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Devices for Use in Defining and Measuring Vehicle Seating AccommodationJ826_202106 (Current)6/22/2021
The devices of this SAE Standard provide the means by which passenger compartment dimensions can be obtained using a deflected seat rather than a free seat contour as a reference for defining seating space. All definitions and dimensions used in conjunction with this document are described in SAE J1100. These devices are intended only to apply to the driver side or center occupant seating spaces and are not to be construed as instruments which measure or indicate occupant capabilities or comfort. This document covers only one H-point machine installed on a seat during each test. Certified H-point templates and machines can be purchased from: SAE International 400 Commonwealth Drive Warrendale, PA 15096-0001 Specific procedures are included in Appendix A for seat measurements in short- and long-coupled vehicles and in Appendix B for measurement of the driver seat cushion angle. Specifications and a calibration inspection procedure for the H-point machine are given in Appendix C. Additional considerations are necessary when a head restraint measuring device (HRMD) is mounted to an H-point machine (Appendix D).
Human Accom and Design Devices Stds Comm
Evaluation of the atomized jet of common rail injectors nozzles working with biodieselSAE-PP-001371/22/2021
The atomization process in a Diesel engine is directly involved with its efficiency, emissions and damage. The biodiesel insertion brought with it interactions not expected by the components involved in the injection process and, consequently, different wear mechanisms. This paper aims to evaluate the injector nozzle hole wear and the consequences to the atomized jet profile by using a high-speed camera. The tests were run in a common rail test rig using two injectors, one to each biodiesel formulation during the period of 20 hours, non-continuous, for each one The injection parameters were set to 800 bar, 700 μs and 18 Hz (representing partial load in a usual common rail engine), for the pressure, time and frequency of injection, respectively. The injectors were placed in a chamber at 1 atm and were filmed in its new condition and after the tests using the camera at 10,000 frames per second (fps) in two different pressures (350 bar and 1400 bar) with the injection frequency at 12 Hz. The results were analyzed using a software to measure the jet length, speed, cone angle and jet density. The wear mechanisms were different for each fuel resulting in a jet profile change and, consequently, modifying the engine efficiency.
MobrxivNonAdmin, Lindsay
Biofidelity of THOR 5th Percentile Female ATD in Ankle Eversion and Inversion2020-01-05284/14/2020
Females have higher frequency and risk of foot and ankle injuries in motor vehicle collisions than similar-sized males. Therefore, lower extremity biofidelity and accurate injury prediction of female ATDs is critical. This paper aims to compare the THOR 5th percentile female (THOR-05F) anthropomorphic test device (ATD) response with male and female PMHS data of various sizes under ankle inversion and eversion. The THOR-05F lower extremity was subjected to dynamic inversion and eversion ankle loading with a constant 2000N axial force applied through the tibia. Twelve THOR-05F tests (3 inversion and 3 eversion on both, left and right legs) were performed with boundary conditions consistent with previous post-mortem human subject (PMHS) lower extremity tests. The biofidelity of THOR-05F ankle stiffness was evaluated via comparison of measured and equal-stress equal-velocity scaled data (using mass-based scale factors) from previous PMHS datasets with mid-size males, small females and larger females. THOR-05F ankle moment-angle response falls within the range of previous mid-sized male and larger female PMHS test data for eversion, when scaled to a small female. However, when compared to PMHS response measured on small female subjects, the THOR-05F response was less stiff in both inversion and eversion. The THOR-05F moments were 65% and 90% less stiff in eversion and inversion respectively, when compared to the average of the measured small female PMHS dataset at 250 ankle rotation. Because ATD stiffness differs from measured PMHS ankle stiffness, care should be taken when applying PMHS-based injury risk functions (IRF) to the THOR-05F ankle.
Kulkarni, Shubham, Roberts, Carolyn, Foltz, Patrick, Forman, Jason
A Study of Driver's Driving Concentration Based on Computer Vision Technology2020-01-05724/14/2020
Driving safety is an eternal theme of the transportation industry. In recent years, with the rapid growth of car ownership, traffic accidents have become more frequent, and the harm it brings to human society has become increasingly serious. In this context, car safety assisted driving technology has received widespread attention. As an effective means to reduce traffic accidents and reduce accident losses, it has become the research frontier in the field of traffic engineering and represents the trend of future vehicle development. However, there are still many technical problems that need to be solved. With the continuous development of computer vision technology, face detection technology has become more and more mature, and applications have become more and more extensive. This article will use the face detection technology to detect the driver's face, and then analyze the changes in driver's driving focus. Firstly, the problem of detecting the eyes and mouth status of the driver is discussed. The purpose is to capture the driver's long-term closed eyes and yawning and other actions closely related to the dozing behavior. Secondly, the problem of estimating the driver's head posture is studied. The purpose is to capture the abnormal movements of the driver's long bow, head up or frequent nodding. The study consists of three parts: detection of facial feature points, estimation of the head posture based on the feature points, and definition of fatigue characteristics. The experimental results show that the method in this paper is not only easy to operate but also has a high accuracy rate for the detection of driver concentration.
Lin, Guan, Zhan, Zhenfei, Peng, Xiangjun, Xu, Huijie, Fu, Yue, Jiang, Ling
A Design and Optimization Method for Pedestrian Lower Extremity Injury Analysis with the aPLI Model2020-01-09294/14/2020
As pedestrian protection tests and evaluations have been officially incorporated into new C-NCAP, more stringent requirements have been placed on pedestrian protection performance. In this study, in order to reduce the injury of the vehicle front end structure to the pedestrian's lower extremity during the collision, the advanced pedestrian legform impactor (aPLI) model was used in conjunction with the finite element vehicle model for collision simulation based on the new C-NCAP legform test evaluation regulation. This paper selected the key components which have significant influences on the pedestrian's leg protection performance based on the CAE vehicle model, including front bumper, front-cover plate, upper impact pillar, impact beam and lower support plate, to form a simplified model and conducted parametric modeling based on it. Then, the variable correlation analysis was carried out on the sample results obtained from the design of experiment (DOE), and the contribution analysis of design variables to the injury measures was discussed. The sample variables and responses were also used to construct the approximate models for further optimization studies. Taking the pedestrian lower extremity injuries as the optimization target, the front end structural parameters were matched and optimized. Finally, an optimal configuration for parameter matching of key components of the front end structure for pedestrian protection was established, which effectively improve the protection of pedestrian lower extremity.
Fu, Yue, Xu, Huijie, Lin, Guan, Zhan, Zhenfei, Wang, Ping, Chen, Ruyi, Yu, Huili
Unpowered, Lightweight Ankle ExoskeletonTBMG-3571712/1/2019
A lightweight, low-profile, inexpensive ankle exoskeleton could be widely used among elderly people, those with impaired lower-leg muscle strength, and workers whose jobs require substantial walking or running.
Biologically Inspired Artificial Skin Improves Sensory Ability of RobotsTBMG-3561112/1/2019
Inspired by human skin, a system was developed that combines artificial skin with control algorithms. The system was used to create the first autonomous humanoid robot with full-body artificial skin.
Origami-Inspired Material Softens Impact ForcesTBMG-351279/1/2019
Landing is stressful on a rocket’s legs because they must handle the force from the impact with the landing pad. One way to combat this is to build legs out of materials that absorb some of the force and soften the blow. Inspired by the paper-folding art of origami, researchers created a paper model of a metamaterial that uses “folding creases” to soften impact forces and instead promote forces that relax stresses in the chain.
Surgeons Use Augmented Reality to Reconnect Blood VesselsTBMG-349258/1/2019
Following severe trauma, patients may have tissue damage or open wounds that require reconstructive surgery using fasciocutaneous flaps. These flaps of tissue, which are taken from elsewhere on the body and include the skin and blood vessels, are used to cover the wound and enable it to close and heal properly. A vital step in the process is connecting the blood vessels of the new tissue with those at the site of the wound, so oxygenated blood can reach the new tissue and keep it alive.
‘Stumbling Device’ Helps Improve Prosthetic LegsTBMG-349748/1/2019
Researchers are addressing the tendency to stumble in lower-body prosthetics by understanding the way people with two legs catch themselves. They accomplished this by covering test subjects with motion-capturing sensors. It also required tripping them over and over — 190 times, to be exact — for a study. But because humans are so mentally geared to resist stumbling, the team first had to design a stumbling device.
Engineers Develop More Stable, Efficient Prosthetic FootTBMG-348057/1/2019
Engineers have developed a more stable prosthetic leg — and a better way of designing them — that could make challenging terrain more manageable for people who have lost a lower leg. The cornerstone of the new design is a kind of tripod foot that responds to rough terrain by actively shifting pressure between three different contact points. As important as the foot is, the team also developed a tool for quickly emulating and improving their prototypes.
Smart, Soft, Back Orthosis Uses Real-Time Motion DetectionTBMG-346136/1/2019
Back pain is inevitable with constrained posture over a number of hours. Permanent damage such as premature spine wear is not uncommon in people who do not adopt proper ergonomic posture. The same applies to those who frequently lift heavy objects.
U.S. Army Aeromedical Research LaboratoryTBMG-346366/1/2019
In October 1962, the U.S. Army Aeromedical Research Unit was established with a goal of providing specialized medical and physiological support to help close the gap between Army combat aviation needs and human capabilities, and to protect aviators from altitude, climate, noise, acceleration, impact, and other stressors in a growing hostile environment. In 1969, the Army re-designated the unit as the U.S. Army Aeromedical Research Laboratory (USAARL).
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
Residual Injury Situation and Accident Characteristics of Severe Motorcycle Accidents2019-01-06384/2/2019
The total number of persons severely and fatally injured in road traffic accidents has reduced considerably in recent decades. However, the number of motorcyclists involved in accidents has not reduced to the same extent, and some countries have even recorded an increase. The aim of this study is to analyse the circumstances of motorcycle accidents in Germany involving vehicles with a cubic capacity of over 125 cm3 with particular reference to severely or fatally injured riders. An analysis is to be made of the characteristics and patterns of injuries suffered by the most severely injured motorcyclists and proposals developed for injury prevention. The study included accident data from 464 motorcycle accidents collected in Hanover and Dresden between 2010 and 2015 by an academic research team in the course of the GIDAS project (German In-Depth Accident Study). This data represents a statistically representative sample from real accidents occurring in Germany. The analysis of the current injury situation shows that motorcyclists are often severely injured, i.e. suffered injuries of grade MAIS 3+ (so called serious injuries) in 16.9% of cases and thus around 9 times more frequently than car occupants. Motorcyclists wearing helmets suffered head injuries in approx. 20 % of cases. The serious injuries sustained were in particular skull fractures, including base of the skull and traumatic brain injuries are rare. Severe thoracic injuries included in particular rib and shoulder/clavicle fractures, often accompanied by injuries to internal organs. In terms of spinal injuries, the most common serious injuries were fractures of the thoracic spine, followed by fractures of the lumbar spine and cervical spine. In the abdominal area there were often severe injuries in the form of fractures in the pelvic area and accompanying injuries to internal organs. Arm injuries included, besides minor injuries (grazes, bruises, etc.), most commonly fractures of the hands/fingers and forearms, followed by elbow and upper arm fractures. Leg injuries seen in particular were femoral fractures as well as injuries to the muscles and tendons around the knee, also fractures of the shin and calf bones. Around the feet there were many fractures and dislocations of the wrist and ankle joints, as well as toes. The causes of the injuries, which were recorded in detail in the study for the various regions of the body and individual injuries, were most often caused by impact with the road and collision with objects and solid vehicle structural elements of cars and trucks. Serious injuries are linked with high energy respectively high relative impact speed.
Otte, Dietmar
Innovative Knee Airbag (KAB) Concept for Small Overlap and Oblique Frontal Impacts2019-01-06214/2/2019
Considerable research has been conducted in terms of attempting to reduce lower leg injury risk in full frontal impacts, in some cases by the use of a knee airbag (KAB). However, there has been limited research into the performance of KAB systems during a crash test with increased oblique loading, such as the IIHS small overlap frontal test, an oblique moving deformable barrier test (OI) being researched by NHTSA, and a mobile progressive deformable barrier test (MPDB) that is expected to be implemented by Euro NCAP in the next few years. The objective of the current numerical study was concentrated on the evaluation of an innovative KAB concept design intended to reduce ATD right inboard lower leg/foot responses under small overlap and oblique loading conditions. A novel appendage KAB concept design was developed with the help of morphing and computational studies which were performed with different ATD sizes. In the study, one of the lower leg/foot responses was monitored and compared over a conventional KAB design. Cases investigated in the study showed that the novel appendage KAB concept design acts as a conventional KAB in full frontal impact modes (similar right inboard femur responses) and has the potential to reduce right inboard lower leg/foot responses by an average 16% (small overlap impact mode) and 20% (oblique impact mode) over the conventional KAB design. Furthermore, it was noted that the novel design could potentially be adapted to achieve targeted right inboard lower leg responses in full, offset and oblique frontal crash tests with minimal impact on the left outboard responses.
Makwana, Rahul, Jindal, Pardeep
Q&A: Siyi Xu, Harvard John A. Paulson School of Engineering and Applied Sciences, Cambridge, MATBMG-339303/1/2019
Working with teams from Harvard, Beth Israel Deaconess Medical Center, and Boston Children's Hospital, Siyi Xu developed a soft, non-toxic, wearable sensor that attaches to the hand and measures grasp force and the motion of the hand and fingers. The sensor is designed to identify neuromotor disabilities in prematurely born children.
Rehab Device Works with All Joints of Lower LimbsTBMG-338542/1/2019
South Ural State University Chelyabinsk, Russia
Computer Detects and Understands Body LanguageTBMG-336091/1/2019
Detecting the nuances of nonverbal communication between individuals will allow robots to serve in social spaces, enabling them to perceive what people around them are doing, what moods they are in, and whether they can be interrupted. A self-driving car could get an early warning that a pedestrian is about to step into the street by monitoring body language. Enabling machines to understand human behavior also could enable new approaches to behavioral diagnosis and rehabilitation for conditions such as autism, dyslexia, and depression.
Device Assesses and Monitors Lymphedema NoninvasivelyTBMG-3344912/1/2018
Lymphedema is the swelling that generally occurs in the arms or legs caused by the removal of or damage to lymph nodes as a part of cancer treatment. Treating it at the earliest possible stage is the best way to manage the condition and prevent it from leading to pain, recurrent infection, reduced mobility, and impaired function.
Reference PMHS Sled Tests to Assess Submarining of the Small Female2018-22-000311/12/2018
In the last decade, extensive efforts have been made to understand the physics of submarining and its consequences in terms of abdominal injuries. For that purpose, 27 Post Mortem Human Subject (PMHS) tests were performed in well controlled conditions on a sled and response corridors were provided to assess the biofidelity of dummies or human body models. All these efforts were based on the 50th percentile male. In parallel, efforts were initiated to transfer the understanding of submarining and the prediction criteria to the THOR dummies. Both the biofidelity targets and the criteria were scaled down from the 50th percentile male to the 5th percentile THOR female. The objective of this project was to run a set of reference PMHS tests in order to check the biofidelity of the THOR F05 in terms of submarining. Three series of tests were performed on nine PMHS, the first one was designed to avoid submarining, the second and third ones were designed to result in submarining. In the first configuration, no submarining was observed in 3 cases out of 4 and only one iliac wing fracture occurred in one subject. In the second and third configurations, all subjects but one sustained submarining. In addition, two subjects out of three in the third configuration sustained substantial iliac wing fractures. Nevertheless, all configurations can be represented by at least one or several cases without any pelvis fracture. Corridors were constructed for the external forces and the PMHS kinematics. They are provided in this paper as new experimental references to assess the biofidelity of small female human surrogates in different configurations where submarining did or did not occur.
Trosseille, Xavier, Petit, Philippe, Uriot, Jérôme, Potier, Pascal, Baudrit, Pascal, Richard, Olivier, Compigne, Sabine, Masuda, Mitsutoshi, Douard, Richard
Dual Therapy Improves Stroke RecoveryTBMG-324538/1/2018
Paralysis of an arm and/or leg is one of the most common effects of a stroke. But thanks to new research, stroke victims may soon be able to recover greater use of their paralyzed limbs. The scientists’ pioneering approach brings together two known types of therapies — a brain-computer interface (BCI) and functional electrical stimulation (FES).
Bringing a Human Touch to Modern ProstheticsTBMG-324588/1/2018
Amputees often experience the sensation of a “phantom limb”—a feeling that a missing body part is still there. That sensory illusion is closer to becoming a reality thanks to a team of engineers at Johns Hopkins University that have created an electronic skin. When layered on top of prosthetic hands, this e-dermis brings back a real sense of touch through the fingertips.
Using Optical 3D Scanning to Measure the Human BodyTBMG-324558/1/2018
The latest advances in 3D technologies are revolutionizing the ability to measure the human body, and this is having a tremendous impact on the healthcare industry and in the development of healthcare products. For example, Japanese research company Unitika Garments Technology is using optical 3D scanning to measure the human body to research use of dimensional inspection for quality control of textile products. Optical 3D measurement produces data that cannot be gathered using traditional methods.
Engineers Design Color-Changing Compression BandageTBMG-297457/1/2018
Compression therapy is a standard form of treatment for patients who suffer from venous ulcers and other conditions in which veins struggle to return blood from the lower extremities. Compression stockings and bandages, wrapped tightly around the affected limb, can help to stimulate blood flow. But there is currently no clear way to gauge whether a bandage is applying an optimal pressure for a given condition.
Simplifying the Structural Design of the Advanced Pedestrian Legform Impactor for Use in Standardized Testing2018-01-10494/3/2018
The advanced Pedestrian Legform Impactor (aPLI) incorporates a number of enhancements for improved lower limb injury prediction capability with respect to its predecessor, the FlexPLI. The aPLI also incorporates a simplified upper body part (SUBP), connected to the lower limb via a mechanical hip joint, that expands the impactor’s applicability to evaluate pedestrian’s lower limb injury risk also in high-bumper cars.As the aPLI has been developed to be used in standardized testing, further considerations on the impactor’s manufacturability, robustness, durability, usability, and repeatability need to be accounted for.. The aim of this study is to define and verify, by means of numerical analysis, a battery of design modifications that may simplify the manufacturing and use of physical aPLIs, without reducing the impactors’ biofidelity. Eight candidate parameters were investigated in a two-step numerical analysis. One of the parameters was related to the SUBP structure, six to the mechanical characteristics of the hip joint (x-rotation, and y and z displacements), and one to the ankle joint characteristics (x-rotation). First, the individual effect of each candidate parameter on biofidelity targets was assessed based on linear regression analysis of three peak lower limb injury measurements (femur bending moment, knee medial collateral ligament elongation and tibia bending moment) from impact simulations conducted with either a human full-body model or with the corresponding aPLI model. Second, the same methodology was applied to assess the cumulative effect of the candidate parameters on the biofidelity targets with different aPLI versions that incorporated a gradually increasing number of simplifications. The most remarkable results revealed that a compact SUBP connected to the mechanical lower limb by a highly simplified cylindrical mechanical hip joint can be incorporated to the aPLI design without reducing its biofidelity. In addition, the methodology applied to simplify the aPLI design proved effective to find the simplest solution.
Isshiki, Takahiro, Antona-Makoshi, Jacobo, Konosu, Atsuhiro, Takahashi, Yukou
Frontal, Lateral, and Free-Operation Impacts of Amusement Bumper Cars: Vehicle Kinematics and Occupant Kinematics2018-01-05434/3/2018
This study conducted a series of rear-impact, side-impact, barrier, and free-operation collisions using a bumper car ride at an active amusement park. Two conditions were studied: staged and free operation. Each staged test included a bullet (impacting) vehicle operated by a rider and a target (impacted) static vehicle or structure. Impact configurations of frontal collisions of the bullet vehicle into the rear and side of a target vehicle were consistent with the existing literature. The free operation condition involved collisions which were not pre-determined, and operators may not have been prepared for collision timing, magnitude, and direction. Results demonstrated high repeatability for vehicle parameters, such as impact velocity, change in velocity, and peak acceleration. Peak changes in velocity during vehicle-to-vehicle collisions were 2.2-2.5 m/s (8-8.9 km/hr; 5-5.5 mph) for the target vehicle and 1.6-1.8 m/s (5.6-6.4 km/hr; 3.5-4 mph) for the bullet vehicle, while those during vehicle-to-retaining barrier collisions were approximately 3.6 m/s (13 km/hr; 8 mph). Coefficients of restitution and overall vehicle and occupant kinematics were similar to prior bumper car studies, and collision magnitudes were similar in the free-operation test to the staged, single-axis collisions. Bumper cars present a model environment to study vehicle and occupant kinematics in vehicle collisions that are within human tolerance and include aware but possibly unprepared occupants. This is relevant to establishing occupant kinematics in and limits to autonomous vehicle emergency handling maneuvers.
Bussone, William R., Moore, Tara, Locey, Caitlin, Cargill, Robert
Ground Landing Mechanisms in Vehicle-To-Pedestrian Impacts Based on Accident Video Records2018-01-10444/3/2018
Accident data have shown that the pedestrian injuries resulting from contact with the ground are serious and may even be worse than the injuries resulting from the primary contact with the vehicle. The landing mechanisms, including the pedestrian trajectory and subsequent sequential body region contacts to the ground, are the basis for understanding the ground impact injuries of pedestrians. However, the landing mechanisms of pedestrian are too complicated to be categorized via investigation of the collision information after an accident has occurred. Nowadays, pedestrian kinematics after vehicle impacts can be observed from the accident videos that have been recorded by road monitoring and driver recorders. This study was aimed at investigating the pedestrian landing mechanisms and analyzing the influencing factors. In the current study, 134 pedestrian cases (involving 136 pedestrians) were selected from the internet, and 13 types of landing mechanisms were classified according to the fall kinematics and landing posture. Our results show that pedestrians who were thrown forward and hit the ground without a clear rotational tendency (ground landing mechanism II) accounted for the highest frequency, 49.3% in all cases. The landing mechanisms of pedestrians were affected by impact velocities and kinematic trajectories during vehicle impacts. The results of this study can benefit the development of vehicle safety systems that reduce pedestrian ground impact injuries.
Li, Quan, Han, Yong, Mizuno, Koji
Investigation on Contralateral Lower Extremity Injuries of Pedestrian and E-Bike Rider Based on C-NCAP2018-01-10454/3/2018
Lower extremities are easily injured in traffic accidents. During pedestrian-vehicle crashes, pedestrian lower extremities are subjected to the influence of combined shear force and bending force, which could bring about ligament tear and bone fracture. According to 2018 China New Car Assessment Program (C-NCAP) pedestrian testing protocol, where the flexible pedestrian legform impactor (FLEX-PLI) is struck from the right lateral by vehicle, the injuries of the ipsilateral side leg are taken into account for assessing the performance of lower extremities. However, the contralateral leg injuries and deformation are neglected in the current testing protocol and the pedestrian walking gaits and the e-bike riding scenario have been little consideration. The purpose of this study is to investigate the injury characteristics of the contralateral lower extremities in pedestrian-vehicle and bicyclist-vehicle crashes. Impact simulations were conducted by the Total Human Model for Safety (THUMS) biomechanical dummy, which the testing vehicle struck the pedestrian of the standing and walking postures as well as the bicyclist at the speed of 40 km/h. The femur, fibula, tibia stress, the stretching ratio of ligaments, and the bending angle of the knee joints for the contralateral side legs were measured. Meanwhile, a comparison of the injuries and motions between the two legs was analyzed. The results show that the walking gait increased the injury risk of long bone fracture and ligation rupture, and the e-bike riding posture enlarged the injury risk of long bone fracture and reduced the ligation stretching ratio compared the standing case. Moreover, the stretching ratio of the contralateral LCL was larger than that of the ipsilateral MCL for all scenarios.
Chen, Chao, Fang, Rui, wang, Longliang
Using Shoulder Bolster and Knee Bolster to Achieve Protection Effect Comparable to Seatbelt and Airbag2018-01-11704/3/2018
Seatbelt and airbags provide effective occupant restraint, but are also potential to induce intrusive deformation and submarining injuries in motor vehicle crashes. To address these issues, this study puts forward a new restraint concept that applies restraint loads on shoulders and knees/femurs, i.e., the sturdiest regions of human body, via a combined use of shoulder bolster and knee bolster based on biomechanical computational analysis. The load characteristics of the two bolsters were optimized to obtain protection effectiveness superior to conventional use of seatbelt and airbag. Occupant kinematics and kinetics were taken into account, including the excursions of head, shoulders and knees, the accelerations of head and chest, and the compressions of thorax on several locations on the ribcage. The injury risk of rib fractures was monitored based on the strain levels of ribcage. Results show that applying adaptive restraint loads on the sturdy regions of human body using shoulder bolster and knee bolster can ensure reasonable kinematical motion and acceptable injury levels of occupant, and can also avoid intrusive deformations in thorax and abdomen as well as airbag hazards. The protection effect of shoulder bolster and knee bolster is comparable or superior to that of using seatbelt and airbag. To achieve a balance of comfort and safety in autonomous driving environment, the system will be activated only when collision is sensed unavoidable.
Huang, Yuan, Zhou, Qing, Ji, Peijun, Nie, Bingbing
Optimizing Occupant Restraint Systems for Tactical Vehicles in Frontal Crashes2018-01-06214/3/2018
The objective of this study was to optimize the occupant restraint systems for a light tactical vehicle in frontal crashes. A combination of sled testing and computational modeling were performed to find the optimal seatbelt and airbag designs for protecting occupants represented by three size of ATDs and two military gear configurations. This study started with 20 sled frontal crash tests to setup the baseline performance of existing seatbelts, which have been presented previously; followed by parametric computational simulations to find the best combinations of seatbelt and airbag designs for different sizes of ATDs and military gear configurations involving both driver and passengers. Then 12 sled tests were conducted with the simulation-recommended restraint designs. The test results were further used to validate the models. Another series of computational simulations and 4 sled tests were performed to fine-tune the optimal restraint design solutions. The sled tests with the optimized seatbelt and airbag designs provided significant improvement of occupant protection from the baseline tests in terms of the head, neck, chest, and lower extremity injury measures. Using a baseline seatbelt without an airbag, the ATD tended to contact the steering wheel or the instrument panel, or sustained a significant head whipping motion inducing large head and neck injury measures. By adding the airbag and reducing the load limit in the seatbelt, the injury measures were improved significantly. This study demonstrated the benefit of adding a properly designed airbag and advanced seatbelt to improve the occupant protection in frontal crashes under an environment representing a light tactical vehicle.
Hu, Jingwen, Ritchie Orton, Nichole, Chen, Cong, Reed, Matthew, Rupp, Jonathan, Gruber, Rebekah, Clark, David, Scherer, Risa
Augmented Reality Helps Surgeons See Through Tissue to Reconnect Blood VesselsTBMG-287434/1/2018
Imperial College London London, UK
Autonomous Robotic Self-RightingTBMG-286994/1/2018
Robots are increasingly being used for various applications including search and rescue operations and combat situations. Unfortunately, during the performance of maneuvers, a robot may fall or tip over, preventing it from moving normally. Controlling the robot to successfully right itself can be a difficult and time-consuming task for operators — a major problem in situations that may be both time-sensitive and dangerous; for example, those controlling the robot must determine how to re-orient the robot to a desired position, if it is possible.
Microextrusion Tubing Advances Help Push Medical Device BoundariesTBMG-285203/1/2018
Over the past five years, technological advances have enabled product applications for microextrusion to penetrate into the medical OEM arena. Simply speaking, micro now really means micro. Years ago, when an OEM was asking for micro tubing, they typically were looking for ranges between 0.060 and 0.100 in. OD with 2-4 lumens. Now micro range dimensions are down to 0.024 in. OD with up to 6 lumens, including an ID range as low as 0.003 in.
Smart Artificial LimbsTBMG-281631/1/2018
Traditional leg prosthetics enable amputees to maintain mobility and lead more active lives. Leg prosthetics most commonly fit amputees’ residual limbs via a socket that encloses the limb like a wooden clog. Because the socket exerts pressure on the limb’s soft tissue, pain and chafing, sores and blisters, and infection can occur. Amputees often must have their socket prosthetics adjusted regularly, which is inconvenient and costly. Consequently, many amputees give up prosthetics for wheelchairs.
Printable Structures Self-Fold Without Heating or Immersion in WaterTBMG-281581/1/2018
As 3D printing has become a mainstream technology, studies have investigated printable structures that will fold themselves into useful three-dimensional shapes when heated or immersed in water. A new printable structure, however, was developed that begins to fold itself up as soon as it is peeled off the printing platform.
Device-Free Motion Tracing Using WiFi SignalsTBMG-2797912/1/2017
Fine-grained human motion tracing — the ability to trace the trajectory of a moving human hand or leg, or even the whole body — is a general capability that is useful in a wide variety of applications. It can be used for gesture recognition and virtual touch-screens (e.g. Kinect-style natural user interfaces), activity recognition, monitoring of young infants and the elderly, or security applications such as intruder detection. Motivated by these applications, depth-sensing-based systems have been developed to implement motion tracing capabilities in cameras; however, these devices are limited because they have a constrained field of view (around 2 to 4 m range with a 60-degree aperture), and do not work in non-line-of-sight scenarios, preventing their use in many applications such as whole-home activity recognition, security, and elderly care.
Computational Tool Simplifies Creating Machines That BendTBMG-2773210/1/2017
Replacing rigid joints and linkages with mechanisms that bend offers a number of potential advantages, even as it makes designing devices more difficult. A computational design tool developed by Disney Research promises to make this transition from rigid to compliant mechanisms easier. The tool can take a design for a conventional, rigidly articulated device and automatically substitute parts that achieve the same function through flexibility, drawing from existing catalogs of compliant mechanisms.
Straws Help Create Simple Robot JointsTBMG-272728/1/2017
Inspired by arthropod insects and spiders, Harvard professor George Whitesides and Alex Nemiroski, a former postdoctoral fellow in Whitesides’ Harvard lab, used ordinary plastic drinking straws to create a type of semi-soft robot capable of standing and walking. The team also created a robotic water strider capable of pushing itself along the liquid surface.
The Future of Wearable TechnologyTBMG-271937/1/2017
The limiter to real-time physiological status monitoring (RT-PSM) has not been engineering technology. More than 50 years ago, John Glenn blasted off from Cape Canaveral while his medical team monitored a modest heart rate increase to 110 beats per minute. This ability to remotely monitor physiological signals has improved in terms of size, weight, comfort, cost, and power. Today, for example, recreational athletes commonly monitor their heart rate with commercial body-worn systems.
Gesture-Based Controls for Robots: Overview and Implications for Use by SoldiersTBMG-268255/1/2017
Afuture vision of the use of autonomous and intelligent robots in dismounted military operations is for soldiers to interact with robots as teammates, much like soldiers interact with other soldiers. Soldiers will no longer be operators in full control of every movement, as the autonomous intelligent systems will have the capability to act without continual human input. However, soldiers will need to use the information available from, or provided by, the robot. One of the critical needs to achieve this vision is the ability of soldiers and robots to communicate with each other. One way to do that is to use human gestures to instruct and command robots.
Gesture-Based Controls for Robots: Overview and Implications for Use by Soldiers17AERP05_065/1/2017
Developing a more effective means to communicate with robotic devices. Army Research Laboratory, Aberdeen Proving Ground, Maryland A future vision of the use of autonomous and intelligent robots in dismounted military operations is for soldiers to interact with robots as teammates, much like soldiers interact with other soldiers. Soldiers will no longer be operators in full control of every movement, as the autonomous intelligent systems will have the capability to act without continual human input. However, soldiers will need to use the information available from, or provided by, the robot. One of the critical needs to achieve this vision is the ability of soldiers and robots to communicate with each other. One way to do that is to use human gestures to instruct and command robots. The use of gestures as a natural means of interacting with devices is a very broad concept that encompasses a range of body movements, including movements of the hands, arms, and legs, facial expressions, eye movements, head movements, and/or 2-dimensional (2-D) swiping gestures against flat surfaces such as touch screens. Gesture-based technology is already in place and commonly used without special instruction required for effective use. A common example of a well-designed gestural command is the use of hands to “wave” to activate devices (e.g., public bathroom faucet). This concept is also common to gaming interfaces and is now extending to other private and public domains such as automobile consoles.
Accelerator-to-Brake Pedal Transition Movements during On-Road Stopping in an Older Population2017-01-13963/28/2017
Unintended acceleration events due to pedal misapplication have been shown to occur more frequently in older vs. younger drivers. While such occurrences are well documented, the nature of these movement errors is not well-characterized in common pedal error scenarios: namely, on-road, non-emergency stopping or slowing maneuvers. It is commonly assumed that drivers move in a ballistic or “direct hit” trajectory from the accelerator to the brake pedal. However, recent simulator studies show that drivers do not always move directly between pedals, with older drivers displaying more variable foot trajectories than younger drivers. Our study investigated pedal movement trajectories in older drivers ages 67.9 ± 5.2 years (7 males, 8 females) during on-road driving in response to variable traffic light conditions. Three different sedans and a pick-up truck were utilized. Pedal movements were recorded in response to traffic lights that turned yellow at four different vehicle-to-stop bar distances, or were red-on-approach (i.e. the light was red when it entered the driver’s visual field). Pedal movements were grouped into four categories based on foot trajectory (ballistic, above-pedal hovering, pedal tapping, or between-pedal hesitation). At the shortest stopping distance (165 ft), drivers only utilized ballistic movements; at intermediate stopping distances (275 ft and 365 ft), drivers displayed other pedal movement behaviors including hovering and tapping, but continued to utilize a ballistic approach for the majority of the trials (approximately 76%); at long stopping distances (500 ft and red-on-approach) drivers utilized hovering, pedal tapping, and between-pedal hesitation behaviors more frequently (in approximately 48% of trials). Such non-ballistic approaches to pedal transitions could lead to an increased incidence of pedal misapplication. Our findings imply that more long duration braking scenerios may predispose drivers to pedal errors, as more variability is observed when long duration braking is available as an option.
Sharpe, Sarah S., Brinkerhoff, Robyn, Crump, Caroline, Young, Douglas
Analysis of Driver Kinematics and Lower Thoracic Spine Injury in World Endurance Championship Race Cars during Frontal Impacts2017-01-14323/28/2017
This study used finite element (FE) simulations to analyze the injury mechanisms of driver spine fracture during frontal crashes in the World Endurance Championship (WEC) series and possible countermeasures are suggested to help reduce spine fracture risk. This FE model incorporated the Total Human Model for Safety (THUMS) scaled to a driver, a model of the detailed racecar cockpit and a model of the seat/restraint systems. A frontal impact deceleration pulse was applied to the cockpit model. In the simulation, the driver chest moved forward under the shoulder belt and the pelvis was restrained by the crotch belt and the leg hump. The simulation predicted spine fracture at T11 and T12. It was found that a combination of axial compression force and bending moment at the spine caused the fractures. The axial compression force and bending moment were generated by the shoulder belt down force as the driver’s chest moved forward. The axial compression force at the spine was also induced by the forces from the crotch belt and the leg hump. Based on these mechanisms, the modifications were made to help reduce the spine fracture risk. The seat back angle was raised, the shoulder belt anchor was lifted, the crotch belt anchor was moved forward, the seat pad thickness was increased and the seat pad stiffness was reduced. These modifications allowed more forward motion of the pelvis and reduced the shoulder belt down force, and generated no spine fracture.
Katsuhara, Tadasuke, Takahira, Yoshiki, Hayashi, Shigeki, Kitagawa, Yuichi, Yasuki, Tsuyoshi
Development, Evaluation, and Sensitivity Analysis of Parametric Finite Element Whole-Body Human Models in Side Impacts2016-22-001411/7/2016
Occupant stature and body shape may have significant effects on injury risks in motor vehicle crashes, but the current finite element (FE) human body models (HBMs) only represent occupants with a few sizes and shapes. Our recent studies have demonstrated that, by using a mesh morphing method, parametric FE HBMs can be rapidly developed for representing a diverse population. However, the biofidelity of those models across a wide range of human attributes has not been established. Therefore, the objectives of this study are 1) to evaluate the accuracy of HBMs considering subject-specific geometry information, and 2) to apply the parametric HBMs in a sensitivity analysis for identifying the specific parameters affecting body responses in side impact conditions. Four side-impact tests with two male post-mortem human subjects (PMHSs) were selected to evaluate the accuracy of the geometry and impact responses of the morphed HBMs. For each PMHS test, three HBMs were simulated to compare with the test results: the original Total Human Model for Safety (THUMS) v4.01 (O-THUMS), a parametric THUMS (P-THUMS), and a subject-specific THUMS (S-THUMS). The P-THUMS geometry was predicted from only age, sex, stature, and BMI using our statistical geometry models of skeleton and body shape, while the S-THUMS geometry was based on each PMHS’s CT data. The simulation results showed a preliminary trend that the correlations between the P-THUMS-predicted impact responses and the four PMHS tests (mean-CORA: 0.84, 0.78, 0.69, 0.70) were better than those between the O-THUMS and the normalized PMHS responses (mean-CORA: 0.74, 0.72, 0.55, 0.63), while they are similar to the correlations between S-THUMS and the PMHS tests (mean-CORA: 0.85, 0.85, 0.67, 0.72). The sensitivity analysis using the P-THUMS showed that, in side impact conditions, the HBM skeleton and body shape geometries as well as the body posture were more important in modeling the occupant impact responses than the bone and soft tissue material properties and the padding stiffness with the given parameter ranges. More investigations are needed to further support these findings.
Hwang, Eunjoo, Hu, Jingwen, Chen, Cong, Klein, Katelyn F., Miller, Carl S., Reed, Matthew P., Rupp, Jonathan D., Hallman, Jason J.
Biomechanical Response of Military Booted and Unbooted Foot-Ankle-Tibia from Vertical Loading2016-22-001011/7/2016
A new anthropomorphic test device (ATD) is being developed by the US Army to be responsive to vertical loading during a vehicle underbody blast event. To obtain design parameters for the new ATD, a series of non-injurious tests were conducted to derive biofidelity response corridors for the foot-ankle complex under vertical loading. Isolated post mortem human surrogate (PMHS) lower leg specimens were tested with and without military boot and in different initial foot-ankle positions. Instrumentation included a six-axis load cell at the proximal end, three-axis accelerometers at proximal and distal tibia, and calcaneus, and strain gages. Average proximal tibia axial forces for a neutral-positioned foot were about 2 kN for a 4 m/s test, 4 kN for 6 m/s test and 6 kN for an 8 m/s test. The force time-to-peak values were from 3 to 5 msec and calcaneus acceleration rise times were 2 to 8 msec. Compared to the neutral posture, the “off-axis” measures (e.g. shear and bending moment) were much greater in magnitude in plantar- or dorsi-flexed posture. The results as a function of velocity demonstrated uniform increases with increasing test velocities. The response corridors supplied from the present investigation will serve as initial design parameters for the ATD lower leg, and can also be used for validation for a human computational model.
Pintar, Frank A., Schlick, Michael B., Yoganandan, Narayan, Voo, Liming, Merkle, Andrew C., Kleinberger, Michael
Foot Device Controls Video Game ActionTBMG-251517/28/2016
A group of graduate students from Johns Hopkins University, Baltimore, MD, devised a sandal-like controller that allows a video game player to control the on-screen action with his feet. The team — dubbed GEAR, for Game Enhancing Augmented Reality — created the device for amputees or those with disabilities that inhibit use of their arms or hands.
Knee Monitor 'Listens' for Cracks, PopsTBMG-248716/26/2016
A knee band from the Georgia Institute of Technology uses microphones and vibration sensors to listen to and measure the sounds inside the joint. The sounds will help doctors determine whether a convalescing joint is healthy or requires more therapy.
Influence of Pre-impact Pedestrian Posture on Lower Extremity Kinematics in Vehicle Collisions2016-01-15074/5/2016
Lower extremities are the most frequently injured body regions in vehicle-to-pedestrian collisions and such injuries usually lead to long-term loss of health or permanent disability. However, influence of pre-impact posture on the resultant impact response has not been understood well. This study aims to investigate the effects of preimpact pedestrian posture on the loading and the kinematics of the lower extremity when struck laterally by vehicle. THUMS pedestrian model was modified to consider both standing and mid-stance walking postures. Impact simulations were conducted under three severities, including 25, 33 and 40 kph impact for both postures. Global kinematics of pedestrian was studied. Rotation of the knee joint about the three axes was calculated and pelvic translational and rotational motions were analyzed. Pedestrian in walking posture exhibited larger knee bending angle (40% for ipsilateral knee joint) and pelvic rotation angle (27.5% for Z-direction pelvis rotation angle) with less constraint due to isolated single-leg interaction with vehicle and nonplanar characteristic from the leg swing. The walking posture increased the injury risk of soft connection tissue about 20-30% and reduced the internal force in bone structure about 25% regardless of impact severity. Two-leg interaction, inertial effect, anatomical features of the knee and pelvis exhibited a coupled influence on lower extremity kinematics. Injury predictors such as tibia stress and collateral ligament stretching ratio was found to be associated with kinematics. The trade-off of injury risks induced by kinematics with different pre-impact postures is a challenge for vehicle front-end structure design. Further research efforts are necessary to include more loading scenarios and to quantify the lower extremity injury risk in detail.
Yasuki, Tsuyoshi, Kitagawa, Yuichi, Tang, Jisi, Zhou, Qing, Nie, Bingbing
A Methodology for Prediction of Periprosthetic Injuries in Occupants with TKR Implants in Vehicle Crashes2016-01-15294/5/2016
Periprosthetic fractures refer to the fractures that occur in the vicinity of the implants of joint replacement arthroplasty. Most of the fractures during an automotive frontal collision involve the long bones of the lower limbs (femur and tibia). Since the prevalence of persons living with lower limb joint prostheses is increasing, periprosthetic fractures that occur during vehicular accidents are likely to become a considerable burden on health care systems. It is estimated that approximately 4.0 million adults in the U.S. currently live with Total Knee Replacement (TKR) implants. Therefore, it is essential to study the injury patterns that occur in the long bone of a lower limb containing a total knee prosthesis. The aim of the present study is to develop an advanced finite element model that simulates the possible fracture patterns that are likely during vehicular accidents involving occupants who have knee joint prostheses in situ. Initially, an NCAP test simulation is carried out for a compact passenger car (Dodge Neon) with a belted Hybrid 3 dummy in the driver's seat. The femoral load history of the left leg is correlated with the NCAP test result. An equivalent sub-system model for the NCAP test simulation is then created by isolating the left legform of the Hybrid 3 dummy and impacting the same against a relevant portion of the instrument panel of the Dodge Neon model. A similar model is then formulated by replacing the legform of the Hybrid 3 dummy with a validated finite element model of a human-like legform with actual human tissue properties assigned to it. Later, the same setup is used for assessing the effect of incorporating a TKR into the human-like knee model. The femoral loads obtained from the sub-system level analyses are compared and it is noticed that there is a successive drop in peak femoral load in the intact human-like and TKR-implanted legforms relative to the peak load in the legform of the Hybrid 3 dummy. The said reductions in loads in the more representative models of a human leg have been found to be due to damages in the inter- and supra-condylar regions of the femoral bone. It is also noted that the magnitude of peak load obtained with the TKR implanted legform is lower than that obtained with the intact knee legform. This reduction in peak load is due to the relatively early initiation of damage that is caused due to reduced amount of high density cortical bone following the TKR. The higher susceptibility of a TKR-implanted knee to bone fracture in a frontal crash scenario as compared to a normal human knee has been brought into focus perhaps for the first time in the current study.
Srinivas, Gunti R., Deb, Anindya, Chou, Clifford C., Kumar, Malhar
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