Browse Topic: Biomechanics

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An Uncertainty Propagation Approach to Collective Bounce Rotorcraft-Pilot Couplings AnalysisF-0080-2024-13215/7/2024
In the context of Rotorcraft Pilot Couplings, the biomechanics of the pilot body play a fundamental role in determining the stability of the pilot-vehicle closed loop system. The response of the pilot body is, in turn, inherently stochastic, being a function of pilot biometrics and muscular activation. Coupling the statistical distribution of pilot biomechanical behavior determined in specialized experimental campaign with linear models of the helicopter heave dynamics, an uncertainty propagation procedure is developed, with the aim of estimating the statistical distribution of the stability margins of the closed loop pilot-vehicle system. Results obtained varying the collective lever characteristics, as well as the helicopter model parameters, align well with results obtained previously in deterministic settings. However, the new scheme allows to define quantitative robustness indices.
Zanoni, Andrea, Masarati, Pierangelo, Colombo, Francesca, Zilletti, Michele, Marchesoli, Davide, Talamo, Carmen, Cassoni, Gianni
Pilot Biomechanics for the Definition of a Rotorcraft-Pilot Interaction ExperimentF-0078-2022-175205/10/2022
ABSTRACT
Colombo, Francesca, Kemp, Sarah, Fosco, Ermanno, Zanoni, Andrea, Cocco,  Alessandro, Marchesoli,  Davide, Masarati,  Pierangelo, Talamo, Carmen
Development of a Subhuman Primate Brain Finite Element Model to Investigate Brain Injury Thresholds Induced by Head Rotation2019-22-00033/31/2020
An anatomically detailed rhesus monkey brain FE model was developed to simulate in vivo responses of the brain of sub-human primates subjected to rotational accelerations resulting in diffuse axonal injury (DAI). The material properties used in the monkey model are those in the GHBMC 50th percentile male head model (Global Human Body Model Consortium). The angular loading simulations consisted of coronal, oblique and sagittal plane rotations with the center of rotation in neck to duplicate experimental conditions. Maximum principal strain (MPS) and Cumulative strain damage measure (CSDM) were analyzed for various white matter structures such as the cerebrum subcortical white matter, corpus callosum and brainstem. The MPS in coronal rotation were 45% to 54% higher in the brainstem, 8% to 48% higher in the corpus callosum, 13% to 22% higher in the white matter when compared to those in oblique and sagittal rotations, suggesting that more severe DAI was expected from coronal and oblique rotations as compared to that from sagittal rotation. The level 1+ DAI was associated with 1.3 to 1.42 MPS and 50% CSDM (0.5) responses in the brainstem, corpus callosum and cerebral white matter. The mass scaling method, sometimes referred to as Holbourn's inverse 2/3 power law, used for development of human brain injury criterion was evaluated to understand the effect of geometrical and anatomical differences between human and animal head. Based on simulations conducted with the animal and human models in three different planes - sagittal, coronal and horizontal - the scaling from animal to human models are not supported due to lack of geometrical similitude between the animal and human brains. Thus, the scaling method used in the development of brain injury criterion for rotational acceleration/velocity is unreliable.
Arora, Tushar, Zhang, Liying, Prasad, Priya
Bio-Inspired Mechanics to Make Robots More EffectiveTBMG-361913/1/2020
In an effort to make robots more effective and versatile teammates for soldiers in combat, researchers are looking to understand the value of the molecular living functionality of muscle and the fundamental mechanics that would need to be replicated in order to artificially achieve the capabilities arising from the proteins responsible for muscle contraction.
Harvesting Energy from the Human KneeTBMG-350979/1/2019
An energy harvester attached to the wearer’s knee can generate 1.6 μW of power while the wearer walks without any increase in effort. The energy is enough to power small electronics like health monitoring equipment.
Wearable Liquid Unit Harvests EnergyTBMG-349338/1/2019
Researchers have created wearable technology to convert mechanical energy into electrical energy. It presents a step toward the practical realization of self-powered, human-integrated technologies.
Flight Simulator Testing to Enhance Comprehension and Modeling of Rotorcraft Pilot CouplingsF-0075-2019-146435/13/2019
This work presents the results of a piloted flight simulator campaign aimed at measuring biomechanical performance indicators -- upper limbs motion and electromiography of main muscle bundles -- of pilots performing complex, realistic tasks. Ship deck landings performed by a single pilot, flying several helicopter configurations with sea conditions of increasing intensity have been considered. The analysis of the results shows an increase in muscular activity in relation with the increase in task difficulty, in agreement with subjective ratings (Bedford workload scale). The study provided useful indications to improve the corresponding biomechanical simulations, as well as to characterize pilot performance during specific tasks.
Zanoni, Andrea, Maisano, Giorgio, Frigerio, Lorenzo, Murawa, Michal, Zago, Matteo, Paolini, Rita, Quaranta, Giuseppe, Masarati, Pierangelo, Galli, Manuela
Investigation of Structural Coupling Problems in Tiltrotor AircraftF-0075-2019-145835/13/2019
The paper investigates structural coupling problems in tiltrotor aircraft. A detailed tiltrotor model, representative of the Bell XV-15, has been built. The airframe model has been modified with a thinner wing to better reveal structural coupling proneness. A linearized FCS has been introduced to analyze the overall stability on an extended frequency band, ranging from the flight mechanics up to the aeroelastic modes. In addition to the FCS, biomechanical models of the pilot, acting on the power-lever and on the center stick, are included in feedback loop. Overall stability analyses demonstrate that the FCS improves handling qualities although several structural coupling mechanisms arise, in combination with the involuntary pilot's response, reducing flutter clearance. A modified version of the XV-15, using differential collective pitch for yaw control in airplane mode, has been also investigated. This configuration reduces costs and weights although the FCS destabilizes the antisymmetric wing chord mode at low speed flight, severely limiting the flight envelope. Means of prevention, based on notch filters, are implemented and discussed.
Muscarello, Vincenzo
Analysis of Rear Seat Sled Tests with the 5th Female Hybrid III: Incorrect Conclusions in Bidez et al. SAE 2005-01-17082019-01-06184/2/2019
Objective: Sled test video and data were independently analyzed to assess the validity of statements and conclusions reported in Bidez et al. SAE paper 2005-01-1708 [7]. Method: An independent review and analysis of the test data and video was conducted for 9 sled tests at 35 km/h (21.5 mph). The 5th female Hybrid III was lap-shoulder belted in the 2nd or 3rd row seat of a SUV buck. For one series, the angle was varied from 0, 15, 30, 45 and 60 deg PDOF. The second series involved shoulder belt pretensioning and other belt modifications. Results: Bidez et al. [7] claimed “The lap belts moved up and over the pelvis of the small female dummy for all impact angles tested.” We found that there was no submarining in any of the tests with the production lap-shoulder belts. Bidez et al. [7] claimed “H3-5F dummies began to roll out of their shoulder belt at… 30 degrees. Complete loss of torso support was seen at 45 degrees without significant kinetic energy dissipation.” We found that the shoulder belt remained in place and restrained the upper torso in the 0, 15 and 30 deg sled tests. At 45 and 60 deg, significant restraint was provided before the belt slipped off the shoulder. It remained in contact with the arm and chest providing restraint. Bidez et al. [7] claimed “The results indicated kinematic movement of the dummies, which were predictive of injury in all sled runs.” We found that the kinematic control was good and the biomechanical responses were well below IARVs for the 5th female Hybrid III. Bidez et al. [7] claimed “a retractor pretensioner (7 ms fire time) eliminated both submarining and torso rollout in the H3-5F in the conditions tested.” We found that the pretensioner firing pulled the lap belt up onto the abdomen inducing submarining and causing abdominal loading in two out of four tests. Conclusion: The independent review of the videos and data shows that Bidez et al. [7] misstated the results, misrepresented the findings and reached incorrect conclusions on the testing.
Viano, David, Parenteau, Chantal
Thoracic Spine Extension Injuries in Occupants with Pre-Existing Conditions during Rear-End Collisions2019-01-12224/2/2019
Certain ankylosing spondyloarthropathies such as ankylosing spondylitis (AS) or diffuse idiopathic skeletal hyperostosis (DISH) can substantially alter clinicopathologic spine biomechanics as well as injury mechanisms in rear-end motor vehicle collisions. AS is an inflammatory disease which can lead to structural impairments of the spine secondary to flowing ossification along the spinal column, including ossification across the spinal discs, facet joints, and ligaments, and it has also been associated with diffuse osteoporosis of the spine. DISH is characterized by excess bone formation along the spinal column, encompassing the annulus and forming the thickest and strongest bridging osteophytes over adjacent vertebral bodies at the level of the disc space. In both conditions the spine is mechanically stiffened and generally more kyphotic than a healthy spine. This paper presents a series of case studies in which a front-seat occupant with ankylosing spondyloarthropathy experienced a moderate- or high-speed rear-end collision and sustained a thoracic spine fracture/dislocation, often with spinal cord injuries. Forward acceleration of the occupant by the seat back in each case resulted in straightening of the kyphotic thoracic spine and consequent extension fractures of the pathologically stiff and brittle thoracic spine. This paper illustrates the predisposition of thoracic fracture for this segment of the population with spinal pathologies such as DISH and AS in rear impacts and notes the role that seat back stiffness could play in injury mechanism for these individuals.
Davis, Mathieu, Isaacs, Jessica, Graber, Martin, Fisher, Jacob
Development of Subject-Specific Elderly Female Finite Element Models for Vehicle Safety2019-01-12244/2/2019
Previous study suggested that female, thin, obese, and older occupants had a higher risk of death and serious injury in motor vehicle crashes. Human body finite element models were a valuable tool in the study of injury biomechanics. The mesh deformation method based on radial basis function(RBF) was an attractive alternative for morphing baseline model to target models. Generally, when a complex model contained many elements and nodes, it was impossible to use all surface nodes as landmarks in RBF interpolation process, due to its prohibitive computational cost. To improve the efficiency, the current technique was to averagely select a set of nodes as landmarks from all surface nodes. In fact, the location and the number of selected landmarks had an important effect on the accuracy of mesh deformation. Hence, how to select important nodes as landmarks was a significant issue. In the paper, an efficient peak point-selection RBF mesh deformation method was used to select landmarks. The multiple peak points were selected to expand landmarks set, so as to improve the morphing quality compared with the traditional point-selection method. A human head model morphing example was used to verify the effectiveness and stability of the proposed method. Furthermore, the proposed mesh deformation methodology was also applied in a full subject-specific elderly female occupant modeling. The findings of this study demonstrated the feasibility of the proposed mesh deformation method to rapidly develop subject-specific human models in advancing occupant safety.
Dong, Wenxiang, Zhan, Zhenfei, Yin, Yunlei, Li, Junming, Wang, Qingmiao, Jin, Xin
Development of Component Level Transfer Equations of Simplified Human and ATD Occupant Models09-06-01-00056/5/2018
Safety systems have historically been evaluated with anthropomorphic test devices for research, development, or regulatory concerns. Human body models are another avenue for use in the investigation of occupant safety. In this study, transfer equations are developed to quantify the response of a human model (Global Human Body Models Consortium average male simplified model) and dummy model (Hybrid-III) in equivalent environments. Environments were selected based on certification test setups used for the Hybrid III ATD as well as a basic frontal sled environment. The tests include a head drop, neck flexion/extension, and chest and knee impacts. Furthermore, models were positioned within a simplified occupant interior for sled tests. In all, 30 matched pair simulations were run, 60 in total. Peak metrics between human and anthropomorphic test device models showed strong linear correlation in component testing however, as the complexity of the simulations increased, agreement tended to decrease. Kinematic data are also presented and they trend similarly between human and anthropomorphic test device models however they exhibit different timing and peaks. Within the range tested, the developed transfer equations can be used to estimate performance of one model if data from the other is available. Furthermore, the evaluation of risk for these equivalent impacts is provided for HIC-15, max chest deflections and femur forces aggregated across all tests. Over the range tested, equivalent impacts result in roughly equivalent risk levels with the exception of the femur, which resulted in higher forces in the Hybrid III and thus predicted higher risk.
Guleyupoglu, Berkan, Koya, Bharath, Gayzik, Francis Scott
A Comprehensive Aeroservoelastic Approach to Detect and Prevent Rotorcraft-Pilot Coupling Phenomena in TiltrotorsF-0074-2018-127535/14/2018
ABSTRACT This work investigates rotorcraft-pilot coupling phenomena in tiltrotors. A detailed tiltrotor model, representative of the Bell-Boeing XV-15, has been built. Biomechanical models of the pilot, acting on the power lever and on the centre stick, are included in feedback loop to define the Pilot-Vehicle System. Pilot-Assisted Oscillation phenomena are investigated on the overall conversion corridor using Nyquist's criterion. Pilot-in-the-loop analyses demonstrate that a critical parameter is detected in the vertical fins geometry. Due to an asymmetric flaperons deflection the wing's wake impacts on the vertical fins, producing a side force. The pulsating tail-side-force makes the fuselage to yaw and excites the asymmetric wing chord mode coupled with the lateral pilot's biomechanics, leading to a reduction, or even a loss, of stability. No unstable event is detected about the longitudinal direction. Conversely, a resonance between the pilot's biomechanics and the aircraft poorly damped symmetric wing bending mode is predicted about the vertical axis. The instability is found on the whole conversion corridor, although the source of excitation changes with reference to the nacelle angle. Means of prevention are implemented and discussed.
Colombo, Francesca, Muscarello, Vincenzo, Quaranta, Giuseppe, Masarati, Pierangelo
System and Method for Managing Autonomous Entities Through ApoptosisTBMG-287064/1/2018
This NASA innovation is a biologically inspired system management method designed to make sensor webs as well as other autonomous and autonomic systems more self-directing and self-managing. Based on the mechanisms of cell apoptosis, this method ensures safe and correct operation over time by enabling self-destruct, self-sleep, or standby actions in response to potentially harmful or compromising situations. The capabilities provided by this technology will benefit systems such as sensors, computer systems, and spacecraft.
Integrated Genomic and Proteomic Information Security ProtocolTBMG-287404/1/2018
The evolving nature of the Internet will require continual advances in authentication and confidentiality protocols. Nature provides some clues as to how this can be accomplished in a distributed manner through molecular biology. Cryptography and molecular biology share certain aspects and operations that allow for a set of unified principles to be applied to problems in either venue.
Malleable ‘Electronic Skin’ Self-Healable, RecyclableTBMG-287484/1/2018
CU Boulder researchers have developed a new type of malleable, self-healing and fully recyclable “electronic skin” that has applications ranging from robotics and prosthetic development to better biomedical devices.
OCE Aids Development of Therapies for Damaged Heart TissueTBMG-282871/24/2018
Researchers have developed a new way to capture the detailed biomechanical properties of heart tissue. The high-resolution optical technique fills an important technology gap necessary to develop and test therapies that might eventually be used to heal heart damage after a heart attack.
3D Textile EngineeringTBMG-2595011/1/2016
Secant Medical, Telford, PA, has developed 3D textile engineering technology by integrating traditional textile engineering with advanced biomaterials. By combining the spatial resolution capability with advanced bioresorbable polymers, the company uses its proprietary bioelastomer Regenerez® to assist in enhancing the biomechanical properties of these 3D structures. This technology transforms a simple, synthetic textile into an elastomeric scaffold, which provides for a broad range of bioresorbable polymers for the structural design. The company has begun development of an anatomical scaffold prototype based on the trachea. The 3D textile engineered trachea scaffold demonstrates the precision of creating 20 Cshaped rings stacked along the length of the prototype with narrow, flexible regions spaced in between to mimic the natural bioarchitecture of the trachea.
Adverse Aeroelastic Roll/Lateral Rotorcraft-Pilot Couplings AnalysisF-0072-2016-114425/17/2016
The paper investigates the basic mechanism of aeroservoelastic Pilot Assisted Oscillation phenomenon (PAO) about the roll axis due to the interaction with the pilot's arm biomechanics. The motivation stems from the observation that a rotor imbalance may occur as a consequence of rotor cyclic lead-lag modes excitation. The instability mechanism is analogous to the 'air resonance' phenomenon, in which the pilot's involuntary action plays the role of the AFCS. Using robust stability analysis, the paper demonstrates that, in particular, the introduction of a gain and a time-delay between the stick motion and the servoactuator displacements may reduce the gain and phase margins of the pilotvehicle system. The mechanism of instability proves that the pilot biodynamics is participating to the destabilization of the system by inputting energy directly into the flapping mode. This destabilizes the airframe roll motion which, in turn, causes lag motion imbalance. It is found that, depending on the value of the time delay involved in the lateral cyclic control, the body couples with rotor motion in a different way. In the presence of small or no time delays, body roll couples with the rotor through the lag degrees of freedom. The increase of the time delay to 140ms modifies this coupling: the body no longer couples with the rotor through lag but directly through flap motion.
Masarati, Pierangelo, Tod, Georges, Pavel, Marilena, Muscarello, Vincenzo, Quaranta, Giuseppe, Malburet, François
A Comprehensive Pilot Model for Voluntary/Involuntary Action in Rotorcraft-Pilot CouplingF-0071-2015-102155/5/2015
ABSTRACT This work proposes a helicopter pilot model identified from experimental results obtained in piloted simulation flight tests. The tests were originally designed to verify predicted unstable pilot-vehicle systems. The results have been further analyzed using methods for the detection of pilot induced oscillation that are available from the literature. The results show that a pilot-assisted oscillation event occurring in one configuration is characterized by a change of biomechanical properties of the pilot. It is conjectured that such change is triggered by a change in the task of the pilot induced by the specific maneuver that is requested of the pilots in the tests.
Jump, Michael, Marguerettaz, Paolo, Masarati, Pierangelo, Lu, Linghai, Guglieri, Giorgio, Muscarello, Vincenzo, Quaranta, Giuseppe
Analysis and optimization of All Terrain Wheelchair2015-01-13684/14/2015
An all-terrain wheelchair is a lever propelled wheelchair which enables an individual to drive on all terrains easily as the driving mechanism is efficient, ergonomic and fast. It also increases the reach capabilities and social boundaries of disabled. The paper is divided into two parts. In the first part, a comparative study of push rim wheelchair and All-terrain Wheelchair (lever propelled) has been done. In the second part, Optimization of this All-terrain Wheelchair has been done. The comparison is done on various parameters such as peak velocity, average velocity, acceleration, retardation, stroke frequency, reduction in effort, mechanical efficiency, obstacle climbing ability, turning radius, the distance travelled per stroke, Pressure cuts and burns caused during propelling the chair. Biomechanical testing is also done considering the heart rate and oxygen consumption level. This information was used to determine the energy demand, which is intrinsically connected to a wheelchair's mechanical efficiency. The optimization mainly focuses on ergonomics and efficiency of design. For this, the main emphasis was given on factors like the position of lever-drive system, configuration of wheel, seating, backrest, chassis, breaking and foot rest. this optimized design would make the chair more efficient and easy to use by enabling the person to drive, steer, and stop without even touching the wheels, thus, eliminating the risk of friction burns and protecting the wrists and shoulders from repetitive stresses. The analysis was done using commercial software ANSYS and CATIA and validation of results was conducted with the users and non-users of wheel chair.
Agarwal, Shikhar, Gautam, Saumya
Biomechanical Responses of PMHS in Moderate-Speed Rear Impacts and Development of Response Targets for Evaluating the Internal and External Biofidelity of ATDs2012-22-000410/29/2012
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).
Kang, Yun-Seok, Bolte IV, John H, Moorhouse, Kevin, Donnelly, Bruce, Herriott, Rodney, Mallory, Ann
BYU Engineers Conceive Disc Replacement to Treat Chronic Low Back PainTBMG-146449/1/2012
In between the vertebrae of the human spine are 23 Oreo™ cookie-sized, cartilage-filled discs that hold the vertebrae together and allow for spine movement.
Probabilistic Structural Analysis ProgramTBMG-79465/1/2010
NASA/NESSUS 6.2c is a general-purpose, probabilistic analysis program that computes probability of failure and probabilistic sensitivity measures of engineered systems. Because NASA/NESSUS uses highly computationally efficient and accurate analysis techniques, probabilistic solutions can be obtained even for extremely large and complex models. Once the probabilistic response is quantified, the results can be used to support risk-informed decisions regarding reliability for safety-critical and one-of-a-kind systems, as well as for maintaining a level of quality while reducing manufacturing costs for larger-quantity products. NASA/NESSUS has been successfully applied to a diverse range of problems in aerospace, gas turbine engines, biomechanics, pipelines, defense, weaponry, and infrastructure.
Biomechanical Response of the Human Face and Corresponding Biofidelity of the FOCUS Headform2010-01-13174/12/2010
In order to evaluate a human surrogate, the human and surrogate response must be defined. The purpose of this study was to evaluate the response of cadaver subjects to blunt impacts to the frontal bone, nasal bone and maxilla. Force-displacement corridors were developed based on the impact response of each region. Variation in the force-displacement response of the cadaver subjects due to the occurrence of fracture and fracture severity was demonstrated. Additionally, impacts were performed at matched locations using the Facial and Ocular CountermeasUre Safety (FOCUS) headform. The FOCUS headform is capable of measuring forces imposed onto facial structures using internal load cells. Based on the tests performed in this study, the nasal region of the FOCUS headform was found to be the most sensitive to impact location. Due to a wide range in geometrical characteristics, the nasal impact response varied significantly, resulting in wide corridors for human response. The FOCUS headform was found to be repeatable and produced similar forces to the cadaver subjects for the frontal bone and maxilla impact locations.
Cormier, Joseph, Manoogian, Sarah, Bisplinghoff, Jill, Rowson, Steve, Santago, Anthony Charles, McNally, Craig, Duma, Stefan, Bolte, John H.
Jaw Loading Response of Current ATDs2009-01-03884/20/2009
Biomechanical surrogates are used in various forms to study head impact response in automotive applications and for assessing helmet performance. Surrogate headforms include those from the National Operating Committee on Standards for Athletic Equipment (NOCSAE) and the many variants of the Hybrid III. However, the response of these surrogates to loading at the chin and how that response may affect the loads transferred from the jaw to the rest of the head are unknown. To address part of that question, the current study compares the chin impact response performance of select human surrogates to that of the cadaver. A selection of Hybrid III and NOCSAE based surrogates with fixed and articulating jaws were tested under drop mass impact conditions that were used to describe post mortem human subject (PMHS) response to impacts at the chin (Craig et al., 2008). Results were compared to the PMHS response with cumulative variance technique (Rhule et al., 2002). A Hybrid III based surrogate headform with an articulating jaw demonstrated the best overall performance of the surrogates evaluated.
Craig, Matthew J., Viano, David C., Bir, Cynthia A.
Dynamic Biaxial Tissue Properties of Pregnant Porcine Uterine Tissue2008-22-000711/3/2008
Automobile crashes are the largest single cause of death for pregnant females and the leading cause of traumatic fetal injury mortality in the United States. Current research for pregnant occupant safety utilizing computational models is limited by available pregnant tissue data. The purpose of this study is to collect experimental data from biaxial tissue tests on pregnant uterine tissue at a dynamic rate. Experimental tests were completed on pregnant porcine uterus which was chosen as a surrogate for the human pregnant uterus given its similarity and availability. Biaxial dynamic tensile tests were performed using a custom-designed system of linear motors to pull a cruciform-shaped specimen in tension simultaneously with four tissue clamps. The test series included 23 tests with corresponding peak stress and strain measurements of the central region of the specimen where optical markers tracked local displacements. The specimen was loaded at a rate of 0.7 strains per second to match the uterine strain rate in a motor vehicle crash. Experimental results include peak stresses and peak strains for the pregnant uterine tissue in tension. When loaded biaxially, the circumferential peak stress is 500 ± 219 kPa with a corresponding peak true strain 0.30 ± 0.09 and the longitudinal peak stress is 320 ± 176 kPa with a corresponding peak true strain 0.30 ± 0.09. This material information can be implemented in pregnant occupant models to evaluate the uterine tissue response to impact loading scenarios.
Manoogian, Sarah J., McNally, Craig, Stitzel, Joel D., Duma, Stefan M.
On the Determination of Joint Motion Coupling for the Human Shoulder Complex2008-01-18706/17/2008
This paper presents a novel approach to determining the joint motion coupling relationship for the human shoulder complex. The human shoulder complex is the most sophisticated part in terms of degrees of freedom and motion. In the literature, different human shoulder biomechanical models have been developed for various purposes. Also, researchers have realized that there are constant movement relationships among the shoulder bones: the clavicle, scapula, and humerus. This is due to muscles and tendons that are involved in skeletal motions. These relationships, which are also called shoulder rhythm, entail joint motion coupling and joint limit coupling. However, the scope of this work is to determine the joint motion coupling relationship. This relationship is available in the literature, but it is an Euler-angle-based relationship. In the virtual human modeling environment, we cannot directly use this Euler-angle-based relationship. A novel approach is proposed to transfer Euler-angle-based coupling equations into a relationship based on the Denavit-Hartenberg (DH) method. A realistic shoulder complex model is built within Virtools. Euler angles are obtained for static positions with intervals of 15 degrees, and the elevation angle of the arm varied between 0 and 120 degrees. For a specific posture, we input the Euler angles to the shoulder complex model for each bone; then a set of DH joint angles can be determined. The new joint motion coupling relationship is obtained by polynomial, trigonometric and Fourier functions fitting of the DH joint angles using Mathematica. This DH-based joint motion coupling relationship can be used for posture and motion prediction.
Feng, Xuemei, Yang, Jingzhou, Abdel-Malek, Karim
Derivation of Boundary Manikins: A Principal Component Analysis2008-01-18796/17/2008
When designing any human-system interface, it is critical to provide realistic anthropometry to properly represent how a person fits within a given space. This study aimed to identify a minimum number of ‘boundary manikins’ or representative models of subjects' anthropometry from a target population, which would realistically represent the population. The boundary manikin anthropometry was derived using, Principal Component Analysis (PCA). PCA is a statistical approach to reduce a multi-dimensional dataset using eigenvectors and eigenvalues. The measurements used in the PCA were identified as those measurements critical for space suit and cockpit design. The PCA yielded a total of 26 manikins per gender, as well as their anthropometry from the target population. Reduction techniques were implemented to reduce this number further with a final result of 20 female and 22 male subjects. The anthropometry of the ‘boundary manikins’ was then be used to create 3D digital models (to be discussed in subsequent papers) intended for use by designers to test components of their space suit design, to verify that the requirements specified in the Human Systems Integration Requirements (HSIR) document are met. The end-goal is to allow for designers to generate suits which accommodate the diverse anthropometry of the user population.
Young, Karen, Margerum, Sarah, Barr, Abbe, Ferrer, Mike A., Rajulu, Sudhakar
Implementation of Child Biomechanical Neck Behaviour into the Hybrid III Crash Test Dummy2008-01-11204/14/2008
This research focuses on comparing the biomechanical response of the head and neck of the Hybrid III 3-year-old anthropometric test device finite element model and pediatric cadaver data, under flexion-extension bending and axial tensile loading conditions. Previous experimental research characterized the quasi-static biomechanical response of the pediatric cervical spine under flexion-extension bending and tolerance in tensile distraction loading conditions. Significant differences in rotational and linear stiffness were found between the Hybrid III model and the pediatric cadaver data. In this research the biomechanical child cadaver neck response has been implemented into the 3-year-old Hybrid III child dummy FE model. An explicit finite element code (LS-DYNA) and the modified Hybrid III model were used to numerically simulate the previous cadaver tests and validate the altered Hybrid III neck. Subsequent simulation of the child cadaver sled tests were completed with the child biomechanical test results implemented into the Hybrid III. The altered Hybrid III dummy illustrated a significant increase in flexion and distraction of the neck during the simulated sled test and a greater degree of chest deflection. The HIC evaluated using a 36 ms window for the altered Hybrid III dummy was observed to be 268 while the unaltered child dummy observed a HIC value of 194 evaluated using the same 36 ms window. The upper neck resultant forces computed from the simulation from the altered Hybrid III were observed to be 2.3 kN which, based upon the pediatric biomechanical response, would indicate tissue failure in this vicinity of the cervical spine.
Tot, Miroslav, Kapoor, Tanya, Altenhof, William, Marino, Wayne, Howard, Andrew
Evaluation of Neck Bracket Angles and Neck Torque Procedures in the Hybrid III Small Female Neck Flexion Test2008-01-05304/14/2008
Lab-to-lab differences are an important consideration in the verification testing of Hybrid III dummy necks in user labs. The authors, the Anthropomorphic test device Certification Research group (ACR), conducted and presented two previous studies investigating lab to lab differences in Hybrid III 5th female dummy neck certification results [1, 2]. The results of both studies underscored the need to have better controls on the test procedure. The complex procedure for dummy neck certification has many setup factors that can contribute to test variation and unacceptable precision. Two steps within this protocol - two aspects of the neck's physical setup - were identified by the ACR group as potential sources for variation: 1) setting the pre-test D-plane angle by neck bracket adjustment, and 2) setting the torque on the neck cable. Fifth female neck flexion tests were conducted with variations in these factors to determine their effect on neck test results. In this paper the authors quantify the results of this investigation and discuss recommendations for reduction of lab-to-lab variation.
Below, John D., Depinet, Paul J., Jenkins, Jason D., Al-Tabakha, Emad, Watters, Virginia L.
Comparison of D-Plane Measurement Methods for the Hybrid III Small Female Neck Flexion Test2008-01-05314/14/2008
This study by the Anthropomorphic test device Certification Research group (ACR) takes a new look at dummy neck rotation measurement methods. The authors' previous SAE Congress paper, Watters et al., 2005, focused on comparing three different rotary pot measurement systems in the same Hybrid III 5th Female neck flexion test at a single laboratory [1]. Differences between the pot systems, and between the pot systems and video analysis of the head rotation, were found to be a significant component of the observed test variation. The 2005 rotary potentiometer study used a modified head known as the Nine Accelerometer Array Head (NAAH). The NAAH data for rotation about the Y-axis, only recently analyzed, showed exceptional agreement with the video analysis as compared to the rotary potentiometer data. This new series of 5th Female neck flexion tests has been conducted using four rotation measurement methods simultaneously: 1) one of the previously- tested conventional rotary potentiometer systems, 2) the NAAH, 3) video analysis, and 4) gyro measurement. A comparison of the four rotation measurement methods is presented.
Jenkins, Jason D., Al-Tabakha, Emad, Below, John D., Depinet, Paul J., Watters, Virginia L.
Evaluations of Physical Fatigue during Long-term Driving with a New Driving Posture2007-01-03484/16/2007
In a previous study, we developed and validated a new driving posture focused on biomechanical loads for physical fatigue reduction in static long-term sitting. In this study, the posture was evaluated in dynamic long-term driving condition by qualitative and quantitative measurements. The results showed physical fatigue of the new posture was halved in comparison with the one of the conventional posture in same car by subjective evaluations. Physiological indices had same tendency with subjective evaluations. From the results, we extracted seven physiological indices as good measures of physical fatigue while driving. Therefore, fatigue reduction of the new posture was qualitatively validated by physiological measurements.
Hirao, Akinari, Kato, Kazuhito, Kitazaki, Satoshi, Yamazaki, Nobutoshi
Scattering-Type Surface-Plasmon-Resonance BiosensorsTBMG-291721/1/2005
Biosensors of a proposed type would exploit scattering of light by surface plasmon resonance (SPR). Related prior biosensors exploit absorption of light by SPR. Relative to the prior SPR biosensors, the proposed SPR biosensors would offer greater sensitivity - in some cases, enough sensitivity to detect bioparticles having dimensions as small as nanometers.
Effect of Head-Neck Position on Cervical Facet Stretch of Post Mortem Human Subjects during Low Speed Rear End Impacts2004-22-001511/1/2004
The purpose of this study was to determine the effect of head-neck position on cervical facet stretch during low speed rear end impact. Twelve tests were conducted on four Post Mortem Human Subjects (PMHS) in a generic bucket seat environment. Three head positions, namely Normal (neutral), Zero Clearance between the head and head restraint, and Body Forward positions were tested. A high-speed x-ray system was used to record the motion of cervical vertebrae during these tests. Results demonstrate that: a) The maximum mean facet stretch at head restraint contact occurs at MS4 and MS5 for the Body Forward condition, b) The lower neck flexion moment, prior to head contact, shows a non-linear relationship with facet stretch, and c) “Differential rebound” during rear end impact increases facet stretch.
Sundararajan, Srini, Prasad, Priya, Demetropoulos, Constantine K., Tashman, Scott, Begeman, Paul C., Yang, King H., King, Albert I.
A Normalization Technique for Developing Corridors from Individual Subject Responses2004-01-02883/8/2004
This paper presents a technique for developing corridors from individual subject responses contained in experimental biomechanical data sets. Force-deflection response is used as an illustrative example. The technique begins with a method for averaging human subject force-deflection responses in which curve shape characteristics are maintained and discontinuities are avoided. Individual responses sharing a common characteristic shape are averaged based upon normalized deflection values. The normalized average response is then scaled to represent the given data set using the mean peak deflection value associated with the set of experimental data. Finally, a procedure for developing a corridor around the scaled normalized average response is presented using standard deviation calculations for both force and deflection.
Lessley, David, Crandall, Jeff, Shaw, Greg, Kent, Richard, Funk, James
Human Tolerance to Impact Conditions as Related to Motor Vehicle DesignJ885_200312 (Historical)12/1/2003
This report reviews current quantitative data on human tolerance levels without recommending specific limits. Data developed on humans (including cadavers) are presented where available; however, in many cases animal data are provided where no suitable human results have been reported. This report confines itself, as much as possible, to information of direct use to the automotive designer and tester. Data of only academic interest are largely omitted; therefore, J885 should not be considered as a complete summary of all available biomechanical data. Most of the data cited in this report applies to adult males since little information is available on women or children. The summary data provided in the tables should be considered with the accompanying descriptive test. This material explains the manner in which the data were obtained and provides an insight as to their limitations The purpose of this reort is to assist the automotive safety designer and tester by providing them with quantitative data on the strength of the human body under impact loading conditions.
Human Biomechanics and Simulations Standards Committee
A Study of Ais1 Neck Injury Parameters in 168 Frontal Collisions Using a Restrained Hybrid Iii Dummy2000-01-SC0811/1/2000
The research of AIS1 neck injuries has focused on rear-end collisions, but a great portion of these injuries occur in frontal impacts. AIS1 neck injuries in frontal impacts can be associated with seat belt use and it can be hypothesized that the seat belt may transfer injurious loads to the neck. This study investigates the influence of the restraint system on the neck loads by using mechanical as well as mathematical (MADYMO) models of the HIII 50th percentile dummy. The mathematical simulations were based on 168 frontal crash pulses collected from crash recorders, installed in passenger cars in Sweden. The neck loads were evaluated by a new neck injury criterion NIC protraction, the upper neck flexion moment and the Nij criterion. It was found that a pretensioner, a load limiter or an airbag have the potential to reduce the neck loads below recently suggested reference values for long-term neck injuries only as well as short- plus long-term neck injuries. Moreover, the interaction between the pretensioner, the load limiter and the airbag was of great importance in order to minimize the neck loads.
Bohman, Katarina, Haland, Yngve
Digital Man Models and Physical Strength – A New Approach in Strength Simulation2000-01-21686/6/2000
ABSTRACT A radical new approach was started to realize physical strength in digital man models. The basic idea is to synthesize individual force exertions by local muscle moments powering relevant body joints. We envelop these articular 3 D-moments by spherical bodies suggesting potatoes. „M-Potatoes“ are describing the local situation in particular: the variety of diverging maximum moments a single joint may generate in a specified joint posture. A total of 244 „M-Potatoes“ was sampled at 34 body joints. Indication is further given how to adjust „M-Potatoes“ to varying target populations and how to integrate „M-Potatoes“ into digital man models.
Schaefer, Peter, Rudolph, Helmut, Schwarz, Wolfgang
Hybrid III Dummy Neck Round-Robin Testing9710432/24/1997
The Hybrid III dummy is the anthropomorphic test device specified in the federal regulation for occupant protection in frontal impacts. Performance requirements for the Hybrid III neck are defined in Part 572E of the Code of Federal Regulations, based on biomechanical research and development by General Motors. Compliance requires meeting specified corridors for the input to the system and the response of the system. In 1991 and 1992, a collaborative test effort was undertaken by a Task Group of the Dummy Testing Equipment Subcommittee of the SAE Human Biomechanics and Simulation Standards Committee. Ten dummy calibration laboratories participated in this effort. The Hybrid III neck flexion test, as specified by Part 572E, was the focus of this investigation. During the design and execution of these neck round-robin tests, it was found that test results were sensitive to many parameters (e.g., test apparatus physical characteristics; Hexcel® crush properties, mounting, and precrush; pendulum impact velocity; and measurement techniques). An attempt was made to control as many of these parameters as possible. In this paper, the Task Group presents the Hybrid III dummy neck round-robin test results, and addresses: repeatability within each laboratory, reproducibility between different laboratories, whether sensitive test parameters are sufficiently prescribed by Part 572E, and whether test input and response specifications provide appropriate assessments of neck performance. Overall, the neck round-robin test effort provided valuable insight to participating laboratories. Based upon the Task Group's experience, sensitive test parameters were identified and suggestions proposed to better specify these parameters in order to reduce within-laboratory and between-laboratory variations. Parameters were also identified that were not significant sources of variations. Improvements in test apparatus and procedures were made by many laboratories from information gained in this collaborative effort. Alternatives to Part 572E pendulum behavior and neck response specifications have been proposed.
Biomechanical Responses and Injuries in Blunt Lateral Impact89243210/1/1989
Viano, David C.
Human Tolerance to Impact Conditions as Related to Motor Vehicle DesignJ885_198607 (Historical)7/1/1986
This report reviews current quantitative data on human tolerance levels without recommending specific limits. Data developed on humans (including cadavers) are presented where available; however, in many cases animal data are provided where no suitable human results have been reported. This report confines itself, as much as possible, to information of direct use to the automotive designer and tester. Data of only academic interest are largely omitted; therefore, J885 should not be considered as a complete summary of all available biomechanical data. Most of the data cited in this report applies to adult males since little information is available on women or children. The summary data provided in the tables should be considered with the accompanying descriptive test. This material explains the manner in which the data were obtained and provides an insight as to their limitations The purpose of this reort is to assist the automotive safety designer and tester by providing them with quantitative data on the strength of the human body under impact loading conditions.
Human Biomechanics and Simulations Standards Committee
Human Mechanical Response CharacteristicsJ1460_198503 (Historical)3/1/1985
Human Biomechanics and Simulations Standards Committee
A New Dummy for Pedestrian Test8560311/1/1985
Improvement of pedestrian safety is considered a priority in crash injury protection. Dummies, however, are not able to give a humanlike and repeatable impact response in pedestrian tests. The Biomechanical Laboratory of ONSER in France and the Department of Traffic Safety of Chalmers University in Götheborg, Sweden have designed a new dummy for pedestrian testing. The dummy is designed according to the latest available anthropometric and biomechanical data. Its symmetry around the vertical axis allows repeatability for the kinematic and injury parameters. It allows a measurement of uncommon biomechanical parameters related to injury mechanisms. Its leg is instrumented to determine the distribution of forces and momenta applied to the leg.
Cesari, Dominique, Bouquet, Robert, Zac, R., Aldman, Bertil, Kajzer, Janusz
The Biomechanics Data Base8408674/1/1984
The Biomechanics Data Base contains the signals recorded during tests of human response to impact. A variety of possible errors in the signals from a test have been discovered, and are described in this paper, as well as the possible corrections for these errors. In addition, the contents of the data base are described as well as the tools available to analyze the data. Finally, plans for future development of the data base are revealed.
Marcus, Jeffrey H.
An Apparatus for studying the Neural Control and Biomechanics of Bilateral Coordination in Conventional Versus Novel Pedaling8400292/1/1984
An unusual stationary pedaling system has been built to teat the interaction of neural control and biomechanics during difficult bilateral coordination tasks. Subjects are tested during both conventional and novel pedaling. Neuromuscular and biomechanical data (electro-mayograms, kinematics and pedaling forces) are collected as the subject pedals. A brief discussion of the study's rationale, theoretical approach and preliminary results is presented as background to an understanding of the functional design features of the apparatus.
Schwandt, Douglas F., Zomlefer, Michael R., Boylls, C. Curtis, Onyski, Jean H., Cohen, Lisa A.
Human Tolerance to Impact Conditions as Related to Motor Vehicle DesignJ885_198004 (Historical)4/1/1980
This report reviews current quantitative data on human tolerance levels without recommending specific limits. Data developed on humans (including cadavers) are presented where available; however, in many cases animal data are provided where no suitable human results have been reported. This report confines itself, as much as possible, to information of direct use to the automotive designer and tester. Data of only academic interest are largely omitted; therefore, J885 should not be considered as a complete summary of all available biomechanical data. Most of the data cited in this report applies to adult males since little information is available on women or children. The summary data provided in the tables should be considered with the accompanying descriptive test. This material explains the manner in which the data were obtained and provides an insight as to their limitations.
Human Biomechanics and Simulations Standards Committee
Improved Laminated Windshield with Reduced Laceration Properties7309692/1/1973
A new laminated automobile windshield called Triplex “Ten-Twenty,” fabricated from two thermally stressed glass plies of 2.3 mm soda-lime float glass laminated with a 0.76 mm HPR polyvinyl butyral interlayer, has been biomechanically evaluated by Triplex Safety Glass Co., Ltd., using a dropping headform and a skull impactor, and by Wayne State University, using a 50th percentile anthropomorphic dummy on the WHAM III sled test facility. The results of these evaluations at velocities up to 60 km/h are expressed in terms of Gadd index, head injury criterion, and various laceration scales including the new Triplex laceration index (TLI). Some details are also given of other properties of the windshield. The results of the evaluations indicate that the Ten-Twenty windshield offers a reduction of about two units on the TLI scale equivalent to one of the following: 1. A 99% reduction in the number of cuts when the length and depth of cuts remain unaltered. 2. A 90% reduction in the length of cuts when the number and depth of cuts remain unaltered. 3. A change in depth of cuts from one layer of skin simulation to another, but in particular a 78.5% reduction in the depth of cuts into the polyvinyl chloride base layer when the number and length of cuts remain unaltered. In practice, the length, number, and depth of cuts all change together so that one typical example taken from the test program of a two-unit reduction in TLI is: 1. A 62% reduction in the average depth of cuts into the polyvinyl chloride base. 2. A 27% reduction in the average length of cuts. 3. No increase in the total number of cuts. On the basis of these results, Ten-Twenty is a much safer laminated automobile windshield than those now commercially available due to decreased laceration to the occupants during a collision.
Kay, S. E., Pickard, J., Patrick, L. M.
Biomechanics and Its Application to Automotive Design P-49 - A Continuing Engineering Education Course developed by SAE Automobile Body Activity, Passenger Protection Committee7304132/1/1973
Application and Development of the Tramasaf Headform6904762/1/1969
The authors discuss the use of Tramasaf, a laboratory instrument that will test the energy absorption capability of automotive components, and will concurrently measure the extent of trauma to the human forehead. The most recently published biomechanics data has required a revision of the original development goals for the device. The paper describes these new goals, the stage of the progress, and some applications which verify the utility of the device.
Holcombe, H.G., Foster, J.K.
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