Refine Your Search

Topic

Author

Affiliation

Search Results

Technical Paper

135 Days in Isolation and Confinement: The Hubes Simulation

1995-07-01
951512
The EUROMIR-95 flight was selected as model for the HUBES experiment: a similar duration (135 days), a similar crew (3 men), similar schedule organisation (8 hours work, 8 hours sleep, 8 hours off-duties), similar workload for the crew and the mission control (performance of scientific experiments), similar setup for communication and data processing, and similar layout of the MIR station, as the simulation was performed in the MIR simulator located at the Institute for BioMedical Problems (IBMP) in Moscow. The Scientific Programme of HUBES had been elaborated by integration of 31 experiments from more than 80 research proposals from Principal Investigators from Europe, USA and Russia, in domains of Physiology, Psychology, Operations and Technology.
Technical Paper

3D Deformation and Dynamics of the Human Cadaver Abdomen under Seatbelt Loading

2008-11-03
2008-22-0011
According to accident analysis, submarining is responsible for most of the frontal car crash AIS 3+ abdominal injuries sustained by restrained occupants. Submarining is characterized by an initial position of the lap belt on the iliac spine. During the crash, the pelvis slips under the lap belt which loads the abdomen. The order of magnitude of the abdominal deflection rate was reported by Uriot to be approximately 4 m/s. In addition, the use of active restraint devices such as pretensioners in recent cars lead to the need for the investigation of Out-Of-Position injuries. OOP is defined by an initial position of the lap belt on the abdomen instead of the pelvis resulting in a direct loading of the abdomen during pretensioning and the crash. In that case, the penetration speed of the belt into the abdomen was reported by Trosseille to be approximately 8 to 12 m/s. The aim of this study was to characterize the response of the human abdomen in submarining and OOP.
Technical Paper

3D-Design, Fabrication and Metrological Characteristics for Knee Meniscus Replacement Prototype using Proposed Polymeric Material

2016-04-05
2016-01-0509
Due to the accidents of the motor vehicles and the osteoporosis, many people enface a lot of troubles and sometimes necessities for replacement of their knee joints. Practically, mechanical properties and surface characteristics of Total Knee Replacement (TKR) are very important parameters for improving the performance response in human. The meniscus is a small element and an essential part of the TKR. The knee meniscus has special feature allows the easy dynamic loading and motion of leg and foot with high accuracy and good balance. Therefore design and analysis of the geometrical shape for the meniscus replacement is worthy to be studied. In this paper, a proposed design using a computer software package has been presented. 3D simulation analyses of a variety of meniscus thickness and different materials under different loads are investigated. The compression stresses and surfaces deformations are determined numerically through the Finite Element Analysis (FEA) technique.
Technical Paper

4994 Tractor Hydraulic System

1984-09-01
841100
J I Case Company has produced four-wheel-drive agricultural tractors since 1964. In 1984 however, the flagship of the Case fleet changed hands. Rising labor costs and larger farming operations spearheaded the need for a more efficient larger tractor. January 1984 marked the introduction of the largest four-wheel-drive tractor in the history of Case, the 4994, a 400-gross engine horsepower tractor, Figure 1. Sheer horsepower alone however, would not meet the requirements of today's farming operations. Case Engineering realized that tomorrows tractors must have sufficient power to handle the wide variety of attachments available. They also realized that along with the unmatched power must come precise control of the attachment. These advancements in farming have required improvements to the tractor hydraulic system. This paper describes the hydraulic system of the 4994, Case's new flagship.
Technical Paper

62TE 6-Speed Transaxle for Chrysler Group

2007-04-16
2007-01-1097
A new six-speed transaxle has been introduced by the Chrysler Group of DaimlerChrysler AG. Along with the six forward ratios in the normal upshift sequence, this transaxle features a seventh forward ratio used primarily in a specific downshift sequence. A significant technical challenge in this design was the control of so-called double-swap shifts, the exchange of two shift elements for two other shift elements. In the case at hand, one of the elements is a freewheel. A unique solution is discussed for successful control of double-swap shifts. The new design replaces a four-speed transaxle but makes use of a large percentage of parts and processes from the four-speed design. This approach enabled the new transaxle to reach production in three years from concept. The new transaxle, referred to as the 62TE, has substantially improved performance and passing maneuvers coupled with a new 4.0L high output engine for which the 62TE was developed.
Technical Paper

64 Ergonomic Approaches to Improved Scooter Riding Comfort

2002-10-29
2002-32-1833
This paper gives a report on ergonomic approaches we tried to scooters for improvements in their riding comfort. First we conducted investigations into riding postures that offer a comfortable scooter ride. That is, we picked out major items for the evaluation of scooter riding postures and investigated a correlation between those items and their physical quantities. Our investigation revealed that room for leg and arm movements played a major role in a scooter riding posture. We further found out a high correlation between the evaluation items for legroom and the knee angles and also high correlation between the evaluation items for legroom and the ankle angle. Next we report on the result of the attempt we made at improved riding comfort by equipping the scooter seat with a backrest. To check the effects of backrest, we measured the seating pressure distribution, myogenic potential, and cardiogenic potential.
Technical Paper

A 25 Degrees of Freedom Hand Geometrical Model for Better Hand Attitude Simulation

2004-06-15
2004-01-2196
Numerical models are used more and more to visualize a human operator within a work environment and simulate his movements. Many models are limited in their ability to simulate complex activities like prehension and objects manipulation. The hand models proposed in the literature are relatively simple, especially assuming the palm as a rigid body, which leads to unrealistic representations of complex attitudes. The objective of the present study is to develop a more advanced hand model, able to properly simulate prehension postures. A 25 degrees of freedom (DOF) hand model has been proposed including 2 DOF for representing the palm arch. Compared to the model without palm arch, the proposed model has made significant improvement of the hand posture representation, suggesting the need of including palm arch for simulating complex hand grasping attitudes.
Technical Paper

A Basic Study on Modeling of Forearm Torsional Operations for Digital Human

2008-06-17
2008-01-1903
The purpose of this study is to propose a method to evaluate operations involving forearm torsion, such as screw driving and knob turning, for digital human models. The rotational ranges of an object gripped with a hand and the working postures of the upper limb were measured at various positions of the object. The results demonstrated that the rotational ranges of the object varied depending on the working posture. The degree of coincidence was defined among direction vectors for each segment in the link model consisting of the upper limb and the rotated object. A method was proposed to estimate the rotational ranges of the object from the degree of coincidence. Based on this method, software has been developed in order to evaluate operations involving forearm torsion.
Technical Paper

A Bio-Engineering Approach to Crash Padding

1968-02-01
680001
The injury-reducing functions of crash padding are discussed as they relate to head impact. The bony structure of the cranial vault (above eyebrows) is strong under localized impact compared with the face. Padding used to protect the cranial vault from impact has the primary function of absorbing energy to reduce the possibility of brain damage. On the other hand, padding for facial protection has the primary function of providing uniform load distribution on the face. The pad understructure then supplies the needed energy absorbing capacity. Test procedures to measure both energy absorption and load distribution are described, and evaluation criteria are shown. Other factors that affect padding, such as temperature and cover stock material, are discussed.
Technical Paper

A Biodynamic Model of the Human Spinal Column

1976-02-01
760771
A biodynamic model of the spine simulated the action of spinal musculature on the head, vertebral bodies and pelvis in the midsagittal plane. Muscle was treated as a force generator whose contractile force was dependant on muscle stretch, stretch rate and neural delay time. Eight model runs were conducted with and without muscle, simulating +Gz and -Gx impact acceleration. The model predicted that spinal musculature was incapable of affecting overall spinal column kinematics. However, as a result of muscle contraction, significantly higher local axial forces were predicted in the discs and facets than were predicted when muscle was absent.
Technical Paper

A Biofidelity Evaluation of the BioRID II, Hybrid III and RID2 for Use in Rear Impacts

2003-10-27
2003-22-0022
In this study, three dummies were evaluated on the component level and as a whole. Their responses were compared with available volunteer and embalmed Post Mortem Human Subject (PMHS) data obtained under similar test conditions to evaluate their biofidelity The volunteer and PMHS data, used as comparators in this study, were used previously to establish some of the biofidelity requirements of the Hybrid III. The BioRID II, the Hybrid III, and the RID2 were all subjected to rear impact HYGE sled tests with ΔVs of 17 and 28 km/hr to determine their biofidelity in these conditions. A static pull test, where a load was manually applied to the head of each dummy, was used to evaluate the static strength of their necks in flexion and extension. Finally, pendulum tests were conducted with the Hybrid III and RID2 to evaluate the dynamic characteristics of their necks in flexion and extension.
Technical Paper

A Biomechanical Analysis of Head, Neck, and Torso Injuries to Child Surrogates Due to Sudden Torso Acceleration

1984-10-01
841656
This paper reports on the injuries to the head, neck and thorax of fifteen child surrogates, subjected to varying levels of sudden acceleration. Measured response data in the child surrogate tests and in matched tests with a three-year-old child test dummy are compared to the observed child surrogates injury levels to develop preliminary tolerance data for the child surrogate. The data are compared with already published data in the literature.
Technical Paper

A Biomechanical Model for the Upper Extremity Using Optimization Techniques

1974-02-01
740272
A biomechanical model has been developed using dynamic programming as a solution technique. The criterion selected for optimization is power-generated to perform a movement. The model predicts the position of the hand in space while performing simple movements, but the study indicates a need for more detailed considerations of model assumptions. However, the basic assumptions and the principles of theoretical mechanics used in dynamic analyses of man in motion continue to be valid and are not refuted by this study.
Technical Paper

A Bioreactor System for the Nitrogen Loop in an Engineered Closed/Controlled Ecosystem

1996-07-01
961506
As space missions become longer in duration, the need to recycle waste into useful compounds rises dramatically. This problem can be addressed through the integration of human and plant modules in an ecological life support system. One of the waste streams leaving the human module is urine. In addition to the reclamation of water from urine, recovery of the nitrogen is important because it can be used as a nutrient for the plant module. A 3-step biological process for the conversion of nitrogenous waste (urea) to resource (nitrate) is proposed. Mathematical modeling was used to investigate the bioreactor system, with the goal of maximizing the ratio of performance to volume and energy requirements. Calculations show that separation of the two microbial conversions into two steps requires a smaller total reactor volume than combining them in a single bioreactor.
Technical Paper

A CRITICAL TRACKING TASK AS AN ALCOHOL INTERLOCK SYSTEM

1973-02-01
730095
A compensatory tracking task (The Critical Tracking Task) requiring the operator to stabilize the output of an unstable system whose level of instability increases monotonically up to the critical point of loss of control is evaluated for its potential to discriminate between sober and intoxicated performances. Quantification of the results obtained in the laboratory controlled environment shows a great deal of promise, indicating that intoxicated failure rates of 50% for blood alcohol concentrations (BAC's) at or above 0.1% and 75% for BAC's at or above 0.14% can be attained with no sober failure rates. A high initial rate of learning is observed, perhaps due to the very nature of the task whereby the operator is always pushed to his limit, and the scores approach a stable asymptote after approximately 50 trials. Finally, the implementation of the task as an ignition interlock system in the automobile environment is discussed.
Technical Paper

A Comparative Analysis of the Pedestrian Injury Risk Predicted by Mechanical Impactors and Post Mortem Human Surrogates

2008-11-03
2008-22-0020
The objective of this study is to compare the risk of injury to pedestrians involved in vehicle-pedestrian impacts as predicted by two different types of risk assessment tools: the pedestrian subsystem impactors recommended by the European Enhanced Vehicle-Safety Committee (EEVC) and post-mortem human surrogates (PMHS). Seven replicate full-scale vehicle-pedestrian impact tests were performed with PMHS and a mid-sized sedan travelling at 40 km/h. The PMHS were instrumented with six-degree-of-freedom sensor cubes and sensor data were transformed and translated to predict impact kinematics at the head center of gravity, proximal tibiae, and knee joints. Single EEVC WG 17/EuroNCAP adult headform, upper legform and lower legform impactor tests of the same vehicle were selected for comparison based on the proximity of their impact locations to that of the PMHS.
Technical Paper

A Comparative Evaluation of Pedestrian Kinematics and Injury Prediction for Adults and Children upon Impact with a Passenger Car

2004-03-08
2004-01-1606
Studies show that the pedestrian population at high risk of injury consists of both young children and adults. The goal of this study is to gain understanding in the mechanisms that lead to injuries for children and adults. Multi-body pedestrian human models of two specific anthropometries, a 6year-old child and a 50th percentile adult male, are applied. A vehicle model is developed that consists of a detailed rigid finite element mesh, validated stiffness regions, stiff structures underlying the hood and a suspension model. Simulations are performed in a test matrix where anthropometry, impact speed and impact location are variables. Bumper impact occurs with the tibia of the 50th percentile adult male and with the thigh of the 6-year-old child. The head of a 50th percentile male impacts the lower windshield, while the 6-year-old child's head impacts the front part of the hood.
Technical Paper

A Comparative Study Between Different Psychological Approaches During an ESA Space Simulation

1994-06-01
941358
The objectives are to compare different psychological methods used to assess the evolution of the interrelations inside the crew and the relationships between the crew and the outside in a sixty days isolation/confinement's simulation. After presenting each method, results are compared. The discussion try to point out if these methods are equivalent or if they are complementary. The specificity of each method is shown and conclusions try to associate some methods with specific scientific goals.
Technical Paper

A Comparative Study of Vehicle Front Shape Based on Multi-Objective Optimization for Minimizing Injury Risks in Pedestrian and Cyclist Impact

2018-04-03
2018-01-1046
This study aims to explore the influence of a vehicle front-end shape on pedestrian and cyclist injuries. The injuries of head, upper leg and lower leg based on 50th human model are considered as design response. A multi-objective optimization approach is developed to design and optimize the front shape for minimizing injury risks of pedestrian and cyclist in this study. The numerical models of pedestrian-vehicle and cyclist-vehicle impact is constructed and validated first. Then, the optimal Latin hypercube sampling (OLHS) method is adopted for design of experiment (DOE) and the surrogate model is constructed through radial basis function (RBF). The optimal problems involving a number of objectives are solved by the multi-objective particle swarm optimization (MOPSO) algorithm in this study.
Technical Paper

A Comparison Between Human Kinematics and the Predictions of Mathematical Crash Victim Simulators

1971-02-01
710849
A study has been conducted as an initial step in determining the differences observed between the motions of a living human impact sled test subject and a dummy test subject. The mechanism which is proposed for accomplishing this is the HSRI Two-Dimensional Mathematical Crash Victim Simulator. A series of measurements were taken on human test subjects, including classical and nonclassical anthropometric measurements, range of motion measurements for the joints, and maximum foot force measurements. A series of mathematical expressions has been used to predict body segment weight, centers of gravity, and moments of inertia using the results of the various body measurements. It was then possible to prepare a data set for use with the mathematical model.
X