Connectivity based human body modeling from monocular camera

Safety of children in cars: A review of biomechanical aspects and human body models

ABSTRACTObjective: Computational human body models (HBMs) are nominally omnidirectional surrogates given their structural basis in human anatomy. As a result, such models are well suited for studies related to occupant safety in anticipated highly automated vehicles (HAVs). We utilize a well-validated HBM to study the head and neck kinematics in simulations of nontraditional occupant seating configurations.Methods: The GHBMC M50-O v. 4.4 HBM was gravity settled into a generic seat buck and situated in a seated posture. The model was simulated in angular increments of 15 degrees clockwise from forward facing to rear facing. A pulse of 17.0 kph (NASS median) was used in each to simulate a frontal impact for each of the 13 seating configurations. Belt anchor points were rotated with the seat; the airbag was appropriately powered based on delta-V, and was not used in rear-facing orientations. Neck forces and moments were calculated.Results: The 30-degree oblique case was found to result in the maximum neck load and sagittal moment, and thus Neck Injury Criteria (NIJ). Neck loads were minimized in the rear facing condition. The moments and loads, however, were greatest in the lateral seating configuration for these frontal crash simulations.Conclusions: In a recent policy statement on HAVs, the NHTSA indicated that vehicle manufacturers will be expected to provide countermeasures that will fully protect occupants given any planned seating or interior configurations. Furthermore, the agency indicated that virtual tests using human models could be used to demonstrate such efficacy. While the results presented are only appropriate for comparison within this study, they do indicate that human models provide reasonable biomechanical data for nontraditional occupant seating arrangements.

The accuracy of electromagnetic (EM) exposure assessments depends mainly on the resolution of a voxel human body model. The resolution of the conventional human body model is limited to a few millimeters. In the millimeter wave (mmWave) frequency range, EM waves are absorbed by the superficial tissues in the human body. Therefore, resolution and skin thickness of the human body model are important for accuracy of the EM wave exposure metrics recommended by international human safety guidelines. Realistic thickness modeling of the skin tissue on the human body may provide greater accuracy in the EM exposure assessment, especially at mmWave frequency range. In this paper, effects of the skin thickness on the EM exposure metrics in one-dimensional multi-layered models obtained from different regions of the body model are investigated using the dispersive algorithm based on the finite-difference time-domain method over the frequency range from 1 to 100 GHz. Furthermore, effects of eyelid tissue in a human eye on the EM exposure metrics are studied over the frequency range. The EM exposure metrics such as absorbed power density, heating factor, and power transmission coefficient are calculated up to 100 GHz to evaluate the limits of EM wave exposure.

In the paper authors present a concept and a modelling method of the static and dynamic loads of human body’s parts: bones and muscles during movement. Currently the problem of human body modelling is very important for many domains of our “better life” programs e.g.: an automotive—to find the best solution for human protection during accidents, sport—to find the most efficient and least tiring movements, to the health protection or extend the active life of the elderly. The human body is not a rigid multi-body system, but elastic, flexible and varying according to time. It consists of semi-stiff bones, elastic muscles and tendons. Other parts like stomach or liver are hanging on elastic wires and move relatively to each other during the whole acceleration process etc. All those elements can be broken or fatigued under some load. So the model of human body is not linear and shouldn’t be modelled by linear equation sets. Authors present the concept of human body modelling based on three types element chain. One type are “bones” that are coupled in joints and conduct loads to the support surface; the elastic tendons that keep the joints and propel bones rotation in joints, and muscles that generate forces for stabilization system or for propelling the bones. In paper the simplified model of human body built in MATLAB/Simulink software is presented. Some results of simulation e.g. load of a knee during squat or landing after jump are compared with real test results.

Explosion and fire cause about 30 reported industrial major accidents a year by ignition source which discharge of electrostatic generated to flammable gas, vapor, dust and mixtures. It brings economically and humanly very large loss that accident was caused by fire and explosion from electrostatic discharge. Thus, it is very important that electrostatic discharge energy is to be control below not to be igniting flammable mixtures. There are two kinds of analysis model for electrostatic discharge, human body model and machine model. Human body model is available the parameter of human's electrical equivalent that capacitance is 100 pF, resistance is . To simulate and visualize the electrostatic discharge from human body need a very expensive and high voltage simulator. In this paper, we measured the value of capacitance and resistance concerned with test materials and sizing of specimen and the value of charged voltage concerned with test specimen and distance to develop an electrostatic charge/discharge simulating tool for teaching with which concerned industrial employee and students. The result of experiments, we conformed that the minimum ignition energy of methane-oxygen mixtures meets well the equation , and found out that the insulating material and sizing of equivalent value having human body mode are the poly ethylene of 200 mm and 300 mm of diameter. Developed electrostatic charge/discharge simulating tool has many merits; simple mechanism, low cost, no need of electric power and so on.

The main objective of this chapter is to provide a comprehensive and intuitive introduction to MRI gradient coil related PNS modeling with human body models. We will present the fundamental concepts and analytical processes behind gradient coil-induced peripheral nerve stimulation (PNS) modeling and also show some new results of our work. We first describe the process of performing electromagnetic simulation of a gradient coil, the neurodynamic simulation of nerves, and the gradient coil design. Then, we present improvements of two existing human body models by adding more nerve trajectories in the head and upper body to reduce the discrepancies between the simulated and measured results for PNS thresholds in head gradient coils. Further, we apply the modified human body models to analyze three folded and non-folded gradient coils and reveal the relationship between the eddy current flow in the human body and the gradient coil wire pattern and its impact on the PNS. We also show the connection between concomitant fields and PNS and assess the accuracy of PNS calculations in human body models with simplified tissue properties. Finally, we give our thoughts on the future direction of this work.

In recent years, a communications system, the Body Area Network, which uses the human body as a transmission path has attracted attention, and there is increasing expectation that it will be used more widely. However, there are still several points on the signal transmission mechanism of using the human body in this way that remain to be clarified, and there has been little research into the interaction of electromagnetic waves and the human body. Therefore, we used the Finite Difference Time Domain (FDTD) method to calculate the Efield distributions around simple and realistic models of the whole human body in free space with a weareble device. Moreover, E-field calculations were carried out when the positions of the body were changed. Our results show that using the simple homogeneous whole human body model is valid for the E-field calculation, and the dominant component of the E-field is normal to the body/air interface in all the positions that the human body assumes in daily life. Furthermore, in the state where the human body is shunted to the Earth ground, it was shown clearly that the E-field distribution is not mostly different from when a body is floating in free space. It can be concluded that these results provide useful information in improving the design of wearable devices.

In order to realize the accurate matching of 3D garment model and human model, a new method for feature extraction of garment and human model is proposed. We first construct local mesh fitting operator based on Voronoi graph and weighted parametric surface. Secondly, on the basis of the use of geometric attributes, the change in the neighborhood is used as the reference value. On this basis, the region is divided and then the feature point extraction of costume model and human body model is realized. Thirdly, a robust feature matching function is established. Finally, the clothing and the human body model can be matched quickly and accurately.

The finite-difference time-domain (FDTD) method is used to analyze clothing materials for reducing RF energy absorption in a human body model. In the simulations, the multiple grid technique is implemented in the FDTD method to improve the computational efficiency. Obtained local maximum SAR induced in the human body model is used for the evaluation of clothing material's shielding effectiveness for EM exposure. It is found that clothing material with a higher conductivity can greatly reduce RF energy absorption in the human body model. These preliminary results provide valuable knowledge to help in the manufacturing of an anti-electromagnetic wave clothing.

Acquisition of various human body models is useful in many cases. In this paper, we present some of our recent work on body creation tools. Our goal is to enable rapid creation of various body models that are immediately usable for animation. In doing so, we aim to carry out realistic deformations on the human body models as well as make its usage simple. Our system is composed of several modules: (1) Skin attachment to an H-Anim skeleton is carried out first in order to get deformation in skeletal shape modification as well as in animation. (2) Volumetric deformation module deals with the volumetric scale of body parts such as breast, belly and bottoms. These deformation operators, together with the skeletal deformation allow the automatic adaptation of the body model to different sizes and proportions to accommodate anthropometrical variations. (3) Surface optimization is used to simplify the model in consideration of not only geometric features but also the animation aspect of it. (4) Finally, the BDP generation module describes the geometry of the model as well as how to animate it according to the MPEG-4 BDP specifications.Key wordsDeformationsimplificationMPEG-4 BDPseamless bodyanimation ready model.

With the gradual increase in the demand for parametric human 3D models, the requirements for the accuracy of modeling and the quality of generation are getting higher and higher. In this paper, the human body structure model is constructed by 3D human posture estimation and spatio-temporal graph convolutional network, and after normalizing the data of the human body base, the 3D human body model based on the human body base is generated by combining the free deformation method, and the local light model is used to make the human body model more three-dimensional and real. In addition, the quality of 3D animation production is investigated by combining blind quality evaluation and validation analysis of the human body-based 3D model. The 3D human body modeling simulation error assessment has an error assessment root-means-square error that falls within 1.5%. In the validation analysis of model generation quality, the quality evaluation model proposed in this paper has a quality correlation coefficient and prediction accuracy of 0.9456 and 0.9454 on the dataset, respectively, and the performance of the ablation experiments and generalization experiments is stable. The mean value of the error between the animation production character generation effect and the actual testers is not more than 10mm.Combined with the research in this paper, it effectively improves the accuracy of human body modeling and provides an evaluation method for the quality of human 3D animation production and generation, which is of practical significance for its development.

An intelligent recommendation system for personalised parametric garment patterns by integrating designer’s knowledge and 3D body measurements

Parametric 3D modeling of young women's lower bodies based on shape classification

Work of an arborist - tree climbing - is a dangerous activity associated with great physical effort, influenced by incorrect body posture and significantly stressed individual parts of the body. This research was initiated with the objective to draw attention to this hitherto little explored issue connected with ergonomics of the work of tree climbers. The goal of the research was to gather information about the fatigue of individual parts of the human body in professional tree climbers who access trees using so-called rope techniques (ascent to the tree crown, movement in the tree crown, descent from the tree crown) by means of a questionnaire. The assessment included 12 body parts (8 in the upper body, 4 in the lower body), with each part being divided into right and left parts. The research was conducted in the Czech Republic, 98 respondents were professional tree climbers. The questionnaire contained two sections of questions. Questions from the questionnaire were analysed, evaluated and plotted into clear graphs which were then statistically quantitatively described. Furthermore, the linear relationship between the duration of work performance and the occurrence of fatigue in individual parts of the body was assessed (Pearson's correlation coefficients). Results indicated that the most stressed part of the body of tree climbers who access trees using rope techniques is the area of wrist and hands. On the other hand, the least stressed part of their body is lower leg. Furthermore, the results of Pearson's correlation analysis show that the relationship between the number of hours and the occurrence of musculoskeletal problems is weak, unstable, and nonlinear in most body segments. The research has shown that arborists who care for trees using rope techniques are exposed to varying degrees of fatigue in different parts of the body.

Objective: A recent emphasis on nontraditional seating and omnidirectional impact directions has motivated the need for deformable representation of the thoracic spine (T-spine) in human body models. The goal of this study was to develop and validate a deformable T-spine for the Global Human Body Models Consortium (GHBMC) M50-O (average male occupant) human model and to demonstrate improved biofidelity.Methods: Eleven functional spinal units (FSUs) were developed with deformable vertebrae (cortical and trabecular), spinal and costovertebral ligaments, and intervertebral discs. Material properties for all parts were obtained from the literature.FSUs were subjected to quasistatic loads per Panjabi et al. (1976) in 6 degrees of freedom. Stiffness values were calculated for each moment (Nm/°) and translational force (N/µm). Updated costovertebral (CV) joints of ribs 2, 6, and 10 were subjected to moments along 3 axes per Duprey et al. (2010). The response was optimized by maximum force and laxity in the ligaments. In both cases, updated models were compared to the baseline approach, which employed rigid bodies and joint-like behavior. The deformable T-spine and CV joints were integrated into the full M50-O model Ver. 5.0β and 2 full-body cases were run: (1) a rear pendulum impact per Forman et al. (2015) at speeds up to 5.5 m/s. and (2) a lateral shoulder impact per Koh (2005) at 4.5 m/s. Quantitative evaluation protocols were used to evaluate the time history response vs. experimental data, with an average correlation and analysis (CORA) score of 0.76.Results: All FSU responses showed reduced stiffness vs. baseline. Tension, extension, torsion, and lateral bending became more compliant than experimental data. Like the experimental results, no trend was observed for joint response by level. CV joints showed good biofidelity. The response at ribs 2, 6, and 10 generally followed the experimental data.Conclusions: Deformable T-spine and CV joint validation has not been previously published and yielded high biofidelity in rear impact and notable improvement in lateral impact at the full body level. Future work will focus on localized T-spine injury criteria made possible by the introduction of this fully deformable representation of the anatomy.