Browse Topic: Knee
Recent successes in cultivating human heart tissue, knee cartilage, and pharmaceutical crystals in space have relied on technology that was initially developed decades ago with support from NASA.
Researchers have developed a fully knitted, circuit-embedded knee wearable for wireless sensing of joint motion in real time. Compared to other knitted electronics, this model has fewer externally integrated components and a more sensitive sensor, making it less error prone.
The purpose of this document is to provide the user with the procedures needed to properly assemble and disassemble the 50th percentile male Hybrid III dummy, certify its components and verify its mass and dimensions. Also within this manual are guidelines for handling accelerometers, repairing flesh and setting joints.
This SAE Recommended Practice outlines a series of performance recommendations, which concern the whole data channel. These recommendations are not subject to any variation and all of them shall be adhered to by any agency conducting tests to this practice. However, the method of demonstrating compliance with the recommendations is flexible and can be adapted to suit the needs of the particular equipment the agency is using. It is not intended that each recommendation be taken in a literal sense, as necessitating a single test to demonstrate that the recommendation is met. Rather, it is intended that any agency proposing to conduct tests to this practice shall be able to demonstrate that if such a single test could be and were carried out, then their equipment would meet the recommendations. This demonstration shall be undertaken on the basis of reasonable deductions from evidence in their possession, such as the results of partial tests. In some systems, it may be necessary to divide the whole channel into subsystems, for calibration and checking purposes. The recommendations have been written only for the whole channel, as this is the sole route by which subsystem performances affect the quality of the output. If it is difficult to measure the whole channel performance, which is usually the case, the test agency may treat the channel as two or more convenient subsystems. The whole channel performance could then be demonstrated on the basis of subsystem results, together with a rationale for combining the subsystem results together. SAE J211-1 of this SAE Recommended Practice covers electronic instrumentation. SAE J211-2 covers photographic instrumentation.
This document describes the 2-D computer-aided design (CAD) template for the HPM-1 H-point machine or HPD available from SAE. The elements of the HPD include the curve shapes, datum points and lines, and calibration references. The intended purpose for this information is to provide a master CAD reference for design and benchmarking. The content and format of the data files that are available are also described.
Researchers have developed a lighter, yet more robust knee brace for the elderly who suffer from knee problems. Using 3D printing techniques, the team has managed to reduce the weight of a traditional exoskeleton knee brace (typically built using metal) by 30 percent, thanks to an innovative design that uses lightweight plastic and assistive springs.
This document describes the 3D computer-aided design (CAD) parts and file formats for the HPM-1 H-point machine available from SAE. The intended purpose for this information is to provide a master CAD reference for design and benchmarking.
The three-wheeled "Auto-Rickshaws" [Auto] plays a significant role in road transportation, especially in India. The crash safety and reconstruction studies have been widely used in four-wheelers, whereas the availability of such data for Auto was limited. In recent times, accident data processing from available videos is being utilized to observe the crash scenario. The crash parameters can be given as inputs to the crash analysis. This paper focuses on the process the real-world accident data and study crash characteristics. With limitation in the availability of detailed injuries post-crash, the study was restricted to reconstructing crash kinematics and estimating indicative injuries to the driver. The source of video data is videos of crash available in public domains like YouTube. PYTHON video processing tool has been used to process the set of real-world accident video data. Object detection, Pixel per meter computation and object tracking are the significant steps to process the accident data, from which the collision speed is obtained. The auto-rickshaw CAE model and driver dummy (Adult male 50 percentile) were used in LS DYNA to conduct crash analysis at obtained collision speed. The reconstructed crash with matching kinematics showed that the driver experienced a noticeable amount of impact forces near the neck joint and knees. This methodology is proposed as a step in the direction of understanding occupant safety in auto rickshaws.
Interest in rear-seat occupant safety has increased in recent years. Information relevant to rear-seat occupant interior space and kinematics are needed to evaluate injury risks in real-world accidents. This study was conducted to first assess the effect of size and restraint conditions, including belt misuse, on second-row occupant kinematics and to then document key clearance measurements for an Anthropomorphic Test Device (ATD) seated in the second row in modern vehicles from model years 2015-2020. Twenty-two tests were performed with non-instrumented ATDs; three with a 5th percentile female Hybrid III, 10 tests with a 10-year-old Hybrid III, and 9 tests with a 6-year-old Hybrid III. Test conditions included two sled bucks (mid-size car and sport utility vehicle (SUV)), two test speeds (56 and 64 km/h), and various restraint configurations (properly restrained and improperly restrained configurations). Head and knee trajectories were assessed. Head excursion was 38 percent greater with the 5th percentile female ATD than with the 6-year-old ATD when lap-shoulder belted in the 56 km/h sled tests with the passenger car. Contact between the head and the seat was only observed when the shoulder belt was placed behind the torso with the 5th percentile female and with the 10-year-old ATD, irrespective of vehicle type. In the static seated position, the nose-to-seatback was more than 11 cm greater with the SUV than with the passenger car used in the sled test series. The analysis of clearance data indicated that the relative distance between the nose and the seatback was smaller in modern compact SUVs than modern small cars at 53.5±5.3 cm and 57.6±5.9 cm respectively. Knee clearance was also lowest in compact SUVs than other vehicle types. The sled test results in combination with the clearance measurements, highlight an increased potential for head contact between the second-row occupant and front seatback in small cars and compact SUVs in frontal crashes, in particular when an occupant is improperly restrained.
With growing environmental concerns associated with gas-powered vehicles and busier city streets, micro-mobility modes, including traditional bicycles and new technologies, such as electric scooters (e-scooters), are becoming solutions. In 2018, e-scooter usage overtook other shared micro-mobility modes with over 38 million e-scooter trips taken. Concurrently, the societal concern regarding the safety of these devices is also increasing. To examine the types of injuries associated with e-scooters and bicycles, the National Electronic Injury Surveillance System (NEISS), a probability sample of US hospitals that collects information from emergency room (ER) visits related to consumer products, was utilized. Records from September 2017 to December 2018 were extracted, and those associated with powered scooters were identified. Injury distributions by age, sex, race, treatment, diagnosis, and location on the body were explored. The number of person-trips was obtained to perform a risk analysis. An estimated 17,772 injuries were associated with powered scooters. Nearly 45% of injuries occurred in persons aged 10-29 years. Almost 87% of ER visits consisted of patients being treated and released, whereas nearly 11% were hospitalized (the remaining 2% either received no treatment or the disposition was unknown). Common injuries included contusions/abrasions, fractures, and lacerations. Almost 15% of the injuries associated with powered scooters occurred to the face; the head, ankle, lower leg, and knee were other common body parts injured. An estimated 51 million person-trips were taken during this time period, resulting in an injury rate of 346 injuries/million trips. In comparison, 4.7 billion person-trips were taken on bicycles, resulting in an injury rate of 114 injuries/million trips.
Occupant dynamics during passenger vehicle underride has not been extensively evaluated. The present study examined the occupant data from IIHS rear underride crash tests. A total of 35 crash tests were evaluated. The tests were classified as full-width (n = 9), 50% overlap (n = 11), and 30% overlap (n = 15). A 2010 Chevrolet Malibu impacted the rear underride guard of a stationary trailer at 35 mph. Several occupant kinematics and dynamics data including head accelerations, head injury criteria, neck shear and axial forces, neck moments, neck indices, chest acceleration, chest displacement, chest viscous criterion, sternum deflection rate, and left/right femur forces/impulses, knee displacements, tibia axial forces, upper/lower tibia moments, upper/lower tibia indices, and foot accelerations were measured. The vehicle accelerations, delta-Vs, and occupant compartment intrusions were also evaluated. The results indicated that the head and neck injury parameters were positively correlated with driver A-pillar rearward intrusion. The 30% overlap crashes showed significantly higher intrusion and head and neck injury values than the 50% and full-width crashes. No strong relationship between head and neck injury parameters and vehicle delta-V or peak acceleration was observed. None of the chest injury criteria exceeded the chest IARV tolerances in the crash tests examined. No relationship between chest injury parameters and vehicle delta-V, acceleration or driver A-pillar rearward intrusion was observed. No strong relationship was observed between left/right leg injury parameters and vehicle delta-V, acceleration or driver A-pillar intrusion. Only for two crash tests, the “left upper tibia A-P moment”, “left upper tibia resultant moment” and “left upper tibia index” exceeded the IARV tolerances. This study suggested that in underride crashes there is a higher chance of head/neck injuries than other body regions. Also, in addition to delta-V, other parameters such as percent overlap and occupant compartment intrusion should be taken into consideration when analyzing the biomechanics of underride.
Limited data exist on the injury tolerance and biomechanical response of humans to high-rate, under-body blast (UBB) loading conditions that are commonly seen in current military operations, and there are no data examining the influence of occupant posture on response. Additionally, no anthropomorphic test device (ATD) currently exists that can properly assess the response of humans to high-rate UBB loading. Therefore, the purpose of this research was to examine the response of post-mortem human surrogates (PMHS) in various seated postures to high-rate, vertical loading representative of those conditions seen in theater. In total, six PMHS tests were conducted using loading pulses applied directly to the pelvis and feet of the PMHS: three in an acute posture (foot, knee, and pelvis angles of 75°, 75°, and 36°, respectively), and three in an obtuse posture (15° reclined torso, and foot, knee, and pelvis angles of 105°, 105°, and 49.5°, respectively). Tests were conducted with a seat velocity pulse that peaked at ~4 m/s with a 30-40 ms time to peak velocity (TTP) and a floor velocity that peaked at 6.9-8.0 m/s (2-2.75 ms TTP). Posture condition had no influence on skeletal injuries sustained, but did result in altered leg kinematics, with leg entrapment under the seat occurring in the acute posture, and significant forward leg rotations occurring in the obtuse posture. These data will be used to validate a prototype ATD meant for use in high-rate UBB loading scenarios.
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.
South Ural State University Chelyabinsk, Russia
Abstract - Shared autonomous vehicles open possibilities for novel seating configurations, enabling greater interior spaciousness by making the front row seats rear-facing or removing one row of seats altogether. Frontal crash simulations with a forward-facing Hybrid III mid-size male FEM demonstrated that the unrestrained legs can swing up freely until they stop at the end of the range of knee extension. High tibia moments and tibia indices result. Similar crash simulations with the GHBMC M50-O demonstrated knee ligament separation, while those with the more advanced GHBMC F05-O did not. To better understand the knee responses, the mass, C.G. and moments of inertia of the GHBMC M50 legs were applied to the GHBMC F05 with its more detailed representation of the knee. The peak knee ligament loads are compared to published failure load data.
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.
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.
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.
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