDD at each frequency. The SEAT values provided good predictions of how the foam seats increased vibration discomfort at frequencies around the 4-Hz resonance but reduced vibration discomfort at frequencies greater than about 6.3 Hz, with discrepancies explained by a known limitation of the frequency weightings. Copyright © 2014 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Tolerances of the human face to crash impact.

DOT National Transportation Integrated Search

1965-07-01

Evaluation of the injury potentials of commercial airline seat structures, light-aircraft instrument panels, and other deforming structures requires data on forces that produce fractures, lacerations, or unconsciousness when applied to different part...

An experimental study for determining human discomfort response to roll vibration

NASA Technical Reports Server (NTRS)

Leatherwood, J. D.; Dempsey, T. K.; Clevenson, S. A.

1976-01-01

An experimental study using a passenger ride quality apparatus (PRQA) was conducted to determine the subjective reactions of passengers to roll vibrations. The data obtained illustrate the effect upon human comfort of several roll-vibration parameters: namely, roll acceleration level, roll frequency, and seat location (i.e., distance from axis of rotation). Results of an analysis of variance indicated that seat location had no effect on discomfort ratings of roll vibrations. The effect of roll acceleration level was significant, and discomfort ratings increased markedly with increasing roll acceleration level at all roll frequencies investigated. Of particular interest, is the fact that the relationship between discomfort ratings and roll acceleration level was linear in nature. The effect of roll frequency also was significant as was the interaction between roll acceleration level and roll frequency.

Environmental and psychosocial factors affecting seat belt use among Turkish front-seat occupants in Ankara: two observation studies.

PubMed

Simşekoğlu, Ozlem; Lajunen, Timo

2008-01-01

Low seat belt use rate among car occupants is one of the main problems contributing to low driver and passenger safety in Turkey, where injury and fatality rates of car occupants are very high in traffic crashes. The present article consists of two observation studies, which were conducted in Ankara. The first study aimed at investigating environmental factors and occupant characteristics affecting seat belt use among front-seat occupants, and the objective of the second study was to investigate the relationship between driver and front-seat passenger seat belt use. In the first study, 4, 227 front-seat occupants (drivers or front seat passengers) were observed on four different road sides and, in the second study 1, 398 front seat occupants were observed in car parks of five different shopping centers in Ankara. In both observations, front-seat occupants' seat bet use (yes, no), sex (male, female), and age (< 30 years, 30-50 years, > 50 years) were recorded. The data were analyzed using chi-square statistics and binary logistic regression techniques. Results of the first study showed that seat belt use proportion among observed front seat occupants was very low (25%). Being female and traveling on intercity roads were two main factors positively related to use a seat belt among front-seat occupants. High correlations between seat belt use of the drivers and front-seat passengers were found in the second study. Overall, low seat belt use rate (25%) among the front-seat occupants should be increased urgently for an improved driver and passenger safety in Turkey. Seat belt campaigns especially tailored for male front-seat occupants and for the front-seat occupants traveling on city roads are needed to increase seat belt use rates among them. Also, both drivers and passengers may have an important role in enforcing seat belt use among themselves.

Integrating Human Factors into Crew Exploration Vehicle Design

NASA Technical Reports Server (NTRS)

Whitmore, Mihriban; Baggerman, Susan; Campbell, paul

2007-01-01

With NASA's new Vision for Exploration to send humans beyond Earth orbit, it is critical to consider the human as a system that demands early and continuous user involvement, and an iterative prototype/test/redesign process. Addressing human-system interface issues early on can be very cost effective even cost reducing when performed early in the design and development cycle. To achieve this goal within Crew Exploration Vehicle (CEV) Project Office, human engineering (HE) team is formed. Key tasks are to apply HE requirements and guidelines to hardware/software, and provide HE design, analysis and evaluation of crew interfaces. Initial activities included many practice-orientated evaluations using low-fidelity CEV mock-ups. What follows is a description of such evaluations that focused on a HE requirement regarding Net Habitable Volume (NHV). NHV is defined as the total remaining pressurized volume available to on-orbit crew after accounting for the loss of volume due to deployed hardware and structural inefficiencies which decrease functional volume. The goal of the NHV evaluations was to develop requirements providing sufficient CEV NHV for crewmembers to live and perform tasks in support of mission goals. Efforts included development of a standard NHV calculation method using computer models and physical mockups, and crew/ stakeholder evaluations. Nine stakeholders and ten crewmembers participated in the unsuited evaluations. Six crewmembers also participated in a suited evaluation. The mock-up was outfitted with volumetric representation of sub-systems such as seats, and stowage bags. Thirteen scenarios were developed to represent mission/crew tasks and considered to be primary volume drivers (e.g., suit donning) for the CEV. Unsuited evaluations included a structured walkthrough of these tasks. Suited evaluations included timed donning of the existing launch and entry suit to simulate a contingency scenario followed by doffing/ stowing of the suits. All mockup evaluations were videotaped. Structured questionnaires were used to document user interface issues and volume impacts of layout configuration. Computer model and physical measures of the NHV agreed within 1 percent. This included measurement of the gross habitable volume, subtraction of intrusive volumes, and other non-habitable spaces. Calculation method developed was validated as a standard means of measuring NHV, and was recommended as a verification method for the NHV requirements. Evaluations confirmed that there was adequate volume for unsuited scenarios and suit donning/ doffing activity. Seats, suit design stowage and waste hygiene system noted to be critical volume drivers. The low-fidelity mock-up evaluations along with human modeling analysis generated discussions that will lead to high-level systems requirements and human-centered design decisions. This approach allowed HE requirements and operational concepts to evolve in parallel with engineering system concepts and design requirements. As the CEV design matures, these evaluations will continue and help with design decisions, and assessment, verification and validation of HE requirements.

Effect of Seating on Exposures to Whole-Body Vibration in Vehicles

NASA Astrophysics Data System (ADS)

PADDAN, G. S.; GRIFFIN, M. J.

2002-05-01

The vibration isolation efficiency of seating has been evaluated in 100 work vehicles in 14 categories (cars, vans, lift trucks, lorries, tractors, buses, dumpers, excavators, helicopters, armoured vehicles, mobile cranes, grass rollers, mowers and milk floats). Seat isolation efficiency, expressed by the SEAT value, was determined for all seats (67 conventional seats and 33 suspension seats) from the vertical acceleration measured on the floors and on the seats of the vehicles.For most categories of vehicle, the average SEAT value was less than 100%, indicating that the average seat provided some attenuation of vibration. However, there were large variations in SEAT values between vehicles within categories. Two alternative vibration frequency weightings (Wb from BS 6841, 1987; Wk from ISO 2631, 1997) yielded SEAT values that differed by less than 6%. Overall, the SEAT values determined by two alternative methods (the ratio of r.m.s. values and the ratio of vibration dose values) differed by less than 4·5% when using weighting Wb, although larger differences may be expected in some situations. The median SEAT value for the suspension seats was 84·6%; the median SEAT value for the conventional seats was 86·9% (based on weighting Wb and the ratio of r.m.s. values).Predicted SEAT values were obtained assuming that each seat could be interchanged between vehicles without altering its transmissibility. The calculations suggest that 94% of the vehicles investigated might benefit from changing the current seat to a seat from one of the other vehicles investigated. Although the predictions are based on assumptions that will not always apply, it is concluded that the severity of whole-body vibration exposures in many work environments can be lessened by improvements to seating dynamics.

Development of a Scientific Basis for Analysis of Aircraft Seating Systems

DTIC Science & Technology

1975-01-01

JOINT MOVEMENTS IN NORMAL MALE HUMAN ADULTS, Human Biology , Vol. 9, pp. 197-211, 1937. 10. Brinkley, J. W., DEVELOPMENT OF AEROSPACE ESCAPE SYSTEMS...Resisting Torque 21 8 Human Joint Resisting Torques: (a) Displacement- Limiting Moment; (b) Muscular Resistance 22 9 Fxternal Forces of Cushions, Floor...head strike on rigid cockpit structure. Also, the relatively low tolerance of the human b.ody to accelerations in a direction parallel to the spine

Computer Simulation of an Aircraft Seat and Occupant in a Crash Environment. Volume 2. Program SOM-LA (Seat/Occupant Model - Light Aircraft) User Manual

DTIC Science & Technology

1983-03-01

349A9 3 Figure A-8. Program SOM-LA body segment dimensions. _ t m • •m v m--, • v_ ,• W:•---:x:--:’ ,•-•• •--" ..- • % ’"•Z>L r -L.J :•":’. 7=- 2 J7.ŗZ...offset from the mid-saggital plane, and the anterior offset of the major upper body segment (lower torso, upper torso, and head) center of masses from... body rotation) energy-absorbing scat model. (See figure A-lI for a detailed de- scription of the parameters.) FORMAT AND EXAMPLE: 2 3 4 6 6 7 1 0123 4

16 CFR 1512.15 - Requirements for seat.

Code of Federal Regulations, 2011 CFR

2011-01-01

....) above the top of the seat surface at the point where the seat surface is intersected by the seat post axis. (b) Seat post. The seat post shall contain a permanent mark or ring that clearly indicates the... integrity of the seat post. This mark shall be located no less than two seat-post diameters from the lowest...

16 CFR 1512.15 - Requirements for seat.

Code of Federal Regulations, 2010 CFR

2010-01-01

....) above the top of the seat surface at the point where the seat surface is intersected by the seat post axis. (b) Seat post. The seat post shall contain a permanent mark or ring that clearly indicates the... integrity of the seat post. This mark shall be located no less than two seat-post diameters from the lowest...

78 FR 20093 - Extension of Application Period for Seats for the Monterey Bay National Marine Sanctuary Advisory...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-03

... Business and Tourism Activity Panel (``BTAP'') co-chaired by the Business/Industry Representative and Tourism Representative, each dealing with matters concerning research, education, conservation and human...

WHIPS seat and occupant motions during simulated rear crashes.

PubMed

Xiao, Ming; Ivancic, Paul C

2010-10-01

Objectives of this study were to investigate the motions of Volvo's Whiplash Protection System (WHIPS) seat and occupant during simulated rear crashes of a human model of the neck (HUMON). HUMON consisted of a human neck specimen (n = 6) mounted to the torso of BioRID II and carrying an anthropometric head stabilized with muscle force replication. HUMON was seated and secured in a 2005 Volvo XC90 minivan seat that included WHIPS and a fixed head restraint. Rear crashes of 9.9 g (ΔV 9.2 kph), 12.0 g (ΔV 11.4 kph), and 13.3 g (ΔV 13.4 kph) were simulated and WHIPS and occupant motions were monitored. Linear regression analyses (P < .05) were used to determine relationships between WHIPS and occupant motion peaks using data from all crashes combined. WHIPS motions consisted of simultaneous rearward and downward translations and extension of the seatback and plastic deformation of the bilateral WHIPS energy-absorbing components. Peak WHIPS motions were linearly correlated only with peak rearward occupant translations. Less rearward pelvis translation was required to cause WHIPS activation as compared to T1 translation. WHIPS reduced peak T1 horizontal acceleration by 39 percent compared to sled acceleration. This was within the range previously reported for WHIPS, between 30 and 60 percent, but higher than the 16 percent reduction previously reported due to active head restraint. Absorption of crash energy occurred during the initial 75 ms and the onset of head support occurred at 114 ms. Differential head-torso motions occurred prior to and during head support, indicating the potential for neck injury even with WHIPS.

Seat belt and child seat use in Lipetskaya Oblast, Russia: frequencies, attitudes, and perceptions.

PubMed

Ma, Sai; Tran, Nhan; Klyavin, Vladimir E; Zambon, Francesco; Hatcher, Kristin W; Hyder, Adnan A

2012-01-01

Despite the importance of understanding seat belt use patterns among drivers and passengers for the purpose of direct interventions or monitoring improvements, no study has described wearing rates for all seat positions in Russia. This study describes observed seat belt use and knowledge, attitudes, and perceptions of seat belt use in Lipetskaya Oblast, Russia. An observational study on the use of seat belts and child restraints in the Lipetskaya region conducted during October 2010 collected data in 6 districts and on 3 different road types. A roadside survey gathered information on knowledge, attitudes, and perceptions toward the use of seat belts from randomly selected drivers. Frequencies of seat belt use by seat position, gender, and road type were calculated. A multivariable logit model disclosed the associations between seat belt use and sociodemographic factors. The study design permitted comparison of observed seat belt use to self-reported seat belt use. A total of 25,795 vehicles and 39,833 drivers and passengers contributed observations. Overall, 55 percent of drivers were observed to be using seat belts. More than half (58%) of front seat passengers wore seat belts and only 9 percent of back seat passengers were observed to be wearing seat belts; 11 percent of cars with children had any type of child safety measure. Drivers on urban roads were less likely to wear seat belts compared to those on main highways and rural roads. Nearly 60 percent of survey respondents mentioned "seat belts save lives," and more than half mentioned law requirements and fines. Although the observed seat belt use in Lipetskaya Oblast is much higher than previous estimates in Russia, overall wearing rates remain far from universal. Rear seat passengers and children are particularly at risk. Because combined education and enforcement has proven to be effective elsewhere, such interventions are needed to improve seat belt use.

A comparison of self-report and direct observation of booster seat use in Latino families.

PubMed

Quistberg, D Alex; Lozano, Paula; Mack, Christopher D; Schwartz, Rachel; Ebel, Beth E

2010-08-01

To develop a reliable self-report tool for measuring child booster seat use among Latino families. Cross-sectional and observational survey of a convenience sample. Five retail stores in King County, Washington. 50 parents of children 4-8 years old that self-identified as Latino or Hispanic. Parent-reported measures of how often the child uses a booster seat, if the child used a booster seat on the last trip, how often the child complains about using a booster seat, how often the child asks to not use a booster seat, and how often other families they know use a booster seat. Observed booster seat use by child. 26 children (52%) were observed using a booster seat. Parent-reported booster seat use was a poor predictor of observed booster seat use. Although 34 parents reported that their child 'always' uses a booster seat, 8 (24%) of these children were not using a booster seat. A logistic model to predict booster seat use had a sensitivity of 81% and a specificity of 71%, and misclassified 24% of the participants' observed use. Reliance on parent-reported booster seat use significantly overstated observed booster seat use in the study. Among this study population, accurate determination of booster seat use required direct observation.

Seat strength in rear body block tests.

PubMed

Viano, David C; White, Samuel D

2016-07-03

This study collected and analyzed available testing of motor vehicle seat strength in rearward loading by a body block simulating the torso of an occupant. The data were grouped by single recliner, dual recliner, and all belts to seat (ABTS) seats. The strength of seats to rearward loading has been evaluated with body block testing from 1964 to 2008. The database of available tests includes 217 single recliner, 65 dual recliner, and 18 ABTS seats. The trends in seat strength were determined by linear regression and differences between seat types were evaluated by Student's t-test. The average peak moment and force supported by the seat was determined by decade of vehicle model year (MY). Single recliner seats were used in motor vehicles in the 1960s to 1970s. The average strength was 918 ± 224 Nm (n = 26) in the 1960s and 1,069 ± 293 Nm (n = 65) in the 1980s. There has been a gradual increase in strength over time. Dual recliner seats started to phase into vehicles in the late 1980s. By the 2000s, the average strength of single recliner seats increased to 1,501 ± 335 Nm (n = 14) and dual recliner seats to 2,302 ± 699 Nm (n = 26). Dual recliner seats are significantly stronger than single recliner seats for each decade of comparison (P < .001). The average strength of ABTS seats was 4,395 ± 1,185 in-lb for 1989-2004 MY seats (n = 18). ABTS seats are significantly stronger than single or dual recliner seats (P < .001). The trend in ABTS strength is decreasing with time and converging toward that of dual recliner seats. Body block testing is an quantitative means of evaluating the strength of seats for occupant loading in rear impacts. There has been an increase in conventional seat strength over the past 50 years. By the 2000s, most seats are 1,700-3,400 Nm moment strength. However, the safety of a seat is more complex than its strength and depends on many other factors.

77 FR 19155 - Federal Motor Vehicle Safety Standards; Seat Belt Assembly Anchorages; Incorporation by Reference

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-30

... representative of a human form than the upper torso and pelvic body blocks. As noted in the docketed test reports... anchorage system during compliance tests of anchorage strength. The device represents a human torso and... proposing this amendment because the devices are significantly easier to use than the current body blocks...

Cabin attendants’ exposure to vibration and shocks during landing

NASA Astrophysics Data System (ADS)

Burström, Lage; Lindberg, Lennart; Lindgren, Torsten

2006-12-01

The Scandinavian Airlines System (SAS) has noted that cabin attendants have reported an increase in health problems associated with landing. The European Union reports cover health problems related to neck, shoulder, and lower-back injuries. Moreover, analysis of these reports shows that the problems are often associated with specific airplanes that have a longer tail behind the rear wheels and appear more often in attendants who sit in the back of planes rather then the front. Against this background, this study measures and describes the vibration during landing in specific airplanes to evaluate the health risk for the cabin attendants. Measurements were conducted on regular flights with passengers in the type of airplane, Boeing 737-800, which was related to the highest per cent of reported health problems. All measurements were performed the same day during three landings in one airplane with the same pilots and cabin attendants. The measurements were carried out simultaneously on the cabin crew seats in the back and front of the passenger cabin. Under the cabin crew's seat cushions, a triaxiell seat-accelerometer was placed to measure the vibration in three axes. The signals from the accelerometers were amplified by charge amplifiers and stored on tape. The stored data were analysed with a computer-based analyse system. For the cabin attendants, the dominant direction for the vibration load during landing is the up-and-down direction although some vibration also occurs in the other horizontal directions. The exposure to vibration is higher on the rear crew seat compared to the front seat. For instance, both the vibration dose value (VDV) and the frequency-weighted acceleration in the dominant direction are more then 50% higher on the rear seat. The frequency-weighted acceleration and the VDV measured at the crew seats are below the exposure limits as described by the European vibration directive. The evaluation of the cabin attendants' exposure to multiple shocks during landing shows that the potential of an adverse health effect for the cabin attendants is low in the front of the airplane and increases to moderate in the rear. Although this is a limited study, it could be conclude that there could be a risk for cabin attendants due to the exposure of multiple shocks. Therefore, efforts should be spent to minimize their risk by developing a better seat cushion and back support to lessen the effects of shocks. In addition, attendants should be informed about the most suitable posture to take during landing.

Impact Response Comparison Between Parametric Human Models and Postmortem Human Subjects with a Wide Range of Obesity Levels.

PubMed

Zhang, Kai; Cao, Libo; Wang, Yulong; Hwang, Eunjoo; Reed, Matthew P; Forman, Jason; Hu, Jingwen

2017-10-01

Field data analyses have shown that obesity significantly increases the occupant injury risks in motor vehicle crashes, but the injury assessment tools for people with obesity are largely lacking. The objectives of this study were to use a mesh morphing method to rapidly generate parametric finite element models with a wide range of obesity levels and to evaluate their biofidelity against impact tests using postmortem human subjects (PMHS). Frontal crash tests using three PMHS seated in a vehicle rear seat compartment with body mass index (BMI) from 24 to 40 kg/m 2 were selected. To develop the human models matching the PMHS geometry, statistical models of external body shape, rib cage, pelvis, and femur were applied to predict the target geometry using age, sex, stature, and BMI. A mesh morphing method based on radial basis functions was used to rapidly morph a baseline human model into the target geometry. The model-predicted body excursions and injury measures were compared to the PMHS tests. Comparisons of occupant kinematics and injury measures between the tests and simulations showed reasonable correlations across the wide range of BMI levels. The parametric human models have the capability to account for the obesity effects on the occupant impact responses and injury risks. © 2017 The Obesity Society.

76 FR 25699 - Eunice Kennedy Shriver National Institute of Child Health & Human Development; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-05

... to make your reservation. Additional seating will be available in the meeting overflow rooms... Federal Domestic Assistance Program Nos. 93.864, Population Research; 93.865, Research for Mothers and...

75 FR 1067 - Eunice Kennedy Shriver National Institute of Child Health and Human Development; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-08

... your reservation. Additional seating will be available in the meeting overflow rooms, Conference Rooms..., Research for Mothers and Children; 93.929, Center for Medical Rehabilitation Research; 93.209...

16 CFR 1512.15 - Requirements for seat.

Code of Federal Regulations, 2014 CFR

2014-01-01

...) above the top of the seat surface at the point where the seat surface is intersected by the seat post axis. This requirement does not apply to recumbent bicycles. (b) Seat post. The seat post shall contain... adjustment); the mark shall not affect the structural integrity of the seat post. This mark shall be located...

16 CFR § 1512.15 - Requirements for seat.

Code of Federal Regulations, 2013 CFR

2013-01-01

...) above the top of the seat surface at the point where the seat surface is intersected by the seat post axis. This requirement does not apply to recumbent bicycles. (b) Seat post. The seat post shall contain... adjustment); the mark shall not affect the structural integrity of the seat post. This mark shall be located...

16 CFR 1512.15 - Requirements for seat.

Code of Federal Regulations, 2012 CFR

2012-01-01

...) above the top of the seat surface at the point where the seat surface is intersected by the seat post axis. This requirement does not apply to recumbent bicycles. (b) Seat post. The seat post shall contain... adjustment); the mark shall not affect the structural integrity of the seat post. This mark shall be located...

76 FR 64795 - Airworthiness Directives; Sicma Aero Seat Passenger Seat Assemblies Installed on Various...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-19

... Airworthiness Directives; Sicma Aero Seat Passenger Seat Assemblies Installed on Various Transport Category..., 91xx, 92xx, 93xx, 95xx, and 96xx series passenger seat assemblies, installed on various transport... seat assemblies identified in Annex 1, Issue 2, dated March 19, 2004, of Sicma Aero Seat Service...

Effects of thermal stress and exercise on blood volume in humans

NASA Technical Reports Server (NTRS)

Harrison, M. H.

1985-01-01

The available experimental data base on the effects of exercise, posture and the environment (heat) on the blood volume, composition and concentration in humans is surveyed in depth to synthesize supportable conclusions. A large disparity is noted in the effective controls which were initiated in previous experimental conditions, resulting in contradictory findings regarding, e.g., hemoconcentrations and hemodilution in response to exercise. Comparisons between the results of exercise and of supine, seated and upright subjects has underscored the importance of gravity in hemoconcentration, particularly in the legs, and the generation of aldotestosterone. Hemoconcentration has been confirmed to increase with exercise in a seated or supine position. Exercise in a heated environment transfers cardiac output from core areas and reduces filtration efficiencies. Also, plasma volume increases, an action which cannot yet be associated with crystalloidal or colloidal influences on the osmotic behavior of cell walls.

Human strength simulations for one and two-handed tasks in zero gravity

NASA Technical Reports Server (NTRS)

1972-01-01

A description is given of a three dimensional hand force capability model for the seated operator and a biomechanical model for analysis of symmetric sagittal plane activities. The models are used to simulate and study human strengths for one and two handed tasks in zero gravity. Specific conditions considered include: (1) one hand active, (2) both hands active but with different force directions on each, (3) body bracing situations provided by portable foot restraint when standing and lap belt when seated, (4) static or slow movement tasks with maximum length of 4 seconds and a minimum rest of 5 minutes between exertions, and (5) wide range of hand positions relative to either the feet or bisection of a line connecting the hip centers. Simulations were also made for shirt sleeved individuals and for the male population strengths with anthropometry matching that of astronauts.

Bringing human resources to the table: utilization of an HR balanced scorecard at Mayo Clinic.

PubMed

Fottler, Myron D; Erickson, Eric; Rivers, Patrick A

2006-01-01

Rather than viewing HR as a critical driver of organizational strategy and outcomes, most health care organizations see HR as a drain on the organization's bottom line. Only by aligning HR with the organizational strategy will HR leaders truly get a seat at the leadership table. HR professionals can overcome impediments and gain a seat at the table by learning the language of business and the ways in which organizational leaders use data to drive their decisions. This article shows how Mayo Clinic uses the popular Balanced Scorecard approach to align its measures of HR performance to the organization's strategic plan.

[Mathematical modeling of the kinematics of a pilot's head while catapulting into an air stream].

PubMed

Kharchenko, V I; Golovleva, N V; Konakhevich, Iu G; Liapin, V A; Mar'in, A V

1987-01-01

The trajectories of head movements in the helmet and velocities of impact contact with the seat and anterior of the cockpit were calculated as applied to every stage of the catapulting process and mass-inertia parameters of helmets taken into account. Kinematic models were used to describe biomechanic parameters of the head-neck system. Special attention was given to the case of catapulting to the air flow. The effect upon the nod of aerodynamic forces acting on the human body and the catapult ejection seat at air flow velocities of 700-800 and 1300 km/hr was calculated.

Psychophysiological Studies in Extreme Environments

NASA Technical Reports Server (NTRS)

Toscano, William B.

2011-01-01

This paper reviews the results from two studies that employed the methodology of multiple converging indicators (physiological measures, subjective self-reports and performance metrics) to examine individual differences in the ability of humans to adapt and function in high stress environments. The first study was a joint collaboration between researchers at the US Army Research Laboratory (ARL) and NASA Ames Research Center. Twenty-four men and women active duty soldiers volunteered as participants. Field tests were conducted in the Command and Control Vehicle (C2V), an enclosed armored vehicle, designed to support both stationary and on-the-move operations. This vehicle contains four computer workstations where crew members are expected to perform command decisions in the field under combat conditions. The study objectives were: 1) to determine the incidence of motion sickness in the C2V relative to interior seat orientation/position, and parked, moving and short-haul test conditions; and 2) to determine the impact of the above conditions on cognitive performance, mood, and physiology. Data collected during field tests included heart rate, respiration rate, skin temperature, and skin conductance, self-reports of mood and symptoms, and cognitive performance metrics that included seven subtests in the DELTA performance test battery. Results showed that during 4-hour operational tests over varied terrain motion sickness symptoms increased; performance degraded by at least 5 percent; and physiological response profiles of individuals were categorized based on good and poor cognitive performance. No differences were observed relative to seating orientation or position.

Distance Learning Plan for the Defense Finance and Accounting Service (DFAS): A Study for the DBMU

DTIC Science & Technology

1994-09-01

according to the standard (H.261) motion video compression algorithm.24 n Schaphorst, Richard, notes presented at TELECON XIII, San Jose , California, 10...include automatic microphone mixing systems with one microphone for every two student seats, a large screen interactive computer display and the Socrates

Social Cues in Multimedia Learning: Role of Speaker's Voice.

ERIC Educational Resources Information Center

Mayer, Richard E.; Sobko, Kristina; Mautone, Patricia D.

2003-01-01

In 2 experiments, learners who were seated at a computer workstation received a narrated animation about lightning formation. Then, they took a retention test, a transfer test, and rated the speaker. The results are consistent with social agency theory, which posits that social cues in multimedia messages can encourage learners to interpret…

Intrinsic and Extrinsic Contributions to Seated Balance in the Sagittal and Coronal Planes: Implications for Trunk Control After Spinal Cord Injury.

PubMed

Audu, Musa L; Triolo, Ronald J

2015-08-01

The contributions of intrinsic (passive) and extrinsic (active) properties of the human trunk, in terms of the simultaneous actions about the hip and spinal joints, to the control of sagittal and coronal seated balance were examined. Able-bodied (ABD) and spinal-cord-injured (SCI) volunteers sat on a moving platform which underwent small amplitude perturbations in the anterior-posterior (AP) and medial-lateral (ML) directions while changes to trunk orientation were measured. A linear parametric model that related platform movement to trunk angle was fit to the experimental data by identifying model parameters in the time domain. The results showed that spinal cord injury leads to a systematic reduction in the extrinsic characteristics, while most of the intrinsic characteristics were rarely affected. In both SCI and ABD individuals, passive characteristics alone were not enough to maintain seated balance. Passive stiffness in the ML direction was almost 3 times that in the AP direction, making more extrinsic mechanisms necessary for balance in the latter direction. Proportional and derivative terms of the extrinsic model made the largest contribution to the overall output from the active system, implying that a simple proportional plus derivative (PD) controller structure will suffice for restoring seated balance after spinal cord injury.

Comparison of car seats in low speed rear-end impacts using the BioRID dummy and the new neck injury criterion (NIC).

PubMed

Boström, O; Fredriksson, R; Håland, Y; Jakobsson, L; Krafft, M; Lövsund, P; Muser, M H; Svensson, M Y

2000-03-01

Long-term whiplash associated disorders (WAD) 1-3 sustained in low velocity rear-end impacts is the most common disability injury in Sweden. Therefore, to determine neck injury mechanisms and develop methods to measure neck-injury related parameters are of importance for current crash-safety research. A new neck injury criterion (NIC) has previously been proposed and evaluated by means of dummy, human and mathematical rear-impact simulations. So far, the criterion appears to be sensitive to the major car and collision related risk factors for injuries with long-term consequences. To further evaluate the applicability of NIC, four seats were tested according to a recently proposed sled-test procedure. 'Good' as well as 'bad' seats were chosen on the basis of a recently presented disability risk ranking list. The dummy used in the current tests was the Biofidelic Rear Impact Dummy (BioRID). The results of this study showed that NICmax values were generally related to the real-world risk of long-term WAD 1-3. Furthermore, these results suggested that NICmax calculated from sled tests using the BioRID dummy can be used for evaluating the neck injury risk of different car seats.

Hair and fiber transfer in an abduction case--evidence from different levels of trace evidence transfer.

PubMed

Taupin, J M

1996-07-01

Levels of trace evidence transfer were examined in a casework context. A girl was allegedly abducted in a car and rape attempted by the accused, who denied any contact with the victim. Clothing worn by the victim and the accused, and the covers from the front seats of the car, were analyzed for trace evidence. Three types of corresponding fibers and four possible pathways of transfer were identified. Synthetic fibers similar to those composing the car seat covers were located on the victim's clothing, consistent with direct transfer. Secondary transfer was indicated by dyed brown human head-type hairs (possibly originating from the accused's wife) located on the seat covers and on the victim's clothing. Secondary and possibly tertiary transfer was indicated by pink synthetic material and associated fibers (possibly originating from the victim's mother) located on the victim's clothing, a car seat cover and the accused's clothing. Light microscopy, comparison microscopy, and cross-sectioning techniques were used. The multiple fiber matches and the differing pathways and levels of transfer increased the strength of the association between the accused and the victim. After the fiber evidence was led at the trial, the accused pleaded guilty, thereby affirming the value of secondary transfer evidence.

Compliance with seat belt use in Benin City, Nigeria.

PubMed

Iribhogbe, Pius Ehiawaguan; Osime, Clement Odigie

2008-01-01

Trauma is a major cause of death and disability worldwide. A quarter of all fatalities due to injury occur due to road traffic crashes with 90% of the fatalities occurring in low- and medium-income countries. Poor compliance with the use of seat belts is a problem in many developing countries. The aim of this study was to evaluate the level of seatbelt compliance in motor vehicles in Benin City, Nigeria. A five-day, observational study was conducted in strategic locations in Benin City. The compliance rates of drivers, front seat passengers, and rear seat passengers in the various categories of vehicles were evaluated, and the data were subjected to statistical processing using the Program for Epidemiology. A total of 369 vehicles were observed. This consisted of 172 private cars, 64 taxis, 114 buses, 15 trucks, and four other vehicles. The seat belt compliance rate for drivers was 52.3%, front seat passengers 18.4%, and rear seat passengers 6.1%. Drivers of all categories of vehicles were more likely to use the seat belt compared to front seat passengers (p = 0.000) and rear seat passengers (p = 0.000). Drivers of private cars were more likely to use seat belts compared to taxi drivers (p = 0.000) and bus drivers (p = 0.000). Front seat passengers in private cars were more likely to use the seat belt compared to front seat passengers in taxis (p = 0.000) and buses (p = 0.000). Rear seat passengers in private cars also were more likely to use seat belts compared to rear seat passengers in taxis (p = 0.000) and buses (p = 0.000). Compliance with seat belt use in Benin City is low. Legislation, educational campaigns, and enforcement of seat belt use are needed.

Interoperability...NMCI and Beyond

DTIC Science & Technology

2001-05-31

wireless. “On The Road” – Pagers – Cell phones – Palm-size PDAs – Two way pagers – Hand-held computing device – Laptop computer – Two-way radios – A...combat capability”… $0 $5 $10 $15 $20 $25 Electric Power NMCI Seat First Run Movie Cell Phone Fed. Civilian Salary 23.80 11.00 4.00 1.380.20 F/A-18...Flying Hour: 1,134.00 Fed. Civilian Salary (mean): 23.80 Cell Phone Air Time: 11.00 First Run Movie: 4.00 DSN

To Err is Human Case Reports of Two Military Aircraft Accidents

PubMed Central

Dikshit, Mohan B

2010-01-01

It has been postulated that pilot error or in-flight incapacitation may be the main contributory factors to 70–80% of aircraft accidents. Two fatal aircraft accidents are presented in which either of the above possibilities may have played a role. The first case report describes an erroneous decision by a fighter pilot to use a seat position adjustment of the ejection seat leading to fatal injuries when he had to eject from his aircraft. Injuries to the body of the pilot, and observations on the state of his flying clothing and the ejection seat were used to postulate the mechanism of fatal injury and establish the cause of the accident. The second case report describes the sequence of events which culminated in the incapacitation of a fighter pilot while executing a routine manouevre. This resulted in a fatal air crash. Possible contributions of environmental factors which may have resulted in failure of his physiological mechanisms are discussed. PMID:21509093

Avoiding the Health Hazard of People from Construction Vehicles: A Strategy for Controlling the Vibration of a Wheel Loader

PubMed Central

Chi, Feng; Zhou, Jun; Zhang, Qi; Wang, Yong; Huang, Panling

2017-01-01

The vibration control of a construction vehicle must be carried out in order to meet the aims of sustainable environmental development and to avoid the potential human health hazards. In this paper, based on market feedback, the driver seat vibration of a type of wheel loader in the left and right direction, is found to be significant over a certain speed range. In order to find abnormal vibration components, the order tracking technique (OTT) and transmission path analysis (TPA) were used to analyze the vibration sources of the wheel loader. Through this analysis, it can be seen that the abnormal vibration comes from the interaction between the tire tread and the road, and this is because the vibration was amplified by the cab mount, which was eventually transmitted to the cab seat. Finally, the seat vibration amplitudes were decreased by up to 50.8%, after implementing the vibration reduction strategy. PMID:28282849

Avoiding the Health Hazard of People from Construction Vehicles: A Strategy for Controlling the Vibration of a Wheel Loader.

PubMed

Chi, Feng; Zhou, Jun; Zhang, Qi; Wang, Yong; Huang, Panling

2017-03-08

The vibration control of a construction vehicle must be carried out in order to meet the aims of sustainable environmental development and to avoid the potential human health hazards. In this paper, based on market feedback, the driver seat vibration of a type of wheel loader in the left and right direction, is found to be significant over a certain speed range. In order to find abnormal vibration components, the order tracking technique (OTT) and transmission path analysis (TPA) were used to analyze the vibration sources of the wheel loader. Through this analysis, it can be seen that the abnormal vibration comes from the interaction between the tire tread and the road, and this is because the vibration was amplified by the cab mount, which was eventually transmitted to the cab seat. Finally, the seat vibration amplitudes were decreased by up to 50.8%, after implementing the vibration reduction strategy.

Abdominal Organ Location, Morphology, and Rib Coverage for the 5(th), 50(th), and 95(th) Percentile Males and Females in the Supine and Seated Posture using Multi-Modality Imaging.

PubMed

Hayes, Ashley R; Gayzik, F Scott; Moreno, Daniel P; Martin, R Shayn; Stitzel, Joel D

The purpose of this study was to use data from a multi-modality image set of males and females representing the 5(th), 50(th), and 95(th) percentile (n=6) to examine abdominal organ location, morphology, and rib coverage variations between supine and seated postures. Medical images were acquired from volunteers in three image modalities including Computed Tomography (CT), Magnetic Resonance Imaging (MRI), and upright MRI (uMRI). A manual and semi-automated segmentation method was used to acquire data and a registration technique was employed to conduct a comparative analysis between abdominal organs (liver, spleen, and kidneys) in both postures. Location of abdominal organs, defined by center of gravity movement, varied between postures and was found to be significant (p=0.002 to p=0.04) in multiple directions for each organ. In addition, morphology changes, including compression and expansion, were seen in each organ as a result of postural changes. Rib coverage, defined as the projected area of the ribs onto the abdominal organs, was measured in frontal, lateral, and posterior projections, and also varied between postures. A significant change in rib coverage between postures was measured for the spleen and right kidney (p=0.03 and p=0.02). The results indicate that posture affects the location, morphology and rib coverage area of abdominal organs and these implications should be noted in computational modeling efforts focused on a seated posture.

Effects of elastic seats on seated body apparent mass responses to vertical whole body vibration.

PubMed

Dewangan, K N; Rakheja, S; Marcotte, Pierre; Shahmir, A

2015-01-01

Apparent mass (AM) responses of the body seated with and without a back support on three different elastic seats (flat and contoured polyurethane foam (PUF) and air cushion) and a rigid seat were measured under three levels of vertical vibration (overall rms acceleration: 0.25, 0.50 and 0.75 m/s(2)) in the 0.5 to 20 Hz range. A pressure-sensing system was used to capture biodynamic force at the occupant-seat interface. The results revealed strong effects of visco-elastic and vibration transmissibility characteristics of seats on AM. The response magnitudes with the relatively stiff air seat were generally higher than those with the PUF seats except at low frequencies. The peak magnitude decreased when sitting condition was changed from no back support to a vertical support; the reduction however was more pronounced with the air seat. Further, a relatively higher frequency shift was evident with soft seat compared with stiff elastic seat with increasing excitation. The effects of visco-elastic properties of the body-seat interface on the apparent mass responses of the seated body are measured under vertical vibration. The results show considerable effects of the coupling stiffness on the seated body apparent mass, apart from those of excitation magnitude and back support.

Evaluation of reaction time performance and subjective drowsiness during whole-body vibration exposure

NASA Astrophysics Data System (ADS)

Azizan, A.; Zali, Z.; Padil, H.

2018-05-01

Despite the automotive industry’s interest in how vibration affects the level of human comfort, there is little focus on the effect of vibration on drowsiness level. Thus, this study involves eighteen healthy male participants to study the effect of exposure to vibration on the drowsiness level. Prior to the experiment, the total transmitted vibration measured at interfaces between the seat pan and seat back to the human body for each participant was modified to become 0.2 ms-2 r.m.s and 0.4 ms-2 r.m.s. During the experiment, the participants were seated and exposed to 20-minutes of Gaussian random vibration with frequency band 1-15 Hz at two level of amplitude (low vibration amplitude and medium vibration amplitude) on separate days. The level of drowsiness was measured using a PVT test prior and after exposure to the vibration while participants rated their subjective drowsiness by using the Karolinska Sleepiness Scale (KSS). The significant increase in the number of lapse and reaction time because of the exposure to vibration in both conditions provide strong evidence of drowsiness. In this regard, the medium vibration amplitude shows a more prominent effect. All participants have shown a steady increase of drowsiness level in KSS. Meanwhile, there are no significant differences found between low vibration amplitude and medium vibration amplitude in the KSS. These findings suggest that human alertness level is greatly affected by the exposure to vibration and these effects are more pronounced at higher vibration amplitude. Both findings indicate that the presence of vibration promotes drowsiness, especially at higher vibration amplitude.

Seat vibration in military propeller aircraft: characterization, exposure assessment, and mitigation.

PubMed

Smith, Suzanne D

2006-01-01

There have been increasing reports of annoyance, fatigue, and even neck and back pain during prolonged operation of military propeller aircraft, where persistent multi-axis vibration occurs at higher frequencies beyond human whole-body resonance. This paper characterizes and assesses the higher frequency vibration transmitted to the occupants onboard these aircraft. Multi-axis accelerations were measured at the occupied seating surfaces onboard the WC/C-130J, C-130H3, and E-2C Hawkeye. The effects of the vibration were assessed in accordance with current international guidelines (ISO 2631-1:1997). The relative psychophysical effects of the frequency components and the effects of selected mitigation strategies were also investigated. The accelerations associated with the blade passage frequency measured on the passenger seat pans located on the side of the fuselage near the propeller plane of the C-130J (102 Hz) and C-130H3 (68 Hz) were noteworthy (5.19 +/- 1.72 ms(-2) rms and 7.65 +/- 0.71 ms(-2) rms, respectively, in the lateral direction of the aircraft). The psychophysical results indicated that the higher frequency component would dominate the side passengers' perception of the vibration. Balancing the props significantly reduced the lower frequency propeller rotation vibration (17 Hz), but had little effect on the blade passage frequency vibration. The relationships among the frequency, vibration direction, and seat measurement sites were complex, challenging the development of seating systems and mitigation strategies. Psychophysical metrics could provide a tool for optimizing mitigation strategies, but the current international vibration standard may not provide optimum assessment methods for evaluating higher frequency operational exposures.

Effects of posture on shear rates in human brachial and superficial femoral arteries

PubMed Central

Newcomer, S. C.; Sauder, C. L.; Kuipers, N. T.; Laughlin, M. H.; Ray, C. A.

2012-01-01

Shear rate is significantly lower in the superficial femoral compared with the brachial artery in the supine posture. The relative shear rates in these arteries of subjects in the upright posture (seated and/or standing) are unknown. The purpose of this investigation was to test the hypothesis that upright posture (seated and/or standing) would produce greater shear rates in the superficial femoral compared with the brachial artery. To test this hypothesis, Doppler ultrasound was used to measure mean blood velocity (MBV) and diameter in the brachial and superficial femoral arteries of 21 healthy subjects after being in the supine, seated, and standing postures for 10 min. MBV was significantly higher in the brachial compared with the superficial femoral artery during upright postures. Superficial femoral artery diameter was significantly larger than brachial artery diameter. However, posture had no significant effect on either brachial or superficial femoral artery diameter. The calculated shear rate was significantly greater in the brachial (73 ± 5, 91 ± 11, and 97 ± 13 s−1) compared with the superficial femoral (53 ± 4, 39 ± 77, and 44 ± 5 s−1) artery in the supine, seated, and standing postures, respectively. Contrary to our hypothesis, our current findings indicate that mean shear rate is lower in the superficial femoral compared with the brachial artery in the supine, seated, and standing postures. These findings of lower shear rates in the superficial femoral artery may be one mechanism for the higher propensity for atherosclerosis in the arteries of the leg than of the arm. PMID:18245564

Rear seat safety: Variation in protection by occupant, crash and vehicle characteristics.

PubMed

Durbin, Dennis R; Jermakian, Jessica S; Kallan, Michael J; McCartt, Anne T; Arbogast, Kristy B; Zonfrillo, Mark R; Myers, Rachel K

2015-07-01

Current information on the safety of rear row occupants of all ages is needed to inform further advances in rear seat restraint system design and testing. The objectives of this study were to describe characteristics of occupants in the front and rear rows of model year 2000 and newer vehicles involved in crashes and determine the risk of serious injury for restrained crash-involved rear row occupants and the relative risk of fatal injury for restrained rear row vs. front passenger seat occupants by age group, impact direction, and vehicle model year. Data from the National Automotive Sampling System Crashworthiness Data System (NASS-CDS) and Fatality Analysis Reporting System (FARS) were queried for all crashes during 2007-2012 involving model year 2000 and newer passenger vehicles. Data from NASS-CDS were used to describe characteristics of occupants in the front and rear rows and to determine the risk of serious injury (AIS 3+) for restrained rear row occupants by occupant age, vehicle model year, and impact direction. Using a combined data set containing data on fatalities from FARS and estimates of the total population of occupants in crashes from NASS-CDS, logistic regression modeling was used to compute the relative risk (RR) of death for restrained occupants in the rear vs. front passenger seat by occupant age, impact direction, and vehicle model year. Among all vehicle occupants in tow-away crashes during 2007-2012, 12.3% were in the rear row where the overall risk of serious injury was 1.3%. Among restrained rear row occupants, the risk of serious injury varied by occupant age, with older adults at the highest risk of serious injury (2.9%); by impact direction, with rollover crashes associated with the highest risk (1.5%); and by vehicle model year, with model year 2007 and newer vehicles having the lowest risk of serious injury (0.3%). Relative risk of death was lower for restrained children up to age 8 in the rear compared with passengers in the right front seat (RR=0.27, 95% CI 0.12-0.58 for 0-3 years, RR=0.55, 95% CI 0.30-0.98 for 4-8 years) but was higher for restrained 9-12-year-old children (RR=1.83, 95% CI 1.18-2.84). There was no evidence for a difference in risk of death in the rear vs. front seat for occupants ages 13-54, but there was some evidence for an increased relative risk of death for adults age 55 and older in the rear vs. passengers in the right front seat (RR=1.41, 95% CI 0.94-2.13), though we could not exclude the possibility of no difference. After controlling for occupant age and gender, the relative risk of death for restrained rear row occupants was significantly higher than that of front seat occupants in model year 2007 and newer vehicles and significantly higher in rear and right side impact crashes. Results of this study extend prior research on the relative safety of the rear seat compared with the front by examining a more contemporary fleet of vehicles. The rear row is primarily occupied by children and adolescents, but the variable relative risk of death in the rear compared with the front seat for occupants of different age groups highlights the challenges in providing optimal protection to a wide range of rear seat occupants. Findings of an elevated risk of death for rear row occupants, as compared with front row passengers, in the newest model year vehicles provides further evidence that rear seat safety is not keeping pace with advances in the front seat. Copyright © 2015 Elsevier Ltd. All rights reserved.

Kinematic behavior of the human body during deceleration.

DOT National Transportation Integrated Search

1962-06-01

The geometry of motion of the head, trunk and appendages was established for one hundred male subjects restrained by a safety belt during forward and side dynamic loadings. Lethal structures of present aircraft seating and cockpit arrangements are re...

Occupant responses in conventional and ABTS seats in high-speed rear sled tests.

PubMed

Viano, David C; Parenteau, Chantal S; Burnett, Roger; Prasad, Priya

2018-01-02

This study compared biomechanical responses of a normally seated Hybrid III dummy on conventional and all belts to seat (ABTS) seats in 40.2 km/h (25 mph) rear sled tests. It determined the difference in performance with modern (≥2000 MY) seats compared to older (<2000 MY) seats and ABTS seats. The seats were fixed in a sled buck subjected to a 40.2 km/h (25 mph) rear sled test. The pulse was a 15 g double-peak acceleration with 150 ms duration. The 50th percentile Hybrid III was lap-shoulder belted in the FMVSS 208 design position. The testing included 11 <2000 MY, 8 ≥2000 MY, and 7 ABTS seats. The dummy was fully instrumented, including head accelerations, upper and lower neck 6-axis load cells, chest acceleration, thoracic and lumbar spine load cells, and pelvis accelerations. The peak responses were normalized by injury assessment reference values (IARVs) to assess injury risks. Statistical analysis was conducted using Student's t test. High-speed video documented occupant kinematics. Biomechanical responses were lower with modern (≥2000 MY) seats than older (<2000 MY) designs. The lower neck extension moment was 32.5 ± 9.7% of IARV in modern seats compared to 62.8 ± 31.6% in older seats (P =.01). Overall, there was a 34% reduction in the comparable biomechanical responses with modern seats. Biomechanical responses were lower with modern seats than ABTS seats. The lower neck extension moment was 41.4 ± 7.8% with all MY ABTS seats compared to 32.5 ± 9.7% in modern seats (P =.07). Overall, the ABTS seats had 13% higher biomechanical responses than the modern seats. Modern (≥2000 MY) design seats have lower biomechanical responses in 40.2 km/h rear sled tests than older (<2000 MY) designs and ABTS designs. The improved performance is consistent with an increase in seat strength combined with improved occupant kinematics through pocketing of the occupant into the seatback, higher and more forward head restraint, and other design changes. The methods and data presented here provide a basis for standardized testing of seats. However, a complete understanding of seat safety requires consideration of out-of-position (OOP) occupants in high-speed impacts and consideration of the much more common, low-speed rear impacts.

The use of modern measurement techniques for designing pro ecological constructions

NASA Astrophysics Data System (ADS)

Wieczorowski, Michał; Gapiński, Bartosz; Szymański, Maciej; Rękas, Artur

2017-10-01

In the paper some possibilities of application modern length and angle metrology techniques to design constructions that support ecology were presented. The paper is based on a project where a lighter bus and train car seat was developed. Different options were presented including static and dynamic photogrammetry, computed tomography and thermography. Research related with dynamic behaviour of designed structures gave input to determine deformation of a seat and passengers sitting on it during communication accidents. Works connected to strength of construction elements made it possible to optimize its dimensions maintaining proper durability. Metrological actions taken in relation to production machines and equipment enabled to better recognize phenomena that take place during manufacturing process and to correct its parameters, what in turns also contributed to slim down the construction.

76 FR 291 - Special Conditions: Gulfstream Model GVI Airplane; Single-Occupant Side-Facing Seats

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-04

...-occupant side-facing seat installations. Dynamic testing of all seats approved for occupancy during takeoff.... 25.562, ``Emergency landing dynamic conditions,'' requires dynamic testing of all seats occupied... seats, or seats equipped with conventional restraint systems. [[Page 292

Selecting seats for steel industry mobile machines based on seat effective amplitude transmissibility and comfort.

PubMed

Conrad, Leanne F; Oliver, Michele L; Jack, Robert J; Dickey, James P; Eger, Tammy R

2014-01-01

The purpose of this work was to help a steel industry partner select the most appropriate of three high end heavy equipment seats to retrofit a number of their heavy mobile machines used in the steel making process. The participants included 8 males (22.3 ± 2.0 yrs.) and 8 females (23.5 ± 1.8 yrs.) with no experience operating heavy mobile equipment. Previously recorded 6-DOF chassis acceleration data from a Pot Hauler (a machine which picks up and transports pots of slag) were used to extract six, 20 second representative profiles for implementation on a lab-based heavy machine simulator (6-DOF Parallel Robotics System Corporation robot). Subjects sat on three heavy equipment seats (BeGe7150, Grammar MSG 95G1721, and a 6801 Isringhausen with the seat pan cushion retrofitted with a Skydex cushion) mounted on the simulator. Each subject completed three trials for each combination of seat (n=3) and vibration profile (n=6). Chassis and operator/seat interface vibration were measured by 2, 6-DOF vibration transducers. Variables included Seat Effective Amplitude Transmissibility (SEAT) (X,Y,Z,Roll,Pitch,Yaw,6DOF Vector Sum) to determine if the seat was attenuating or amplifying the vibration, 6-degree of freedom (DOF) vibration total value weighted predicted comfort (Avc) (according to ISO 2631-1) and operator reported comfort (ORC). Factorial ANOVAs revealed significant differences (p < or = 0.05) between seats for all SEAT variables but different seats performed better than others depending on the axis. Significant differences between males and females were observed for SEAT in X,Y, and Pitch as well as for Avs. As expected there were significant differences between vibration profiles for all assessed variables. A number of interaction effects were observed, the most frequently occurring of which was between seat and vibration profile. Based upon the number of seat and vibration profile interactions, results suggest that a single seat is not suited for all tested conditions. However, SEAT values for all of the seats tested were extremely low (e.g., 6-DOF SEAT < 30%) indicating that all of the seats were capable of providing good vibration attenuation.

The Effects of Ejection Seat Cushion Design on Physical Fatigue and Cognitive Performance

DTIC Science & Technology

2006-11-01

Protection Division Biomechanics Branch Wright-Patterson AFB Ohio 45433-7947 Approved for public release; distribution is unlimited. NOTICE...ADDRESS(ES *Air Force Materiel Command Air Force Research Laboratory Human Effectiveness Directorate Biosciences & Protection Division Biomechanics ...Dayton, Ohio. Analyses of the data were accomplished by the Biomechanics Branch, Human Effectiveness Directorate of the Air Force Research Laboratory

An Ergonomic Evaluation of Aircraft Pilot Seats

NASA Astrophysics Data System (ADS)

Andrade, Yolanda Nicole

Seat comfort has become increasingly important in today's society as we spend more time at consoles, instrument panels, or just online. However, seat comfort is hard to define and difficult to measure. Several measures both objective and subjective were used to evaluate seat comfort in commercially available average pilot seats. Three pilot seats, which had the same material and similar adjustments but different physical attributes, and a universal classroom seat, with different material and no adjustments, were compared by 20 volunteers using subjective and objective measures in a Latin square controlled repeated measures design. A Friedman's test was used to determine that both the comfort questionnaire and the body-map rating results were able to discriminate objective comfort levels between the seats. One-way repeated measures ANOVA tests were used to analyze both the objective tests, actigraph and pressure pad data. All results indicated that one seat was clearly the most comfortable and another, the classroom seat was clearly the most uncomfortable seat. Furthermore, the overall comments per seat were compiled and compared to Fazlollahtabar's 2010) predictive automobile seat comfort theory to determine which factors influence comfort perception. The use of both subjective and objective data can better distinguish comfort from one seat over the other. These results have implications for future tests of seats that will be used for long durations. Limitations and future recommendations are discussed later in the paper. An interesting finding may explain why pressure pad data are typically seemingly at odds with subjective measures of seat comfort.

Securing Public Safety Vehicles: Reducing Vulnerabilities by Leveraging Smart Technology and Design Strategies

DTIC Science & Technology

2013-12-01

Protective Equipment Sizing and Design ,” Human Factors: The Journal of the Human Factors and Ergonomics Society 55, no. 1 (2013): 6–35; Hsiao...firefighters. The information will be used to improve apparatus design , revise NFPA 1901 Standard for Automotive Fire Apparatus, and improve cab, seat ... Design .” Human Factors: The Journal of the Human Factors and Ergonomics Society 55, no. 1 (2013): 6–35. ———. Sizing Firefighters and Fire Apparatus

A Wireless Lingual Feedback Device to Reduce Overpressures in Seated Posture: A Feasibility Study

PubMed Central

Chenu, Olivier; Vuillerme, Nicolas; Demongeot, Jacques; Payan, Yohan

2009-01-01

Background Pressure sores are localized injuries to the skin and underlying tissues and are mainly resulting from overpressure. Paraplegic peoples are particularly subjects to pressure sores because of long-time seated postures and sensory deprivation at the lower limbs. Methodology/Principal Findings Here we report outcomes of a feasibility trial involving a biofeedback system aimed at reducing buttock overpressure whilst an individual is seated. The system consists of (1) pressure sensors, (2) a laptop coupling sensors and actuator (3) a wireless Tongue Display Unit (TDU) consisting of a circuit embedded in a dental retainer with electrodes put in contact with the tongue. The principle consists in (1) detecting overpressures in people who are seated over long periods of time, (2) estimating a postural change that could reduce these overpressures and (3) communicating this change through directional information transmitted by the TDU.Twenty-four healthy subjects voluntarily participated in this study. Twelve healthy subjects initially formed the experimental group (EG) and were seated on a chair with the wireless TDU inside their mouth. They were asked to follow TDU orders that were randomly spread throughout the session. They were evaluated during two experimental sessions during which 20 electro-stimulations were sent. Twelve other subjects, added retrospectively, formed the control group (CG). These subjects participated in one session of the same experiment without any biofeedback.Three dependent variables were computed: (1) the ability of subjects to reach target posture (EG versus CG), (2) high pressure reductions after a biofeedback (EG versus CG) and (3) the level of these reductions relative to their initial values (EG only). Results show (1) that EG reached target postures in 90.2% of the trials, against 5,3% in the CG, (2) a significant reduction in overpressures in the EG compared to the CG and (3), for the EG, that the higher the initial pressures were, the more they were decreased. Conclusions/Significance The findings suggest that, in this trial, subjects were able to use a tongue tactile feedback system to reduce buttock overpressure while seated. Further evaluation of this system on paraplegic subjects remains to be done. PMID:19888336

Evaluation of ISO CRS Envelopes Relative to U.S. Vehicles and Child Restraint Systems.

PubMed

Hu, Jingwen; Manary, Miriam A; Klinich, Kathleen D; Reed, Matthew P

2015-01-01

The objectives of this study are to use computer simulation to evaluate the International Organization for Standardization (ISO) 13216-3:2006(E) child restraint system (CRS) envelopes relative to rear seat compartments from vehicles and CRSs in the U.S. market, investigate the potential compatibility issues of U.S. vehicles and CRSs, and demonstrate whether necessary modifications can be made to introduce such a system into compatibility evaluations between U.S. vehicles and CRSs. Three-dimensional geometry models for 26 vehicles and 16 convertible CRS designs developed previously were used. Geometry models of 3 forward-facing and 3 rear-facing CRS envelopes provided by the ISO were built in the current study. The virtual fit process closely followed the physical procedures described in the ISO standards. The results showed that the current ISO rear-facing envelopes can provide reasonable classifications for CRSs and vehicles, but the forward-facing envelopes do not represent products currently in the U.S. market. In particular, all of the selected vehicles could accommodate the largest forward-facing CRS envelope at the second-row seat location behind the driver seat. In contrast, half of the selected CRSs could not fit within any of the forward-facing ISO CRS envelopes, mainly due to protrusion at the rear-top corner of the envelope. The results also indicate that the rear seat compartment in U.S. vehicles often cannot accommodate a large portion of convertible CRSs in the rear-facing position. The increased demand for vehicle fuel economy and the recommendation to keep children rear-facing longer may lead to smaller cars and larger CRSs, which may increase the potential for fit problems. The virtual classifications indicated that contact between the forward-facing CRSs and the head restraints in the rear seats as well as that between the rear-facing CRSs and the back of the front seats is a main concern regarding the compatibility between the vehicles and the CRSs. Therefore, modification of the current ISO forward-facing CRS envelopes will likely to be necessary to ensure that they are useful for the U.S. market.

The seating mechanics of head-neck modular tapers in vitro: Load-displacement measurements, moisture, and rate effects.

PubMed

Ouellette, Eric S; Shenoy, Aarti A; Gilbert, Jeremy L

2018-04-01

The mechanically assisted crevice corrosion performance of head-neck modular tapers is a significant concern in orthopedic biomaterials. Fretting crevice corrosion processes in modular tapers are thought to be influenced by a wide array of factors including seating mechanics of the junction, hence there is a need for in vitro test methods that can assess their performance. This study presented a test method to directly measure the load-displacement seating mechanics of modular tapers and used this method to compare the seating mechanics for different tapers, moisture, seating loads and seating rates. Seating mechanics were explored whereby the instantaneous load-displacement behavior of the head seating onto the neck is captured and used to define the mechanics of seating. Two distinct taper design/material combinations were assembled wet or dry using axially applied loads (500, 1,000, 2,000, and 4,000 N) at two loading rates of 100 and 10 4  N/s (n = 5 for each condition) using a servohydraulic test frame. The results showed that pull-off strength scaled with seating load and ranged between 43% and 68% of seating load depending on sample and wetness. Tapers seated wet had higher pull-off strengths (2,200 ± 300 N) than those seated dry (1,800 ± 200 N, p < 0.05). Seating mechanics (load-displacement plots) varied due to sample type and due to wetness with differences in seating energy, seating stiffness, and seating displacement. These results show the detailed mechanics of seating during assembly and provide significant insight into the complex interplay of factors associated with even "ideal" seating (axial, quasistatic) loading. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1164-1172, 2018. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Assessment of Prone Positioning of Restrained, Seated Crewmembers in a Post Landing Stable 2 Orion Configuration

NASA Technical Reports Server (NTRS)

Barr, Yael; Fogarty, Jennifer

2010-01-01

During the Orion landing and recovery subsystem design review, June 2009, it was noted that the human system and various vehicle systems, the environmental control and life support (ECLSS) and guidance, navigation and control (GN&C) systems for example, are negatively affected by Orion assuming a stable 2 (upside down; Figure A) configuration post landing. The stable 2 configuration is predicted to occur about 50% of the time based on Apollo landing data and modeling of the current capsule. The stable 2 configuration will be countered by an active up-righting system (crew module up-righting system; CMUS). Post landing balloons will deploy and inflate causing the vehicle to assume or maintain the stable 1 (up-right; Figure B) configuration. During the design review it was proposed that the up-righting system could be capable of righting the vehicle within 60 seconds. However, this time limit posed a series of constraints on the design which made it less robust than desired. The landing and recovery subsystem team requested an analysis of Orion vehicle systems as well as the human system with regard to the effect of stable 2 in order to determine if an up-righting response time greater than 60 seconds could be tolerated. The following report focuses on the assessment of the human system in the posture assumed when Orion is in the stable 2 configuration. Stable 2 will place suited, seated, and restrained crewmembers in a prone (facedown), head-up position for a period of time dependent on the functionality of the up-righting systems, ability of the crew to release themselves from the seat and restraints, and/or time to arrival of rescue forces. Given that the Orion seat and restraint system design is not complete and therefore, not available for evaluation, Space Medicine assessed how long a healthy but deconditioned crewmember could stay in this prone, restrained position and the physiological consequences of this posture by researching terrestrial analogs and considered the known physiological alterations and deconditioning experienced by long duration crewmembers.

Computer users' postures and associations with workstation characteristics.

PubMed

Gerr, F; Marcus, M; Ortiz, D; White, B; Jones, W; Cohen, S; Gentry, E; Edwards, A; Bauer, E

2000-01-01

This investigation tested the hypotheses that (1) physical workstation dimensions are important determinants of operator posture, (2) specific workstation characteristics systematically affect worker posture, and (3) computer operators assume "neutral" upper limb postures while keying. Operator head, neck, and upper extremity posture and selected workstation dimensions and characteristics were measured among 379 computer users. Operator postures were measured with manual goniometers, workstation characteristics were evaluated by observation, and workstation dimensions by direct measurement. Considerably greater variability in all postures was observed than was expected from application of basic geometric principles to measured workstation dimensions. Few strong correlations were observed between worker posture and workstation physical dimensions; findings suggest that preference is given to keyboard placement with respect to the eyes (r = 0.60 for association between keyboard height and seated elbow height) compared with monitor placement with respect to the eyes (r = 0.18 for association between monitor height and seated eye height). Wrist extension was weakly correlated with keyboard height (r = -0.24) and virtually not at all with keyboard thickness (r = 0.07). Use of a wrist rest was associated with decreased wrist flexion (21.9 versus 25.1 degrees, p < 0.01). Participants who had easily adjustable chairs had essentially the same neck and upper limb postures as did those with nonadjustable chairs. Sixty-one percent of computer operators were observed in nonneutral shoulder postures and 41% in nonneutral wrist postures. Findings suggest that (1) workstation dimensions are not strong determinants of at least several neck and upper extremity postures among computer operators, (2) only some workstation characteristics affect posture, and (3) contrary to common recommendations, a large proportion of computer users do not work in so-called neutral postures.

Advanced Infant Car Seat Would Increase Highway Safety

NASA Technical Reports Server (NTRS)

Dabney, Richard; Elrod, Susan

2004-01-01

An advanced infant car seat has been proposed to increase highway safety by reducing the incidence of crying, fussy behavior, and other child-related distractions that divert an adult driver s attention from driving. In addition to a conventional infant car seat with safety restraints, the proposed advanced infant car seat would include a number of components and subsystems that would function together as a comprehensive infant-care system that would keep its occupant safe, comfortable, and entertained, and would enable the driver to monitor the baby without having to either stop the car or turn around to face the infant during driving. The system would include a vibrator with bulb switch to operate; the switch would double as a squeeze toy that would make its own specific sound. A music subsystem would include loudspeakers built into the seat plus digital and analog circuitry that would utilize plug-in memory modules to synthesize music or a variety of other sounds. The music subsystem would include a built-in sound generator that could synthesize white noise or a human heartbeat to calm the baby to sleep. A second bulb switch could be used to control the music subsystem and would double as a squeeze toy that would make a distinct sound. An anti-noise sound-suppression system would isolate the baby from potentially disturbing ambient external noises. This subsystem would include small microphones, placed near the baby s ears, to detect ambient noise. The outputs of the microphone would be amplified and fed to the loudspeakers at appropriate amplitude and in a phase opposite that of the detected ambient noise, such that the net ambient sound arriving at the baby s ears would be almost completely cancelled. A video-camera subsystem would enable the driver to monitor the baby visually while continuing to face forward. One or more portable miniature video cameras could be embedded in the side of the infant car seat (see figure) or in a flip-down handle. The outputs of the video cameras would be transmitted by radio or infrared to a portable, miniature receiver/video monitor unit that would be attached to the dashboard of the car. The video-camera subsystem can also be used within transmission/reception range when the seat was removed from the car. The system would include a biotelemetric and tracking subsystem, which would include a Global Positioning System receiver for measuring its location. This subsystem would transmit the location of the infant car seat (even if the seat were not in a car) along with such biometric data as the baby s heart rate, perspiration rate, urinary status, temperature, and rate of breathing. Upon detecting any anomalies in the biometric data, this subsystem would send a warning to a paging device installed in the car or carried by the driver, so that the driver could pull the car off the road to attend to the baby. A motion detector in this subsystem would send a warning if the infant car seat were to be moved or otherwise disturbed unexpectedly while the infant was seated in it: this warning function, in combination with the position- tracking function, could help in finding a baby who had been kidnapped with the seat. Removable rechargeable batteries would enable uninterrupted functioning of all parts of the system while transporting the baby to and from the car. The batteries could be recharged via the cigarette-lighter outlet in the car or by use of an external AC-powered charger.

Multi-Variant/Capability Next Generation Troop Seat (M-V/C NGTS)

DTIC Science & Technology

2009-01-01

John Plaga , Work Unit Manager MARK M. HOFFMAN Deputy Chief Biomechanics Branch Biosciences and Protection Division Human...John A. Plaga a. REPORT U b. ABSTRACT U c. THIS PAGE U SAR 20 19b. TELEPHONE NUMBER (include area

78 FR 50425 - Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD); Notice of...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-19

..., NICHD, at 301- 496-0536 to make your reservation, additional seating will be available in the meeting.... 93.864, Population Research; 93.865, Research for Mothers and Children; 93.929, Center for Medical...

76 FR 55076 - Eunice Kennedy Shriver National Institute of Child Health & Human Development Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-06

... Liaison Office, NICHD, at 301-496-0536 to make your reservation. Additional seating will be available in....865, Research for Mothers and Children; 93.929, Center for Medical Rehabilitation Research; 93.209...

ANTHROPOMETRIC CHARACTERISTICS OF FLIGHT PERSONNEL FOR DESIGNING DAMPERS FOR SHOCKPROOF SEATS OF HELICOPTER CREWS.

PubMed

Moiseev, Yu B; Ignatovich, S N; Strakhov, A Yu

The article discusses anthropometric design of shockproof pilot seats for state-of-the-art helicopters. Object of the investigation was anthropometric parameters of the helicopter aviation personnel of the Russian interior troops. It was stated that the body parameters essential for designing helicopter seat dampers are mass of the body part that presses against the seat in the seating position, and eye level above the seat surface. An uncontrolled seat damper ensuring shockproof safety to 95 % helicopter crews must be designed for the body mass contacting the seat of 99.7 kg and eye level above the seat of 78.6 cm. To absorb.shock effectively, future dampers should be adjustable to pilot's body parameters. The optimal approach to anthropometric design of a helicopter seat is development of type pilot' body models with due account of pilot's the flight outfit and seat geometry. Principle criteria of type models are body mass and eye level. The authors propose a system of type body models facilitating specification of anthropometric data helicopter seat developers.

Normative Misperceptions of Peer Seat Belt Use Among High School Students and Their Relationship to Personal Seat Belt Use

PubMed Central

LITT, DANA M.; LEWIS, MELISSA A.; LINKENBACH, JEFFREY W.; LANDE, GARY; NEIGHBORS, CLAYTON

2016-01-01

Objectives This research examined gender-specific perceptions of peer seat belt use norms among high school students and their relationship with one’s own seat belt use. We expected that students would underestimate the seat belt use of their peers and that these perceptions would be positively associated with their own seat belt use. Methods High school students from 4 schools (N = 3348; 52% male) completed measures assessing perceived seat belt use and personal seat belt use. Results Findings demonstrated that students perceived that others engaged in less seat belt use than they do and that perceived norms were positively associated with one’s own seat belt use. Conclusions Peer influences are a strong predictor of behavior, especially among adolescents. Ironically, adolescents’ behaviors are often influenced by inaccurate perceptions of their peers. This research establishes the presence of a misperception related to seat belt use and suggests that misperception is associated with own behaviors. This research provides a foundation for social norms–based interventions designed to increase seat belt use by correcting normative misperceptions among adolescents. PMID:24628560

Car Seat Safety

MedlinePlus

... Staying Safe Videos for Educators Search English Español Car Seat Safety KidsHealth / For Parents / Car Seat Safety ... certified child passenger safety technician.) Guidelines for Choosing Car Seats Choose a seat with a label that ...

75 FR 30775 - Availability of Seats for the Monitor National Marine Sanctuary Advisory Council

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-02

... to fill existing seats for the following vacant seats: Heritage Tourism seat, Citizen-at-Large seat... stakeholders, including: Citizen-at-Large, Conservation, Economic Development, Education, Heritage Tourism...

Exploring the design of a lightweight, sustainable and comfortable aircraft seat.

PubMed

Kokorikou, A; Vink, P; de Pauw, I C; Braca, A

2016-07-19

Making a lightweight seat that is also comfortable can be contradictory because usually comfort improvement means adding a feature (e.g. headrest, adjustable lumbar support, movable armrests, integrated massage systems, etc.), which makes seats heavier. This paper explores the design of an economy class aircraft seat that aims to be lightweight, comfortable and sustainable. Theory about comfort in seats, ergonomics, lightweight design, Biomimicry and Cradle to cradle was studied and resulted in a list of requirements that the new seat should satisfy. The design process resulted in a new seat that is 36% lighter than the reference seat, which showed that a significant weight reduction can be achieved. This was completed by re-designing the backrest and seat pan and integrating their functions into a reduced number of parts. Apart from the weight reduction that helps in reducing the airplane's environmental impact, the seat also satisfies most of the other sustainability requirements such as the use of recyclable materials, design for disassembly, easy to repair. A user test compared the new seat with a premium economy class aircraft seat and the level of comfort was similar. Strong points of the new design were identified such as the lumbar support and the cushioning material, as well as shortcomings on which the seat needs to be improved, like the seat pan length and the first impression. Long term comfort tests are still needed as the seat is meant for long-haul flights.

The Benefit of Supplementary Text for the Resolution of Auditory Overload

DTIC Science & Technology

2015-05-01

3 3.3 Experimental design ...degrees of noise-induced hearing loss on their ability to recognize consonants and sentences presented either binaurally over a headset at a comfortable ...tested individually while seated in front of a laptop computer in a mock-up of a CAF land vehicle, the Bison Command, Control, Communications and

Seat belt use to save face: impact on drivers' body region and nature of injury in motor vehicle crashes.

PubMed

Han, Guang-Ming; Newmyer, Ashley; Qu, Ming

2015-01-01

Seat belt use is the single most effective way to save lives and reduce injuries in motor vehicle crashes. However, some case reports described seat belt use as a double-edged sword because some injuries are related to seat belt use in motor vehicle crashes. To comprehensively understand the effects of seat belt use, we systemically investigated the association between seat belt use and injuries based on anatomic body region and type of injury in drivers involved in motor vehicle crashes. The injury information was obtained by linking crash reports with hospital discharge data and categorized by using the diagnosis codes based on the Barell injury diagnosis matrix. A total of 10,479 drivers (≥15 years) in passenger vehicles involved in motor vehicle crashes from 2006 to 2011 were included in this study. Seat belt use significantly reduced the proportions of traumatic brain injury (10.4% non-seat belt; 4.1% seat belt) and other head, face, and neck injury (29.3% non-seat belt; 16.6% seat belt) but increased the proportion of spine: thoracic to coccyx injury (17.9% non-seat belt; 35.5% seat belt). Although the proportion of spine: thoracic to coccyx injury was increased in drivers with seat belt use, the severity of injury was decreased, such as fracture (4.2% with seat belt use; 22.0% without seat belt use). Furthermore, the total medical charges decreased due to the change of injury profiles in drivers with seat belt use from a higher percentage of fractures (average cost for per case $26,352) to a higher percentage of sprains and/or strains ($1,897) with spine: thoracic to coccyx injury. This study provide a comprehensive picture for understanding the protective effect of seat belt use on injuries based on anatomic body region and type of injury in drivers involved in motor vehicle crashes.

The repeatability and reproducibility of the BioRID IIg in a repeatable laboratory seat based on a production car seat.

PubMed

Hynd, David; Depinet, Paul; Lorenz, Bernd

2013-01-01

The United Nations Economic Commission for Europe Informal Group on GTR No. 7 Phase 2 are working to define a build level for the BioRID II rear impact (whiplash) crash test dummy that ensures repeatable and reproducible performance in a test procedure that has been proposed for future legislation. This includes the specification of dummy hardware, as well as the development of comprehensive certification procedures for the dummy. This study evaluated whether the dummy build level and certification procedures deliver the desired level of repeatability and reproducibility. A custom-designed laboratory seat was made using the seat base, back, and head restraint from a production car seat to ensure a representative interface with the dummy. The seat back was reinforced for use in multiple tests and the recliner mechanism was replaced by an external spring-damper mechanism. A total of 65 tests were performed with 6 BioRID IIg dummies using the draft GTR No.7 sled pulse and seating procedure. All dummies were subject to the build, maintenance, and certification procedures defined by the Informal Group. The test condition was highly repeatable, with a very repeatable pulse, a well-controlled seat back response, and minimal observed degradation of seat foams. The results showed qualitatively reasonable repeatability and reproducibility for the upper torso and head accelerations, as well as for T1 Fx and upper neck Fx . However, reproducibility was not acceptable for T1 and upper neck Fz or for T1 and upper neck My . The Informal Group has not selected injury or seat assessment criteria for use with BioRID II, so it is not known whether these channels would be used in the regulation. However, the ramping-up behavior of the dummy showed poor reproducibility, which would be expected to affect the reproducibility of dummy measurements in general. Pelvis and spine characteristics were found to significantly influence the dummy measurements for which poor reproducibility was observed. It was also observed that the primary neck response in these tests was flexion, not extension. This correlates well with recent findings from Japan and the United States showing a correlation between neck flexion and injury in accident replication simulations and postmortem human subjects (PMHS) studies, respectively. The present certification tests may not adequately control front cervical spine bumper characteristics, which are important for neck flexion response. The certification sled test also does not include the pelvis and so cannot be used to control pelvis response and does not substantially load the lumbar bumpers and so does not control these parts of the dummy. The stiffness of all spine bumpers and of the pelvis flesh should be much more tightly controlled. It is recommended that a method for certifying the front cervical bumpers should be developed. Recommendations are also made for tighter tolerance on the input parameters for the existing certification tests.

Sitting biomechanics, part II: optimal car driver's seat and optimal driver's spinal model.

PubMed

Harrison, D D; Harrison, S O; Croft, A C; Harrison, D E; Troyanovich, S J

2000-01-01

Driving has been associated with signs and symptoms caused by vibrations. Sitting causes the pelvis to rotate backwards and the lumbar lordosis to reduce. Lumbar support and armrests reduce disc pressure and electromyographically recorded values. However, the ideal driver's seat and an optimal seated spinal model have not been described. To determine an optimal automobile seat and an ideal spinal model of a driver. Information was obtained from peer-reviewed scientific journals and texts, automotive engineering reports, and the National Library of Medicine. Driving predisposes vehicle operators to low-back pain and degeneration. The optimal seat would have an adjustable seat back incline of 100 degrees from horizontal, a changeable depth of seat back to front edge of seat bottom, adjustable height, an adjustable seat bottom incline, firm (dense) foam in the seat bottom cushion, horizontally and vertically adjustable lumbar support, adjustable bilateral arm rests, adjustable head restraint with lordosis pad, seat shock absorbers to dampen frequencies in the 1 to 20 Hz range, and linear front-back travel of the seat enabling drivers of all sizes to reach the pedals. The lumbar support should be pulsating in depth to reduce static load. The seat back should be damped to reduce rebounding of the torso in rear-end impacts. The optimal driver's spinal model would be the average Harrison model in a 10 degrees posterior inclining seat back angle.

Car Seats for Growing Children: Guidelines for Counselling Parents on Which Type of Car Seat To Use.

ERIC Educational Resources Information Center

Illinois State Dept. of Transportation, Springfield. Div. of Traffic Safety.

Children's car seats provide protection from the types of injury with the worst consequences. This document presents guidelines for selecting and installing child car seats, booster seats, and seat belts. The document includes suggestions for identifying when a child's safety restraint system should be changed, for determining if the restraint…

76 FR 13620 - Opportunity to Partner; Testing of Patient Compartment Seating and Restraints to Proposed Test...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-14

... current or comparable pre-test or pre-standard seat, seat retention device, and occupant restraint and its... Partner; Testing of Patient Compartment Seating and Restraints to Proposed Test Standard Authority: 29 U.S... proposed ambulance component test standards. One such standard, AMD STANDARD 026--Seat, Seat Mount and...

Seat belt use among rear passengers: validity of self-reported versus observational measures

PubMed Central

Zambon, Francesco; Fedeli, Ugo; Marchesan, Maria; Schievano, Elena; Ferro, Antonio; Spolaore, Paolo

2008-01-01

Background The effects of seat belt laws and public education campaigns on seat belt use are assessed on the basis of observational or self-reported data on seat belt use. Previous studies focusing on front seat occupants have shown that self-reports indicate a greater seat belt usage than observational findings. Whether this over-reporting in self reports applies to rear seat belt usage, and to what extent, have yet to be investigated. We aimed to evaluate the over-reporting factor for rear seat passengers and whether this varies by gender and under different compulsory seat belt use conditions. Methods The study was conducted in the Veneto Region, an area in the North-East of Italy with a population of 4.7 million. The prevalence of seat belt use among rear seat passengers was determined by means of a cross-sectional self-report survey and an observational study. Both investigations were performed in two time periods: in 2003, when rear seat belt use was not enforced by primary legislation, and in 2005, after rear seat belt use had become compulsory (June 2003). Overall, 8138 observations and 7902 interviews were recorded. Gender differences in the prevalence of rear seat belt use were examined using the chi-square test. The over-reporting factor, defined as the ratio of the self-reported to the observed prevalence of rear seat belt use, was calculated by gender before and after the rear seat belt legislation came into effect. Results Among rear seat passengers, self-reported rates were always higher than the observational findings, with an overall over-reporting factor of 1.4. We registered no statistically significant changes over time in the over-reporting factor, nor any major differences between genders. Conclusion Self-reported seat belt usage by rear passengers represents an efficient alternative to observational studies for tracking changes in actual behavior, although the reported figures need to be adjusted using an appropriate over-reporting factor in order to gain an idea of genuine seat belt use. PMID:18613955

RF Loading Effects of Aircraft Seats in an Electromagnetic Reverberating Environment

NASA Technical Reports Server (NTRS)

Nguyen, Truong

2000-01-01

Loading effects of aircraft seats in an electromagnetic reverberating environment are investigated. The effects are determined by comparing the reverberation chamber s insertion losses with and without the seats. The average per-seat absorption cross-sections are derived for coach and first class seats, and the results are compared for several seat configurations. An example is given for how the seat absorption cross-sections can be used to estimate the loading effects on the RF environment in an aircraft passenger cabin.

RF Loading Effects of Aircraft Seats in an Electromagnetic Reverberating Environment

NASA Technical Reports Server (NTRS)

Nguyen, Truong X.

2000-01-01

Loading effects of aircraft seats in an electromagnetic reverberating environment are investigated. The effects are determined by comparing the reverberation chamber's insertion losses with and without the seats. The average per-seat absorption cross-sections are derived for coach and first class seats, and the results are compared for several seat configurations. An example is given for how the seat absorption cross-sections can be used to estimate the loading effects on the RF environment in an aircraft passenger cabin.

NASA space shuttle lightweight seat

NASA Technical Reports Server (NTRS)

Hansen, Chris; Jermstad, Wayne; Lewis, James; Colangelo, Todd

1996-01-01

The Space Shuttle Lightweight Seat-Mission Specialist (LWS-MS) is a crew seat for the mission specialists who fly aboard the Space Shuttle. The LWS-MS is a lightweight replacement for the mission specialist seats currently flown on the Shuttle. Using state-of-the-art analysis techniques, a team of NASA and Lockheed engineers from the Johnson Space Center (JSC) designed a seat that met the most stringent requirements demanded of the new seats by the Shuttle program, and reduced the weight of the seats by 52%.

A lower body negative pressure box for +Gz simulation in the upright seated position.

DOT National Transportation Integrated Search

1979-02-01

The cost of purchasing and operating a human centrifuge is substantial. Lower body negative pressure (LBNP) is considered an acceptable experimental substitute for the +Gz stress of the centrifuge. Since civil aviation pilots are usually subjected to...

Whole-body Vibration Exposure Intervention among Professional Bus and Truck Drivers: A Laboratory Evaluation of Seat-suspension Designs.

PubMed

Blood, Ryan P; Yost, Michael G; Camp, Janice E; Ching, Randal P

2015-01-01

Long-term exposure to seated whole-body vibration (WBV) is one of the leading risk factors for the development of low back disorders. Professional bus and truck drivers are regularly exposed to continuous WBV, since they spend the majority of their working hours driving heavy vehicles. This study measured WBV exposures among professional bus and truck drivers and evaluated the effects of seat-suspension designs using simulated field-collected data on a vibration table. WBV exposures were measured and compared across three different seat designs: an air-ride bus seat, an air-ride truck seat, and an electromagnetically active (EM-active) seat. Air-ride seats use a compressed-air bladder to attenuate vibrations, and they have been in operation throughout the transportation industry for many years. The EM-active seat is a relatively new design that incorporates a microprocessor-controlled actuator to dampen vibration. The vibration table simulated seven WBV exposure scenarios: four segments of vertical vibration and three scenarios that used field-collected driving data on different road surfaces-a city street, a freeway, and a section of rough roadway. The field scenarios used tri-axial WBV data that had been collected at the seat pan and at the driver's sternum, in accordance with ISO 2631-1 and 2631-5. This study found that WBV was significantly greater in the vertical direction (z-axis) than in the lateral directions (x-and y-axes) for each of the three road types and each of the three types of seats. Quantitative comparisons of the results showed that the floor-to-seat-pan transmissibility was significantly lower for the EM-active seat than for either the air-ride bus seat or the air-ride truck seat, across all three road types. This study also demonstrated that seat-suspension designs have a significant effect on the vibrations transmitted to vehicle operators, and the study's results may prove useful in designing future seat suspensions.

Assessment of potential catastrophic landslides in Taiwan by airborne LiDAR-derived DEM

NASA Astrophysics Data System (ADS)

Hou, Chin-Shyong; Hsieh, Yu-Chung; Hu, Jyr-Ching; Chiu, Cheng-Lung; Chen, Hung-Jen; Fei, Li-Yuan

2013-04-01

The heavy rainfall of Typhoon Morakot caused severe damage to infrastructures, property and human lives in southern Taiwan in 2009. The most atrocious incident was the Hsiaolin landslide, which buried more than 400 victims. After this catastrophic event, the recognition of localities of deep-seated landslides becomes a critical issue in landslide hazard mitigation induced from extreme climate events. Consequently the airborne LiDAR survey was carried out in first phase from 2010 to 2012 by Central Geological Survey, MOEA in Taiwan in order to assess the potential catastrophic deep-seated landslides in the steep and rocky terrain in south-central Taiwan. The second phase of LiDAR survey is ongoing from 2013 to 2015 for the recognition and the assessment of possible impact area induced by deep-seated landslide in the mountainous area of whole Taiwan. Transitionally, the recognition of potential deep-seated landslide sites is adopted in term of landslide inventories from space-borne images, aerial photographs and field investigation. However, it is difficult to produce robust landslide inventories due to the poor spatial resolution of ground elevation and highly dense vegetation in mountainous area in Taiwan. In this study, the 1 m LiDAR-derived DEM is used to extract key geomorphological features such as crown cracks, minor scarps, toe of surface rupture at meter to sub-meter scale hidden under forests with high degree of accuracy. Preliminary result shows that about 400 potential landslide sites have been recognized to improve the quality of landslide inventories. In addition, detailed contour maps and visualized images are reproduced to outline the shape of potential deep-seated landslides. Further geomorphometric analyses based on hillshade, aspect, slope, eigenvalue ratio (ER) and openness will be integrated to easily create landslide inventories to mitigate landslide disasters in Taiwan mountainous area.

Three-dimensional multimodality fusion imaging as an educational and planning tool for deep-seated meningiomas.

PubMed

Sato, Mitsuru; Tateishi, Kensuke; Murata, Hidetoshi; Kin, Taichi; Suenaga, Jun; Takase, Hajime; Yoneyama, Tomohiro; Nishii, Toshiaki; Tateishi, Ukihide; Yamamoto, Tetsuya; Saito, Nobuhito; Inoue, Tomio; Kawahara, Nobutaka

2018-06-26

The utility of surgical simulation with three-dimensional multimodality fusion imaging (3D-MFI) has been demonstrated. However, its potential in deep-seated brain lesions remains unknown. The aim of this study was to investigate the impact of 3D-MFI in deep-seated meningioma operations. Fourteen patients with deeply located meningiomas were included in this study. We constructed 3D-MFIs by fusing high-resolution magnetic resonance (MR) and computed tomography (CT) images with a rotational digital subtraction angiogram (DSA) in all patients. The surgical procedure was simulated by 3D-MFI prior to operation. To assess the impact on neurosurgical education, the objective values of surgical simulation by 3D-MFIs/virtual reality (VR) video were evaluated. To validate the quality of 3D-MFIs, intraoperative findings were compared. The identification rate (IR) and positive predictive value (PPV) for the tumor feeding arteries and involved perforating arteries and veins were also assessed for quality assessment of 3D-MFI. After surgical simulation by 3D-MFIs, near-total resection was achieved in 13 of 14 (92.9%) patients without neurological complications. 3D-MFIs significantly contributed to the understanding of surgical anatomy and optimal surgical view (p < .0001) and learning how to preserve critical vessels (p < .0001) and resect tumors safety and extensively (p < .0001) by neurosurgical residents/fellows. The IR of 3D-MFI for tumor-feeding arteries and perforating arteries and veins was 100% and 92.9%, respectively. The PPV of 3D-MFI for tumor-feeding arteries and perforating arteries and veins was 98.8% and 76.5%, respectively. 3D-MFI contributed to learn skull base meningioma surgery. Also, 3D-MFI provided high quality to identify critical anatomical structures within or adjacent to deep-seated meningiomas. Thus, 3D-MFI is promising educational and surgical planning tool for meningiomas in deep-seated regions.

49 CFR 571.202a - Standard No. 202a; Head restraints; Mandatory applicability begins on September 1, 2009.

Code of Federal Regulations, 2011 CFR

2011-10-01

... restraints in rear outboard seats. Measure the height of the top of a rear seat back or the top of any independently adjustable seat component attached to or adjacent to the rear seat back in its highest position of... seat back inclination position less than the design seat back angle. (a)(1) For head restraints in...

NASA/FAA general aviation crash dynamics program - An update

NASA Technical Reports Server (NTRS)

Hayduk, R. J.; Thomson, R. G.; Carden, H. D.

1979-01-01

Work in progress in the NASA/FAA General Aviation Crash Dynamics Program for the development of technology for increased crash-worthiness and occupant survivability of general aviation aircraft is presented. Full-scale crash testing facilities and procedures are outlined, and a chronological summary of full-scale tests conducted and planned is presented. The Plastic and Large Deflection Analysis of Nonlinear Structures and Modified Seat Occupant Model for Light Aircraft computer programs which form part of the effort to predict nonlinear geometric and material behavior of sheet-stringer aircraft structures subjected to large deformations are described, and excellent agreement between simulations and experiments is noted. The development of structural concepts to attenuate the load transmitted to the passenger through the seats and subfloor structure is discussed, and an apparatus built to test emergency locator transmitters in a realistic environment is presented.

Extreme D'Hondt and round-off effects in voting computations

NASA Astrophysics Data System (ADS)

Konstantinov, M. M.; Pelova, G. B.

2015-11-01

D'Hondt (or Jefferson) method and Hare-Niemeyer (or Hamilton) method are widely used worldwide for seat allocation in proportional systems. Everything seems to be well known in this area. However, this is not the case. For example the D'Hondt method can violate the quota rule from above but this effect is not analyzed as a function of the number of parties and/or the threshold used. Also, allocation methods are often implemented automatically as computer codes in machine arithmetic believing that following the IEEE standards for double precision binary arithmetics would guarantee correct results. Unfortunately this may not happen not only for double precision arithmetic (usually producing 15-16 true decimal digits) but also for any relative precision of the underlying binary machine arithmetics. This paper deals with the following new issues.Find conditions (threshold in particular) such that D'Hondt seat allocation violates maximally the quota rule. Analyze possible influence of rounding errors in the automatic implementation of Hare-Niemeyer method in machine arithmetic.Concerning the first issue, it is known that the maximal deviation of D'Hondt allocation from upper quota for the Bulgarian proportional system (240 MP and 4% barrier) is 5. This fact had been established in 1991. A classical treatment of voting issues is the monograph [1], while electoral problems specific for Bulgaria have been treated in [2, 4]. The effect of threshold on extreme seat allocations is also analyzed in [3]. Finally we would like to stress that Voting Theory may sometimes be mathematically trivial but always has great political impact. This is a strong motivation for further investigations in this area.

Video Game Playing Is Independently Associated with Blood Pressure and Lipids in Overweight and Obese Adolescents

PubMed Central

Goldfield, Gary S.; Kenny, Glen P.; Hadjiyannakis, Stasia; Phillips, Penny; Alberga, Angela S.; Saunders, Travis J.; Tremblay, Mark S.; Malcolm, Janine; Prud'homme, Denis; Gougeon, Rejeanne; Sigal, Ronald J.

2011-01-01

Objective To examine the association between duration and type of screen time (TV, video games, computer time) and blood pressure (BP) and lipids in overweight and obese adolescents. Design This is a cross-sectional study of 282 overweight or obese adolescents aged 14–18 years (86 males, 196 females) assessed at baseline prior to beginning a lifestyle intervention study for weight control. Sedentary behaviours, defined as hours per day spent watching TV, playing video games, recreational computer use and total screen time were measured by self-report. We examined the associations between sedentary behaviours and BP and lipids using multiple linear regression. Results Seated video gaming was the only sedentary behaviour associated with elevated BP and lipids before and after adjustment for age, sex, pubertal stage, parental education, body mass index (BMI), caloric intake, percent intake in dietary fat, physical activity (PA) duration, and PA intensity. Specifically, video gaming remained positively associated with systolic BP (adjusted r = 0.13, β = 1.1, p<0.05) and total cholesterol/HDL ratio (adjusted r = 0.12, β = 0.14, p<0.05). Conclusions Playing video games was the only form of sedentary behaviour that was independently associated with increased BP and lipids. Our findings provide support for reducing time spent playing seated video games as a possible means to promote health and prevent the incidence of cardiovascular disease (CVD) risk factors in this high risk group of overweight and obese adolescents. Future research is needed to first replicate these findings and subsequently aim to elucidate the mechanisms linking seated video gaming and elevated BP and lipids in this high risk population. Trial Registration Clinicaltrials.gov NCT00195858 PMID:22069461

Development of a crashworthy seat for commuter aircraft.

DOT National Transportation Integrated Search

1990-09-01

A series of dynamic impact tests were conducted using a prototype seat with an energy absorbing mechanism as part of the seat pan. The seat frame was designed to represent a typical commuter aircraft passenger seat. Tests were conducted in an orienta...

Preventive Effects of Seat Belt on Clinical Outcomes for Road Traffic Injuries

PubMed Central

2015-01-01

Proper seat belt use saves lives; however, the use rate decreased in Korea. This study aimed to measure the magnitude of the preventive effect of seat belt on case-fatality across drivers and passengers. We used the Emergency Department based Injury In-depth Surveillance (EDIIS) database from 17 EDs between 2011 and 2012. All of adult injured patients from road traffic injuries (RTI) in-vehicle of less than 10-seat van were eligible, excluding cases with unknown seat belt use and outcomes. Primary and secondary endpoints were in-hospital mortality and intracranial injury. We calculated adjusted odds ratios (AORs) of seat belt use and driving status for study outcomes adjusting for potential confounders. Among 23,698 eligible patients, 15,304 (64.6%) wore seat belts. Driver, middle aged (30-44 yr), male, daytime injured patients were more likely to use seat belts (all P < 0.001). In terms of clinical outcome, no seat belt group had higher proportions of case-fatality and intracranial injury compared to seat belt group (both P < 0.001). Compared to seat belt group, AORs (95% CIs) of no seat belt group were 10.43 (7.75-14.04) for case-fatality and 2.68 (2.25-3.19) for intracranial injury respectively. In the interaction model, AORs (95% CIs) of no seat belt use for case-fatality were 11.71 (8.45-16.22) in drivers and 5.52 (2.83-14.76) in non-driving passengers, respectively. Wearing seat belt has significantly preventive effects on case-fatality and intracranial injury. Public health efforts to increase seat belt use are needed to reduce health burden from RTIs. PMID:26713066

Design and evaluation of a suspension seat to reduce vibration exposure of subway operators: a case study.

PubMed

Marcotte, Pierre; Beaugrand, Sylvie; Boutin, Jérôme; Larue, Christian

2010-01-01

Subway operators have complained about discomfort caused by whole-body vibration. To address this problem, a suspension seat with extensive ergonomic features has been adapted to the confined space of the subway operator cab. The suspension was modified from an existing suspension in order to reduce the dominant frequency of the subway vertical vibration (2.4 Hz). The suspension seat has been extensively tested on a vertical hydraulic shaker. These tests have shown that the SEAT value was lower for a higher vibration level, for higher subject weight, and for the suspension adjusted at median height. The seat also produces a lower SEAT value when there was a predominance of the 6 Hz vibration component. The horizontal seat adjustments had no influence on the suspension SEAT value. Removing the suspension damper also decreases the SEAT value for all the tested configurations. The final version of the suspension seat prototype was validated during normal subway operation with 19 different operators having weight in the 5th, 50th and 95th percentile of the operator population. Accelerations were measured with triaxial accelerometers at the seat cushion, above the suspension and on the floor. In addition to the vibration measurements, each operator was asked about his perceived discomfort from vibration exposure. Globally, the suspension seat attenuated the vertical vibration (SEAT values from 0.86 to 0.99), but discomfort due to amplification of the 2.4 Hz component occurred when the suspension height was adjusted at the minimum, even when the global weighted acceleration was lower (SEAT value < 1). These results suggest that in order to reduce the discomfort caused by whole-body vibration, the transmissibility of the seat should also be considered, in particular when there is a dominant frequency in the vibration spectra.

76 FR 66274 - Availability of Seats for the Cordell Bank National Marine Sanctuary Advisory Council

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-26

...The ONMS is seeking applications for the following vacant seats on the Cordell Bank National Marine Sanctuary Advisory Council: Education, Primary and Alternate seats; Fishing, Primary and Alternate seats; Research, Alternate seat; Community-at-Large Mann County, Alternate seat; Community-at-Large Sonoma County, Alternate seat. Applicants are chosen based upon their particular expertise and experience in relation to the seat for which they are applying; community and professional affiliations; philosophy regarding the protection and management of marine resources; and possibly the length of residence in the area affected by the sanctuary. Applicants who are chosen as members should expect to serve three-year terms, pursuant to the council's Charter.

Motor Vehicle Crashes, Medical Outcomes, and Hospital Charges Among Children Aged 1-12 Years - Crash Outcome Data Evaluation System, 11 States, 2005-2008.

PubMed

Sauber-Schatz, Erin K; Thomas, Andrea M; Cook, Lawrence J

2015-10-02

Motor vehicle crashes are a leading cause of death among children. Age- and size-appropriate restraint use is an effective way to prevent motor vehicle-related injuries and deaths. However, children are not always properly restrained while riding in a motor vehicle, and some are not restrained at all, which increases their risk for injury and death in a crash. 2005-2008. The Crash Outcome Data Evaluation System (CODES) is a multistate program facilitated by the National Highway Traffic Safety Administration to probabilistically link police crash reports and hospital databases for traffic safety analyses. Eleven participating states (Connecticut, Georgia, Kentucky, Maryland, Minnesota, Missouri, Nebraska, New York, Ohio, South Carolina, and Utah) submitted data to CODES during the reporting period. Descriptive analysis was used to describe drivers and child passengers involved in motor vehicle crashes and to summarize crash and medical outcomes. Odds ratios and 95% confidence intervals were used to compare a child passenger's likelihood of sustaining specific types of injuries by restraint status (optimal, suboptimal, or unrestrained) and seating location (front or back seat). Because of data constraints, optimal restraint use was defined as a car seat or booster seat use for children aged 1-7 years and seat belt use for children aged 8-12 years. Suboptimal restraint use was defined as seat belt use for children aged 1-7 years. Unrestrained was defined as no use of car seat, booster seat, or seat belt for children aged 1-12 years. Optimal restraint use in the back seat declined with child's age (1 year: 95.9%, 5 years: 95.4%, 7 years: 94.7%, 8 years: 77.4%, 10 years: 67.5%, 12 years: 54.7%). Child restraint use was associated with driver restraint use; 41.3% of children riding with unrestrained drivers also were unrestrained compared with 2.2% of children riding with restrained drivers. Child restraint use also was associated with impaired driving due to alcohol or drug use; 16.4% children riding with drivers suspected of alcohol or drug use were unrestrained compared with 2.9% of children riding with drivers not suspected of such use. Optimally restrained and suboptimally restrained children were less likely to sustain a traumatic brain injury than unrestrained children. The 90th percentile hospital charges for children aged 4-7 years who were in motor vehicle crashes were $1,630.00 and $1,958.00 for those optimally restrained in a back seat and front seat, respectively; $2,035.91 and $3,696.00 for those suboptimally restrained in a back seat and front seat, respectively; and $9,956.60 and $11,143.85 for those unrestrained in a back seat and front seat, respectively. Proper car seat, booster seat, and seat belt use among children in the back seat prevents injuries and deaths, as well as averts hospital charges. However, the number, severity, and cost of injuries among children in crashes who were not optimally restrained or who were seated in a front seat indicates the need for improvements in proper use of age- and size-appropriate car seats, booster seats, and seat belts in the back seat. Effective interventions for increasing proper child restraint use could be universally implemented by states and communities to prevent motor vehicle-related injuries among children and their resulting costs.

Effect of crash pulse shape on seat stroke requirements for limiting loads on occupants of aircraft

NASA Technical Reports Server (NTRS)

Carden, Huey D.

1992-01-01

An analytical study was made to provide comparative information on various crash pulse shapes that potentially could be used to test seats under conditions included in Federal Regulations Part 23 Paragraph 23.562(b)(1) for dynamic testing of general aviation seats, show the effects that crash pulse shape can have on the seat stroke requirements necessary to maintain a specified limit loading on the seat/occupant during crash pulse loadings, compare results from certain analytical model pulses with approximations of actual crash pulses, and compare analytical seat results with experimental airplace crash data. Structural and seat/occupant displacement equations in terms of the maximum deceleration, velocity change, limit seat pan load, and pulse time for five potentially useful pulse shapes were derived; from these, analytical seat stroke data were obtained for conditions as specified in Federal Regulations Part 23 Paragraph 23.562(b)(1) for dynamic testing of general aviation seats.

Discomfort during lateral acceleration: influence of seat cushion and backrest.

PubMed

Beard, George F; Griffin, Michael J

2013-07-01

Lateral acceleration causes discomfort but how the discomfort depends on the frequency of acceleration or characteristics of seating is poorly understood. Using magnitude estimation, twelve male subjects rated the discomfort caused by lateral oscillation at eight frequencies (0.2-1.0 Hz) across four seating conditions (a rigid seat and a train seat, both with and without backrests). Discomfort increased with increasing frequency of lateral acceleration in a similar manner for all four seating conditions. However, at all frequencies and with both seats there was less discomfort when sitting with backrest support than without. Least discomfort occurred on the train seat with backrest and greatest discomfort on the rigid seat without backrest. Current standards predict an additive effect of backrest on vibration discomfort, but the findings show that low frequency lateral acceleration can cause less discomfort when sitting with a backrest than when sitting on the same seat without a backrest. Copyright © 2012 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Functional seating for school-age children with cerebral palsy: an evidence-based tutorial.

PubMed

Costigan, F Aileen; Light, Janice

2011-04-01

This tutorial is designed to teach speech-language pathologists (SLPs) best practices to support functional seating of children with cerebral palsy (CP) in the classroom and in school-based therapy sessions. This tutorial teaches SLPs to (a) recognize the positive effects of seating intervention, (b) identify the characteristics of functional seating that may produce these positive effects, and (c) realize their role in supporting functional seating for school-age children with CP. The research reporting positive effects of seating intervention for school-age children with CP is presented according to the International Classification of Functioning, Disability and Health (World Health Organization, 2001). Recommended guidelines for functional seating for school-age children with CP are gleaned from the research evidence. The specific role of the SLP in providing functional seating for children with CP is then discussed. Seating intervention may produce positive body structure and function, activities, and participation effects for school-age children with CP when appropriate equipment is provided for weight bearing, the pelvis is positioned for stability and mobility, and the body is properly aligned. SLPs can support functional seating for school-age children with CP by communicating with professionals with seating expertise and by invoking and monitoring recommended guidelines for children with basic and complex seating needs, respectively.

Promoting booster seat use for young children: A school-based intervention pilot study.

PubMed

Bruce, Beth S; Mundle, Kim; Cramm, Camille F; Williams, Devon P

2017-05-01

Misuse and/or lack of booster seat use are often associated with high rates of injury and death among school-aged children. This pilot study examined the efficacy and the potential effectiveness of a booster seat intervention in the classroom. Two elementary schools participated (randomly assigned as one intervention school and one control school). At the intervention school, a certified car seat specialist and a police officer held an interactive booster seat session. The height and age for each child were recorded. Children received a certificate indicating whether they met the requirements for booster seat use and a postcard with car seat restraint specifications. Children in the control school received a brochure on car seat safety. Pre- and post-intervention self-reports were collected and booster seat use was observed. Observational findings showed a decline in booster seat use at the control school and an increase in use at the intervention school. Self-reports of booster seat use indicated a decline at both schools; however, cell sizes were too small to permit statistical analyses. Anecdotally researchers found the sessions were easy to conduct and were well received by the children and could be easily integrated into programming in schools. Classroom sessions may have the potential to positively influence booster seat use among 6- to 8-year-olds.

Hemodynamic and ADH responses to central blood volume shifts in cardiac-denervated humans

NASA Technical Reports Server (NTRS)

Convertino, V. A.; Thompson, C. A.; Benjamin, B. A.; Keil, L. C.; Savin, W. M.; Gordon, E. P.; Haskell, W. L.; Schroeder, J. S.; Sandler, H.

1990-01-01

Hemodynamic responses and antidiuretic hormone (ADH) were measured during body position changes designed to induce blood volume shifts in ten cardiac transplant recipients to assess the contribution of cardiac and vascular volume receptors in the control of ADH secretion. Each subject underwent 15 min of a control period in the seated posture, then assumed a lying posture for 30 min at 6 deg head down tilt (HDT) followed by 20 min of seated recovery. Venous blood samples and cardiac dimensions (echocardiography) were taken at 0 and 15 min before HDT, 5, 15, and 30 min of HDT, and 5, 15, and 30 min of seated recovery. Blood samples were analyzed for hematocrit, plasma osmolality, plasma renin activity (PRA), and ADH. Resting plasma volume (PV) was measured by Evans blue dye and percent changes in PV during posture changes were calculated from changes in hematocrit. Heart rate (HR) and blood pressure (BP) were recorded every 2 min. Results indicate that cardiac volume receptors are not the only mechanism for the control of ADH release during acute blood volume shifts in man.

Teens and seat belt use: What makes them click?

PubMed

Shults, Ruth A; Haegerich, Tamara M; Bhat, Geeta; Zhang, Xinjian

2016-06-01

Motor vehicle crashes kill more adolescents in the United States than any other cause, and often the teen is not wearing a seat belt. Using data from the 2011 Youth Risk Behavior Surveys from 38 states, we examined teens' self-reported seat belt use while riding as a passenger and identified individual characteristics and environmental factors associated with always wearing a seat belt. Only 51% of high school students living in 38 states reported always wearing a seat belt when riding as a passenger; prevalence varied from 32% in South Dakota to 65% in Delaware. Seat belt use was 11 percentage points lower in states with secondary enforcement seat belt laws compared to states with primary enforcement laws. Racial/ethnic minorities, teens living in states with secondary enforcement seat belt laws, and those engaged in substance use were least likely to always wear their seat belts. The likelihood of always being belted declined steadily as the number of substance use behaviors increased. Seat belt use among teens in the United States remains unacceptably low. Results suggest that environmental influences can compound individual risk factors, contributing to even lower seat belt use among some subgroups. This study provides the most comprehensive state-level estimates to date of seat belt use among U.S. teens. This information can be useful when considering policy options to increase seat belt use and for targeting injury prevention interventions to high-risk teens. States can best increase teen seat belt use by making evidence-informed decisions about state policy options and prevention strategies. Published by Elsevier Ltd.

77 FR 34387 - Proposed Information Collection Activity; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-11

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Administration for Children and Families Proposed... transportation requirement provides the requirement that each child be seated in a child restraint system while... in the best interest of the children involved. Respondents: Head Start and Early Head Start program...

Human heart rate variability relation is unchanged during motion sickness

NASA Technical Reports Server (NTRS)

Mullen, T. J.; Berger, R. D.; Oman, C. M.; Cohen, R. J.

1998-01-01

In a study of 18 human subjects, we applied a new technique, estimation of the transfer function between instantaneous lung volume (ILV) and instantaneous heart rate (HR), to assess autonomic activity during motion sickness. Two control recordings of ILV and electrocardiogram (ECG) were made prior to the development of motion sickness. During the first, subjects were seated motionless, and during the second they were seated rotating sinusoidally about an earth vertical axis. Subjects then wore prism goggles that reverse the left-right visual field and performed manual tasks until they developed moderate motion sickness. Finally, ILV and ECG were recorded while subjects maintained a relatively constant level of sickness by intermittent eye closure during rotation with the goggles. Based on analyses of ILV to HR transfer functions from the three conditions, we were unable to demonstrate a change in autonomic control of heart rate due to rotation alone or due to motion sickness. These findings do not support the notion that moderate motion sickness is manifested as a generalized autonomic response.

Car Seat Inspection Among Children Older Than Three: Using Data to Drive Practice in Child Passenger Safety

PubMed Central

Kroeker, Amber M.; Teddy, Amy J.; Macy, Michelle L.

2015-01-01

Background Motor vehicle crashes (MVCs) are a leading cause of unintentional death and disability among children ages 4-12 in the United States. Despite this high risk of injury from MVCs in this age group, parental awareness, and child passenger safety programs in particular may lack focus on this age group. Methods Retrospective cross-sectional analysis of child passenger safety seat checklist forms from two Safe Kids coalitions in Michigan (2013) to identify restraint type upon arrival to car seat inspections. Other variables included, if the coalition provided a new child safety seat and if the child had a sibling who underwent a car seat inspection. Chi-square statistics were used to compare change in restraint use upon arrival and at departure, the proportion of children attending a car seat inspection event by age, the age category of children by site, the proportion of children with siblings also undergoing a car seat inspection by age, and the distribution of a new child safety seat by age. Results Data were available from 1,316 Safe Kids Huron Valley and 3,215 Safe Kids Greater Grand Rapids car seat inspections. Just 10.8% of total seats inspected were booster seats. Child safety seats for infant and young children were more commonly inspected [rear-facing carrier (40.3%), rear-facing convertible (10.2%), and forward-facing (19.3%) car seats]. Few children at inspections used a seat belt only (5.4%) or had no restraint (13.8%). Children age 4 and above were found to be in a sub-optimal restraint at least 30% of the time. Conclusion Low proportions of parents use car seat inspections for children in the booster seat age group. The proportion of children departing the inspection in a more protective restraint increased with increasing age. This highlights an area of weakness in child passenger safety programs and signals an opportunity to strengthen efforts on The Forgotten Child. Level of Evidence Level III PMID:26308122

Visual Attention in Deaf and Normal Hearing Adults: Effects of Stimulus Compatibility

ERIC Educational Resources Information Center

Sladen, Douglas P.; Tharpe, Anne Marie; Ashmead, Daniel H.; Grantham, D. Wesley; Chun, Marvin M.

2005-01-01

Visual perceptual skills of deaf and normal hearing adults were measured using the Eriksen flanker task. Participants were seated in front of a computer screen while a series of target letters flanked by similar or dissimilar letters was flashed in front of them. Participants were instructed to press one button when they saw an "H," and another…

Ingress clearance requirements and seat positioning for automatic belt systems

DOT National Transportation Integrated Search

1981-06-01

The purposes of this study were (1) to determine how much clearance between a seat belt and seat cushion is needed for a driver to enter the front seat of an automobile equipped with automatic seat belts---without his/her having to lift the webbing, ...

A human body model with active muscles for simulation of pretensioned restraints in autonomous braking interventions.

PubMed

Osth, Jonas; Brolin, Karin; Bråse, Dan

2015-01-01

The aim of this work is to study driver and passenger kinematics in autonomous braking scenarios, with and without pretensioned seat belts, using a whole-body finite element (FE) human body model (HBM) with active muscles. Upper extremity musculature for elbow and shoulder flexion-extension feedback control was added to an HBM that was previously complemented with feedback controlled muscles for the trunk and neck. Controller gains were found using a radial basis function metamodel sampled by making 144 simulations of an 8 ms(-2) volunteer sled test. The HBM kinematics, interaction forces, and muscle activations were validated using a second volunteer data set for the passenger and driver positions, with and without 170 N seat belt pretension, in 11 ms(-2) autonomous braking deceleration. The HBM was then used for a parameter study in which seat belt pretension force and timing were varied from 170 to 570 N and from 0.25 s before to 0.15 s after deceleration onset, in an 11 ms(-2) autonomous braking scenario. The model validation showed that the forward displacements and interaction forces of the HBM correlated with those of corresponding volunteer tests. Muscle activations and head rotation angles were overestimated in the HBM when compared with volunteer data. With a standard seat belt in 11 ms(-2) autonomous braking interventions, the HBM exhibited peak forward head displacements of 153 and 232 mm for the driver and passenger positions. When 570 N seat belt pretension was applied 0.15 s before deceleration onset, a reduction of peak head displacements to 60 and 75 mm was predicted. Driver and passenger responses to autonomous braking with standard and pretensioned restraints were successfully modeled in a whole-body FE HBM with feedback controlled active muscles. Variations of belt pretension force level and timing revealed that belt pretension 0.15 s before deceleration onset had the largest effect in reducing forward head and torso movement caused by the autonomous brake intervention. The displacement of the head relative to the torso for the HBM is quite constant for all variations in timing and belt force; it is the reduced torso displacements that lead to reduced forward head displacements.

Investigation on occupant ejection in high severity rear impact based on post mortem human subject sled tests.

PubMed

Petit, Philippe; Luet, Carole; Potier, Pascal; Vallancien, Guy

2011-11-01

Occupant protection in rear impact involves two competing challenges. On one hand, allowing a deformation of the seat would act as an energy absorber in low severity impacts and would consequently decrease the risk of neck injuries. However, on the other hand, large deformations of the seat may increase the likelihood of occupant ejection in high severity cases. Green et al. 1987 analyzed a total of 919 accidents in Great Britain. They found that occupant ejection resulted in a risk of severe injuries and fatalities between 3.6 and 4.5 times higher than those cases where no ejection was observed. The sample included single front, side and rear impacts as well as multiple impacts and rollover. The rate of belt use in the sample was 50%. While this analysis included all forms of impact scenarios, nevertheless, it highlights the relative injury severity of occupant ejection. Extensive literature search has found no full-scale rear impact tests involving Post Mortem Human Subjects (PMHS) conducted in a laboratory environment and resulting in ejection. This paper describes a total of 10 sled tests conducted on 3 belted PMHS using a simplified seat design composed of rigid plates assembled such that the angular and linear stiffness of the seatback (including the foam) was modeled. The initial angular position and the range of motion of the seatback, the size of the PMHS, the slack length of the seatbelt, the angular stiffness of the seatback, and the use of headrest were varied in the test matrix while the pulse was kept constant (triangular acceleration with a peak of 17 G at 30 ms and a duration of 95 ms). In the test series, the tests were not run randomly but the likelihood of occupant ejection was increased systematically until ejection occurred. PMHS seat ejection was observed only for the 95th percentile, initially positioned with a seatback angle relative to the vertical equal to 22°, a range of seatback angular motion equal to 44° and no headrest. Repeating the test under the same conditions but with the pretentionner fired did not prevent the ejection. In addition, the 50th percentile belted specimen were not observed to sustain rearward seat ejection under realistic conditions including the use of head-rest.

Experimental investigation of airborne contaminant transport by a human wake moving in a ventilated aircraft cabin

NASA Astrophysics Data System (ADS)

Poussou, Stephane B.

The air ventilation system in jetliners provides a comfortable and healthy environment for passengers. Unfortunately, the increase in global air traffic has amplified the risks presented by infectious aerosols or noxious material released during flight. Inside the cabin, air typically flows continuously from overhead outlets into sidewall exhausts in a circular pattern that minimizes secondary flow between adjacent seat rows. However, disturbances frequently introduced by individuals walking along an aisle may alter air distribution, and contribute to spreading of contaminants. Numerical simulation of these convoluted transient flow phenomena is difficult and complex, and experimental assessment of contaminant distribution in real cabins often impractical. A fundamental experimental study was undertaken to examine the transport phenomena, to validate computations and to improve air monitoring systems. A finite moving body was modeled in a 10:1 scale simplified aircraft cabin equipped with ventilation, at a Reynolds number (based on body diameter) of the order of 10,000. An experimental facility was designed and constructed to permit measurements of the ventilation and wake velocity fields using particle image velocimetry (PIV). Contaminant migration was imaged using the planar laser induced fluorescence (PLIF) technique. The effect of ventilation was estimated by comparison with a companion baseline study. Results indicate that the evolution of a downwash predominant behind finite bodies of small aspect ratio is profoundly perturbed by the ventilation flow. The reorganization of vortical structures in the near-wake leads to a shorter longitudinal recirculation region. Furthermore, mixing in the wake is modified and contaminant is observed to convect to higher vertical locations corresponding to seated passenger breathing level.

49 CFR 571.207 - Standard No. 207; Seating systems.

Code of Federal Regulations, 2011 CFR

2011-10-01

... standard establishes requirements for seats, their attachment assemblies, and their installation to... longitudinal direction; (c) For a seat belt assembly attached to the seat—the force specified in paragraph (a... applied simultaneously with the forces imposed on the seat by the seat belt assembly when it is loaded in...

28 CFR 36.308 - Seating in assembly areas.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Seating in assembly areas. 36.308 Section... PUBLIC ACCOMMODATIONS AND IN COMMERCIAL FACILITIES Specific Requirements § 36.308 Seating in assembly... in assembly areas shall— (i) Provide a reasonable number of wheelchair seating spaces and seats with...

14 CFR 125.317 - Inspector's credentials: Admission to pilots' compartment: Forward observer's seat.

Code of Federal Regulations, 2011 CFR

2011-01-01

... pilots' compartment: Forward observer's seat. 125.317 Section 125.317 Aeronautics and Space FEDERAL... pilots' compartment: Forward observer's seat. (a) Whenever, in performing the duties of conducting an... of safety. (b) A forward observer's seat on the flight deck, or forward passenger seat with headset...

14 CFR 135.75 - Inspectors credentials: Admission to pilots' compartment: Forward observer's seat.

Code of Federal Regulations, 2011 CFR

2011-01-01

...' compartment: Forward observer's seat. 135.75 Section 135.75 Aeronautics and Space FEDERAL AVIATION...' compartment: Forward observer's seat. (a) Whenever, in performing the duties of conducting an inspection, an.... (b) A forward observer's seat on the flight deck, or forward passenger seat with headset or speaker...

Alternative seating for young children with Autism Spectrum Disorder: effects on classroom behavior.

PubMed

Schilling, Denise Lynn; Schwartz, Ilene S

2004-08-01

A single subject, withdrawal design was used to investigate the effects of therapy balls as seating on engagement and in-seat behavior of young children with Autism Spectrum Disorder (ASD). In addition, social validity was assessed to evaluate teachers' opinions regarding the intervention. During baseline and withdrawal (A phases) participants used their typical classroom seating device (chair, bench or carpet square). During the intervention (B phases) participants sat on therapy balls. Results indicated substantial improvements in engagement and in-seat behavior when participants were seated on therapy balls. Social validity findings indicated that the teachers' preferred the therapy balls. This study suggests therapy balls as classroom seating may facilitate engagement and in-seat behavior and create opportunities to provide effective instruction.

Active vibration attenuating seat suspension for an armored helicopter crew seat

NASA Astrophysics Data System (ADS)

Sztein, Pablo Javier

An Active Vibration Attenuating Seat Suspension (AVASS) for an MH-60S helicopter crew seat is designed to protect the occupants from harmful whole-body vibration (WBV). Magnetorheological (MR) suspension units are designed, fabricated and installed in a helicopter crew seat. These MR isolators are built to work in series with existing Variable Load Energy Absorbers (VLEAs), have minimal increase in weight, and maintain crashworthiness for the seat system. Refinements are discussed, based on testing, to minimize friction observed in the system. These refinements include the addition of roller bearings to replace friction bearings in the existing seat. Additionally, semi-active control of the MR dampers is achieved using special purpose built custom electronics integrated into the seat system. Experimental testing shows that an MH-60S retrofitted with AVASS provides up to 70.65% more vibration attenuation than the existing seat configuration as well as up to 81.1% reduction in vibration from the floor.

Car seat safety: literature review.

PubMed

Lincoln, Michelle

2005-01-01

After staggering numbers of infants were killed in automotive crashes in the 1970s, the American Academy of Pediatrics (AAP) recommended in 1974 universal use of car seats for all infants. However, positional problems were reported when car seats are used with premature infants less than 37 weeks gestational age as a result of head slouching and its sequelae. In 1990, the AAP responded with another policy statement introducing car seat testing. It recommended that any infant at or under 37 weeks gestational age be observed in a car seat prior to discharge from the hospital. The AAP did not give specific guidelines on type of car seat, length of testing, equipment, or personnel proficiency, however. Few nurseries have standard policies to evaluate car seats, to teach parents about car seats, or to position newborns in them, and not all hospitals actually conduct car seat challenges or have common standards for testing that is performed.

Development of an MR seat suspension with self-powered generation capability

NASA Astrophysics Data System (ADS)

Sun, S. S.; Ning, D. H.; Yang, J.; Du, H.; Zhang, S. W.; Li, W. H.; Nakano, M.

2017-08-01

This paper proposes a self-powered magnetorheological (MR) seat suspension on the basis of a rotary MR damper and an electromagnetic induction device. By applying the self-powering component to the MR seat suspension, the operation cost of the semi-active seat is much cheaper because no external energy is required to control the MR damper. In this paper, the structure, design and analysis of the seat suspension were presented following the introduction section. The property tests of the self-powered seat suspension were conducted using an MTS machine. A robust control algorithm was developed to control the self-powered MR seat suspension and the vibration attenuation performance of the seat suspension was tested under two different vibration excitations, i.e. harmonic excitation and random excitation. The testing result verifies that the self-powered MR seat suspension under proper control can improve the ride comfort for passengers and drivers.

The effect of rear-seat overloading in a car crash: pathological and kinematics evidences.

PubMed

Luchini, Duccio; Sammicheli, Michele; Cortucci, Cristiano

2013-09-01

Seat belts have been shown to decrease the incidence of lethal lesions to the head, chest, and abdomen. Since the introduction of seat belts, it is reported that the incidence of traumatic lesions in these body parts is reduced. In the meantime, the characteristic lesions to the chest and abdomen caused by the use of seat belts are described (J Trauma. 2007;62(6):1473-1480).Reported is a peculiar case of an oblique front-to-rear car collision, in which overloading of the rear seat with packages pushed forward the passenger front seat in an abnormal way, causing fatal thoracic and abdominal lesions.The authors underline that the seat belt protection device is defeated if front seats are damaged by heavy unanchored bags on the rear seat or on the rear parcel shelf of a motor vehicle.

Patterns of correlation between vehicle occupant seat pressure and anthropometry.

PubMed

Paul, Gunther; Daniell, Nathan; Fraysse, François

2012-01-01

Seat pressure is known as a major factor of seat comfort in vehicles. In passenger vehicles, there is lacking research into the seat comfort of rear seat occupants. As accurate seat pressure measurement requires significant effort, simulation of seat pressure is evolving as a preferred method. However, analytic methods are based on complex finite element modeling and therefore are time consuming and involve high investment. Based on accurate anthropometric measurements of 64 male subjects and outboard rear seat pressure measurements in three different passenger vehicles, this study investigates if a set of parameters derived from seat pressure mapping are sensitive enough to differentiate between different seats and whether they correlate with anthropometry in linear models. In addition to the pressure map analysis, H-Points were measured with a coordinate measurement system based on palpated body landmarks and the range of H-Point locations in the three seats is provided. It was found that for the cushion, cushion contact area and cushion front area/force could be modeled by subject anthropometry, while only seatback contact area could be modeled based on anthropometry for all three vehicles. Major differences were found between the vehicles for other parameters.

Carpooling and booster seats: a national survey of parents.

PubMed

Macy, Michelle L; Clark, Sarah J; Freed, Gary L; Butchart, Amy T; Singer, Dianne C; Sasson, Comilla; Meurer, William J; Davis, Matthew M

2012-02-01

Booster seat use among school-aged children has been consistently lower than national goals. In this study, we sought to explore associations between parental experiences with booster seats and carpooling. We conducted a cross-sectional Web-based survey of a nationally representative panel of US parents in January 2010. As part of a larger survey, parents of 4- to 8-year-old children responded to 12 questions related to booster seats and carpooling. Of 1612 parents responding to the full survey (response rate = 71%), 706 had a 4- to 8-year-old child and 681 met inclusion rules. Most parents (76%) reported their child used a safety seat when riding in the family car. Of children reported to use seat belts, 74% did so in accordance with their state law. Parent report of child safety seat use was associated with younger child age and with the presence of state booster seat laws. Sixty-four percent of parents carpool. Among parents who carpool and whose children use a child safety seat: 79% indicated they would always ask another driver to use a booster seat for their child and 55% reported they always have their child use their booster seat when driving friends who do not have boosters. Carpooling is a common driving situation during which booster seat use is inconsistent. Social norms and self-efficacy are associated with booster seat use. Clinicians who care for children should increase efforts to convey the importance of using the size-appropriate restraint for every child on every trip.

Defense of Defense Human Factors Engineering Technical Advisory Group Meeting Summary

DTIC Science & Technology

2012-07-01

Survivability ( Plaga ) • Wright, N; OSD and DSOC Helicopter Seating Studies Zehner, G; An Overview of USAF Anthropometry Plaga , J & Hill; SAFE Association...predictions. – 1230 - 1430 Standardization - 1472H (Poston) – 1230 - 1430 Human Factors in Extreme Environments & SS ( Plaga ) • Ganey, HCN...Classification (Personnel) LT Chris Foster Dr. Hector Acosta System Safety/Health Hazards/ Survivability (SS/HH/Sv) Mr. John Plaga Technical Society

Modeling of Spinal Column of Seated Human Body under Exposure to Whole-Body Vibration

NASA Astrophysics Data System (ADS)

Tamaoki, Gen; Yoshimura, Takuya; Kuriyama, Kaoru; Nakai, Kazuma

In vehicle systems occupational drivers might expose themselves to vibration for a long time. This may cause illness of the spinal column such as low back pain. Therefore, it is necessary to evaluate the influence of vibration to the spinal column. Thus the modeling of seated human body is conducted in order to evaluate the effect of whole-body vibration to the spinal column. This model has the spinal column and the support structures such as the muscles of the back and the abdomen. The spinal column is made by the vertebrae and the intervertebral disks that are considered the rigid body and the rotational spring and damper respectively. The parameter of this model is decided by the literature and the body type of the subject with respect to the mass and the model structure. And stiffness and damping parameters are searched by fitting the model simulation results to the experimental measured data with respect to the vibration transmissibilities from the seat surface to the spinal column and the head and with respect to the driving-point apparent mass. In addition, the natural modes of the model compare with the result of experimental modal analysis. The influence of the abdomen and the muscles of the back are investigated by comparing three models with respect to above vibration characteristics. Three model are the proposed model, the model that has the spinal column and the model that has the muscles of the back in addition to the spinal column.

Locomotor training improves reciprocal and nonreciprocal inhibitory control of soleus motoneurons in human spinal cord injury

PubMed Central

Smith, Andrew C.; Mummidisetty, Chaithanya K.

2015-01-01

Pathologic reorganization of spinal networks and activity-dependent plasticity are common neuronal adaptations after spinal cord injury (SCI) in humans. In this work, we examined changes of reciprocal Ia and nonreciprocal Ib inhibition after locomotor training in 16 people with chronic SCI. The soleus H-reflex depression following common peroneal nerve (CPN) and medial gastrocnemius (MG) nerve stimulation at short conditioning-test (C-T) intervals was assessed before and after training in the seated position and during stepping. The conditioned H reflexes were normalized to the unconditioned H reflex recorded during seated. During stepping, both H reflexes were normalized to the maximal M wave evoked at each bin of the step cycle. In the seated position, locomotor training replaced reciprocal facilitation with reciprocal inhibition in all subjects, and Ib facilitation was replaced by Ib inhibition in 13 out of 14 subjects. During stepping, reciprocal inhibition was decreased at early stance and increased at midswing in American Spinal Injury Association Impairment Scale C (AIS C) and was decreased at midstance and midswing phases in AIS D after training. Ib inhibition was decreased at early swing and increased at late swing in AIS C and was decreased at early stance phase in AIS D after training. The results of this study support that locomotor training alters postsynaptic actions of Ia and Ib inhibitory interneurons on soleus motoneurons at rest and during stepping and that such changes occur in cases with limited or absent supraspinal inputs. PMID:25609110

Assessment of dental student posture in two seating conditions using RULA methodology - a pilot study.

PubMed

Gandavadi, A; Ramsay, J R E; Burke, F J T

2007-11-24

To assess dental students' posture on two different seats in order to determine if one seat predisposes to a difference in working posture. A between-subject experimental design was selected. The study was undertaken at the University of Birmingham School of Dentistry in 2006. Subjects (materials) and methods Sixty second year dental students at the University of Birmingham who were attending their fi rst classes in the phantom head laboratory were randomly selected and allocated to two different seats (30 Bambach Saddle Seats and 30 conventional seats). Students were trained in the use of the seats. After ten weeks, the students were observed, photographs were taken by the researcher and these were assessed using Rapid Upper Limb Assessment (RULA). The posture of the students was assessed using the RULA. Each student was given a risk score. A Mann Whitney test was used for statistical analysis. The results indicated that the students using the conventional seat recorded significantly higher risk scores (p <0.05) when compared with the students using Bambach Saddle Seat, suggesting an improvement in posture when using the Bambach Saddle Seat. RULA has identified that dental students using a Bambach Saddle Seat were able to maintain an acceptable working posture during simulated dental treatment and this seating may reduce the development of work-related musculoskeletal disorders.

Promoting booster seat use for young children: A school-based intervention pilot study

PubMed Central

Mundle, Kim; Cramm, Camille F.; Williams, Devon P.

2017-01-01

Abstract Purpose: Misuse and/or lack of booster seat use are often associated with high rates of injury and death among school-aged children. This pilot study examined the efficacy and the potential effectiveness of a booster seat intervention in the classroom. Methods: Two elementary schools participated (randomly assigned as one intervention school and one control school). At the intervention school, a certified car seat specialist and a police officer held an interactive booster seat session. The height and age for each child were recorded. Children received a certificate indicating whether they met the requirements for booster seat use and a postcard with car seat restraint specifications. Children in the control school received a brochure on car seat safety. Pre- and post-intervention self-reports were collected and booster seat use was observed. Results: Observational findings showed a decline in booster seat use at the control school and an increase in use at the intervention school. Self-reports of booster seat use indicated a decline at both schools; however, cell sizes were too small to permit statistical analyses. Conclusion: Anecdotally researchers found the sessions were easy to conduct and were well received by the children and could be easily integrated into programming in schools. Classroom sessions may have the potential to positively influence booster seat use among 6- to 8-year-olds. PMID:29479188

Evaluation of an Energy Absorbing Truck Seat for Increased Protection from Landmine Blasts.

DTIC Science & Technology

1996-01-01

acceleration (top curve, Figure 4) reveals the wire bending action of the passenger seat as it absorbs energy. No data from the standard (driver) seat...Vertical accelerations were limited by the wire bending action. 17 Passenger seat velocities 120894 Demo (8 Dec 94) - center blast, EA passenger seat

Multiposition Seat

NASA Technical Reports Server (NTRS)

Macconochie, Ian O.

1994-01-01

Back of seat pivots about either of two axes: one axis for folding back to form bed and second, higher axis for folding forward to form compact ottoman, even when seat thickly padded. Long and short links used to adjust back of seat to variety of positions. Multiposition seat designed for use in spacecraft also adapted to airplanes and land vehicles.

14 CFR 135.113 - Passenger occupancy of pilot seat.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Passenger occupancy of pilot seat. 135.113... Operations § 135.113 Passenger occupancy of pilot seat. No certificate holder may operate an aircraft type certificated after October 15, 1971, that has a passenger seating configuration, excluding any pilot seat, of...

14 CFR 135.113 - Passenger occupancy of pilot seat.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Passenger occupancy of pilot seat. 135.113... Operations § 135.113 Passenger occupancy of pilot seat. No certificate holder may operate an aircraft type certificated after October 15, 1971, that has a passenger seating configuration, excluding any pilot seat, of...

Marketing Classroom Spaces: Is It Really Better at the Front?

ERIC Educational Resources Information Center

Vander Schee, Brian A.

2011-01-01

Students spend much of their time in college seated in a classroom. Their seating choice can indicate something about students' general perceptions regarding seat selection and academic achievement. However, actual seat location may also play a role in student performance. This preliminary research focused on the seating choices of 373…

36 CFR 1192.27 - Priority seating signs.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Priority seating signs. 1192... Buses, Vans and Systems § 1192.27 Priority seating signs. (a) Each vehicle shall contain sign(s) which indicate that seats in the front of the vehicle are priority seats for persons with disabilities, and that...

49 CFR 38.27 - Priority seating signs.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 1 2010-10-01 2010-10-01 false Priority seating signs. 38.27 Section 38.27... SPECIFICATIONS FOR TRANSPORTATION VEHICLES Buses, Vans and Systems § 38.27 Priority seating signs. (a) Each vehicle shall contain sign(s) which indicate that seats in the front of the vehicle are priority seats for...

Seating position, seat belt wearing, and the consequences in facial fractures in car occupants.

PubMed

Fonseca, Alexandre Siqueira Franco; Goldenberg, Dov; Alonso, Nivaldo; Bastos, Endrigo; Stocchero, Guilherme; Ferreira, Marcus Castro

2007-06-01

Trauma caused by traffic accidents is among the main etiologies involved in the occurrence of facial fractures throughout the world. However, the trauma mechanisms involved are different according to the location where the study was performed, due to different conditions of development, legislation, and culture. A retrospective study was done between February 2001 and July 2006, with the purpose of determining the epidemiology and the mechanisms involved in the occurrence of facial fractures among car occupants in the metropolitan area of São Paulo. Data were collected from 297 patients admitted with facial fractures to the emergency room of the Hospital das Clínicas, São Paulo University Medical School. Within this period, 151 individuals had been involved in traffic accidents, among which 56 (37.08%) were inside passenger cars. These were grouped based on the seating position that they were occupying at the time of the accident and the wearing of seat belts. Data concerning the number and location of fracture lines were obtained from the different groups, and a fracture/patient index (F/P I) was calculated to compare and make reference to the impact energy among these groups, for subsequent analysis and discussion. 323 fracture lines occurred among 56 patients who were car occupants. By applying the F/P I, we obtained higher values in the group of rear-seat passengers who were not wearing seat belts (7.23 fractures per patient), followed by the group of drivers not wearing seat belts (6.33 fractures per patient), the group of front-seat passengers not wearing seat belts (5.58 fractures per patient), the group of drivers wearing seat belts (5.54 fractures per patient) and, finally, the group of front-seat passengers wearing seat belts (4.00 fractures per patient). None of the rear-seat passengers was wearing seat belts. The data collected indicate that the driver position shows a high incidence of facial fractures, not being effectively protected by the seat belt, although the wearing of seat belts seems to have a protective role against the occurrence of facial fractures in front-seat passengers. It was not possible to evaluate the wearing of seat belts among rear-seat passengers, even though the high incidence of fractures in this group showed its high susceptibility to the occurrence of facial fractures, which highlights the need of taking protective measures against this situation.

77 FR 46762 - Submission for OMB Review; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-06

... children involved. Respondents: Head Start and Early Head Start program grants recipients. Annual Burden... DEPARTMENT OF HEALTH AND HUMAN SERVICES Administration for Children and Families Submission for... requirement that each child be seated in a child restraint system while the vehicle is in motion, and the...

Injury and violence prevention: a primer.

PubMed

Gielen, Andrea Carlson

2002-03-01

Unintentional and intentional injuries cause a great deal of human suffering throughout the world. They exact a huge toll on societies in terms of mortality, years of potential life lost, disability, and health care costs. The good news is that great strides have been made in understanding the causes of injuries and how to prevent them. Using seat belts and car seats, installing air bags in cars, replacing dangerous playground equipment, enforcing drinking and driving laws are but a few examples of modifying behavior, products, and environments to reduce injury risk. This paper provides an overview of the science of injury control and selected examples of how professionals in the field of patient education and counseling can contribute to enhancing the safety of the public.

Comparison of water immersion and saline infusion as a means of inducing volume expansion in man

NASA Technical Reports Server (NTRS)

Epstein, M.; Pins, D. S.; Arrington, R.; Denunzio, A. G.; Engstrom, R.

1975-01-01

The study compares the natriuresis induced by head-out water immersion to that of a standard saline infusion and assesses the relative effectiveness of these two techniques as volume determinants of renal sodium and water handling in humans in a seated posture. The data obtained show that the volume stimulus of immersion is identical to that of standard saline-induced extracellular fluid volume expansion (ECVE) in normal seated subjects. The ability of head-out water immersion to induce a natriuresis without a concomitant increase in total blood volume and with a decrease in body weight suggests that water immersion may be preferred as an investigative tool for assessing the effects of ECVE in man.

76 FR 9551 - Availability of Seats for the Monitor National Marine Sanctuary Advisory Council

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-18

... (2) Recreational/Commercial Fishing seats, Heritage Tourism seat, and Economic Development seat...-at-Large, Conservation, Economic Development, Education, Heritage Tourism, Maritime Archaeological...

Auto Safety

MedlinePlus

... certified child passenger safety technician to assist you.) Guidelines for Choosing a Safety Seat Choose a seat ... and are between 8 and 12 years old. Guidelines for Choosing a Booster Seat Choose a seat ...

Integrated seat frame and back support

DOEpatents

Martin, Leo

1999-01-01

An integrated seating device comprises a seat frame having a front end and a rear end. The seat frame has a double wall defining an exterior wall and an interior wall. The rear end of the seat frame has a slot cut therethrough both the exterior wall and the interior wall. The front end of the seat frame has a slot cut through just the interior wall thereof. A back support comprising a generally L shape has a horizontal member, and a generally vertical member which is substantially perpendicular to the horizontal member. The horizontal member is sized to be threaded through the rear slot and is fitted into the front slot. Welded slat means secures the back support to the seat frame to result in an integrated seating device.

Qualitative models of seat discomfort including static and dynamic factors.

PubMed

Ebe, K; Griffin, M J

2000-06-01

Judgements of overall seating comfort in dynamic conditions sometimes correlate better with the static characteristics of a seat than with measures of the dynamic environment. This study developed qualitative models of overall seat discomfort to include both static and dynamic seat characteristics. A dynamic factor that reflected how vibration discomfort increased as vibration magnitude increased was combined with a static seat factor which reflected seating comfort without vibration. The ability of the model to predict the relative and overall importance of dynamic and static seat characteristics on comfort was tested in two experiments. A paired comparison experiment, using four polyurethane foam cushions (50, 70, 100, 120 mm thick), provided different static and dynamic comfort when 12 subjects were exposed to one-third octave band random vertical vibration with centre frequencies of 2.5 and 5.5 Hz, at magnitudes of 0.00, 0.25 and 0.50 m x s(-2) rms measured beneath the foam samples. Subject judgements of the relative discomfort of the different conditions depended on both static and dynamic characteristics in a manner consistent with the model. The effect of static and dynamic seat factors on overall seat discomfort was investigated by magnitude estimation using three foam cushions (of different hardness) and a rigid wooden seat at six vibration magnitudes with 20 subjects. Static seat factors (i.e. cushion stiffness) affected the manner in which vibration influenced the overall discomfort: cushions with lower stiffness were more comfortable and more sensitive to changes in vibration magnitude than those with higher stiffness. The experiments confirm that judgements of overall seat discomfort can be affected by both the static and dynamic characteristics of a seat, with the effect depending on vibration magnitude: when vibration magnitude was low, discomfort was dominated by static seat factors; as the vibration magnitude increased, discomfort became dominated by dynamic factors.

On 4-degree-of-freedom biodynamic models of seated occupants: Lumped-parameter modeling

NASA Astrophysics Data System (ADS)

Bai, Xian-Xu; Xu, Shi-Xu; Cheng, Wei; Qian, Li-Jun

2017-08-01

It is useful to develop an effective biodynamic model of seated human occupants to help understand the human vibration exposure to transportation vehicle vibrations and to help design and improve the anti-vibration devices and/or test dummies. This study proposed and demonstrated a methodology for systematically identifying the best configuration or structure of a 4-degree-of-freedom (4DOF) human vibration model and for its parameter identification. First, an equivalent simplification expression for the models was made. Second, all of the possible 23 structural configurations of the models were identified. Third, each of them was calibrated using the frequency response functions recommended in a biodynamic standard. An improved version of non-dominated sorting genetic algorithm (NSGA-II) based on Pareto optimization principle was used to determine the model parameters. Finally, a model evaluation criterion proposed in this study was used to assess the models and to identify the best one, which was based on both the goodness of curve fits and comprehensive goodness of the fits. The identified top configurations were better than those reported in the literature. This methodology may also be extended and used to develop the models with other DOFs.

Possible causes of socioeconomic and ethnic differences in seat belt use among high school students.

PubMed

Shin, D; Hong, L; Waldron, I

1999-09-01

This study has assessed seat belt use and factors which may influence seat belt use among high school students from three types of schools. The inner city schools had high proportions of African American and Hispanic American students from low income families, whereas the middle class school and private schools had high proportions of non-Hispanic white students from middle class families with college educated parents. Students from the inner city schools reported less seat belt use than students from the middle class school or private schools. Our analyses evaluated several hypotheses concerning possible reasons why inner city youth had lower rates of seat belt use. In accord with the social influences hypothesis, inner city youth reported lower rates of parental seat belt use and less often being told by parents to use their seat belts, and our regression results indicate that less parental modeling and encouragement of seat belt use was an important cause of inner city youth's lower rates of seat belt use. Our other hypotheses received weaker support, but we did find evidence for two hypothesized differences in attitudes which influence seat belt use. Specifically, inner city youth were more likely to agree with the statement, 'there is no point in wearing seat belts since you have no control over your fate or destiny', and inner city youth attributed less importance to safety concerns as a motivation for seat belt use. These attitudes appeared to contribute to lower rates of seat belt use by inner city youth.

Impact Test of a NACA-Designed Pilot Seat and Harness

NASA Image and Video Library

1955-02-21

This time-lapse photograph shows the test of a pilot seat and restraint designed by researchers at the National Advisory Committee for Aeronautics (NACA) Lewis Flight Propulsion Laboratory. The laboratory had undertaken a multi-year investigation into the causes and preventative measures for fires resulting from low altitude aircraft crashes. The program was expanded in the mid-1950s to include the study of crash impact on passengers, new types of types of seat restraints, and better seat designs. The impact program began by purposely wrecking surplus transport Fairchild C-82 Packet and Piper Cub aircraft into barricades at the end of a test runway. Instrumented dummies and cameras were installed in the pilot and passenger areas. After determining the different loads experienced during a crash and the effects on the passengers, the NACA researchers began designing new types of seats and restraints. The result was an elastic seat that flexed upon impact, absorbing 75 percent of the loads before it slowly recoiled. This photograph shows the seats mounted on a pendulum with a large spring behind the platform to provide the jolt that mimicked the forces of a crash. The seat was constructed without any potentially damaging metal parts and included rubber-like material, an inflated back and arms, and a seat cushion. After the pendulum tests, the researchers compared the flexible seats to the rigid seats during a crash of a transport aircraft. They found the passengers in the rigid seats received 66 percent higher g-forces than the NACA-designed seats.

NACA Researcher Sets up a Test of a New Seat Design

NASA Image and Video Library

1954-05-21

A researcher at the National Advisory Committee for Aeronautics (NACA) Lewis Flight Propulsion Laboratory prepares for a test of an NACA-designed aircraft seat. The laboratory had undertaken a multi-year investigation into the causes and prevention of fires on low altitude aircraft crashes. The program was expanded in the mid-1950s to include the study of impact on passengers, types of seat restraints, and seat design. The crash impact portion of the program began by purposely wrecking surplus Fairchild C-82 Packet and Piper Cub aircraft into barricades at the end of a test runway at the Ravenna Arsenal, located approximately 40 miles south of the Lewis lab in Cleveland. Instrumented dummies and cameras were installed in the pilot and passenger areas. After determining the different loads and their effects on the passengers, the NACA researchers began designing new types of seats and restraints. The result was an elastic seat that flexed upon impact, absorbing 75 percent of the loads before it slowly recoiled. This photograph shows the seats mounted on a pendulum with a large spring behind the platform to provide the jolt that mimicked the forces of a crash. The seat was constructed without any potentially damaging metal parts and included rubber-like material, an inflated back and arms, and a seat cushion. After the pendulum tests, the researchers compared the flexible seats to the rigid seats during a crash of a transport aircraft. They found the passengers in the rigid seats received 66 percent higher g-forces than the NACA-designed seats.

Pattern of seat belt use by drivers in Trinidad and Tobago, West Indies

PubMed Central

2011-01-01

Background In Trinidad and Tobago, the law on the mandatory use of seat belts was passed in 1995, but this law is hardly enforced. The objective of this study was to determine the frequency and predictors of seat belt use by motor vehicle drivers in the country. Findings A cross-sectional study of 959 motor vehicle drivers using a self-administered questionnaire. Data analysis included Pearson Chi square test and multinomial logistic regression analysis in order to determine the possible predictors of seat belt use by the drivers in Trinidad and Tobago. A majority of the drivers sometimes (51.8%) or always (31.6%) use a seat belt. About 16.7%, 29% and 54.2% of the drivers perceived that the other drivers use their seat belts more frequently, with the same frequency and less frequently respectively compared to themselves. The main reason for not using seat belt by the drivers was given as frequent stops (40.7%) and the main motivation to use seat belt by the drivers was given as stiffer penalties for non-compliance with the seat belt law (44.5%). The predictors of seat belt use were male driver, no formal or lower level of education, driving for less than 10 years, and the perception that the other drivers use seat belts with the same or higher frequency compared to the respondents. Conclusion Only a small proportion of the drivers in Trinidad and Tobago always use a seat belt when driving. There is the need to enforce the seat belt legislation in the country. PMID:21679410

Design and Evaluation Methods for Optimizing Ejection Seat Cushions for Comfort and Safety

DTIC Science & Technology

1977-02-01

buttocks to the seat cushion or seat pan. Kohara , a Japaners Investigator discussed the problems of seating comfort and the measuren.ent of buttock/seat...loads In an unpublished report in 1965 (23) and subsequently In a magazine article In 1966 (24). Kohara was able to weasure pressures by means of...Isolation. Kohara has also studied the vibration Isolation requirements in high speed trains (23, 2’). Howeveri the seat cushion has been used only rarely in

Car seat inspection among children older than 3 years: Using data to drive practice in child passenger safety.

PubMed

Kroeker, Amber M; Teddy, Amy J; Macy, Michelle L

2015-09-01

Motor vehicle crashes are the leading cause of unintentional death and disability among children 4 years to 12 years of age in the United States. Despite the high risk of injury from motor vehicle crashes in this age group, parental awareness and child passenger safety programs in particular may lack focus on this age group. This is a retrospective cross-sectional analysis of child passenger safety seat checklist forms from two Safe Kids coalitions in Michigan (2013) to identify restraint type upon arrival to car seat inspections. Other variables were included if the coalition provided a new child safety seat and if the child had a sibling who underwent a car seat inspection. χ statistics were used to compare change in restraint use on arrival and at departure, the proportion of children attending a car seat inspection event by age, the age category of children by site, the proportion of children with siblings also undergoing a car seat inspection by age, and the distribution of a new child safety seat by age. Data were available from 1,316 Safe Kids Huron Valley and 3,215 Safe Kids Greater Grand Rapids car seat inspections. Just 10.8% of the total seats inspected were booster seats. Child safety seats for infant and young children were more commonly inspected (rear-facing carrier [40.3%], rear-facing convertible [10.2%], and forward-facing [19.3%] car seats). Few children at inspections used a seat belt only (5.4%) or had no restraint (13.8%). Children 4 years and older were found to be in a suboptimal restraint at least 30% of the time. Low proportions of parents use car seat inspections for children in the booster seat age group. The proportion of children departing the inspection in a more protective restraint increased with increasing age. This highlights an area of weakness in child passenger safety programs and signals an opportunity to strengthen efforts on The Booster Age Child. Epidemiologic/prognostic study, level III.

An energy-absorbing sliding seat for reducing neck injury risks in rear impact--analysis for prototype built.

PubMed

Zhang, Xiaowei; Zhou, Qing

2016-01-01

This study investigated overall performance of an energy-absorbing sliding seat concept for whiplash neck injury prevention. The sliding seat allows its seat pan to slide backward for some distance under certain restraint force to absorb crash energy in rear impacts. A numerical model that consisted of vehicle interior, seat, seat belt, and BioRID II dummy was built in MADYMO to evaluate whiplash neck injury in rear impact. A parametric study of the effects of sliding seat parameters, including position and cushion stiffness of head restraint, seatback cushion stiffness, recliner characteristics, and especially sliding energy-absorbing (EA) restraint force, on neck injury criteria was conducted in order to compare the effectiveness of the sliding seat concept with that of other existing anti-whiplash mechanisms. Optimal sliding seat design configurations in rear crashes of different severities were obtained. A sliding seat prototype with bending of a steel strip as an EA mechanism was fabricated and tested in a sled test environment to validate the concept. The performance of the sliding seat under frontal and rollover impacts was checked to make sure the sliding mechanism did not result in any negative effects. The protective effect of the sliding seat with EA restraint force is comparable to that of head restraint-based and recliner stiffness-based anti-whiplash mechanisms. EA restraint force levels of 3 kN in rear impacts of low and medium severities and 6 kN in impacts of high severity were obtained from optimization. In frontal collision and rollover, compared to the nonsliding seat, the sliding seat does not result in any negative effects on occupant protection. The sled test results of the sliding seat prototype have shown the effectiveness of the concept for reducing neck injury risks. As a countermeasure, the sliding seat with appropriate restraint forces can significantly reduce whiplash neck injury risk in rear impacts of low, medium, and high severities with no negative effects on other crash load cases.

49 CFR 571.10 - Designation of seating positions.

Code of Federal Regulations, 2012 CFR

2012-10-01

... positions (N) for any seat location with a seating surface width greater than 330 mm (13 inches) is as... 1400 mm (55.2 inches): N = [Seating surface width (in mm)/350] round down to the nearest whole number... equal to 1400 mm (55.2 inches): N = [Seating surface width (in mm)/450] round down to the nearest whole...

49 CFR 571.10 - Designation of seating positions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... positions (N) for any seat location with a seating surface width greater than 330 mm (13 inches) is as... 1400 mm (55.2 inches): N = [Seating surface width (in mm)/350] round down to the nearest whole number... equal to 1400 mm (55.2 inches): N = [Seating surface width (in mm)/450] round down to the nearest whole...

The Data Egg: A new solution to text entry barriers

NASA Technical Reports Server (NTRS)

Friedman, Gary L.

1993-01-01

A unit that allows text entry with only one hand has been developed, and holds the promise of allowing computers to be truly portable. It is unique in that it allows operation in any position, freeing the user from the traditional constraints of having to be seated near a desk. This hand held, chord-key-based unit can be used either autonomously for idea capturing, or tethered to a personal computer and used as an auxiliary keyboard. Astronauts, journalists, the bedridden, and anyone else normally barred from using a computer while on the job could also benefit from this form of man-machine interface, which has been dubbed the 'Data Egg'.

Evaluation of wheelchair seating system crashworthiness: "drop hook"-type seat attachment hardware.

PubMed

Bertocci, G; Ha, D; Deemer, E; Karg, P

2001-04-01

To evaluate the crashworthiness of commercially available hardware that attaches seat surfaces to the wheelchair frame. A low cost static crashworthiness test procedure that simulates a frontal impact motor vehicle crash. Safety testing laboratory. Eleven unique sets of drop-hook hardware made of carbon steel (4), stainless steel (4), and aluminum (3). Replicated seat-loading conditions associated with a 20g/48 kph frontal impact. Test criterion for seat loading was 16,680 N (3750 lb). Failure load and deflection of seat surface. None of the hardware sets tested met the crashworthiness test criterion. All failed at less than 50% of the load that seating hardware could be exposed to in a 20g/48 kph frontal impact. The primary failure mode was excessive deformation, leading to an unstable seat support surface. Results suggest that commercially available seating drop hooks may be unable to withstand loading associated with a frontal crash and may not be the best option for use with transport wheelchairs.

Do parental decision-making patterns predict compliance with use of child booster seats?

PubMed

Shimony-Kanat, Sarit; Gofin, Rosa; Kienski Woloski Wruble, Anna C; Mann, Leon

2018-03-01

Booster seat use for 4-9 year olds remains the lowest of all age groups in many countries. The objective of this study is to examine whether parents' decision-making patterns, as measured by the Melbourne Decision Making Questionnaire, relate to car booster seat use. Israeli parents of 4-7 years old children (n = 398) answered a questionnaire about car safety and decision-making habits. Ninety per cent of parents reported having a booster seat; 70.5% reported consistent booster seat use in general and on short drives during the last month (booster seat use compliance index). Greater compliance index was positively related to a vigilant decision-making pattern, passenger compliance with rear seat belts and families with fewer children. Lower booster seat use compliance index was associated with buck-passing decision-making pattern. Health professionals and policy-makers should take into account parents' habitual decision-making patterns when designing interventions for car booster seat compliance.

Structural loads preliminary results

NASA Technical Reports Server (NTRS)

Alfaro-Bou, E.

1986-01-01

From a total of 351 instrumentation channels, 341 channels (97%) were in operation during the initial impact of the airplane. Both NASA seats, the energy absorbing seat and the standard seat, maintained their integrity during the impact. The floor accelerations at the seat locations were lower than the accelerations required for the energy absorbers to stroke; consequently, the energy absorbing seat did not stroke. The two seats remained firm in place during the crash and no seat attachment failures were observed. Due to the low accelerations experienced during the crash, both seats performed as standard seats. In the airplane structure, the accelerations were higher at both the point of impact in the left wing and at the forward end of the fuselage. The accelerations on the floor were higher toward the front than toward the rear and the floor accelerations on the left side were higher than on the right side at the front of the fuselage, but toward the rear they evened out.

High levels of incorrect use of car seat belts and child restraints in Fife--an important and under-recognised road safety issue.

PubMed

Campbell, H; Macdonald, S; Richardson, P

1997-03-01

To pilot data collection instruments and to make a preliminary estimate of the level of incorrect use of car seat belts and child restraints in Fife, Scotland. Cross sectional survey of cars containing adults and children at a number of public sites across Fife in 1995 to assess use of car occupant restraints. Trained road safety officers assessed whether seat restraints were appropriate for the age of the passengers and whether restraints were used correctly. These assessments were based on standards published by the Child Accident Prevention Trust. The survey gathered data from 596 occupants in 180 cars: 327 adults and 269 children. Ten per cent of drivers who were approached refused to participate. Car occupant restraint was assessed in 180 drivers, 151 front seat passengers, and 265 rear seat passengers. Three hundred and sixty one occupants wore seat belts, 68 were restrained by a seat belt and booster cushion, 63 in toddler seats, 25 in two way seats, and 18 in rear facing infant carriers. Ninety seven per cent of drivers, 95% of front seat passengers, and 77% of rear seat passengers were restrained. However, in 98 (52%) vehicles at least one passenger was restrained by a device that was used incorrectly. Seven per cent of adults and 28% of children were secured incorrectly. The commonest errors were loose seat belts and restraint devices not adequately secured to the seat. Rates of incorrect use were highest in child seat restraints, reaching 60% with two way seats and 44% with rear facing infant seats. The incorrect use of car occupant restraints is an under-recognised problem, both by health professionals, and the general public. Incorrect use has been shown to reduce the effectiveness of restraints, can itself result in injury, and is likely to be an important factor in child passenger injuries. The correct use of car seat restraints merits greater attention in strategies aiming to reduce road traffic casualties. Areas of intervention that could be considered include raising public awareness of this problem, improving information and instruction given to those who purchase child restraints, and encouraging increased collaboration between manufacturers of cars and child restraints, in considering safety issues.

High levels of incorrect use of car seat belts and child restraints in Fife--an important and under-recognised road safety issue.

PubMed Central

Campbell, H.; Macdonald, S.; Richardson, P.

1997-01-01

OBJECTIVE: To pilot data collection instruments and to make a preliminary estimate of the level of incorrect use of car seat belts and child restraints in Fife, Scotland. DESIGN: Cross sectional survey of cars containing adults and children at a number of public sites across Fife in 1995 to assess use of car occupant restraints. Trained road safety officers assessed whether seat restraints were appropriate for the age of the passengers and whether restraints were used correctly. These assessments were based on standards published by the Child Accident Prevention Trust. PARTICIPANTS: The survey gathered data from 596 occupants in 180 cars: 327 adults and 269 children. Ten per cent of drivers who were approached refused to participate. Car occupant restraint was assessed in 180 drivers, 151 front seat passengers, and 265 rear seat passengers. MAIN RESULTS: Three hundred and sixty one occupants wore seat belts, 68 were restrained by a seat belt and booster cushion, 63 in toddler seats, 25 in two way seats, and 18 in rear facing infant carriers. Ninety seven per cent of drivers, 95% of front seat passengers, and 77% of rear seat passengers were restrained. However, in 98 (52%) vehicles at least one passenger was restrained by a device that was used incorrectly. Seven per cent of adults and 28% of children were secured incorrectly. The commonest errors were loose seat belts and restraint devices not adequately secured to the seat. Rates of incorrect use were highest in child seat restraints, reaching 60% with two way seats and 44% with rear facing infant seats. CONCLUSIONS: The incorrect use of car occupant restraints is an under-recognised problem, both by health professionals, and the general public. Incorrect use has been shown to reduce the effectiveness of restraints, can itself result in injury, and is likely to be an important factor in child passenger injuries. The correct use of car seat restraints merits greater attention in strategies aiming to reduce road traffic casualties. Areas of intervention that could be considered include raising public awareness of this problem, improving information and instruction given to those who purchase child restraints, and encouraging increased collaboration between manufacturers of cars and child restraints, in considering safety issues. PMID:9113842

Conical Seat Shut-Off Valve

NASA Technical Reports Server (NTRS)

Farner, Bruce

2013-01-01

A moveable valve for controlling flow of a pressurized working fluid was designed. This valve consists of a hollow, moveable floating piston pressed against a stationary solid seat, and can use the working fluid to seal the valve. This open/closed, novel valve is able to use metal-to-metal seats, without requiring seat sliding action; therefore there are no associated damaging effects. During use, existing standard high-pressure ball valve seats tend to become damaged during rotation of the ball. Additionally, forces acting on the ball and stem create large amounts of friction. The combination of these effects can lead to system failure. In an attempt to reduce damaging effects and seat failures, soft seats in the ball valve have been eliminated; however, the sliding action of the ball across the highly loaded seat still tends to scratch the seat, causing failure. Also, in order to operate, ball valves require the use of large actuators. Positioning the metal-to-metal seats requires more loading, which tends to increase the size of the required actuator, and can also lead to other failures in other areas such as the stem and bearing mechanisms, thus increasing cost and maintenance. This novel non-sliding seat surface valve allows metal-to-metal seats without the damaging effects that can lead to failure, and enables large seating forces without damaging the valve. Additionally, this valve design, even when used with large, high-pressure applications, does not require large conventional valve actuators and the valve stem itself is eliminated. Actuation is achieved with the use of a small, simple solenoid valve. This design also eliminates the need for many seals used with existing ball valve and globe valve designs, which commonly cause failure, too. This, coupled with the elimination of the valve stem and conventional valve actuator, improves valve reliability and seat life. Other mechanical liftoff seats have been designed; however, they have only resulted in increased cost, and incurred other reliability issues. With this novel design, the seat is lifted by simply removing the working fluid pressure that presses it against the seat and no external force is required. By eliminating variables associated with existing ball and globe configurations that can have damaging effects upon a valve, this novel design reduces downtime in rocket engine test schedules and maintenance costs.

AAP Updates Recommendations on Car Seats

MedlinePlus

... Size Email Print Share AAP Updates Recommendations on Car Seats Page Content Article Body Children should ride ... of approved car safety seats. Healthy Children Radio: Car Seat Safety Dennis Durbin, MD, FAAP, lead author ...

CDC Vital Signs: Motor Vehicle Crash Deaths

MedlinePlus

... those that address: Primary enforcement of seat belt laws that cover everyone in every seat. Police officers ... seat belt use with primary enforcement seat belt laws that cover everyone in the vehicle. www.cdc. ...

14 CFR 135.155 - Fire extinguishers: Passenger-carrying aircraft.

Code of Federal Regulations, 2011 CFR

2011-01-01

... OPERATING REQUIREMENTS: COMMUTER AND ON DEMAND OPERATIONS AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT... passenger seating configuration, excluding any pilot seat, of at least 10 seats but less than 31 seats. ...

14 CFR 135.155 - Fire extinguishers: Passenger-carrying aircraft.

Code of Federal Regulations, 2010 CFR

2010-01-01

... OPERATING REQUIREMENTS: COMMUTER AND ON DEMAND OPERATIONS AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT... passenger seating configuration, excluding any pilot seat, of at least 10 seats but less than 31 seats. ...

Vibration control of an energy regenerative seat suspension with variable external resistance

NASA Astrophysics Data System (ADS)

Ning, Donghong; Sun, Shuaishuai; Du, Haiping; Li, Weihua; Zhang, Nong

2018-06-01

In this paper, an energy regenerative seat suspension with a variable external resistance is proposed and built, and a semi-active controller for its vibration control is also designed and validated. The energy regenerative seat suspension is built with a three-phase generator and a gear reducer, which are installed in the scissors structure centre of the seat suspension, and the vibration energy is directly harvested from the rotary movement of suspension's scissors structure. The electromagnetic torque of the semi-active seat suspension actuator is controlled by an external variable resistor. An integrated model including the seat suspension's kinematics and the generator is built and proven to match the test result very well. A simplified experimental phenomenon model is also built based on the test results for the controller design. A state feedback H∞ controller is proposed for the regenerative seat suspension's semi-active vibration control. The proposed regenerative seat suspension and its controller are validated with both simulations and experiments. A well-tuned passive seat suspension is applied to evaluate the regenerative seat's performance. Based on ISO 2631-1, the frequency-weighted root mean square (FW-RMS) acceleration of the proposed seat suspension has a 22.84% reduction when compared with the passive one, which indicates the improvement of ride comfort. At the same time, the generated RMS power is 1.21 W. The proposed regenerative seat suspension can greatly improve the driver's ride comfort and has the potential to be developed to a self-powered semi-active system.

Effectiveness of media and enforcement campaigns in increasing seat belt usage rates in a state with a secondary seat belt law.

PubMed

Vasudevan, Vinod; Nambisan, Shashi S; Singh, Ashok K; Pearl, Traci

2009-08-01

In 2005, in terms of seat belt usage rates, Nevada ranked third nationally and first among states with secondary seat belt use enforcement laws in the United States. An effective combination of a media-based education and enforcement campaign helped in this regard. The objective of this article is to document the effectiveness of enforcement and media-based education and outreach campaigns on the seat belt usage rates in Nevada, a state with a secondary seat belt usage law. Observational data on seat belt usage and passenger fatality data are used to evaluate the effectiveness of enforcement campaigns and media-based education and outreach campaigns. Data based on observations of about 40,000 vehicles in each of the years 2003 to 2005 were analyzed. Statistical analyses show that a significant increase in seat belt usage rates among both drivers and passengers for both genders resulted from the accompanying the media and enforcement campaigns. The results from this study indicate that effective and well-planned media/enforcement campaigns can have a significant impact on seat belt usage rates even in a state where the enforcement of seat belt laws can only be as a secondary violation. They validate and expand on findings from other efforts documented in the literature. These results demonstrate that, if coordinated properly, media and enforcement campaigns work very effectively in increasing seat belt usage rates even in states with secondary seat belt laws.

Nonintrusive biological signal monitoring in a car to evaluate a driver's stress and health state.

PubMed

Baek, Hyun Jae; Lee, Haet Bit; Kim, Jung Soo; Choi, Jong Min; Kim, Ko Keun; Park, Kwang Suk

2009-03-01

Nonintrusive monitoring of a driver's physiological signals was introduced and evaluated in a car as a test of extending the concept of ubiquitous healthcare to vehicles. Electrocardiogram, photoplethysmogram, galvanic skin response, and respiration were measured in the ubiquitous healthcare car (U-car) using nonintrusively installed sensors on the steering wheel, driver's seat, and seat belt. Measured signals were transmitted to the embedded computer via Bluetooth(R) communication and processed. We collected and analyzed physiological signals during driving in order to estimate a driver's stress state while using this system. In order to compare the effect of stress on physical and mental conditions, two categories of stresses were defined. Experimental results show that a driver's physiological signals were measured with acceptable quality for analysis without interrupting driving, and they were changed meaningfully due to elicited stress. This nonintrusive monitoring can be used to evaluate a driver's state of health and stress.

Aircraft cockpit vision: Math model

NASA Technical Reports Server (NTRS)

Bashir, J.; Singh, R. P.

1975-01-01

A mathematical model was developed to describe the field of vision of a pilot seated in an aircraft. Given the position and orientation of the aircraft, along with the geometrical configuration of its windows, and the location of an object, the model determines whether the object would be within the pilot's external vision envelope provided by the aircraft's windows. The computer program using this model was implemented and is described.

Number Meaning and Number Grammar in English and Spanish

ERIC Educational Resources Information Center

Bock, Kathryn; Carreiras, Manuel; Meseguer, Enrique

2012-01-01

Grammatical agreement makes different demands on speakers of different languages. Being widespread in the languages of the world, the features of agreement systems offer valuable tests of how language affects deep-seated domains of human cognition and categorization. Number agreement is one such domain, with intriguing evidence that typological…

Intimacy and Ethical Action in Adult Education

ERIC Educational Resources Information Center

Plumb, Donovan

2009-01-01

This article suggests that thinking about the nature of intimacy, especially sexual intimacy, is a good way of deepening our understanding of how deep-seated psychic vulnerabilities play an important role in adult education contexts. Drawing on psychoanalytic accounts of human development, the paper outlines how the capacity for ethical action in…

49 CFR 571.207 - Standard No. 207; Seating systems.

Code of Federal Regulations, 2014 CFR

2014-10-01

... means the part of the seat that provides forward and rearward positioning of the seat bench and back... than a school bus; a passenger seat on a school bus with a GVWR greater than 4,536 kilograms (10,000 pounds); and, a passenger seat on a school bus with a GVWR less than or equal to 4,536 kg manufactured...

49 CFR 571.207 - Standard No. 207; Seating systems.

Code of Federal Regulations, 2013 CFR

2013-10-01

... means the part of the seat that provides forward and rearward positioning of the seat bench and back... than a school bus; a passenger seat on a school bus with a GVWR greater than 4,536 kilograms (10,000 pounds); and, a passenger seat on a school bus with a GVWR less than or equal to 4,536 kg manufactured...

49 CFR 571.207 - Standard No. 207; Seating systems.

Code of Federal Regulations, 2012 CFR

2012-10-01

... means the part of the seat that provides forward and rearward positioning of the seat bench and back... than a school bus; a passenger seat on a school bus with a GVWR greater than 4,536 kilograms (10,000 pounds); and, a passenger seat on a school bus with a GVWR less than or equal to 4,536 kg manufactured...

49 CFR 571.222 - Standard No. 222; School bus passenger seating and crash protection.

Code of Federal Regulations, 2014 CFR

2014-10-01

..., comprised of at least a frame, seat, and wheels. Wheelchair occupant restraint anchorage means the provision... passenger seat that has another seat behind it is subjected to the application of force as specified in S5.1.3.1 and S5.1.3.2, and subsequently, the application of additional force to the seat back as...

49 CFR 571.222 - Standard No. 222; School bus passenger seating and crash protection.

Code of Federal Regulations, 2013 CFR

2013-10-01

..., comprised of at least a frame, seat, and wheels. Wheelchair occupant restraint anchorage means the provision... passenger seat that has another seat behind it is subjected to the application of force as specified in S5.1.3.1 and S5.1.3.2, and subsequently, the application of additional force to the seat back as...

49 CFR 571.222 - Standard No. 222; School bus passenger seating and crash protection.

Code of Federal Regulations, 2011 CFR

2011-10-01

..., comprised of at least a frame, seat, and wheels. Wheelchair occupant restraint anchorage means the provision... passenger seat that has another seat behind it is subjected to the application of force as specified in S5.1.3.1 and S5.1.3.2, and subsequently, the application of additional force to the seat back as...

49 CFR 571.222 - Standard No. 222; School bus passenger seating and crash protection.

Code of Federal Regulations, 2012 CFR

2012-10-01

..., comprised of at least a frame, seat, and wheels. Wheelchair occupant restraint anchorage means the provision... passenger seat that has another seat behind it is subjected to the application of force as specified in S5.1.3.1 and S5.1.3.2, and subsequently, the application of additional force to the seat back as...

Car Safety Seat Usage and Selection Among Families Attending University Hospital Limerick.

PubMed

Scully, P; Finner, N; Letshwiti, J B; O'Gorman, C

2016-05-10

The safest way for children to travel within a car is by provision of a weight-appropriate safety-seat. To investigate this, we conducted a cross-sectional study of adult parents who had children under 12 years, and collected information related to: car use, safety-seat legislation, and type of safety-seat employed. Data were reviewed on 120 children from 60 respondents. Ninety-eight (81.7%) children were transported daily by car. Forty-eight (81.4%) respondents were aware that current safety-seat legislation is based on the weight of the child. One hundred and seven (89.9%) children were restrained during travel using a car safety-seat. One hundred and two (96.2%) safety seats were newly purchased, installed in 82.3% (88) cases by family members with installation instructions fully read in 58 (55.2%) cases. Ninety-nine (83.2%) children were restrained using an appropriate safety-seat for their weight. The results show that four out of five families are employing the most appropriate safety-seat for their child, so providing an effective mechanism to reduce car-related injury. However, the majority of safety-seats are installed by family members, which may have child safety consequences.

The scope and nature of injuries to rear seat passengers in NSW using linked hospital admission and police data.

PubMed

Brown, Julie; Bilston, Lynne E

2014-01-01

To compare the pattern of injuries to front and rear seat occupants and test the hypothesis that rear seat passengers of different ages sustain different patterns of injury. Patients admitted to a hospital following involvement in a crash in New South Wales (NSW) Australia between 2005 and 2007 were identified using International Classification of Diseases (10th edition [ICD10]) codes. Hospital admissions data were linked with NSW police crash data using probabilistic techniques. The profiles and patterns of injury of front and rear seat passengers were compared. Logistic regression was used to examine how age influenced the pattern of injury among rear seat passengers. Sixty-three percent of hospital admissions were linked with police records. One in 5 passengers were rear seat passengers. There were more unrestrained occupants in the rear (7%) compared to drivers (3%) and front seat passengers (2%). Younger (9-15 years) injured passengers were seated in the rear more often than in the front passenger position and older injured passengers (>50 years) were seated more often in the front passenger position than in the rear (15% rear compared to 5% front aged 9-15 years; 22% rear compared to 37% front aged >50 years; χ(2), P < .001). There were proportionally more fatal injuries among rear seat passengers (10%) than among drivers (5%) and front seat passengers (6%), and the pattern of injury between front and rear passengers also varied. Rear seat passengers had more head and abdominal injuries and fewer thoracic and knee/lower leg injuries than front seat passengers. After adjusting for vehicle age, restraint status, travel speed, and whether or not a fatality occurred in the crash, older (>50 years) rear passengers had 6.3 times the odds of sustaining thoracic injuries (95% confidence interval [CI], 2.6-15.0) and lower odds (odds ratio [OR] = 0.4, 95% CI, 0.2-0.9) of sustaining abdominal/lumbar injuries than the youngest occupants (9-15 years).The odds of sustaining a head injury did not vary with age, and the odds of sustaining thoracic, abdominal, or lower extremity injuries did not differ significantly between rear seat passengers aged 16-50 years and 9-15 years. The findings suggest that there is a need for enhanced protection for rear seat passengers, because they have proportionally more fatal injuries than front-seated occupants. The frequency of abdominal injury and the differences between injury patterns observed in front seat passengers suggests a potential benefit from adding abdominal injury risk assessment to rear seat occupant protection test protocols. There is also scope to improve chest protection for older rear seat passengers.

NASA Occupant Protection Standards Development

NASA Technical Reports Server (NTRS)

Somers, Jeffrey T.; Gernhardt, Michael A.; Lawrence, Charles

2011-01-01

Current National Aeronautics and Space Administration (NASA) occupant protection standards and requirements are based on extrapolations of biodynamic models, which were based on human tests performed under pre-Space Shuttle human flight programs where the occupants were in different suit and seat configurations than is expected for the Multi Purpose Crew Vehicle (MPCV) and Commercial Crew programs. As a result, there is limited statistical validity to the occupant protection standards. Furthermore, the current standards and requirements have not been validated in relevant spaceflight suit, seat configurations or loading conditions. The objectives of this study were to develop new standards and requirements for occupant protection and rigorously validate these new standards with sub-injurious human testing. To accomplish these objectives we began by determining which critical injuries NASA would like to protect for. We then defined the anthropomorphic test device (ATD) and the associated injury metrics of interest. Finally, we conducted a literature review of available data for the Test Device for Human Occupant Restraint New Technology (THOR-NT) ATD to determine injury assessment reference values (IARV) to serve as a baseline for further development. To better understand NASA s environment, we propose conducting sub-injurious human testing in spaceflight seat and suit configurations with spaceflight dynamic loads, with a sufficiently high number of subjects to validate no injury during nominal landing loads. In addition to validate nominal loads, the THOR-NT ATD will be tested in the same conditions as the human volunteers, allowing correlation between human and ATD responses covering the Orion nominal landing environment and commercial vehicle expected nominal environments. All testing will be conducted without the suit and with the suit to ascertain the contribution of the suit to human and ATD responses. In addition to the testing campaign proposed, additional data analysis is proposed to mine existing human injury and response data from other sources, including military volunteer testing, automotive Crash Injury Research Engineering Network (CIREN), and IndyCar impact and injury data. These data sources can allow a better extrapolation of the ATD responses to off-nominal conditions above the nominal range that can safely be tested. These elements will be used to develop injury risk functions for each of the injury metrics measured from the ATD. These risk functions would serve as the basis for the NASA standards. Finally, we propose defining standard test methodology for evaluating future spacecraft designs against the IARVs, including developing a star-rating system to allow crew safety comparisons between vehicles.

A seat cushion to provide realistic acceleration cues for aircraft simulators

NASA Technical Reports Server (NTRS)

Ashworth, B. R.

1976-01-01

A seat cushion to provide acceleration cues for aircraft simulator pilots was built, performance tested, and evaluated. The four cell seat, using a thin air cushion with highly responsive pressure control, attempts to reproduce the same events which occur in an aircraft seat under acceleration loading. The pressure controller provides seat cushion responses which are considered adequate for current high performance aircraft simulations. The initial tests of the seat cushions have resulted in excellent pilot opinion of the cushion's ability to provide realistic and useful cues to the simulator pilot.

Pattern of seat belt wearing in Nanjing, China

PubMed Central

Routley, V; Ozanne‐Smith, J; Li, D; Hu, X; Wang, P; Qin, Y

2007-01-01

Objective To describe the patterns of seat belt wearing in Nanjing, China for drivers, front seat passengers, and rear occupants of motor vehicles. Design Roadside observational study. Setting Four sites in central and northern Nanjing during daylight hours over 1 week in April 2005. Subjects Drivers and passengers of 17 147 cars, taxis, goods vans, and pickups, which traveled in the inside traffic lane. Main outcome measures Percentage seat belt wearing for each of seating position, age/sex, time of day, vehicle type, day of week. Results The rate of seat belt wearing was significantly higher in drivers (67.3%, 95% CI 66.6 to 68.0) than front seat passengers (18.9%, 95% CI, 18.0 to 19.8). It was negligible for second front seat passengers (2.6%, 95% CI 0.3 to 4.9) and rear seat passengers (0.5%, 95% CI 0.3 to 0.7). Belt tampering, such that protection would be reduced in the event of a crash, was observed for 18.5% of taxi drivers. Drivers were most likely to wear seat belts in cars and vans and at a city roundabout; front seat passengers were most likely to wear seat belts in non‐taxi vehicles, during the evening rush hour, if the driver was wearing a belt, and on the local north road. Drivers were least likely to wear a belt in the early morning, in pickups and taxis, on Tuesday (or the following week), and on the local north road; front seat passengers were least likely to wear a belt in taxis and if the driver was not wearing a belt. Conclusions Rates of seat belt wearing by passengers were low despite national legislation and provincial regulations coming into effect several months before the survey. Combined education and enforcement are necessary accompaniments to legislation. PMID:18056315

Effectiveness of Booster Seats Compared With No Restraint or Seat Belt Alone for Crash Injury Prevention

PubMed Central

Ma, Xiaoguang; Griffin, Russell; McGwin, Gerald; Allison, David B.; Heymsfield, Steven B.; He, Wei; Zhu, Shankuan

2013-01-01

Objectives The objective was to evaluate the effectiveness of belt-positioning booster seats, compared with no restraint use and with seat belt use only, during motor vehicle crashes among U.S. children. Methods This was a retrospective matched cohort study with data from the 1998 through 2009 National Automotive Sampling System (NASS) Crashworthiness Data System (CDS). The study sample consisted of children aged 0 to 10 years who were not seated in the front seat of the vehicle. We used Cox proportional hazards models to estimate the risk of overall, fatal, and regional body injury. Results Children using seat belts in belt-positioning booster seats experienced less overall injury (Injury Severity Score [ISS] > 0, adjusted risk ratio [RR] = 0.73, 95% confidence interval [CI] = 0.55 to 0.96; Abbreviated Injury Scale [AIS] score of 2 or higher, adjusted RR = 0.30, 95% CI = 0.16 to 0.58; ISS > 8, adjusted RR = 0.19, 95% CI = 0.06 to 0.56), and less injury in most body regions except the neck (adjusted RR = 4.79, 95% CI = 1.43 to 16.00) than did children with no restraint use. Children using seat belts in belt-positioning booster seats had an equal risk of injury but higher risks of neck (adjusted RR = 1.86, 95% CI = 1.02 to 3.40) and thorax (adjusted RR = 2.86, 95% CI = 1.33 to 6.15) injury than did children restrained by seat belts only. Conclusions Children using belt-positioning booster seats appear to experience a higher risk of AIS > 0 injury to the neck and thorax than do children using seat belts only. Future research should examine whether the observed increase in neck and thorax injuries can be attributed to improper use of booster seats. PMID:24050794

Computer Simulation of Ejection Seat Performance and Preliminary Correlation with Empirical Data

DTIC Science & Technology

1980-04-01

L. . .. . 3 I r AFFDL-TR-79-31 50 TABLE OF CONTENTS SECTION PAGE I INTRODUCTION 1 1I SAFEST COMPUTER PROGRAM DESCRIPTION 8 III HITECH ...ZEARTH vs TIME 49E-I1A 53 34 ZEARTH vs XEARTH 49E-IIA 54 AFFDL-TR-79-3150 LIST OF TABLES TABLE PAGE 1 ACES II EVENT-TIME SEQUENCE 3 2 HITECH 49E-JlF...Initial Conditions 13 3 HITECH 49E-I1A Initial Conditions 14 4 HITECH Program Test Data Summary 15 5 SAFEST 49E-JIF Initial Conditions 20 6 SAFEST 49E-IIA

The Effects of Microgravity on Seated Height (Spinal Elongation)

NASA Technical Reports Server (NTRS)

Young, K. S.; Rajulu, S.

2011-01-01

ABSTRACT Many physiological factors, such as spinal elongation, fluid shifts, bone atrophy, and muscle loss, occur during an exposure to a microgravity environment. Spinal elongation is just one of the factors that can also affect the safety and performance of a crewmember while in space. Spinal elongation occurs due to the lack of gravity/compression on the spinal column. This allows for the straightening of the natural spinal curve. There is a possible fluid shift in the inter-vertebral disks that may also result in changes in height. This study aims at collecting the overall change in seated height for crewmembers exposed to a microgravity environment. During previous Programs, Apollo-Soyuz Test Project (ASTP) and Skylab, spinal elongation data was collected from a small number of subjects in a standing posture but were limited in scope. Data from these studies indicated a quick increase in stature during the first few days of weightlessness, after which stature growth reached a plateau resulting in up to a 3% increase of the original measurement [1-5]. However, this data was collected only for crewmembers in standing posture and not in a seated posture. Seated height may have a different effect than standing height due to a change in posture as well as due to a compounded effect of wearing restraints and a potential compression of the gluteal area. Seated height was deemed as a critical measurement in the design of the Constellation Program s (CxP) Crew Exploration Vehicle (CEV), called Orion which is now the point-of-departure vehicle for the Multi-Purpose Crew Vehicle (MPCV) Program; therefore a better understanding of the effects of microgravity on seated height is necessary. Potential changes in seated height that may not have impacted crew accommodation in previous Programs will have significant effects on crew accommodation due to the layout of seats in the Orion.. The current and existing configuration is such that the four crewmembers are stacked two by two with the commander and pilot seats on the top and the two remaining seats underneath, thereby limiting the amount of clearance for the crewmembers seated in the bottom seat. The inner mold line of these types of vehicles are fixed due to other design constraints; therefore, it is essential that all seats incorporate additional clearance to account for adequate spinal growth thereby ensuring that the crew can safely ingress the seat and be strapped in prior to its return to earth. If there is not enough clearance to account for spinal growth deltas between seats then there is the potential that crewmembers will not be able to comfortably and safely fit into their seats. The crewmember in the bottom stacked seat may even have negative clearance with the seat above him or her which could lead to potential ingress/egress issues or potentially injury of the crewmember during landing. These impacts are specific to these types of vehicles with stacked seat configuration. Without proper knowledge of the amount of spinal elongation, or growth, which occurs due to microgravity and space flight, the design of future vehicle(s) or suits may cause injury, discomfort, and limit crew accommodation and crew complements. The experiment primarily aimed to collect seated height data for subjects exposed to microgravity environments, and feed new information regarding the effect of elongation of the spine forward into the design of the Orion. The data collected during the experiment included, two seated height measurement and two digital pictures of seated height pre-, in-, and post-flight. In addition to seated height, crewmembers had an optional task of collecting stature , standing height. Seated height data was obtained from 29 crewmembers that included 8 ISS increment crew (2 females and 6 males) and 21 Shuttle crew (1 female, 20 males), and whose mean age was 48 years ( 4 years). This study utilized the last six Shuttle flights, STS-128 to STS-134. The results show that partipating crewmembers experienced growth up to 6% in seated height and up to 3% in stature. Based on the worst case statistical analysis of the subject data, the recommended seated height growth of 6% will be provided to the designers as the necessary seated height adjustment.

Using haptic feedback to increase seat belt use : traffic tech.

DOT National Transportation Integrated Search

2011-07-01

The legacy of research on increasing seat belt use has : focused on enactment of seat belt legislation, public education, : high-visibility police enforcement, and seat belt : reminder systems. Several behavioral programs have : produced large, susta...

Validation of a Functional Pyelocalyceal Renal Model for the Evaluation of Renal Calculi Passage While Riding a Roller Coaster.

PubMed

Mitchell, Marc A; Wartinger, David D

2016-10-01

The identification and evaluation of activities capable of dislodging calyceal renal calculi require a patient surrogate or validated functional pyelocalyceal renal model. To evaluate roller coaster facilitation of calyceal renal calculi passage using a functional pyelocalyceal renal model. A previously described adult ureteroscopy and renoscopy simulator (Ideal Anatomic) was modified and remolded to function as a patient surrogate. Three renal calculi of different sizes from the patient who provided the original computed tomographic urograph on which the simulator was based were used. The renal calculi were suspended in urine in the model and taken for 20 rides on the Big Thunder Mountain Railroad roller coaster at Walt Disney World in Orlando, Florida. The roller coaster rides were analyzed using variables of renal calculi volume, calyceal location, model position on the roller coaster, and renal calculi passage. Sixty renal calculi rides were analyzed. Independent of renal calculi volume and calyceal location, front seating on the roller coaster resulted in a passage rate of 4 of 24. Independent of renal calculi volume and calyceal location, rear seating on the roller coaster resulted in a passage rate of 23 of 36. Independent of renal calculi volume in rear seating, calyceal location differed in passage rates, with an upper calyceal calculi passage rate of 100%; a middle calyceal passage rate of 55.6%; and a lower calyceal passage rate of 40.0%. The functional pyelocalyceal renal model serves as a functional patient surrogate to evaluate activities that facilitate calyceal renal calculi passage. The rear seating position on the roller coaster led to the most renal calculi passages.

Factors Affecting Booster Seat Use.

PubMed

Aita-Levy, Jerussa; Henderson, Lauren

2016-10-01

Objective To identify general awareness of booster seats as well as reasons for use and nonuse in an urban pediatric emergency room. Methods A total of 100 questionnaires were completed consisting of 24 questions each. Questions included knowledge of booster seat guidelines, source of knowledge, awareness of risks, and confidence in booster seats. Afterward, participants were provided an educational handout. Results Majority of parents reported currently using or having used a booster seat. The most popular reason was to protect from injury (78%), and reason for nonuse was size (44%). Majority of parents agreed that motor vehicle crashes were the leading cause of death in children. However, 56% of parents prematurely transitioned child out of a booster seat. Only 20% reported learning about booster seats from their pediatrician. Conclusion Parents continue to transition their children prematurely from booster seats. Current state laws need revision as well as further education using simplified illustrated guidelines. © The Author(s) 2015.

Seat Experiment Results of Full-Scale Transport Aircraft Controlled Impact Demonstration.

DTIC Science & Technology

1986-07-01

31 CONCLUSIONS . . . . . . . . . . . . . . . . . . . . .. .. .. .... 31 APPENDIX A - FLOOR, SEAT, AND PELVIS VERTICAL...ACCELERATIONS . ... A-1 APPENDIX B - FLOOR, SEAT, AND PELVIS LONGITUDINAL ACCELERATIONS .B-1 APPENDIX C - FLOOR, SEAT, AND PELVIS LATERAL ACCELERATIONS ... . C...The current asymmetry of the tracks in the 8720 and 727 causes the window-side legs of the triple- passenger seat to support twice as much load as the

The Seated Soldier Study: Posture and Body Shape in Vehicle Seats

DTIC Science & Technology

2013-10-31

ergonomics and safety assessments. UNCLASSIFIED UNCLASSIFIED 3 INTRODUCTION The design of seats and interiors for a wide variety of...DHMs) began to be used for ergonomic assessments and design of vehicle interiors and seats , particularly for driver workstation layout (Chaffin 2001...in a vehicle mockup by varying the steering wheel position relative to the pedals. The participants adjusted the seat to obtain a comfortable

Contact dermatitis to training toilet seat (potty seat dermatitis).

PubMed

Dorfman, Claire O; Barros, Mark A; Zaenglein, Andrea L

2018-05-29

Allergic contact dermatitis from various components of toilet seats has been well described. We report a case of a young boy presenting with an atypical pattern of dermatitis who was found to be allergic to his training toilet seat. This case highlights the importance of recognizing this diagnosis and the role of potty seats as the causative factor. © 2018 Wiley Periodicals, Inc.

Injury risk for matched front and rear seat car passengers by injury severity and crash type: An exploratory study.

PubMed

Mitchell, R J; Bambach, M R; Toson, Barbara

2015-09-01

The risk of serious injury or death has been found to be reduced for some front compared to rear seat car passengers in newer vehicles. However, differences in injury severity between car occupants by seating position has not been examined. This study examines the injury severity risk for rear compared to front seat car passengers. A retrospective matched-cohort analysis was conducted of vehicle crashes involving injured rear vs front seat car passengers identified in linked police-reported, hospitalisation and emergency department (ED) presentation records during 2001-2011 in New South Wales (NSW), Australia. Odds ratios were estimated using an ordinal logistic mixed model and logistic mixed models. There were 5419 front and 4588 rear seat passengers in 3681 vehicles. There was a higher odds of sustaining a higher injury severity as a rear-compared to a front seat car passenger, with a higher odds of rear seat passengers sustaining serious injuries compared to minimal injuries. Where the vehicle occupant was older, travelling in a vehicle manufactured between 1990 and 1996 or after 1997, where the airbag deployed, and where the vehicle was driven where the speed limit was ≥70km/h there was a higher odds of the rear passenger sustaining a higher injury severity then a front seated occupant. Rear seat car passengers are sustaining injuries of a higher severity compared to front seat passengers travelling in the same vehicle, as well as when travelling in newer vehicles and where the front seat occupant is shielded by an airbag deployed in the crash. Rear seat occupant protective mechanisms should be examined. Pre-hospital trauma management policies could influence whether an individual is transported to a hospital ED, thus it would be beneficial to have an objective measure of injury severity routinely available in ED records. Further examination of injury severity between rear and front seat passengers is warranted to examine less severe non-fatal injuries by car seating position and vehicle intrusion. Copyright © 2015 Elsevier Ltd. All rights reserved.

Association between exposure/non-exposure to the mandatory seat belt law with regards to compliance in vehicle accident victims--a hospital review.

PubMed

Williams, E W; Reid, M; Lindo, J L M; Williams-Johnson, J; French, S; Singh, P; McDonald, A H

2007-06-01

Injuries sustained in motor vehicle accidents (MVAs) are a major challenge to the Jamaican healthcare system. In November 1999, Jamaica enacted legislation to make seat belt usage in motor vehicles compulsory. The effect of this policy change on seat belt usage is unclear. This study therefore sought to determine the prevalence of seat belt usage and to determine the association between exposure/non-exposure to the mandatory seat belt law and seat belt use in subjects who presented to the Accident and Emergency Department (A&E) of the University Hospital of the West Indies (UHWI) as a result of motor vehicle accidents. Subjects were recruited from June to November 2003, post-seat belt law (POBL) period, and May to October 1999, pre-seat belt law (PRBL) period. Data collected included demographic variables, seat belt use and position of the occupants in the vehicle. Of the 277 patients who were eligible for inclusion, data were complete in 258 subjects, 87 in the PRBL period and 171 in the POBL period. The prevalence of seat belt use was 47% (PRBL) and 63% (POBL) respectively. There was no significant gender difference at each period. The odds of wearing seat belt in the rear of a motor vehicle were significantly lower than that of a driver (Table 3, OR 0.19, 95% CI 0.07, 0.48). Adjusting for age, gender and position in vehicle exposure, there was about 100% increase in the odds of seat belt use during the post seat belt law era (OR = 2.09, 95% CI 1.21, 3.61). It is concluded from this hospital-based study that the mandatory seat belt law legislature was associated with increased seat belt use in motor vehicle accident victims. However, current data from the Road Traffic Agency indicate that there is still an alarming number of fatalities. This clearly suggests that additional public health measures are needed to address the epidemic of motor vehicle trauma in Jamaica.

Effect of Booster Seat Design on Children’s Choice of Seating Positions During Naturalistic Riding

PubMed Central

Andersson, Marianne; Bohman, Katarina; Osvalder, Anna-Lisa

2010-01-01

The purpose of this naturalistic study was to investigate the effect of booster seat design on the choice of children’s seating positions during naturalistic riding. Data was collected through observations of children during in-vehicle riding by means of a film camera. The children were positioned in high back boosters in the rear seat while a parent drove the car. The study included two different booster designs: one with large head and torso side supports, and one with small head side supports and no torso side supports. Six children between three and six years of age participated in the study. Each child was observed in both boosters. The duration of the seating positions that each child assumed was quantified. The design with large side head supports resulted more often in seating positions without head and shoulder contact with the booster’s back. There was shoulder-to-booster back contact during an average of 45% of riding time in the seat with the large head side supports compared to 75% in the seat with the small head supports. The children in the study were seated with the head in front of the front edge of the head side supports more than half the time, in both boosters. Laterally, the children were almost constantly positioned between the side supports of the booster in both seats. The observed seating positions probably reduce the desired protective effect by the side supports in side impact, and may increase the probability of head impact with the vehicle interior in frontal impact. PMID:21050601

A program to increase seat belt use along the Texas-Mexico border.

PubMed

Cohn, Lawrence D; Hernandez, Delia; Byrd, Theresa; Cortes, Miguel

2002-12-01

A school-based, bilingual intervention was developed to increase seat belt use among families living along the Texas-Mexico border. The intervention sought to increase seat belt use by changing perceived norms within the community (i.e., making the nonuse of seat belts less socially acceptable). The intervention was implemented in more than 110 classrooms and involved more than 2100 children. Blind coding, validity checks, and reliability estimates contributed to a rigorous program evaluation. Seat belt use increased by 10% among children riding in the front seat of motor vehicles in the intervention community, as compared with a small but nonsignificant decline in use among control community children. Seat belt use among drivers did not increase.

75 FR 34172 - Lordstown Seating Systems, a Subsidiary of Magna Seating, Including Workers Whose Unemployment...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-16

... certification for workers of the subject firm. The workers produce seating for automobiles. New information... secondarily affected as a supplier of seating for automobiles to a TAA certified firm. The amended notice...

Guidelines for observing child safety seat use

DOT National Transportation Integrated Search

1987-06-01

This manual provides guidelines for collecting observational data needed to assess the use of child safety seats. Specific directions are included for (a) observing child safety seat use, (b) child seats, and (c) instructing observers on how to use s...

Stadium seating--a market analysis.

Treesearch

Jerry A. Sesco; Edwin Kallio

1967-01-01

This report describes the characteristics of stadiums and seating in six North Central States; summarizes the purchasing methods for stadium seats; presents estimates of the present and future market; and points out the increasing competition to wood stadium seating form substitute materials.

76 FR 23793 - Extension of Application Period for Seats for the Stellwagen Bank National Marine Sanctuary...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-28

... seats on the Stellwagen Bank National Marine Sanctuary Advisory Council: (1) Research Member seat and (2... relation to the seat for which they are applying; community and professional affiliations; philosophy...

Seat-belt use still low in Kuwait: self-reported driving behaviours among adult drivers.

PubMed

Raman, Sudha R; Ottensmeyer, C Andrea; Landry, Michel D; Alfadhli, Jarrah; Procter, Steven; Jacob, Susan; Hamdan, Elham; Bouhaimed, Manal

2014-01-01

Kuwait mandated seat-belt use by drivers in 1976 and by front seat passengers in 1994. The study objectives were to identify and estimate current factors associated with seat-belt use and levels of potentially unsafe driving behaviours in Kuwait. In 2010, 741 adults were surveyed regarding driving habits and history. Only 41.6% of drivers reported always using a seat belt. Front seat passenger belt use was more common (30.5%) than rear seat belt use (6.5%). Distracted driving behaviours were common, including mobile phone use ('always' or 'almost always': 51.1%) and texting/SMS (32.4%). Logistic regression indicated that drivers who were young (18-19 years), male, Kuwaiti nationals or non-Kuwaiti Arabs, drove over the speed limit, had traffic violation tickets or >1 car crashes in the last year, were less likely to use seat belts. Targeted initiatives to increase public awareness and to enforce car-safety legislation, including use of seat belts, are necessary to decrease the health burden of car crashes in Kuwait.

Hidden Figures Tour Kennedy Space Center Visitor Complex

NASA Image and Video Library

2016-12-12

Cast and crew members of the upcoming motion picture "Hidden Figures" participate in a question and answer session at the Kennedy Space Center Visitor Complex. From the left are Pharrell Williams, musician and producer of “Hidden Figures," Taraji P. Henson, who portrays Katherine Johnson in the film, Janelle Monáe, who portrays Mary Jackson, and Octavia Spencer, who portrays Dorothy Vaughan. They are seated in front of the original consoles of the Mercury Mission Control room with the world map that was used to follow the path of capsules between tracking stations. The movie is based on the book of the same title, by Margot Lee Shetterly. It chronicles the lives of Katherine Johnson, Dorothy Vaughan and Mary Jackson, three African-American women who worked for NASA as human "computers.” Their mathematical calculations were crucial to the success of Project Mercury missions including John Glenn’s orbital flight aboard Friendship 7 in 1962. The film is due in theaters in January 2017.

Seat belt use-inducing system effectiveness

DOT National Transportation Integrated Search

1975-04-01

Seat belt use inducing system effectiveness was measured in fleet automobiles of a private business and in rental automobiles at a large airport. There were three parts to the activity: 1. Seat belt use inducing systems and seat belt use counting sys...

Restraint use (seat belt and child passenger seat) survey

DOT National Transportation Integrated Search

2008-12-01

In Arizona, lack of restraint usage (seat belts and child passenger seats) was a contributing factor to an average of 687 fatalities per year which is nearly 60% of total fatalities. These tragic statistics could be dramatically decreased if effectiv...

Commuter rail seat testing and analysis of facing seats

DOT National Transportation Integrated Search

2003-12-01

Tests have been conducted on the Bombardier back-to-back commuter rail car seat in a facing-seat configuration to evaluate its performance under static and dynamic loading conditions. Quasi-static tests have been conducted to establish the load defle...

49 CFR 571.202a - Standard No. 202a; Head restraints; Mandatory applicability begins on September 1, 2009.

Code of Federal Regulations, 2014 CFR

2014-10-01

..., representing the head position of a seated 50th percentile male, with sliding scale at the back of the head for... any rear outboard designated seating position, a rear seat back, or any independently adjustable seat component attached to or adjacent to a seat back, that has a height equal to or greater than 700 mm, in any...

49 CFR 571.202a - Standard No. 202a; Head restraints; Mandatory applicability begins on September 1, 2009.

Code of Federal Regulations, 2012 CFR

2012-10-01

..., representing the head position of a seated 50th percentile male, with sliding scale at the back of the head for... any rear outboard designated seating position, a rear seat back, or any independently adjustable seat component attached to or adjacent to a seat back, that has a height equal to or greater than 700 mm, in any...

49 CFR 571.202a - Standard No. 202a; Head restraints; Mandatory applicability begins on September 1, 2009.

Code of Federal Regulations, 2013 CFR

2013-10-01

..., representing the head position of a seated 50th percentile male, with sliding scale at the back of the head for... any rear outboard designated seating position, a rear seat back, or any independently adjustable seat component attached to or adjacent to a seat back, that has a height equal to or greater than 700 mm, in any...

The Seated Soldier Study: Posture and Body Shape in Vehicle Seats

DTIC Science & Technology

2014-01-28

vehicle interior layout Current design guidance is based on outdated anthropometry Previous studies of seated anthropometry have not included the...personal protective equipment (PPE) for seat and vehicle interior layout • Current design guidance is based on outdated anthropometry • Previous...studies of seated anthropometry have not included the effects of PPE on posture and body shape • Detailed anthropometric data needed for the design

Blast resistant vehicle seat

DOEpatents

Ripley, Edward B

2013-02-12

Disclosed are various seats for vehicles particularly military vehicles that are susceptible to attack by road-bed explosive devices such as land mines or improvised explosive devices. The seats often have rigid seat shells and may include rigid bracing for rigidly securing the seat to the chassis of the vehicle. Typically embodiments include channels and particulate media such as sand disposed in the channels. A gas distribution system is generally employed to pump a gas through the channels and in some embodiments the gas is provided at a pressure sufficient to fluidize the particulate media when an occupant is sitting on the seat.

Effects of Wheelchair Seat-height Settings on Alternating Lower Limb Propulsion With Both Legs.

PubMed

Murata, Tomoyuki; Asami, Toyoko; Matsuo, Kiyomi; Kubo, Atsuko; Okigawa, Etsumi

2014-01-01

This study investigated the effects of seat-height settings of wheelchairs with alternating propulsion with both legs. Seven healthy individuals with no orthopedic disease participated. Flexion angles at initial contact (FA-IC) of each joint, range of motion during propulsion period (ROM-PP), and ground reaction force (GRF) were measured using a three dimensional motion capture system and force plates, and compared with different seat-height settings. Statistically significant relationships were found between seat-height and speed, stride length, knee FA-IC, ankle FA-IC, hip ROM-PP, vertical ground reaction force (VGRF), and anterior posterior ground reaction force (APGRF). Speed, hip ROM-PP, VGRF and APGRF increased as the seat-height was lowered. This effect diminished when the seat-height was set below -40 mm. VGRF increased as the seat-height was lowered. The results suggest that the seat-height effect can be attributed to hip ROM-PP; therefore, optimal foot propulsion cannot be achieved when the seat height is set either too high or too low. Efficient foot propulsion of the wheelchair can be achieved by setting the seat height to lower leg length according to a combination of physical characteristics, such as the user's physical functions, leg muscles, and range of motion.

Evaluation of Safe Kids Week 2004: age 4 to 9? It's booster seat time!

PubMed

Howard, A; Beben, N; Rothman, L; Fiissel, D; MacArthur, C

2006-10-01

To assess the effectiveness of a national one week media campaign promoting booster seat use. Pre-test, post-test design based on nationally representative random digit dialing telephone survey, with control for exposure to campaign. Canada. Parents of children aged 4-9 years. During a one week campaign in May 2004, information on booster seat use was distributed via a national media campaign, retail stores, medical clinics, and community events. Information included pamphlets with guidelines for booster seat use, as well as a growth chart (designed by Safe Kids Canada) to assist parents in determining if their child should be using a booster seat. Assessing seat belt fit was described in detail on the growth chart. Knowledge, attitudes, and self-reported behaviors regarding booster seat use. Respondents in the group exposed to the campaign were twice as likely to report using a booster seat with lap and shoulder belt for their child (47%), compared to those in the pre-test (24%) and the unexposed (23%) groups (p<0.001). However, only small differences in general knowledge regarding booster seat use were found between the groups. A one week national media campaign substantially increased self-reported use of booster seats. Parents did not remember details of the campaign content, but did remember implications for their own child.

Seat design principles to reduce neck injuries in rear impacts.

PubMed

Viano, David C

2008-12-01

In the 1990s, research was conducted at General Motors R&D Center on seat safety in rear impacts. It led to the development of high retention seats and an active head restraint to improve occupant safety. This article provides an overview of the design principles found from that research and focuses on seat characteristics that lower whiplash risks. Sled and quasistatic seat testing showed how occupants interact with the seat in rear impacts and what seat characteristics improve occupant retention, energy management, and support of the head-neck, lowering injury risks. Neck displacements, moments, and forces were used to assess whiplash and more severe injury risks. A QST test was developed to quasi-statically push a dummy rearward into the seat to determine seat stiffness (k), frame strength (j), and peak bending moment (M(Hpt)). These parameters were related to neck displacements associated with whiplash. Sled tests were run with in-position and out-of-position male and female Hybrid III dummies to assess performance. A high retention seat and active head restraint were developed and put into production in 1997. High retention seats have 2.3 times greater moment, develop 2.2 times greater load, but have the same stiffness as earlier yielding seats. Seat stiffness was found to be a principle characteristic related to neck displacements associated with whiplash. The combination of a stronger frame, yielding seatback, and high-forward head restraint in the high retention seat provides early head support and low neck displacements in rear impacts. Larger reductions in neck displacement were obtained by adding an active head restraint that moves the head restraint forward and upward by occupant penetration into the seatback. This substantially reduces head contact time, neck displacements, and loads. Whiplash risks are related to seat stiffness, the position of the head restraint, and frame strength. Low seat stiffness allows the occupant to move into the seatback without high loads on the torso until the head-neck is supported by the head restraint. A strong seat frame reduces early seatback rotation that increases the gap to the head restraint and drops it in relation to the occupant's head. A high and forward head restraint provides support of the head and neck. Large forces can be applied to the occupant once the head, neck, and torso are supported by the seat and head restraint without adverse loading of the spine. The addition of an active head restraint closes the gap behind the head before significant load develops on the neck. The movement provides a more upward trajectory of the head restraint. Low-speed rear crashes are not just a matter of whiplash; older occupants, some with cervical stenosis, are at risk for paralyzing spinal cord injury.

Evaluation of seatback vibration based on ISO 2631-1 (1997) standard method: The influence of vehicle seat structural resonance.

PubMed

Ittianuwat, R; Fard, M; Kato, K

2017-01-01

Although much research has been done in developing the current ISO 2631-1 (1997) standard method for assessment seat vibration comfort, little consideration has been given to the influence of vehicle seat structural dynamics on comfort assessment. Previous research has shown that there are inconsistencies between standard methods and subjective evaluation of comfort at around vehicle seat twisting resonant frequencies. This study reports the frequency-weighted r.m.s. accelerations in [Formula: see text], [Formula: see text] and [Formula: see text] axes and the total vibration (point vibration total value) at five locations on seatback surface at around vehicle seat twisting resonant frequencies. The results show that the vibration measured at the centre of seatback surface, suggested by current ISO 2631-1 (1997), at around twisting resonant frequencies was the least for all tested vehicle seats. The greatest point vibration total value on the seatback surface varies among vehicle seats. The variations in vibration measured at different locations on seatback surface at around twisting resonant frequencies were sufficiently great that might affect the comfort assessment of vehicle seat.Practitioner Summary: The influence of vehicle seat structural dynamics has not been considered in current ISO 2631-1 (1997). The results of this study show that the vibration measures on seatback surface at around vehicle seat twisting resonant frequency depends on vehicle seats and dominate at the top or the bottom of seatback but not at the centre.

Design of Mechanism for Assisting Standing Movement Using Planar Linkage and Gear Train

NASA Astrophysics Data System (ADS)

Nango, Jun; Yoshizawa, Hisato; Liu, Jiajun

The number of people who are in need of nursing care due to difficulties they experience with performing various activities of daily living is increasing. In particular, the action of standing up is performed frequently in daily life, and this action starts to induce pain in joints as people age. In this research, we develop a device whose seat plate follows the movement of the thigh in the action of standing up for the purpose of relieving the burden from the joints and reducing the effort associated with nursing care. The device is designed by using a planar five-link mechanism and a gear train, and only a single input is needed to drive the device. The respective lengths of the links are determined by comparing the movement of the seat plate of the device with the movement of the human thigh in the action of standing up. In addition, this device is expected to be useful for assisting users in standing up in a natural manner, including in the case when the body remains supported by the seat plate, as well as for guiding the individual movements of users in the action of standing up.

KSC-2014-2730

NASA Image and Video Library

2014-05-29

HAWTHORNE, Calif. - The Dragon V2 spacecraft's seating arrangement with the control panel swung up to allow crewmembers to get into their seats. Once the crew is in place, the control panel swings down and locks in launch position. SpaceX unveiled the new spacecraft during a ceremony at its headquarters in Hawthorne, Calif. The Dragon V2 is designed to carry people into Earth's orbit and was developed in partnership with NASA's Commercial Crew Program under the Commercial Crew Integrated Capability agreement. SpaceX is one of NASA's commercial partners working to develop a new generation of U.S. spacecraft and rockets capable of transporting humans to and from Earth's orbit from American soil. Ultimately, NASA intends to use such commercial systems to fly U.S. astronauts to and from the International Space Station. Photo credit: NASA/Dimitri Gerondidakis

Factors related to nonuse of seat belts in Michigan.

DOT National Transportation Integrated Search

1987-09-01

This study combined direct observation of seat belt use with interview methods to : identify factors related to seat belt use in a state with a mandatory seat belt use law. Trained : observers recorded restraint use for a probability sample of motori...

Seat belt use increases in Maine following change to primary enforcement : traffic tech.

DOT National Transportation Integrated Search

2010-04-01

Primary seat belt laws are associated with higher selfreported : seat belt use rates and fewer traffic fatalities following : enactment. Primary laws allow police to issue a citation : solely upon observation of a seat belt violation. In contrast, : ...

Portable seat lift

NASA Technical Reports Server (NTRS)

Weddendorf, Bruce (Inventor)

1994-01-01

A portable seat lift that can help individuals either (1) lower themselves to a sitting position or (2) raise themselves to a standing position is presented. The portable seat lift consists of a seat mounted on a base with two levers, which are powered by a drive unit.

Injuries to seat occupants of light airplanes.

DOT National Transportation Integrated Search

1989-02-01

A series of 55 light-airplane accidents was examined in an effort to demonstrate the role of seats in the genesis of injury in seat occupants. Good engineering, design of airplane seats is an important related issue which is not treated in this study...

Muscle activity of the core during bilateral, unilateral, seated and standing resistance exercise.

PubMed

Saeterbakken, Atle Hole; Fimland, Marius Steiro

2012-05-01

Little is known about the effect of performing common resistance exercises standing compared to seated and unilaterally compared to bilaterally on muscle activation of the core. Thus, the purpose of this study was to compare the electromyographic activity (EMG) of the superficial core muscles (i.e. rectus abdominis, external oblique and erector spinae) between seated, standing, bilateral and unilateral dumbbell shoulder presses. 15 healthy males performed five repetitions at 80% of one-repetition maximum of the exercises in randomized order. Results were analyzed with a two-way analysis of variance and a Bonferroni post hoc test. The position × exercise interaction was significantly different for rectus abdominis (P = 0.016), but not for external oblique (P = 0.100) and erector spinae (P = 0.151). The following EMG results were observed: For rectus abdominis: ~49% lower in seated bilateral versus unilateral (P < 0.001), similar in standing bilateral versus unilateral (P = 0.408), ~81% lower in bilateral seated versus standing (P < 0.001), ~59% lower in unilateral seated versus standing (P < 0.001); For external oblique: ~81% lower in seated bilateral versus unilateral (P < 0.001), ~68% lower in standing bilateral than unilateral (P < 0.001), ~58% lower in bilateral seated versus standing (P < 0.001), ~28% lower in unilateral seated versus standing (P = 0.002); For erector spinae: similar in seated bilateral versus unilateral (P = 0.737), ~18% lower in standing bilateral versus unilateral (P = 0.001), similar in seated versus standing bilateral (P = 0.480) and unilateral (P = 0.690). In conclusion, to enhance neuromuscular activation of the superficial core muscles, standing exercises should be used instead of seated exercises, and unilateral exercises should be used instead of bilateral exercises.

Lumbar load attenuation for rotorcraft occupants using a design methodology for the seat impact energy-absorbing system

NASA Astrophysics Data System (ADS)

Moradi, Rasoul; Beheshti, Hamid K.; Lankarani, Hamid M.

2012-12-01

Aircraft occupant crash-safety considerations require a minimum cushion thickness to limit the relative vertical motion of the seat-pelvis during high vertical impact loadings in crash landings or accidents. In military aircraft and helicopter seat design, due to the potential for high vertical accelerations in crash scenarios, the seat system must be provided with an energy absorber to attenuate the acceleration level sustained by the occupants. Because of the limited stroke available for the seat structure, the design of the energy absorber becomes a trade-off problem between minimizing the stroke and maximizing the energy absorption. The available stroke must be used to prevent bottoming out of the seat as well as to absorb maximum impact energy to protect the occupant. In this study, the energy-absorbing system in a rotorcraft seat design is investigated using a mathematical model of the occupant/seat system. Impact theories between interconnected bodies in multibody mechanical systems are utilized to study the impact between the seat pan and the occupant. Experimental responses of the seat system and the occupant are utilized to validate the results from this study for civil and military helicopters according to FAR 23 and 25 and MIL-S-58095 requirements. A model for the load limiter is proposed to minimize the lumbar load for the occupant by minimizing the relative velocity between the seat pan and the occupant's pelvis. The modified energy absorber/load limiter is then implemented for the seat structure so that it absorbs the energy of impact in an effective manner and below the tolerable limit for the occupant in a minimum stroke. Results show that for a designed stroke, the level of occupant lumbar spine injury would be significantly attenuated using this modified energy-absorber system.

Study to develop improved fire resistant aircraft passenger seat materials

NASA Technical Reports Server (NTRS)

Duskin, F. E.; Schutter, K. J.; Sieth, H. H.; Trabold, E. L.

1980-01-01

The Phase 3 study of the NASA 'Improved Fire Resistant Aircraft Seat Materials' involved fire tests of improved materials in multilayered combinations representative of cushion configurations. Tests were conducted to determine their thermal, smoke, and fire resistance characteristics. Additionally, a 'Design Guideline' for Fire Resistant Passenger Seats was written outlining general seat design considerations. Finally, a three-abreast 'Tourist Class' passenger seat assembly fabricated from the most advanced fire-resistant materials was delivered.

H-60A/L Passenger Airbag Protection: Vertical and Horizontal Impact Tests

DTIC Science & Technology

2013-04-30

aft facing seating . While impact testing has been widely performed on ejection seats , only limited testing has been done on helicopter seating ...manikins with the LARD scaled to represent large occupants in the aerospace environment. LARD is also used by the Air Force and JSF in ejection seat ...for all rigid seat tests, resulting in no notable differences (manikin motion , manikin response) between the standard and airbag restraints. The

Driver Injury Risk Variability in Finite Element Reconstructions of Crash Injury Research and Engineering Network (CIREN) Frontal Motor Vehicle Crashes.

PubMed

Gaewsky, James P; Weaver, Ashley A; Koya, Bharath; Stitzel, Joel D

2015-01-01

A 3-phase real-world motor vehicle crash (MVC) reconstruction method was developed to analyze injury variability as a function of precrash occupant position for 2 full-frontal Crash Injury Research and Engineering Network (CIREN) cases. Phase I: A finite element (FE) simplified vehicle model (SVM) was developed and tuned to mimic the frontal crash characteristics of the CIREN case vehicle (Camry or Cobalt) using frontal New Car Assessment Program (NCAP) crash test data. Phase II: The Toyota HUman Model for Safety (THUMS) v4.01 was positioned in 120 precrash configurations per case within the SVM. Five occupant positioning variables were varied using a Latin hypercube design of experiments: seat track position, seat back angle, D-ring height, steering column angle, and steering column telescoping position. An additional baseline simulation was performed that aimed to match the precrash occupant position documented in CIREN for each case. Phase III: FE simulations were then performed using kinematic boundary conditions from each vehicle's event data recorder (EDR). HIC15, combined thoracic index (CTI), femur forces, and strain-based injury metrics in the lung and lumbar vertebrae were evaluated to predict injury. Tuning the SVM to specific vehicle models resulted in close matches between simulated and test injury metric data, allowing the tuned SVM to be used in each case reconstruction with EDR-derived boundary conditions. Simulations with the most rearward seats and reclined seat backs had the greatest HIC15, head injury risk, CTI, and chest injury risk. Calculated injury risks for the head, chest, and femur closely correlated to the CIREN occupant injury patterns. CTI in the Camry case yielded a 54% probability of Abbreviated Injury Scale (AIS) 2+ chest injury in the baseline case simulation and ranged from 34 to 88% (mean = 61%) risk in the least and most dangerous occupant positions. The greater than 50% probability was consistent with the case occupant's AIS 2 hemomediastinum. Stress-based metrics were used to predict injury to the lower leg of the Camry case occupant. The regional-level injury metrics evaluated for the Cobalt case occupant indicated a low risk of injury; however, strain-based injury metrics better predicted pulmonary contusion. Approximately 49% of the Cobalt occupant's left lung was contused, though the baseline simulation predicted 40.5% of the lung to be injured. A method to compute injury metrics and risks as functions of precrash occupant position was developed and applied to 2 CIREN MVC FE reconstructions. The reconstruction process allows for quantification of the sensitivity and uncertainty of the injury risk predictions based on occupant position to further understand important factors that lead to more severe MVC injuries.

Active control of an innovative seat suspension system with acceleration measurement based friction estimation

NASA Astrophysics Data System (ADS)

Ning, Donghong; Sun, Shuaishuai; Li, Hongyi; Du, Haiping; Li, Weihua

2016-12-01

In this paper, an innovative active seat suspension system for vehicles is presented. This seat suspension prototype is built with two low cost actuators each of which has one rotary motor and one gear reducer. A H∞ controller with friction compensation is designed for the seat suspension control system where the friction is estimated and compensated based on the measurement of seat acceleration. This principal aim of this research was to control the low frequency vibration transferred or amplified by the vehicle (chassis) suspension, and to maintain the passivity of the seat suspension at high frequency (isolation vibration) while taking into consideration the trade-off between the active seat suspension cost and its high frequency performance. Sinusoidal excitations of 1-4.5 Hz were applied to test the active seat suspension both when controlled and when uncontrolled and this is compared with a well-tuned passive heavy duty vehicle seat suspension. The results indicate the effectiveness of the proposed control algorithm within the tested frequencies. Further tests were conducted using the excitations generated from a quarter-car model under bump and random road profiles. The bump road tests indicate the controlled active seat suspension has good transient response performance. The Power Spectral Density (PSD) method and ISO 2631-1 standards were applied to analyse the seat suspension's acceleration under random road conditions. Although some low magnitude and high frequency noise will inevitably be introduced by the active system, the weighted-frequency Root Mean Square (RMS) acceleration shows that this may not have a large effect on ride comfort. In fact, the ride comfort is improved from being an 'a little uncomfortable' to a 'not uncomfortable' level when compared with the well-tuned passive seat suspension. This low cost active seat suspension design and the proposed controller with the easily measured feedback signals are very practical for real applications.

[Use of seat belts and mobile phone while driving in Florence: trend from 2005 to 2009].

PubMed

Lorini, Chiara; Pellegrino, Elettra; Mannocci, Federico; Allodi, Guendalina; Indiani, Laura; Mersi, Anna; Petrioli, Giuseppe; Santini, Maria Grazia; Garofalo, Giorgio; Bonaccorsi, Guglielmo

2012-01-01

to evaluate the trend over time of the use of seat belts by drivers and passengers of cars and vans and the use of hand held mobile phone while driving in Florence from 2005 to 2009. DESIGN, SETTING AND PARTICIPANTS AND MAIN OUTCOME MEASURES: direct observations (58,773 vehicles) have been conducted to detect the use of seat belts by occupants of cars and vans, and the use of mobile phone while driving. It has been carried out correlation analysis between the use of the seat belt by occupants of vehicles and between the simultaneous use of this device and mobile phone while driving.Moreover, it has been carried out time series analysis (ARIMA Box Jenkins) of in the prevalence of the use of seat belts by occupants of vehicles observed, of mobile phone by drivers and the trend of the risk to drive using the mobile phone with unfastened seat belt rather than to drive using the mobile phone with fastened seat belt. seat belts were used on average by 75.7% of drivers, 75.5% of front passengers and 25.1% of rear passengers. The average mobile phone use while driving was 4.5%. Drivers most frequently fasten seat belt if front passengers use it and while they do not use mobile phone. The use of seat belts by drivers and front passengers has not changed over time, whereas the use of mobile phone while driving has significantly increased. The prevalence of using mobile phone with unfastened seat belt rather than to use it with fastened seat belt while driving has significantly decreased over the years, indicating an increase in the use of mobile phone, especially among those who fasten the seat belt. it is necessary to plan and realize stronger interventions in the whole area.

Residence Hall Seating That Works.

ERIC Educational Resources Information Center

Wiens, Janet

2003-01-01

Describes the seating chosen for residence halls at the Massachusetts Institute of Technology and the University of New England. The seating required depends on ergonomics, aesthetics, durability, cost, and code requirements. In addition, residence halls must have a range of seating types to accommodate various uses. (SLD)

Observations of seating position of front seat occupants relative to the side of the vehicle.

PubMed

Dinas, Arthur; Fildes, Brian N

2002-01-01

This study was an on-road observational study of the seating position and limb position of front seat occupants relevant to the side of the car for a representative sample of occupants during straight road driving and turning manoeuvres. A video camera captured over 650 front-on images of passenger car occupants in Metropolitan Melbourne. Results showed a significant numbers of occupants were seated out-of-position while travelling on the road and that a number of these were seated in a manner that may possibly result in injury from the deployment of a side airbag. This was particularly so while turning, a situation common in many side impacts. A substantial number of front seat occupants' arms were exposed to severe injury in the event of a side impact crash. These findings highlight a number of aspects of seating behaviour of driver and front passengers that need to be taken into account when designing side impact airbags.

Coach design for the Korean high-speed train: a systematic approach to passenger seat design and layout.

PubMed

Jung, E S; Han, S H; Jung, M; Choe, J

1998-12-01

Proper ergonomic design of a passenger seat and coach layout for a high-speed train is an essential component that is directly related to passenger comfort. In this research, a systematic approach to the design of passenger seats was described and the coach layout which reflected the tradeoff between transportation capacity and passenger comfort was investigated for the Korean high-speed train. As a result, design recommendations and specifications of the passenger seat and its layout were suggested. The whole design process is composed of four stages. A survey and analysis of design requirement was first conducted, which formed the base for designing the first and second class passenger seats. Prototypes were made and evaluated iteratively, and seat arrangement and coach layout were finally obtained. The systematic approach and recommendations suggested in this study are expected to be applicable to the seat design for public transportations and to help modify and redesign existing vehicular seats.

Proposed test method for and evaluation of wheelchair seating system (WCSS) crashworthiness.

PubMed

van Roosmalen, L; Bertocci, G; Ha, D R; Karg, P; Szobota, S

2000-01-01

Safety of motor vehicle seats is of great importance in providing crash protection to the occupant. An increasing number of wheelchair users use their wheelchairs as motor vehicle seats when traveling. A voluntary standard requires that compliant wheelchairs be dynamically sled impact tested. However, testing to evaluate the crashworthiness of add-on wheelchair seating systems (WCSS) independent of their wheelchair frame is not addressed by this standard. To address this need, this study developed a method to evaluate the crash-worthiness of WCSS with independent frames. Federal Motor Vehicle Safety Standards (FMVSS) 207 test protocols, used to test the strength of motor vehicle seats, were modified and used to test the strength of three WCSS. Forward and rearward loads were applied at the WCSS center of gravity (CGSS), and a moment was applied at the uppermost point of the seat back. Each of the three tested WCSS met the strength requirements of FMVSS 207. Wheelchair seat-back stiffness was also investigated and compared to motor vehicle seat-back stiffness.

Seat belts are more effective than airbags in reducing thoracic aortic injury in frontal motor vehicle crashes.

PubMed

Brasel, Karen J; Quickel, Robert; Yoganandan, Narayan; Weigelt, John A

2002-08-01

Airbags reduce the probability of death in frontal collisions, but the effect is small compared with seat belts. Little is known about the influence of seat belts and airbags on the incidence of thoracic aortic injury (TAI). The National Automotive Sampling System database was queried for the years 1993 to 1998 to determine the impact of seat belts and airbags on the incidence of TAI in survivors of frontal motor vehicle crashes. Proportions were compared using the two-sample Z test. Seat belts prevent TAI regardless of airbag deployment. The effect of airbags is limited to those wearing seat belts. In frontal collisions without seat belt use, airbag deployment does not alter TAI incidence. Seat belts are considerably more effective in preventing TAI than airbags after frontal motor vehicle crashes. Prevention efforts should continue to emphasize the use of active restraints. Restraint use should be considered a risk factor in evaluating patients for potential TAI.

Well-circumscribed deep-seated lipomas of the upper extremity. A report of 13 cases.

PubMed

Elbardouni, A; Kharmaz, M; Salah Berrada, M; Mahfoud, M; Elyaacoubi, M

2011-04-01

The purpose of this study is to determine if giant size is of bad prognosis in deep lipomas of the upper extremity. We report a retrospective study of 13 patients with deep-seated lipomas of the upper extremity treated during the period from April 1997 to April 2008. We evaluated the clinical and radiological characteristics, treatment and evolution profile of these patients. There were 10 women and three men, with an average age of 53 years (range 30-79 years). Seven of these lipomas were in the arm, one in the shoulder, and five in the forearm. Six lipomas were intramuscular, six intermuscular (three of them being attached to bone and labelled parosteal lipoma) and one epivaginal lipoma of the flexor tendon sheath. All patients presented a progressive slow-growing mass that was associated with radial paralysis in one case and carpal tunnel syndrome in one case. Plain radiographs showed a radiolucent soft-tissue image in all cases and an associated osteochondroma in one parosteal lipoma. Computer tomography (CT) or magnetic resonance imaging (MRI) suggested the lipomatous nature and benign characteristics of these deep lipomas that were giant in all cases (mean size: 7 cm). Lipoma marginal excision was performed and histopathological examination demonstrated features consistent with a benign lipoma. There was good function and no clinical recurrence was observed after a mean follow-up of three years. Giant deep-seated lipomas of the upper extremity are uncommon and can be intermuscular or intramuscular. A painless soft-tissue mass is the most frequent chief complaint. MRI with fat suppression suggests the diagnosis and studies the extension of deep lipoma. Marginal excision is the treatment of choice and histopathology eliminates diagnosis of well-differentiated liposarcoma. Appropriate evaluation of deep lipoma is to rule out malignancy by systematically performing MRI and biopsy. In contrast to deep-seated lipomas of the lower extremity or the retroperitoneal space, the prognosis of deep-seated lipomas of the upper extremity is good irrelevant of their size. Recurrence and the degeneration are very rare. Level 4. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Simple force feedback for small virtual environments

NASA Astrophysics Data System (ADS)

Schiefele, Jens; Albert, Oliver; van Lier, Volker; Huschka, Carsten

1998-08-01

In today's civil flight training simulators only the cockpit and all its interaction devices exist as physical mockups. All other elements such as flight behavior, motion, sound, and the visual system are virtual. As an extension to this approach `Virtual Flight Simulation' tries to subsidize the cockpit mockup by a 3D computer generated image. The complete cockpit including the exterior view is displayed on a Head Mounted Display (HMD), a BOOM, or a Cave Animated Virtual Environment. In most applications a dataglove or virtual pointers are used as input devices. A basic problem of such a Virtual Cockpit simulation is missing force feedback. A pilot cannot touch and feel buttons, knobs, dials, etc. he tries to manipulate. As a result, it is very difficult to generate realistic inputs into VC systems. `Seating Bucks' are used in automotive industry to overcome the problem of missing force feedback. Only a seat, steering wheel, pedal, stick shift, and radio panel are physically available. All other geometry is virtual and therefore untouchable but visible in the output device. In extension to this concept a `Seating Buck' for commercial transport aircraft cockpits was developed. Pilot seat, side stick, pedals, thrust-levers, and flaps lever are physically available. All other panels are simulated by simple flat plastic panels. They are located at the same location as their real counterparts only lacking the real input devices. A pilot sees the entire photorealistic cockpit in a HMD as 3D geometry but can only touch the physical parts and plastic panels. In order to determine task performance with the developed Seating Buck, a test series was conducted. Users press buttons, adapt dials, and turn knobs. In a first test, a complete virtual environment was used. The second setting had a plastic panel replacing all input devices. Finally, as cross reference the participants had to repeat the test with a complete physical mockup of the input devices. All panels and physical devices can be easily relocated to simulate a different type of cockpit. Maximal 30 minutes are needed for a complete adaptation. So far, an Airbus A340 and a generic cockpit are supported.

Indirect zirconia-reinforced lithium silicate ceramic CAD/CAM restorations: Preliminary clinical results after 12 months.

PubMed

Zimmermann, Moritz; Koller, Christina; Mehl, Albert; Hickel, Reinhard

2017-01-01

No clinical data are available for the new computer-aided design/computer-assisted manufacture (CAD/CAM) material zirconia-reinforced lithium silicate (ZLS) ceramic. This study describes preliminary clinical results for indirect ZLS CAD/CAM restorations after 12 months. Indirect restorations were fabricated, using the CEREC method and intraoral scanning (CEREC Omnicam, CEREC MCXL). Sixty-seven restorations were seated adhesively (baseline). Sixty restorations were evaluated after 12 months (follow-up), using modified FDI criteria. Two groups were established, according to ZLS restorations' post-processing procedure prior to adhesive seating: group I (three-step polishing, n = 32) and group II (fire glazing, n = 28). Statistical analysis was performed with Mann-Whitney U test and Wilcoxon test (P < .05). The success rate of indirect ZLS CAD/CAM restorations after 12 months was 96.7%. Two restorations clinically failed as a result of bulk fracture (failure rate 3.3%). No statistically significant differences were found for baseline and follow-up criteria (Wilcoxon test, P > .05). Statistically significant differences were found for criteria surface gloss for group I and group II (Mann-Whitney U test, P < .05). This study demonstrates ZLS CAD/CAM restorations have a high clinical success rate after 12 months. A longer clinical evaluation period is necessary to draw further conclusions.

Experimental injury study of children seated behind collapsing front seats in rear impacts.

PubMed

Saczalski, Kenneth J; Sances, Anthony; Kumaresan, Srirangam; Burton, Joseph L; Lewis, Paul R

2003-01-01

In the mid 1990's the U.S. Department of Transportation made recommendations to place children and infants into the rear seating areas of motor vehicles to avoid front seat airbag induced injuries and fatalities. In most rear-impacts, however, the adult occupied front seats will collapse into the rear occupant area and pose another potentially serious injury hazard to the rear-seated children. Since rear-impacts involve a wide range of speeds, impact severity, and various sizes of adults in collapsing front seats, a multi-variable experimental method was employed in conjunction with a multi-level "factorial analysis" technique to study injury potential of rear-seated children. Various sizes of Hybrid III adult surrogates, seated in a "typical" average strength collapsing type of front seat, and a three-year-old Hybrid III child surrogate, seated on a built-in booster seat located directly behind the front adult occupant, were tested at various impact severity levels in a popular "minivan" sled-buck test set up. A total of five test configurations were utilized in this study. Three levels of velocity changes ranging from 22.5 to 42.5 kph were used. The average of peak accelerations on the sled-buck tests ranged from approximately 8.2 G's up to about 11.1 G's, with absolute peak values of just over 14 G's at the higher velocity change. The parameters of the test configuration enabled the experimental data to be combined into a polynomial "injury" function of the two primary independent variables (i.e. front seat adult occupant weight and velocity change) so that the "likelihood" of rear child "injury potential" could be determined over a wide range of the key parameters. The experimentally derived head injury data was used to obtain a preliminary HIC (Head Injury Criteria) polynomial fit at the 900 level for the rear-seated child. Several actual accident cases were compared with the preliminary polynomial fit. This study provides a test efficient, multi-variable, method to compare the injury biomechanical data with actual accident cases.

A New Frontier in a New Domain of Space

NASA Astrophysics Data System (ADS)

Mann, Alfred K.

2004-07-01

A deep-seated belief in the existence of a primordial atomistic structure of matter has not always been present in human thinking. The religions of ancient eastern civilizations---essentially spiritual in nature---did not concern themselves with such a speculation, and Christianity of the Middle Ages---essentially rational and deistic in nature---repudiated it.

Securing a (New) Seat at the Table: Distributed Leadership and School Psychologists

ERIC Educational Resources Information Center

Enz, Ashley; McCullum, Charcelor

2018-01-01

In a time of greater demands on school systems and increased strain on human and material resources, the need for expanded leadership models is becoming increasingly apparent. As a result, educational stakeholders are investing in leadership roles beyond the traditional school administrators, engaging various educators' leadership capacities at…

75 FR 9390 - Availability of Seats for the Cordell Bank National Marine Sanctuary Advisory Council

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-02

...The ONMS is seeking applications for the following vacant seats on the Cordell Bank National Marine Sanctuary Advisory Council: Fishing, Primary and Alternate seats; Maritime Activities, Primary and Alternate seats; Community-at-Large Sonoma County, Primary and Alternate seats. Applicants are chosen based upon their particular expertise and experience in relation to the seat for which they are applying; community and professional affiliations; philosophy regarding the protection and management of marine resources; and possibly the length of residence in the area affected by the sanctuary. Applicants who are chosen as members should expect to serve three-year terms, pursuant to the council's Charter.

76 FR 12069 - Availability of Seats for the Cordell Bank National Marine Sanctuary Advisory Council

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-04

...The ONMS is seeking applications for the following vacant seats on the Cordell Bank National Marine Sanctuary Advisory Council: Fishing, Primary and Alternate seats; Research, Primary and Alternate seats; Community-at-Large Mann County, Primary and Alternate seats. Applicants are chosen based upon their particular expertise and experience in relation to the seat for which they are applying; community and professional affiliations; philosophy regarding the protection and management of marine resources; and possibly the length of residence in the area affected by the sanctuary. Applicants who are chosen as members should expect to serve three-year terms, pursuant to the council's Charter.

Development of crashworthy passenger seats for general-aviation aircraft

NASA Technical Reports Server (NTRS)

Reilly, M. J.; Tanner, A. E.

1979-01-01

Two types of energy absorbing passenger seat concepts suitable for installation in light twin-engine fixed wing aircraft were developed. An existing passenger seat for such an aircraft was used to obtain the envelope constraints. Ceiling suspended and floor supported seat concept designs were developed. A restraint system suitable for both concepts was designed. Energy absorbing hardware for both concepts was fabricated and tension and compression tests were conducted to demonstrate the stroking capability and the force deflection characteristics. Crash impact analysis was made and seat loads developed. The basic seat structures were analyzed to determine the adequacy of their strength under impact loading.

The effect of shaped wheelchair cushion and lumbar supports on under-seat pressure, comfort, and pelvic rotation.

PubMed

Samuelsson, Kersti; Björk, Maarit; Erdugan, Ann-Marie; Hansson, Anna-Karin; Rustner, Birgitta

2009-09-01

A wheelchair seat and position help clients perform daily activities. The comfort of the wheelchair can encourage clients to participate in daily activities and can help prevent future complications. This study evaluates how a shaped seat-cushion and two different back supports affect under-seat pressure, comfort, and pelvic rotation. Thirty healthy subjects were tested using two differently equipped manual wheelchairs. One wheelchair had a Velcro adjustable back seat and a plane seat-cushion. The other wheelchair had a non-adjustable sling-back seat and a plane cushion. The second wheelchair was also equipped with a shaped cushion and/or a detachable lumbar support. Under-seat pressure, estimated comfort, and pelvic rotation were measured after 10 min in each wheelchair outfit. Peak pressure increased with the shaped cushion compared to the plane cushion. No significant difference in estimated comfort was found. Pelvic posterior-rotation was reduced with the adjustable or detachable back-support irrespective of the shape of the seat cushion. To support a neutral pelvic position and spinal curvature, a combination of a shaped cushion and a marked lumbar support is most effective.

Design and testing of an energy-absorbing crewseat for the F/FB-111 aircraft. Volume 2: Data from seat testing

NASA Technical Reports Server (NTRS)

Shane, S. J.

1985-01-01

The unacceptably high injury rate during the escape sequence (including the ejection and ground impact) of the crew module for F/FB-111 aircraft is reviewed. A program to determine if the injury potential could be reduced by replacing the existing crewseats with energy absorbing crewseats is presented. An energy absorbing test seat is designed using much of the existing seat hardware. An extensive dynamic seat test series, designed to duplicate various crew module ground impact conditions is conducted at a sled test facility. Comparative tests with operational F-111 crewseats are also conducted. After successful dynamic testing of the seat, more testing is conducted with the seats mounted in an F-111 crew module. Both swing tests and vertical drop tests are conducted. The vertical drop tests are used to obtain comparative data between the energy absorbing and operational seats. Volume 1 describes the energy absorbing test seat and testing conducted, and evaluates the data from both test series. Volume 2 presents the data obtained during the seat test series, while Volume 3 presents the data from the crew module test series.

Factors associated with rear seating of children in motor vehicles: a study in two low-income, predominantly Hispanic communities.

PubMed

Greenberg-Seth, Jennifer; Hemenway, David; Gallagher, Susan S; Lissy, Karen S; Ross, Julie B

2004-07-01

This study examined child seating patterns in two predominantly low-income, Hispanic communities in Massachusetts. The purpose was to determine the factors associated with child rear seating in the community as a whole and for a subset of Hispanic motorists. Five hundred and five vehicles carrying child passengers and no adult other than the driver were observed in parking lots of fast food restaurants and grocery stores. Four hundred and thirty-two vehicle drivers agreed to be interviewed. A child was defined as a passenger younger than age 12 as determined by appearance and height (head below the vehicle headrest when seated). Variables under study included driver gender, age, ethnicity, and educational attainment; driver shoulder belt use; driver perception of passenger-side airbag presence; and the number and ages of children in the car. Overall, 51% of vehicles were observed with all children seated in the rear. In a bivariate analysis, child rear seating was strongly associated with female drivers ( P = 0.01), younger drivers ( P = 0.02) driver shoulder belt use ( P < 0.00), perceived presence of a passenger-side airbag ( P < 0.00), all children in the vehicle

Geometry of rear seats and child restraints compared to child anthropometry.

PubMed

Bilston, Lynne E; Sagar, Nipun

2007-10-01

The objective of this study was to evaluate the geometry of a wide range of restraints (child restraints, booster seats and rear seats) used by children, and how these match their anthropometry, and to determine limitations to restraint size for the population of children using them. The study is motivated by the widespread premature graduation from one restraint type to another, which parents often attribute to children outgrowing their previous restraint. Currently, recommended transitions are based on a small sample of vehicles and children. Outboard rear seat and seat belt geometry (anchorage locations, sash belt angles) from 50 current model vehicles were measured using a custom-developed measuring jig. For 17 child restraints, a 3-dimensional measuring arm was used to measure the geometry of the restraint including interior size and strap slot locations (where relevant). These measurements were compared to anthropometric measurements, to determine the suitability of a given restraint for children of particular ages. The results for the rear seat geometry indicate that all seat cushions were too deep for a child whose upper leg length is at the 50th percentile until approximately 11.5 years, and half of vehicle seat cushions were too deep for a 15 year old child whose upper leg length is at the 50th percentile. Sash belt geometry was more variable, with approximately a third of vehicles accommodating 6-8 year olds who approximate the shoulder geometry measurements at the 50th percentile. Dedicated child restraints accommodated most children within recommended age groups, with two exceptions. Several high back booster seats were not tall enough for a child whose seated height is at the 50th percentile for 8 year olds (who is still too short for an adult belt according to current guidelines and the results from the rear seat geometry study), and a small number of forward facing restraints and high back boosters were too narrow for children at the upper end of the recommended age ranges. Analysis of the results from this study indicates that alterations in restraint geometry, particularly shortening the seat cushion, allowing for adjustable upper sash belt anchorages in the rear seat of vehicles, and increasing the height of high back booster seats would substantially improve the fit of restraints for child occupants. This data confirms findings from a recent study that looked only at rear seat cushion depths and provides new data on seat belt and child restraint geometry for child occupants.

Trends in child passenger safety practices in Indiana from 2009 to 2015.

PubMed

O'Neil, Joseph; Bull, Marilyn J; Talty, Judith

2018-02-28

This study reviews trends in rear-facing direction, top tether use, booster seat use, and seating position for children 12 years or younger among motor vehicle passengers in Indiana. This is an observational, cross-sectional survey of drivers transporting children 15 years and younger collected at 25 convenience locations randomly selected in Indiana during summers of 2009-2015. Observations were conducted by certified child passenger safety technicians (CPST). As the driver completed a written survey collecting demographic data on the driver, the CPST recorded the child demographic data, vehicle seating location, the type of restraint, direction the car safety seat (CSS) was facing, and use of the CSS harness or safety belt as appropriate. Data were analyzed for infants and toddlers younger than 24 months, children in forward-facing CSS, booster seat use, and seating position for children 12 years or younger. During the study period, 4,876 drivers were queried, and 7,725 children 15 years and younger were observed in motor vehicles. Between 2009 and 2015, 1,115 infants and toddlers (age birth to 23 months) were observed in motor vehicles. For infants <1 year, rear-facing increased from 84% to 91%. During the study years the greatest increase in rear facing was for toddlers age 12-17 months (12-61%). Rear facing for those from 18-23 months did not significantly change. Of the 1,653 vehicles observed with a forward-facing car seat, using either the seat belt system or lower anchors, an average of 27% had the top tether attached. For installations of forward-facing seats using the lower anchor, 66% employed the top tether. Among children age 4-7 years observed booster seat use decreased from 72% to 65% during the observation period. Finally, for vehicle seating position, in our sample, more than 85% of children 12 years or younger were seated in a rear seat vehicle position. Unfortunately, 31% of 8- to 12-year-old children were observed in the front seat. Overall, these trends demonstrate an improvement in child passenger safety practices among Indiana drivers. However, this study illuminates areas to improve child passenger safety, such as rear facing for toddlers 18 to 23 months, increasing top tether use, booster seat use, and an emphasis on rear seat position for children 8 to 12 years. This information can be used by primary care providers and child passenger safety technicians and other child passenger safety advocates to develop counseling points and targeted educational campaigns.

Shock Mitigating Seat Single Impact Program

DTIC Science & Technology

2014-04-24

new seats from Shockwave, SHOXS and Zodiac , were tested during the third and fourth phases of the final test program and these were conducted between...test program to the four single jockey style seats from Shockwave, SHOXS, Ullman and Zodiac because of budget and time constraints. The program...along with the Zodiac jockey pod seat that replaced the Ullman seat. 2711 (NETE CS) ZT4110-R 23 April 2014 QF035 32/39 Rev. 05/2011.11.14 69. The

Simulation of Adaptive Seat Energy Absorber for Military Rotorcraft Crash Safety Enhancement

DTIC Science & Technology

2014-04-01

design guidelines and detailed requirements were developed for military crew seats as defined in MIL-S-85510(AS) (12) and for civil rotorcraft seats in...rotorcraft vertical crash pulse as stipulated in military design standards was used to evaluate the performance of MREA seat energy absorber with a...Desjardins, S. P.; Zimmerman, R. E.; Bolukbasi, A. O.; Merritt, N. A. Aircraft Crash Survival Design Guide Vol. IV – Aircraft Seats , Restraints, Litters

Evaluation of Safe Kids Week 2004: Age 4 to 9? It's Booster Seat Time!

PubMed Central

Howard, A; Beben, N; Rothman, L; Fiissel, D; MacArthur, C

2006-01-01

Objective To assess the effectiveness of a national one week media campaign promoting booster seat use. Design Pre‐test, post‐test design based on nationally representative random digit dialing telephone survey, with control for exposure to campaign. Setting Canada. Subjects Parents of children aged 4–9 years. Interventions During a one week campaign in May 2004, information on booster seat use was distributed via a national media campaign, retail stores, medical clinics, and community events. Information included pamphlets with guidelines for booster seat use, as well as a growth chart (designed by Safe Kids Canada) to assist parents in determining if their child should be using a booster seat. Assessing seat belt fit was described in detail on the growth chart. Main outcome measures Knowledge, attitudes, and self‐reported behaviors regarding booster seat use. Results Respondents in the group exposed to the campaign were twice as likely to report using a booster seat with lap and shoulder belt for their child (47%), compared to those in the pre‐test (24%) and the unexposed (23%) groups (p<0.001). However, only small differences in general knowledge regarding booster seat use were found between the groups. Conclusions A one week national media campaign substantially increased self‐reported use of booster seats. Parents did not remember details of the campaign content, but did remember implications for their own child. PMID:17018673

Thirty years of anthropometric changes relevant to the width and depth of transportation seating spaces, present and future.

PubMed

Molenbroek, J F M; Albin, T J; Vink, P

2017-11-01

This paper reports the results of an investigation into changes in body shape anthropometry over the past several decades and discusses the impact of those changes on seating in transport, especially airliners. Changes in some body shape dimensions were confirmed in a sample of students at TU Delft; several of the changes, e.g. hip breadth, seated, are relevant to the ongoing design of seating. No change in buttock knee length was observed. The fit between current user anthropometry and current airline seat design, especially regarding seat width, was investigated. A comparison of the average current seat breadth with global anthropometric data suggests that accommodation may be problematic, with less than optimal width for passengers' shoulder and elbow widths. Copyright © 2017 Elsevier Ltd. All rights reserved.

All metal valve structure for gas systems

DOEpatents

Baker, Ray W.; Pawlak, Donald A.; Ramey, Alford J.

1984-11-13

A valve assembly with a resilient metal seat member is disclosed for providing a gas-tight seal in a gas handling system. The valve assembly also includes a valve element for sealing against the valve seat member; and an actuating means for operating the valve element. The valve seat member is a one-piece stainless steel ring having a central valve port and peripheral mounting flange, and an annular corrugation in between. A groove between the first and second ridges serves as a flexure zone during operation of the valve member and thus provides the seating pressure between the inner ridge or valve seat and the valve element. The outer annular ridge has a diameter less than said valve element to limit the seating motion of the valve element, preventing non-elastic deformation of the seat member.

Design and testing of an energy-absorbing crewseat for the F/FB-111 aircraft, volume 1

NASA Technical Reports Server (NTRS)

Shane, S. J.

1985-01-01

A program to determine if the injury potential could be reduced by replacing the existing crewseats with energy absorbing crewseats is explored. An energy-absorbing test seat was designed using much of the existing seat hardware. An extensive dynamic seat test series, designed to duplicate various crew module ground impact conditions, was conducted at a sled test facility. Comparative tests with operational F-111 crewseats were also conducted. After successful dynamic testing of the seat, more testing was conducted with the seats mounted in an F-111 crew module. Both swing tests and vertical drop tests were conducted. The vertical drop tests were used to obtain comparative data between the energy-absorbing and operational seats. Volume 1 describes the energy absorbing test seat and testing conducted, and evaluates the data from both test series.

All-metal valve structure for gas systems

DOEpatents

Baker, R.W.; Pawlak, D.A.; Ramey, A.J.

1982-06-10

A valve assembly with a resilient metal seat member is disclosed for providing a gas-tight seal in a gas handling system. The valve assembly also includes a valve element for sealing against the valve seat member; and an actuating means for operating the valve element. The valve seat member is a one-piece stainless steel ring having a central valve port and peripheral mounting flange, and an annular corrugation in between. A groove between the first and second ridges serves as a flexure zone during operation of the valve member and thus provides the seating pressure between the inner ridge or valve seat and the valve element. The outer annular ridge has a diameter less than said valve element to limit the seating motion of the valve element, preventing non-elastic deformation of the seat member.

A kinematic and kinetic analysis of the sit-to-stand transfer using an ejector chair: implications for elderly rheumatoid arthritic patients.

PubMed

Munro, B J; Steele, J R; Bashford, G M; Ryan, M; Britten, N

1998-03-01

Twelve elderly female rheumatoid arthritis patients (mean age = 65.5 +/- 8.6 yr) were assessed rising from an instrumented Eser Ejector chair under four conditions: high seat (540 mm), low seat (450 mm), with and without the ejector mechanism operating. Sagittal plane motion, ground reaction forces, and vertical chair arm rest forces were recorded during each trial with the signals synchronised at initial subject head movement. When rising from a high seat, subjects displayed significantly (p < 0.05) greater time to seat off; greater trunk, knee and ankle angles at seat off; increased ankle angular displacement; decreased knee angular displacement; and decreased total net and normalised arm rest forces compared to rising from a low seat. When rising using the ejector mechanism, time to seat off and trunk and knee angle at seat off significantly increased, whereas trunk and knee angular displacement, and total net and normalised arm rest forces significantly decreased compared to rising unassisted. Regardless of seat height or ejector mechanism use, there were no significant differences in the peak, or time to peak horizontal velocity of the subjects' total body centre of mass, or net knee and ankle moments. It was concluded that increased seat height and use of the ejector mechanism facilitated sit-to-stand transfers performed by elderly female rheumatoid arthritic patients. However, using the ejector chair may be preferred by these patients compared to merely raising seat height because it does not necessitate the use of a footstool, a possible obstacle contributing to falls.

Seating type and cognitive performance after 3 hours travel by high-speed boat in sea states 2-3.

PubMed

McMorris, Terry; Myers, Stephen; Dobbins, Trevor; Hall, Ben; Dyson, Rosemary

2009-01-01

Transit in high-speed marine craft subjects occupants to a rough ride as the boat impacts the waves. This induces high levels of physical stress, which may inhibit cognitive performance during military operations and life-saving activities. Land-based research suggests that suspension seats reduce vibration and, therefore, stress. We hypothesized that subjects using suspension seats would demonstrate better cognitive performance, lower perceptions of exertion, fatigue, and sleepiness, and lower salivary concentrations of cortisol than those using fixed seats. Subjects, naval personnel, were divided into fixed (N = 6) and suspension seat (N = 6) groups. Subjects undertook forward and backward number recall and random number generation tests pre- and post-transit (3 h in sea states 2-3). Salivary cortisol concentrations were sampled pre- (1100 h) and post-transit (1700 h) and at the same times on a control day. Post-transit perceptions of exertion, fatigue, and sleepiness were measured subjectively. The suspension seat group demonstrated better performance post-transit than the fixed seat group for forward number recall and showed a significant pre- to post-transit improvement in backward number recall. The suspension seat group reported less fatigue and sleepiness. The suspension seat group had significantly higher salivary cortisol concentrations than the fixed seat group post-transit. Regression analyses found a quadratic correlation between delta cortisol concentrations and delta random number generation scores (R2 = 0.68). Results show that the use of suspension seats during transit in high-speed marine craft may be advantageous with regard to cognitive performance.

Injury Risk for Rear-Seated Occupants in Small Overlap Crashes

PubMed Central

Arbogast, Kristy B.; Locey, Caitlin M.; Hammond, Rachel; Belwadi, Aditya

2013-01-01

Small overlap crashes, where the primary crash engagement is outboard from the longitudinal energy absorbing structures of the vehicle, have received recent interest as a crash dynamic that results in high likelihood of injury. Previous analyses of good performing vehicles showed that 24% of crashes with AIS 3+ injuries to front seat occupants were small overlap crashes. However, similar evaluations have not been conducted for those rear seated. Vehicle dynamics suggest that rear seat occupants may be at greater risk due to lack of lateral seating support and a steering wheel to hold, making them more sensitive to lateral movement seen in these crashes. Thus, the objective was to calculate injury risk for rear-seated occupants in small overlap collisions. AIS 2+ and AIS 3+ injury risk was calculated from NASS-CDS data from 2000–2011. Inclusion criteria were vehicles of model year 2000 or later, with CDC codes of “FL” or “FR”, and an occupant in the second or third row. AIS2+ injury risk was 5.1%, and AIS3+ injury risk was 2.4%. Of note, half of the occupants were <15 years of age indicating rear seat protection should emphasize the young. Occupants seated near side were nearly three times as likely to sustain an AIS2+ injury than occupants seated far side. Particular attention should be paid to the prominence of head injuries in this crash dynamic and consideration given to their mitigation. Additional research should determine whether countermeasures being implemented for front seat occupants can be beneficial to rear seat occupants. PMID:24406964

IIHS head restraint ratings and insurance injury claim rates.

PubMed

Trempel, Rebecca E; Zuby, David S; Edwards, Marcy A

2016-08-17

The Insurance Institute for Highway Safety (IIHS) rates front seat/head restraint designs using a combination of static and dynamic measurements following RCAR-IIWPG procedures. The purpose of this study was to determine whether vehicles with better IIHS-rated seats/head restraints had lower injury risk in rear-end collisions and how the effect of better rated seats interacted with driver gender and age. The presence of an associated insurance injury claim was determined for rear-impact crashes using 2001-2014 model year cars and SUVs. Logistic regression was used to compare injury risk for vehicles with good, acceptable, and marginal IIHS-rated seats/head restraints with poor-rated seats/head restraints. Analyses were run by gender and driver age and also by the rate of more severe injury claims. Injury rates were 11.2% lower for vehicles with seats/head restraints rated good compared to vehicles with seats/head restraints rated poor. The percentage reduction for good- versus poor-rated seats was greater for females (12.7%) than males (8.9%). Comparing good- with poor-rated seats, driver ages 15-24 had the largest reduction at 19.8%, followed by 10.7% for driver ages 45-64 and 10.4% for driver ages 25-44. Seats/head restraints with better IIHS ratings are associated with lower injury rates in rear-impact collisions than seats rated poor. The reductions in injury rates were strongest for females and for young-to-middle-age drivers. The strong reductions in injury rates for these groups are encouraging given their high initial injury rates.

Reduced Protection for Belted Occupants in Rear Seats Relative to Front Seats of New Model Year Vehicles

PubMed Central

Sahraei, Elham; Digges, Kennerly; Marzougui, Dhafer

2010-01-01

Effectiveness of the rear seat in protecting occupants of different age groups in frontal crashes for 2000–2009 model years (MY) of vehicles was estimated and compared to 1990–1999 model years of vehicles. The objective was to determine the effectiveness of the rear seat compared to the front seat for various age groups in newer model year vehicles. The double paired comparison method was used to estimate relative effectiveness. For belted adults of the 25–49 age group, the fatality reduction effectiveness of the rear seat compared to the right front seat was 25 % (CI 11% to 36%), in the 1990–1999 model year vehicles. The relative effectiveness was −31% (CI −63% to −5%) for the same population, in the 2000–2009 model year vehicles. For restrained children 0–8 years old, the relative effectiveness was 55% (CI 48% to 61%) when the vehicles were of the 1990–1999 period. The level of effectiveness for this age group was reduced to 25% (CI −4% to 46%) in the 2000–2009 MYs of vehicles. Results for other age groups of belted occupants have followed a similar trend. All belted adult occupants of 25+ years old were significantly less protected in rear seats as compared to right front seats in the 2000–2009 model years of vehicles. For unbelted occupants however, rear seats were still a safer position than front seats, even in the 2000–2009 model years of vehicles. PMID:21050599

Pilot tests of a seat belt gearshift delay on the belt use of commercial fleet drivers.

DOT National Transportation Integrated Search

2009-12-01

the seat belt was buckled. Participants, commercial drivers from the United States and Canada who did not consistently wear their seat belts, could avoid the delay by fastening their seat belts. Unbelted participants experienced a delay of either a c...

Video monitoring system for car seat

NASA Technical Reports Server (NTRS)

Elrod, Susan Vinz (Inventor); Dabney, Richard W. (Inventor)

2004-01-01

A video monitoring system for use with a child car seat has video camera(s) mounted in the car seat. The video images are wirelessly transmitted to a remote receiver/display encased in a portable housing that can be removably mounted in the vehicle in which the car seat is installed.

7 CFR 1206.30 - Establishment and membership.

Code of Federal Regulations, 2011 CFR

2011-01-01

... INFORMATION Mango Promotion, Research, and Information Order Definitions National Mango Promotion Board § 1206... on the volume of mangos imported into the Customs Districts identified by their name and Code Number... seats for District I, three seats for District II, two seats for District III, and one seat for District...

75 FR 36062 - Availability of Conservation Seat and Diving Operations Seat for the Flower Garden Banks National...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-24

... Conservation Seat and Diving Operations Seat for the Flower Garden Banks National Marine Sanctuary Advisory... Flower Garden Banks National Marine Sanctuary Advisory Council: Conservation and Diving Operations... Jennifer Morgan, NOAA--Flower Garden Banks National Marine Sanctuary, 4700 Avenue U, Bldg. 216, Galveston...

49 CFR 571.210 - Standard No. 210; Seat belt assembly anchorages.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 6 2013-10-01 2013-10-01 false Standard No. 210; Seat belt assembly anchorages... STANDARDS Federal Motor Vehicle Safety Standards § 571.210 Standard No. 210; Seat belt assembly anchorages. S1. Purpose and scope. This standard establishes requirements for seat belt assembly anchorages to...

49 CFR 571.210 - Standard No. 210; Seat belt assembly anchorages.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 6 2011-10-01 2011-10-01 false Standard No. 210; Seat belt assembly anchorages... STANDARDS Federal Motor Vehicle Safety Standards § 571.210 Standard No. 210; Seat belt assembly anchorages. S1. Purpose and scope. This standard establishes requirements for seat belt assembly anchorages to...

49 CFR 571.210 - Standard No. 210; Seat belt assembly anchorages.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 6 2014-10-01 2014-10-01 false Standard No. 210; Seat belt assembly anchorages... STANDARDS Federal Motor Vehicle Safety Standards § 571.210 Standard No. 210; Seat belt assembly anchorages. S1. Purpose and scope. This standard establishes requirements for seat belt assembly anchorages to...

49 CFR 571.210 - Standard No. 210; Seat belt assembly anchorages.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 6 2012-10-01 2012-10-01 false Standard No. 210; Seat belt assembly anchorages... STANDARDS Federal Motor Vehicle Safety Standards § 571.210 Standard No. 210; Seat belt assembly anchorages. S1. Purpose and scope. This standard establishes requirements for seat belt assembly anchorages to...

Poppet valve tester

NASA Technical Reports Server (NTRS)

Tellier, G. F.

1973-01-01

Tester investigates fundamental factors affecting cyclic life and sealing performance of valve seats and poppets. Tester provides for varying impact loading of poppet against seat and rate of cycling, and controls amount and type of relative motion between sealing faces of seat and poppet. Relative motion between seat and poppet can be varied in three modes.

49 CFR 571.201 - Standard No. 201; Occupant protection in interior impact.

Code of Federal Regulations, 2011 CFR

2011-10-01

... seat. Ambulance means a motor vehicle designed exclusively for the purpose of emergency medical care... designated seating position, with adjustable forward seats in their rearmost design driving position and reclinable forward seat backs in their nominal design driving position; (b) Direction of impact shall be...

49 CFR 571.201 - Standard No. 201; Occupant protection in interior impact.

Code of Federal Regulations, 2010 CFR

2010-10-01

... seat. Ambulance means a motor vehicle designed exclusively for the purpose of emergency medical care... designated seating position, with adjustable forward seats in their rearmost design driving position and reclinable forward seat backs in their nominal design driving position; (b) Direction of impact shall be...

IRTAD Special Report : the availability of seat belt wearing data in OECD member countries, 1995

DOT National Transportation Integrated Search

1997-03-01

This reports surveys the availability of seat belt wearing data in OECD Member countries. The injury-reducing effect of seat belts is estimated to be around 50 per cent for fatal and serious injuries. Seat belts are most effective in frontal and roll...

Classroom Seating Considerations for 21st Century Students and Faculty

ERIC Educational Resources Information Center

Harvey, Eugene J.; Kenyon, Melaine C.

2013-01-01

This quantitative, cross-sectional research study explored students' perceptions of five different seating styles within typical classrooms in an urban public higher education institution. The five seating styles included: modern mobile chairs, tablet arm chairs, fixed tiered seating with tablet arms, rectangle tables with standard chairs, and…

Proper seat placement of children aged 12 or younger within vehicles : a rural/urban comparison.

DOT National Transportation Integrated Search

2010-09-01

Seating children in the rear of vehicles has been shown to decrease the odds of being fatally injured in a motor vehicle crash by 36% to 40%. Although rear seating is safer, rates of children being front-seated remain high, especially for older child...

Medical students' responses to the dissection of the heart and brain: A dialogue on the seat of the soul.

PubMed

Martyn, Helen; Barrett, Anthony; Trotman, Paul; Nicholson, Helen

2012-04-01

The search for the soul has been documented since the fifth Century BCE when philosophers and physicians began to explore the role of human consciousness and emotion. Traditionally in western civilization, there have been two distinct followings with some believing that the brain was the seat of the soul and others believing that this role belonged to the heart. The aim of this study was to assess the attitudes of medical students towards the heart and brain during their anatomy laboratory dissections to evaluate if any extra meaning is given to these organs and where they perceived the origin of the soul. Medical students (n = 16) at the University of Otago were interviewed in regards to their thoughts about body dissection and particularly their views towards the brain and the heart. Semi-structured interviews were conducted following the dissection of these two organs, and then transcribed and analyzed. There were mixed opinions among students with some experiencing difficulty dissecting the brain because this organ had special meaning to them; they perceived it as the organ that "made a person who they were." Others commented on their emotional reactions when removing the heart, which they viewed as the "seat of emotion." Some students experienced emotional and physical reactions to these two dissections and Anatomy faculty need to be aware that students may struggle because they viewed these organs as special. A dialogue emerged amongst some medical students on the seat of the soul which gave extra meaning to the dissection. Copyright © 2011 Wiley Periodicals, Inc.

[Medical aspect of cosmonauts' safety during emergency landing. Respicere et prospicere].

PubMed

Barer, A S

2008-01-01

Participating in the comprehensive development of the system for safe emergency landing in space vehicles Voskhod and Soyuz, enterprise "Zvezda" undertook an extensive program of technical and physiological experiments with volunteers, including a group of physicians, in the interest of designing personal protection means for space crew. Over 130 physiological pile-engine experiments with the impact velocity of up to 9 m/s were performed between 1963 and 1967. The article presents medical and biomechanical analysis of the experimental data. The central part of the crew safety system in the event of emergency landing is a shock-absorbing seat with an individually molded support surface. This support surface ensures a uniform load distribution and also attenuates shock hardness by dint of own deformation. The Voskhod seat was outfitted with a pendulum hanger bracket on two shock-absorbers. The Soyuz seat has only one shock-absorber at the head end. The shock-absorber allows seat turns at high angular velocities and, consequently, appearance of additional mechanic and biomechanical reactions. The article attempts to analyze this phenomenon as well as the whole aggregate of human body responses onto the spacecraft impact with ground. To give readers the opportunity of independent conclusions from the data of the unlikely to be replicated experiments, the article is supplemented with graphs visualizing a larger part of the tests data, and their interpretations. It is aimed to help young specialists fill up the gap in knowledge about this medical aspect which remains of high topicality in many fields including safety of future piloted space programs.

Does Using a Chair Backrest or Reducing Seated Hip Flexion Influence Trunk Muscle Activity and Discomfort? A Systematic Review.

PubMed

Curran, Máire; O'Sullivan, Leonard; O'Sullivan, Peter; Dankaerts, Wim; O'Sullivan, Kieran

2015-11-01

This paper systematically reviews the effect of chair backrests and reducing seated hip flexion on low back discomfort (LBD) and trunk muscle activation. Prolonged sitting commonly exacerbates low back pain (LBP). Several modifications to seated posture and chair design have been recommended, including using chairs with backrests and chairs that reduce hip flexion. Electronic databases were searched by two independent assessors. Part 1 of this review includes 26 studies comparing the effect of sitting with at least two different hip angles. In Part 2, seven studies that compared the effect of sitting with and without a backrest were eligible. Study quality was assessed using the PEDro scale. Significant confounding variables and a relatively small number of randomized controlled trials (RCTs) involving people with LBP complicates analysis of the results. There was moderate evidence that chair backrests reduce paraspinal muscle activation, and limited evidence that chair backrests reduce LBD. There was no evidence that chairs involving less hip flexion reduce LBP or LBD, or consistently alter trunk muscle activation. However, participants in several studies subjectively preferred the modified chairs involving less hip flexion. The limited evidence to support the use of chairs involving less seated hip flexion, or the effect of a backrest, is consistent with the limited evidence that other isolated chair design features can reduce LBP. LBP management is likely to require consideration of several factors in addition to sitting position. Larger RCTs involving people with LBP are required. © 2015, Human Factors and Ergonomics Society.

De Sedibus et Causis Morborum: is Essential Tremor a Primary Disease of the Cerebellum?

PubMed

Louis, Elan D

2016-06-01

Morgagni's 1761 publication of De sedibus et causis morborum (i.e., of the Seats and Causes of Diseases) represented a paradigmatic moment in the history of medicine. The book ushered in a new way of conceptualizing human disease, shattering old dogma, and linking constellations of symptoms and signs (i.e., clinical disease) with anatomic pathology in specific organs (i.e., organ disease). This was the anatomical-clinical method, and it attempted to unveil "the seat" of each disease in a specific organ. Essential tremor (ET) is among the most common neurological diseases. There is little debate that the origin of ET lies in the brain, but if one tries to delve more deeply than this, things become murky. The dogma for the past 40 years has been that the seat of ET is the inferior olivary nucleus. Closer scrutiny of this model, however, has revealed its many flaws, and the model, based on little if any empiric evidence, has increasingly lost favor. Arising from a wealth of research in recent years is a growing body of knowledge that links ET to a disarrangement of the cerebellum. Data from a variety of sources reviewed in this issue (clinical, neuroimaging, neurochemical, animal model, physiological, and pathological) link ET to the cerebellum. That the cerebellum is involved in an abnormal brain loop that is responsible for ET is not debated. The tantalizing question is whether an abnormality in the cerebellum is the prime mover, and whether the cerebellum is the seat of this particular disease.

Polymer Optical Fiber Sensor and the Prediction of Sensor Response Utilizing Artificial Neural Networks

NASA Astrophysics Data System (ADS)

Haroglu, Derya

The global market researches showed that there is a growing trend in the field of polymer optical fiber (POF) and POF sensors. Telecommunications, medicine, defense, aerospace, and automotive are the application areas of fiber optic sensors, where the automotive industry is the most promising application area for innovations in the field of POF sensors. The POF sensors in automobiles are particularly for detection of seat occupancy, and intelligent pedestrian protection systems. This dissertation investigates graded index perfluorinated polymer optical fiber as an intensity modulated intrinsic sensor for application in automotive seat occupancy sensing. Since a fiber optic sensor has a high bandwidth, is small in size, is lightweight, and is immune to electromagnetic interference (EMI) it offers higher performance than that of its electrical based counterparts such as strain gauge, elastomeric bladder, and resistive sensor systems. This makes the fiber optic sensor a potential suitable material for seat occupancy sensing. A textile-based fiber optic sensor was designed to be located in the area beneath the typical seated human's thighs. The pressure interval under which the proposed POF sensor design could perform well was found to be between 0.18 and 0.21 N/cm2, where perfluorinated (PF) graded index (GI) POF (62.5/750 mum) was used as the POF material. In addition, the effect of the automotive seat covering including face material (fabric) and foam backing to the sensor's performance was analyzed. The face fabric structure and the thickness of foam backing were not found to be significant factors to change the sensor results. A research study, survey, was conducted of which purpose was to better understand market demands in terms of sensor performance characteristics for automotive seat weight sensors, as a part of the Quality Function Deployment (QFD) House of Quality analysis. The companies joined the survey agreed on the first 5 most important sensor characteristics: reproducibility, accuracy, selectivity, aging, and resolution. Artificial neural network (ANN), a mathematical model formed by mimicking the human nervous system, was used to predict the sensor response. Qwiknet (version 2.23) software was used to develop ANNs and according to the results of Qwiknet the prediction performances for training and testing data sets were 75%, and 83.33% respectively. In this dissertation, Chapter 1 describes the worldwide plastic optical fiber (POF) and fiber optic sensor markets, and the existing textile structures used in fiber optic sensing design particularly for the applications of biomedical and structural health monitoring (SHM). Chapter 2 provides a literature review in detail on polymer optical fibers, fiber optic sensors, and occupancy sensing in the passenger seats of automobiles. Chapter 3 includes the research objectives. Chapter 4 presents the response of POF to tensile loading, bending, and cyclic tensile loading with discussion parts. Chapter 5 includes an e-mail based survey to prioritize customer needs in a Quality Function Deployment (QFD) format utilizing Analytic Hierarchy Process (AHP) and survey results. Chapter 6 describes the POF sensor design and the behavior of it under pressure. Chapter 7 provides a data analysis based on the experimental results of Chapter 6. Chapter 8 presents the summary of this study and recommendations for future work.

Mathematical Models for the Apparent Mass of the Seated Human Body Exposed to Vertical Vibration

NASA Astrophysics Data System (ADS)

Wei, L.; Griffin, M. J.

1998-05-01

Alternative mathematical models of the vertical apparent mass of the seated human body are developed. The optimum parameters of four models (two single-degree-of-freedom models and two two-degree-of-freedom models) are derived from the mean measured apparent masses of 60 subjects (24 men, 24 women, 12 children) previously reported. The best fits were obtained by fitting the phase data with single-degree-of-freedom and two-degree-of-freedom models having rigid support structures. For these two models, curve fitting was performed on each of the 60 subjects (so as to obtain optimum model parameters for each subject), for the averages of each of the three groups of subjects, and for the entire group of subjects. The values obtained are tabulated. Use of a two-degree-of-freedom model provided a better fit to the phase of the apparent mass at frequencies greater than about 8 Hz and an improved fit to the modulus of the apparent mass at frequencies around 5 Hz. It is concluded that the two-degree-of-freedom model provides an apparent mass similar to that of the human body, but this does not imply that the body moves in the same manner as the masses in this optimized two-degree-of-freedom model.

Seat belt use in cars with air bags.

PubMed Central

Williams, A F; Wells, J K; Lund, A K

1990-01-01

Seat belt use was observed in 1,628 cars with air bags and manual belts and 34,223 cars with manual seat belts only. Sixty-six percent of drivers in cars with air bags wore seat belts compared to 63 percent of drivers in cars with manual belts only. The study found no evidence for the speculation that drivers with air bags will reduce their seat belt use because they believe an air bag alone provides sufficient protection. PMID:2240346

Cushion System for Multi-Use Child Safety Seat

NASA Technical Reports Server (NTRS)

Dabney, Richard W. (Inventor); Elrod, Susan V. (Inventor)

2007-01-01

A cushion system for use with a child safety seat has a plurality of bladders assembled to form a seat cushion that cooperates with the seat's safety harness. One or more sensors coupled to the safety harness sense tension therein and generate a signal indicative of the tension. Each of the bladders is individually pressurized by a pressurization system to define a support configuration of the seat cushion. The pressurization system is disabled when tension in the safety harness has attained a threshold level.

Cushion system for multi-use child safety seat

NASA Technical Reports Server (NTRS)

Elrod, Susan V. (Inventor); Dabney, Richard W. (Inventor)

2007-01-01

A cushion system for use with a child safety seat has a plurality of bladders assembled to form a seat cushion that cooperates with the seat's safety harness. One or more sensors coupled to the safety harness sense tension therein and generate a signal indicative of the tension. Each of the bladders is individually pressurized by a pressurization system to define a support configuration of the seat cushion. The pressurization system is disabled when tension in the safety harness has attained a threshold level.

Planning of electroporation-based treatments using Web-based treatment-planning software.

PubMed

Pavliha, Denis; Kos, Bor; Marčan, Marija; Zupanič, Anže; Serša, Gregor; Miklavčič, Damijan

2013-11-01

Electroporation-based treatment combining high-voltage electric pulses and poorly permanent cytotoxic drugs, i.e., electrochemotherapy (ECT), is currently used for treating superficial tumor nodules by following standard operating procedures. Besides ECT, another electroporation-based treatment, nonthermal irreversible electroporation (N-TIRE), is also efficient at ablating deep-seated tumors. To perform ECT or N-TIRE of deep-seated tumors, following standard operating procedures is not sufficient and patient-specific treatment planning is required for successful treatment. Treatment planning is required because of the use of individual long-needle electrodes and the diverse shape, size and location of deep-seated tumors. Many institutions that already perform ECT of superficial metastases could benefit from treatment-planning software that would enable the preparation of patient-specific treatment plans. To this end, we have developed a Web-based treatment-planning software for planning electroporation-based treatments that does not require prior engineering knowledge from the user (e.g., the clinician). The software includes algorithms for automatic tissue segmentation and, after segmentation, generation of a 3D model of the tissue. The procedure allows the user to define how the electrodes will be inserted. Finally, electric field distribution is computed, the position of electrodes and the voltage to be applied are optimized using the 3D model and a downloadable treatment plan is made available to the user.

Neck posture and muscle activity are different when upside down: a human volunteer study.

PubMed

Newell, Robyn S; Blouin, Jean-Sébastien; Street, John; Cripton, Peter A; Siegmund, Gunter P

2013-11-15

Rollover crashes are dynamic and complex events in which head impacts with the roof can cause catastrophic neck injuries. Ex vivo and computational models are valuable in understanding, and ultimately preventing, these injuries. Although neck posture and muscle activity influence the resulting injury, there is currently no in vivo data describing these parameters immediately prior to a head-first impact. The specific objectives of this study were to determine the in vivo neck vertebral alignment and muscle activation levels when upside down, a condition that occurs during a rollover. Eleven human subjects (6F, 5M) were tested while seated upright and inverted in a custom-built apparatus. Vertebral alignment was measured using fluoroscopy and muscle activity was recorded using surface and indwelling electrodes in eight superficial and deep neck muscles. In vivo vertebral alignment and muscle activation levels differed between the upright and inverted conditions. When inverted and relaxed, the neck was more lordotic, C1 was aligned posterior to C7, the Frankfort plane was extended, and the activity of six muscles increased compared to upright and relaxed. When inverted subjects were asked to look forward to eliminate head extension, flexor muscle activity increased, C7 was more flexed, and C1 was aligned anterior to C7 versus upright and relaxed. Combined with the large inter-subject variability observed, these findings indicate that cadaveric or computational models designed to study injuries and prevention devices while inverted need to consider a variety of postures and muscle conditions to be relevant to the in vivo situation. © 2013 Elsevier Ltd. All rights reserved.

Dynamic Model of Aircraft Passenger Seats for Vibration Comfort Evaluation and Control

NASA Astrophysics Data System (ADS)

Šika, Z.; Valášek, Michael; Vampola, T.; Füllekrug, U.; Klimmek, T.

The paper deals with the development of the seat dynamical model for vibration comfort evaluation and control. The aircraft seats have been tested extensively by vibrations on the 6 DOF vibrating platform. The importance of the careful comfort control together with the flight mechanics control is namely stressed for the blended wing body (BWB) aircrafts. They have a very large fuselage, where the mechanical properties (accelerations, angular accelerations) vary considerably for different seat places. The model have been improved by adding of dynamical models of the aircraft passenger seats identified by the measurements on the 6 DOF vibrating platform. The experiments, their results and the identification of the dynamical seat model are described. The model is further modified by adding of the comfort evaluation norms represented by dynamical filters. The structure and identification of the seat model is briefly described and discussed.

Seat and seatbelt accommodation in fire apparatus: Anthropometric aspects

PubMed Central

Hsiao, Hongwei; Whitestone, Jennifer; Wilbur, Michael; Lackore, J. Roger; Routley, J. Gordon

2015-01-01

This study developed anthropometric information on U.S. firefighters to guide fire-apparatus seat and seatbelt designs and future standards development. A stratified sample of 863 male and 88 female firefighters across the U.S. participated in the study. The study results suggested 498 mm in width, 404 mm in depth, and 365–476 mm in height for seat pans; 429–522 mm in width and 542 mm in height for seat back; 871 mm in height for head support; a seat space of 733 mm at shoulder and 678 mm at hip; and a knee/leg clearance of 909 mm in fire truck cab. Also, 1520 mm of lap belt web effective length and 2828 mm of lap-and-shoulder belt web effective length were suggested. These data for firetruck seats and seatbelts provide a foundation for fire apparatus manufacturers and standards committees to improve firefighter seat designs and seatbelt usage compliance. PMID:26154212

Effect of Increased Rear Row Occupancy on Injury to Seat Belt Restrained Children in Side Impact Crashes

PubMed Central

Maltese, Matthew R.; Chen, Irene G.; Arbogast, Kristy B.

2005-01-01

Previous work identified a similar risk of injury for children seated on the struck side and center rear in side impact crashes in passenger cars. In order to further explain this finding, we investigated the effect of sharing the rear row with other occupants on injury risk and delineated differences in injury patterns among the seat positions. These analyses, conducted from a large child specific crash surveillance system, included: children 4–15 years old, rear seated, seat belt restrained, in a passenger car, and in a side impact crash. Injury risk was compared among each rear seat position stratified by the presence of other occupants on the rear row. Occupants are at an increased risk of injury if they sit alone on their row as compared to sitting with other occupants. Patterns of injuries distinct to each seat position were delineated. PMID:16179151

Primary laws and fine levels are associated with increases in seat belt use, 1997–2008 : traffic tech.

DOT National Transportation Integrated Search

2010-11-01

Increasing seat belt usage in the United States has proved to be a : slow and difficult task. It has taken about 30 years since NHTSA : conducted the first seat belt and child restraint workshops in : 1978 to reach 84% usage in 2009. In general, seat...

78 FR 65756 - Notice of Receipt of Petition for Decision That Nonconforming 1992 Jeep Wrangler Multi-Purpose...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-01

... comments were received, please enclose a stamped, self-addressed postcard with the comments. Note that all... Control Rearward Displacement, 205 Glazing Materials, 207 Seating Systems, 210 Seat Belt Assembly... the vehicle is not already so equipped. Standard No. 209 Seat Belt Assemblies: Inspection of seat...

75 FR 35877 - Bentley Motors Inc., Receipt of Petition for Decision of Inconsequential Noncompliance

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-23

...) of Federal Motor Vehicle Safety Standard (FMVSS) No. 209, Seat Belt Assemblies. BMI filed an... approximately 300 nonconforming seat belt assemblies, produced during the 12 months prior to December 18, 2009...) Installation instructions. A seat belt assembly, other than a seat belt assembly installed in a motor vehicle...

Seat belt use, especially among low-use drivers, increases as Florida upgrades to primary seat belt enforcement : traffic tech.

DOT National Transportation Integrated Search

2012-08-01

As a secondary seat belt law State, Florida had worked : for many years to encourage more drivers to wear : their seat belts by participating in annual Click It or : Ticket (CIOT) mobilizations, and by conducting special : programs in rural areas of ...

Strategies to increase seat belt use : an analysis of levels of fines and the type of law.

DOT National Transportation Integrated Search

2010-11-01

The main objectives of this study were to determine the relationships between seat belt use in the States and (1) the : type of seat belt law enforcement (primary versus secondary), and (2) seat belt fine levels. : The study examined law type and lev...

49 CFR 38.107 - Restrooms.

Code of Federal Regulations, 2010 CFR

2010-10-01

... closet. Fold-down or retractable seats or shelves may overlap the clear floor space at a lower height... 17 inches to 19 inches measured to the top of the toilet seat. Seats shall not be sprung to return to... at least one seating location for persons using mobility aids and shall be connected to such a space...

49 CFR 38.107 - Restrooms.

Code of Federal Regulations, 2012 CFR

2012-10-01

... closet. Fold-down or retractable seats or shelves may overlap the clear floor space at a lower height... 17 inches to 19 inches measured to the top of the toilet seat. Seats shall not be sprung to return to... at least one seating location for persons using mobility aids and shall be connected to such a space...

49 CFR 38.107 - Restrooms.

Code of Federal Regulations, 2011 CFR

2011-10-01

... closet. Fold-down or retractable seats or shelves may overlap the clear floor space at a lower height... 17 inches to 19 inches measured to the top of the toilet seat. Seats shall not be sprung to return to... at least one seating location for persons using mobility aids and shall be connected to such a space...

49 CFR 38.107 - Restrooms.

Code of Federal Regulations, 2014 CFR

2014-10-01

... closet. Fold-down or retractable seats or shelves may overlap the clear floor space at a lower height... 17 inches to 19 inches measured to the top of the toilet seat. Seats shall not be sprung to return to... at least one seating location for persons using mobility aids and shall be connected to such a space...

76 FR 18042 - Uniform Criteria for State Observational Surveys of Seat Belt Use

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-01

... [Docket No. NHTSA-2010-0002] RIN 2127-AK41 Uniform Criteria for State Observational Surveys of Seat Belt... designing and conducting State seat belt use observational surveys and the procedures for obtaining NHTSA... use rate, known as the Uniform Criteria for State Observational Surveys of Seat Belt Use (the Uniform...

The Mutual Impact of Personality Traits on Seating Preference and Educational Achievement

ERIC Educational Resources Information Center

Hemyari, Camellia; Zomorodian, Kamiar; Ahrari, Iman; Tavana, Samar; Parva, Mohammad; Pakshir, Keyvan; Jafari, Peyman; Sahraian, Ali

2013-01-01

Several studies have investigated the association between students' seating positions and their classroom performance. However, the role of personality traits on seating preference in the classroom has not been well investigated. The aim of the study was to understand how students choose their seats according to their personality traits in a…

14 CFR 382.81 - For which passengers must carriers make seating accommodations?

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false For which passengers must carriers make seating accommodations? 382.81 Section 382.81 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF... TRAVEL Seating Accommodations § 382.81 For which passengers must carriers make seating accommodations? As...

14 CFR 382.83 - Through what mechanisms do carriers make seating accommodations?

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Through what mechanisms do carriers make seating accommodations? 382.83 Section 382.83 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF... TRAVEL Seating Accommodations § 382.83 Through what mechanisms do carriers make seating accommodations...

14 CFR 382.81 - For which passengers must carriers make seating accommodations?

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false For which passengers must carriers make seating accommodations? 382.81 Section 382.81 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF... TRAVEL Seating Accommodations § 382.81 For which passengers must carriers make seating accommodations? As...

14 CFR 382.83 - Through what mechanisms do carriers make seating accommodations?

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Through what mechanisms do carriers make seating accommodations? 382.83 Section 382.83 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF... TRAVEL Seating Accommodations § 382.83 Through what mechanisms do carriers make seating accommodations...

Spinal Elongation and its Effects on Seated Height in a Microgravity Environment

NASA Technical Reports Server (NTRS)

Rajulu, Sudhakar; Young, Karen

2009-01-01

Objectives: 1. To collect spinal elongation induced seated height data for subjects exposed to microgravity environments. 2. To provide information relating to the seated height rate of change over time for astronauts subjected to microgravity. We will collect: Seated Height measurement (ground & flight) and digital still photograph (ground and flight).

14 CFR 135.76 - DOD Commercial Air Carrier Evaluator's Credentials: Admission to pilots compartment: Forward...

Code of Federal Regulations, 2011 CFR

2011-01-01

... Credentials: Admission to pilots compartment: Forward observer's seat. 135.76 Section 135.76 Aeronautics and... Commercial Air Carrier Evaluator's Credentials: Admission to pilots compartment: Forward observer's seat. (a.... (b) A forward observer's seat on the flight deck or forward passenger seat with headset or speaker...

14 CFR 135.76 - DOD Commercial Air Carrier Evaluator's Credentials: Admission to pilots compartment: Forward...

Code of Federal Regulations, 2010 CFR

2010-01-01

... Credentials: Admission to pilots compartment: Forward observer's seat. 135.76 Section 135.76 Aeronautics and... Commercial Air Carrier Evaluator's Credentials: Admission to pilots compartment: Forward observer's seat. (a.... (b) A forward observer's seat on the flight deck or forward passenger seat with headset or speaker...

14 CFR 382.83 - Through what mechanisms do carriers make seating accommodations?

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Through what mechanisms do carriers make seating accommodations? 382.83 Section 382.83 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF... TRAVEL Seating Accommodations § 382.83 Through what mechanisms do carriers make seating accommodations...

14 CFR 382.83 - Through what mechanisms do carriers make seating accommodations?

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Through what mechanisms do carriers make seating accommodations? 382.83 Section 382.83 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF... TRAVEL Seating Accommodations § 382.83 Through what mechanisms do carriers make seating accommodations...

14 CFR 382.83 - Through what mechanisms do carriers make seating accommodations?

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Through what mechanisms do carriers make seating accommodations? 382.83 Section 382.83 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF... TRAVEL Seating Accommodations § 382.83 Through what mechanisms do carriers make seating accommodations...

Evaluation of biofeedback seat insert for improving active sitting posture in children with cerebral palsy. A clinical report.

PubMed

Bertoti, D B; Gross, A L

1988-07-01

Biofeedback devices have been used successfully to improve head control and symmetrical standing in children with cerebral palsy. This clinical report describes a biofeedback seat insert developed to improve erect sitting posture in children with cerebral palsy who have inadequate trunk control. The seat insert is easily placed against the back of any seating device. A momentary-contact pressure switch on the seat insert is activated when the child exerts pressure on it by extending his trunk. The pressure switch then activates a videocassette recorder or can be adapted to activate a television or radio. Five children with spastic cerebral palsy participated in this evaluation of the biofeedback seat insert. The results of this evaluation show that the children used the biofeedback seat insert effectively to actively improve their sitting posture by voluntarily extending their trunk against the pressure switch. The biofeedback seat insert offers physical therapists a valuable therapeutic training tool to encourage carry-over of improved sitting posture away from the clinical setting for children with cerebral palsy.

Evaluation of wheelchair sling seat and sling back crashworthiness.

PubMed

Ha, D; Bertocci, G; Karg, P; Deemer, E

2002-07-01

Many wheelchairs are used as vehicle seats by those who cannot transfer to a vehicle seat. Although ANSI/RESNA WC-19 has been recently adopted as a standard to evaluate crashworthiness of the wheelchairs used as motor vehicle seats, replacement or after-market seats may not be tested to this standard. This study evaluated the crashworthiness of two specimens each of three unique sling backs and three unique sling seats using a static test procedure intended to simulate crash loading conditions. To pass the test, a sling back is required to withstand a 2290 lb load, and a sling seat should be capable of withstanding a 3750 lb load. All, but two sling back specimens which failed at 1567 lb and 1787 lb, withstood the test criterion load. Two of six tested sling seats failed to pass the test: one failed at 3123 lb and the other failed to sustain the load for 5 s although it reached the test criterion load. Most of the failures occurred at the seams of the side openings of upholsteries where the wheelchair frame inserts for attachment.

Improving paddling efficiency through raising sitting height in female white water kayakers.

PubMed

Broomfield, Shelley A L; Lauder, Mike

2015-01-01

The study compared female white water paddlers over two conditions: with seat raise and with no seat raise. The aim was to determine whether raising the sitting height would improve paddling efficiency. Sitting height of each participant was recorded in order to calculate the seat raise height required and three-dimensional kinematic data was collected for six participants over both conditions. Twelve measures of efficiency were utilised. The efficiency of all participants improved on the seat condition for ≥4 of the measures, with three participants showing improvement for ≥6 of the measures. The stern snaking measure had the highest value of significance (P = 0.1455) and showed an average of 11.98% reduction in movement between no seat and seat conditions. The results indicate that improvements were seen although these were individualistic. Therefore it can be concluded that it is worth experimenting with a seat raise for a female kayaker who is lacking efficiency, noting, however, that improvements might depend on anthropometrics and the seat height selected, and therefore could elicit differing results.

Statistical Performance Evaluation Of Soft Seat Pressure Relief Valves

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harris, Stephen P.; Gross, Robert E.

2013-03-26

Risk-based inspection methods enable estimation of the probability of failure on demand for spring-operated pressure relief valves at the United States Department of Energy's Savannah River Site in Aiken, South Carolina. This paper presents a statistical performance evaluation of soft seat spring operated pressure relief valves. These pressure relief valves are typically smaller and of lower cost than hard seat (metal to metal) pressure relief valves and can provide substantial cost savings in fluid service applications (air, gas, liquid, and steam) providing that probability of failure on demand (the probability that the pressure relief valve fails to perform its intendedmore » safety function during a potentially dangerous over pressurization) is at least as good as that for hard seat valves. The research in this paper shows that the proportion of soft seat spring operated pressure relief valves failing is the same or less than that of hard seat valves, and that for failed valves, soft seat valves typically have failure ratios of proof test pressure to set pressure less than that of hard seat valves.« less

Seating positions and children's risk of dying in motor vehicle crashes

PubMed Central

Braver, E.; Whitfield, R.; Ferguson, S.

1998-01-01

Objectives—To determine the effects of seating position, combined with restraint use and airbag status, on children's risk of dying in crashes. Methods—Using 1988–95 data from the United States Fatality Analysis Reporting System, risk of death was compared among front and rear seated passengers aged 12 and younger who were involved in fatal crashes for different categories of restraint use and in vehicles with and without passenger airbags. Results—Restrained children in rear seats had the lowest risk of dying in fatal crashes. Among children seated in the rear, risk of death was reduced 35% in vehicles without any airbags, 31% in vehicles equipped only with driver airbags, and 46% in vehicles with passenger airbags. Both restrained and unrestrained children aged 0–12 were at lower risk of dying in rear seats. Rear seats also afforded additional protection to children aged 5–12 restrained only with lap belts compared with lap/shoulder belted children in front seats. Children were about 10–20% less likely to die in rear center than in rear outboard positions. Conclusions—Parents and others who transport children should be strongly encouraged to place infants and children in rear seats whether or not vehicles have airbags. Existing laws requiring restraint use by children should be strengthened and actively enforced. PMID:9788087

The influence of seat height, trunk inclination and hip posture on the activity of the superior trapezius and longissimus

PubMed Central

Bertolaccini, Guilherme da Silva; Nakajima, Rafael Kendi; Filho, Idinei Francisco Pires de Carvalho; Paschoarelli, Luis Carlos; Medola, Fausto Orsi

2016-01-01

[Purpose] This study was aimed at investigating the influence of seat height and body posture on the activity of the superior trapezius and longissimus muscles. [Subjects and Methods] Twenty two healthy subjects were instructed to perform a total of eight different body postures, varying according three main factors: seat height (low and high seat); trunk inclination (upright and leaning forward at 45°); and the hips in abduction and adduction. Electromyography of the superior trapezius and longissimus was collected bilaterally, and the average values were obtained and compared across all the postures. [Results] The activity of the superior trapezius and longissimus significantly changes according to the seat height and trunk inclination. For both seat heights, sitting with trunk leaning forward resulted in a significant increase in the activity of both muscles. When sitting in a high seat and the trunk leaning forward, the superior trapezius activity was significantly reduced when compared to the same posture in a low seat. [Conclusion] This study contributes to the knowledge on the influence of the body posture and seat configuration on the activity of postural muscles. Reducing the biomechanical loads on the postural muscles must be targeted in order to improve users’ comfort and safety. PMID:27313381

Noncompliance with seat-belt use in patients involved in motor vehicle collisions

PubMed Central

Ball, Chad G.; Kirkpatrick, Andrew W.; Brenneman, Frederick D.

2005-01-01

Background Seat-belt compliance in trauma patients involved in motor vehicle collisions (MVCs) appears low when compared with compliance of the general public. In this study we wished to define the relative frequency of seat-belt use in injured Canadian drivers and passengers and to determine if there are risk factors particular to seat-belt noncompliance in this cohort. Methods We identified trauma patients who were involved in MVCs over a 24-month period and contacted them 2–4 years after the injury by telephone to administer a standardized survey. Potential determinants of seat-belt noncompliance were compared with the occurrence of an MVC by multiple logistic regression. Results Seat-belt noncompliance in 386 MVC patients was associated with drinking and driving, youth, speeding, male sex, being a passenger, smoking, secondary roads, rural residence, low level of education, overnight driving, having no dependents, licence demerit points, previous collisions, unemployment and short journeys. There was an increase in seat-belt awareness and a decrease in self-rated driving ability after the MVC. Conclusions Factors that indicate poor driving habits (alcohol, speeding, previous MVCs and driving offences) also predict seat-belt noncompliance. Injury prevention programs should selectively target these high-risk drivers to improve seat-belt compliance and limit associated injury and consumption of health care resources. PMID:16248134