Virtual Human Model Research Articles

The Application Research on Ergonomics Based on the CATIA Software Platform

Through the ergonomic analysis module that is based on the CATIA software platform, the virtual human body model is introduced into the rescue cabin digital module of ambulance and thus the virtual man-machine relationship is established; meanwhile, the theories of ergonomics are employed as guidance for the optimization design of rescue cabin so as to probe into how the CATIA-based ergonomic analysis module is applied in product development and design.

Development of a new generation of high-resolution anatomical models for medical device evaluation: the Virtual Population 3.0

The Virtual Family computational whole-body anatomical human models were originally developed for electromagnetic (EM) exposure evaluations, in particular to study how absorption of radiofrequency radiation from external sources depends on anatomy. However, the models immediately garnered much broader interest and are now applied by over 300 research groups, many from medical applications research fields. In a first step, the Virtual Family was expanded to the Virtual Population to provide considerably broader population coverage with the inclusion of models of both sexes ranging in age from 5 to 84 years old. Although these models have proven to be invaluable for EM dosimetry, it became evident that significantly enhanced models are needed for reliable effectiveness and safety evaluations of diagnostic and therapeutic applications, including medical implants safety. This paper describes the research and development performed to obtain anatomical models that meet the requirements necessary for medical implant safety assessment applications. These include implementation of quality control procedures, re-segmentation at higher resolution, more-consistent tissue assignments, enhanced surface processing and numerous anatomical refinements. Several tools were developed to enhance the functionality of the models, including discretization tools, posing tools to expand the posture space covered, and multiple morphing tools, e.g., to develop pathological models or variations of existing ones. A comprehensive tissue properties database was compiled to complement the library of models. The results are a set of anatomically independent, accurate, and detailed models with smooth, yet feature-rich and topologically conforming surfaces. The models are therefore suited for the creation of unstructured meshes, and the possible applications of the models are extended to a wider range of solvers and physics. The impact of these improvements is shown for the MRI exposure of an adult woman with an orthopedic spinal implant. Future developments include the functionalization of the models for specific physical and physiological modeling tasks.

ANTROPOMETRYCZNE ZRÓŻNICOWANIE ODDZIAŁYWANIA NA PRACOWNIKA RADIOFALOWYCH PÓL ELEKTROMAGNETYCZNYCH O CZĘSTOTLIWOŚCIACH 100 MHz

Thermal effects of radiofrequency electromagnetic fields (REMF) exposure of humans may be assessed by calculations of the parameter recognized as SAR (specific energy absorption rate) in virtual human body models, which actually do not represent anthropometric properties of the entire population. Therefore, it is important to determine the relations between SAR values and anthropometric parameters that enable individualization of SAR estimation independently of body properties of a given person. The analysis concerned 48 exposure scenarios of 4 virtual body models (male and female) to vertically or horizontally polarized REMF of 27 MHz or 100 MHz frequency of various directions of propagation. In the subgroup of results 100 MHz/vertical polarization statistically significant (strong; p < 0.05) correlations were identified between SAR averaged in the whole body and height, mass, BMI, circumference of chest, waist, neck and frontal cross-section area, and between local SAR in head and neck and the height, mass, circumference of chest waist or neck and frontal cross-section area. Identified relations and SAR in the Gustav model were used to estimate the variety of SAR in Polish population of adults (5-95. percentile of female and male): +/- 30% for SAR averaged in the whole body, +/- 50% for localized SAR. It was demonstrated that in the preliminary classified type of assessed REMF exposure (e.g., in terms of field polarization and frequency) it is possible to identify statistical relations between various SAR parameters and anthropometric properties of the exposed body. Related quantities can be used for individualized assessment of worker's electromagnetic hazards.

Feature-Based Human Model for Digital Apparel Design

Three-dimensional (3D) body scanning technology opens opportunities for virtual try-on and automatic made-to-measure apparel design. This paper proposes a new feature-based parametric method for modeling human body shape from scanned point clouds of a 3D body scanner [TC] <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . The human body model consists of two layers: the skeleton and the cross sections of each body part. First, a simple skeleton model from the body scanner [TC] <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> system has been improved by adding and adjusting the position of joints in order to better address some fit issues related to body shape changes such as spinal bending. Second, an automatic approach to extracting semantic features for cross sections has been developed based on the body hierarchy. For each cross section, it is described by a set of key points which can be fit with a closed cardinal spline. According to the point distribution in point clouds, an extraction method of key points on cross sections has been studied and developed. Third, this paper presents an interpolation approach to fitting the key points on a cross section to a cardinal spline, in which different tension parameters are tested and optimized to represent simple deformations of body shape. Finally, a connection approach of body parts is proposed by sharing a boundary curve. The proposed method has been tested with the developed virtual human model (VHM) system which is robust and easier to use. The model can also be imported in a CAD environment for other applications.

Virtual Human Modeling and Simulation for Toll Booth Design in Indonesia

This research studies the ergonomic aspect from toll booth and operators performance. It is mainly based on working posture and service time of operators. The analysis of working posture based on Posture Evaluation Index using Software Jack 6.1, meanwhile service time based on queuing theory using WinQsb. The output of the study can be divided to actual and 36 reconfiguration design. The results suggest that the most ergonomic design is with 51 cm in seat height, 5 cm in foot rest height, and 80 cm in desk height. Based on simulation, it can reduce the average time of costumer spend in the queue until 82% from 35.31 seconds to 6.4 seconds.

Interaction Motivation Driven Virtual Human Emotion Modeling in Computer Engineering and Application

Affective computing had been widely used in computer engineering and applications fields. Emotion generation is an important research component in affective computing field and there were a lot of works had been put into generating lifelike emotion reaction and emotional behaviors [1-. OCC model is the most common used emotion model and can be integrated with other component to generate virtual humans emotion states. However

Virtual human hybrid control in virtual assembly and maintenance simulation

To improve virtual human motion simulation and generation efficiency in virtual assembly and maintenance (A&M) environment, based on a detailed analysis of virtual human control methods in A&M simulation, a virtual human hybrid control method is presented in this paper. In the proposed method, virtual human A&M motion is divided into three types: primitive motion (PM), fine motion (FM) and transitional motion (TM). For PM, a real operator can drive a virtual human in real time for A&M operation via virtual reality interactive devices; in this way, the PM can be quickly generated. As for FM and TM generation, their semantic-level parameterized models including engineering attributes are created; then, their generation processes are represented; in the generation processes, a virtual human posture automatic reasoning model is established to support auto-generating A&M motion. The approaches in the present study are validated by generating virtual human motions in partial assembly process of auto engine. Results show that the proposed method can improve A&M motion simulation efficiency and support the fast generation of realistic A&M motion.

Virtual human modeling for interactive assembly and disassembly operation in virtual reality environment

Real operators are the initiators in assembly and disassembly activities. They participate throughout the whole process. In this sense, as an avatar of a real operator, virtual human (VH) plays an important role in virtual assembly and maintenance simulations. After detailed analysis of interactive assembly and disassembly process, the function requirements for VH are defined. Based on the defined requirements, the following works are done. First, a real-time driving model is established with a dynamic constraint applied to support personalized human model driving. Then, a driving error model is proposed for quantitatively analysis of VH’s driving error coming from the motion capture system. After that, on the basis of constraint processing method, an interactive operation modeling method for VH is presented. This method deals with interactive operation modeling in scenarios where VH manipulates the product directly, VH manipulates tools, and VH manipulates the product using tools. Finally, an assembly simulation for automobile engine connecting rod caps is implemented and a user survey is carried out. The survey result demonstrates the feasibility and validity of the proposed model and method.

Parametric Human Body Model for Digital Apparel Design

With the advance in 3D body scanning technology, it opens opportunities for virtual try-on and automatic made-to-measure in apparel products domain. This paper proposed a novel feature-based parametric method of human body shape from the cloud points of 3D body scanner [T2. Firstly, we improved the skeleton construction through adding and adjusting the position of joints. Secondly, automatic extraction approach of semantic feature cross-sections is developed based on the hierarchy. According to the unique distribution of cloud points of each cross-section of each body part, the extraction method of key points on the cross-section is described. Thirdly, we presented an interpolation approach of key points which fit cardinal spline to cross-section for each body part, in which tension parameter is used to represent the simple deformation of body shape. Finally, a connection approach of body part is proposed by sharing a boundary curve. The proposed method has been tested with our virtual human model (VHM) system which is robust and easier to use. The process generally requires about five minutes for generating a full body model that represents the body shape captured by 3D body scanner. The model can be imported in a CAD environment for application to a wide variety of ergonomic analyses.

Research on Dynamic Modeling of Virtual CNC System of Human Machine Interface

In this paper, a Virtual CNC system of Human machine interface Modeling described the structure of the real CNC system operator panel, virtual modeling and parser function of CNC panel using Delphi language programming logic as an advanced dynamic modeling concepts and techniques to carry out the virtual CNC system Human machine interface dynamic modeling in the trend to advance the overall level of the domestic NC simulation software industry.

Emotional Postures for the Humanoid-Robot Nao

This paper presents the development of emotional postures for the humanoid robot Nao. The approach is based on adaptation of the postures that are developed for a virtual human body model to the case of the physical robot Nao. In the paper the association between the joints of the human body model and the joints of the Nao robot are described and the transformation of postures is explained. The non-correspondence between the joints of the actual physical robot and the joints of the human body model was a major challenge in this work. Moreover, the implementation of the postures into the robot was constrained by the physical structure and the artificial mass distribution. Postures for the three emotions of anger, sadness, and happiness are studied. Thirty two postures are generated for each emotion. Among them the best five postures for each emotion are selected based on the votes of twenty five external observers. The distribution of the votes indicates that many of the implemented postures do not convey the intended emotions. The emotional content of the selected best five postures are tested by the votes of forty observers. The intended emotions received the highest recognition rate for each group of these selected postures. This study can be considered to be the last step of a general process for developing emotional postures for robots. This process starts with qualitative descriptions of human postures, continues with encoding those descriptions in quantitative terms, and ends with adaptation of the quantitative values to a specific robot. The present study demonstrates the last step of this process.

The influence of patient's sex, race and depression on clinician pain treatment decisions

Pain treatments often vary across patients' demographic and mental health characteristics. Most research on this topic has been observational, has focused on opioid therapy exclusively and has not examined individual differences in clinician decision making. The current study examined the influence of patient's sex, race and depression on clinicians' chronic pain treatment decisions. We used virtual human technology and lens model methodology to enhance study realism and facilitate a richer understanding of treatment decisions. Clinicians and trainees (n = 100) made treatment decisions (opioid, antidepressant, pain specialty referral, mental health referral) for 16 computer-simulated patients with chronic low back pain. Patients' sex, race and depression status were manipulated across vignettes (image and text). Individual- and group-level analyses indicated that patient's depression status had the strongest and most consistent influence on treatment decisions. Although less influential overall, patient's sex and race were significantly influential for a subset of participants. Furthermore, the results indicated that participants who were influenced by patient's race had less experience in treating chronic pain than those who were not influenced by patient's race [t(11.59) = 4.75; p = 0.001; d = 1.20]. The results of this study indicated considerable variability in participants' chronic pain treatment decisions. These data suggest that interventions to reduce variability in treatment decision making and improve pain care should be individually tailored according to clinicians' decision profiles.

Simulating the decentralized processes of the human immune system in a virtual anatomy model

BackgroundMany physiological processes within the human body can be perceived and modeled as large systems of interacting particles or swarming agents. The complex processes of the human immune system prove to be challenging to capture and illustrate without proper reference to the spacial distribution of immune-related organs and systems. Our work focuses on physical aspects of immune system processes, which we implement through swarms of agents. This is our first prototype for integrating different immune processes into one comprehensive virtual physiology simulation.ResultsUsing agent-based methodology and a 3-dimensional modeling and visualization environment (LINDSAY Composer), we present an agent-based simulation of the decentralized processes in the human immune system. The agents in our model - such as immune cells, viruses and cytokines - interact through simulated physics in two different, compartmentalized and decentralized 3-dimensional environments namely, (1) within the tissue and (2) inside a lymph node. While the two environments are separated and perform their computations asynchronously, an abstract form of communication is allowed in order to replicate the exchange, transportation and interaction of immune system agents between these sites. The distribution of simulated processes, that can communicate across multiple, local CPUs or through a network of machines, provides a starting point to build decentralized systems that replicate larger-scale processes within the human body, thus creating integrated simulations with other physiological systems, such as the circulatory, endocrine, or nervous system. Ultimately, this system integration across scales is our goal for the LINDSAY Virtual Human project.ConclusionsOur current immune system simulations extend our previous work on agent-based simulations by introducing advanced visualizations within the context of a virtual human anatomy model. We also demonstrate how to distribute a collection of connected simulations over a network of computers. As a future endeavour, we plan to use parameter tuning techniques on our model to further enhance its biological credibility. We consider these in silico experiments and their associated modeling and optimization techniques as essential components in further enhancing our capabilities of simulating a whole-body, decentralized immune system, to be used both for medical education and research as well as for virtual studies in immunoinformatics.

Reuse of Pilot Motions for Improving Layout Design of Aircraft Cockpit

The layout design of aircraft cockpit is of great importance to the efficiency of the operation and the flight safety. In this paper, the reuse method of pilot motions for improving layout design of cockpit is proposed. The pilot motions are inertial tracked with man-in-the-loop mode and obtained on the basis of the operation procedures. The motions are represented by mapping the orientation of the pilot body segments to the virtual human model as motion cases. The case base is established, and the spatial position of the manipulation device is determined by case-based reasoning (CBR). The application instance presented indicates that the method proposed is effective and practical.

Estimation of Upper Limb Joint Angle Using Surface EMG Signal

In the development of robot-assisted rehabilitation systems for upper limb rehabilitation therapy, human electromyogram (EMG) is widely used due to its ability to detect the user intended motion. EMG is one kind of biological signal that can be recorded to evaluate the performance of skeletal muscles by means of a sensor electrode. Based on recorded EMG signals, user intended motion could be extracted via estimation of joint torque, force or angle. Therefore, this estimation becomes one of the most important factors to achieve accurate user intended motion. In this paper, an upper limb joint angle estimation methodology is proposed. A back propagation neural network (BPNN) is developed to estimate the shoulder and elbow joint angles from the recorded EMG signals. A Virtual Human Model (VHM) is also developed and integrated with BPNN to perform the simulation of the estimated angle. The relationships between sEMG signals and upper limb movements are observed in this paper. The effectiveness of our developments is evaluated with four healthy subjects and a VHM simulation. The results show that the methodology can be used in the estimation of joint angles based on EMG.

Virtual human hand: model and kinematics

The human hand plays an important role in daily life. It is the interface between the human and the exterior world by positioning, orienting, touching and grasping objects. The human hand has multiple degrees of freedom (DOFs) to enable mobility and dexterity. A virtual human hand model can be inserted into CAD (Computer Aided Design) models to assess the manipulation capabilities in the early design stage to reduce design time and cost. Joystick assessment is one of the important design cases. This study is a first step towards a comprehensive hand simulation tool to simulate the manipulation and grasping of objects. This paper presents a novel 25 DOFs' hand skeletal model based on hand anatomy and hand kinematics: (1) joint range of motion, (2) Denavit–Hartenberg method to define the joint relationship and (3) finger workspace determination. Novelty for this hand model includes arching the palm with the four DOFs added in the carpometacarpal and wrist joints for the ring and small fingers.

Provider decision making in chronic pain management: influence of patient sex, race, and depression

Our previously published work using Virtual Human technology and lens model methodology has found that the pain assessment and treatment decisions of healthcare trainees and providers often vary across patient demographic characteristics and facial expressions. This work has focused on acute pain and has not considered the influence of relevant comorbidities, such as depression, on chronic pain management decisions. In the current report, we present preliminary data from an ongoing study investigating the effects of patient sex, race, and depression on providers' decisions for chronic pain management.

DHM simulation in virtual environments: a case-study on control room design

This paper will present the workflow developed for the application of serious games in the design of complex cooperative work settings. The project was based on ergonomic studies and development of a control room among participative design process. Our main concerns were the 3D human virtual representation acquired from 3D scanning, human interaction, workspace layout and equipment designed considering ergonomics standards. Using Unity3D platform to design the virtual environment, the virtual human model can be controlled by users on dynamic scenario in order to evaluate the new work settings and simulate work activities. The results obtained showed that this virtual technology can drastically change the design process by improving the level of interaction between final users and, managers and human factors team.

1313 デジタルマネキンを利用したユニバーサルデザイン教育(OS14 設計教育)

This paper reports an education of universal design (UD) by using a digital mannequin in Kinki University. A digital mannequin is a virtual human model, which is used in 3D-CAD system to evaluate the usability of a product during product design process. In the course, after training on operations of 3D-CAD product modeling and 2D-CAD mechanical drawing, students start exercises on design of UD products by using a digital mannequin. Firstly, students learn the skills to evaluate the usability of the products which is analyzed with digital mannequin such as posture, balance, view, static load (force and torque) at each body part, and so forth. Then, they learn how to develop the products' usability through UD exercises of actual products. This paper also shows the design examples presented by the students and discusses the future works of the course.

Verification of cardiac tissue electrophysiology simulators using an N -version benchmark

Ongoing developments in cardiac modelling have resulted, in particular, in the development of advanced and increasingly complex computational frameworks for simulating cardiac tissue electrophysiology. The goal of these simulations is often to represent the detailed physiology and pathologies of the heart using codes that exploit the computational potential of high-performance computing architectures. These developments have rapidly progressed the simulation capacity of cardiac virtual physiological human style models; however, they have also made it increasingly challenging to verify that a given code provides a faithful representation of the purported governing equations and corresponding solution techniques. This study provides the first cardiac tissue electrophysiology simulation benchmark to allow these codes to be verified. The benchmark was successfully evaluated on 11 simulation platforms to generate a consensus gold-standard converged solution. The benchmark definition in combination with the gold-standard solution can now be used to verify new simulation codes and numerical methods in the future.