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Fu Y.,Huazhong University of Science and Technology | Chen X.,Wuhan Institute of Physical Education | Li S.,Huazhong University of Science and Technology | Chen J.G.,Foxconn Technology Group | Zhou B.,China Astronaut Training and Research Center
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2014

An accurate disability evaluation provides good basis for job placement of the handicapped and corresponding accommodations. In this study a work disability analysis model is firstly developed to predict human performance in certain task scenarios and the disability index is finally correlated to DOF of joints, the inner joint moments, the muscle pressure around the stump. The model is made of three levels. The outcome of the third level algorithm will be reflected in digital human in simulated task scenarios. To simulate handicapped behavior, the study further presents a simulation framework to realize the above three-level model, which integrate the two kinds of constraints: task constraints and physical function constraints, reflecting on posture and motion of the digital man. To validate the modeling framework, the study used material handling task as an ex-ample. Ten male BKAs were recruited in Chinese electronic manufacturing companies. The model calculated the optimization angles and moments of knee, hip, elbow joints of healthy and unhealthy parts. The calculated results are put to biomechanical-disability spectrum to generate a weighted disability index, compared to evaluation results by an occupational therapist. Meanwhile, results were put in Jack environment and a manikin was created and compared to another manikin created by motion capture data. The matching results will validate the applicability of the proposed framework to modeling handicapped behavior. © 2014 Springer International Publishing Switzerland. Source


Wang D.,Shanghai JiaoTong University | Shi D.,Shanghai JiaoTong University | Li X.,Fudan University | Dong J.,Fudan University | And 2 more authors.
Applied Mechanics and Materials | Year: 2012

This study was designed to compare the biomechanical effects of three posterior fixations for thoracolumbar burst fractures using the finite element (FE) method. Five T11-L1 FE models, including the intact, the fractured at T12, the monosegment fixated at the level of the fracture, the short-segment fixated with four pedicle screws and the short-segment fixated with five pedicle screws, were created. And four loading conditions (flexion, extension, lateral bending and torsion) were imposed on these models and deformations in these models under different loading conditions were calculated by finite element method. The biomechanical effects of the three different pedicle screw fixations for thoracolumbar burst fractures were compared and analyzed. The results showed that the displacement level in monosegment fixation model was close to that in the intact one. The extension motion was more limited in short-segment fixation models than that in monosegment fixation model. Under the lateral bending condition, the level of the displacements in these models were similar and the peak rotation angles in the three fixation models were close to that in the intact one. The displacements in fractured T12 were increased in monosegment fixation model under all loading conditions. These indicated that the monosegment fixation couldn't provide desirable stability for the fractured T11-L1 and the short-segment fixation with five pedicle screws was the best selection because of ideal stability and movability. © (2012) Trans Tech Publications. Source


Lei Z.-J.-X.,Shanghai JiaoTong University | Wang D.-M.,Shanghai JiaoTong University | Wang C.-H.,China Astronaut Training and Research Center | Chen S.-G.,China Astronaut Training and Research Center
Chinese Journal of Biomedical Engineering | Year: 2014

Functional adaptation of bone occurs due to the influence and regulation of mechanical factors. Establishment of numerical model and quantitative analysis for bone remodeling process has significant clinical value. Nowadays, models developed in the literature to simulate the functional adaptation of bone fall into two classes: mechanical models and physiological models. This paper reviews bone remodeling models from several aspects, including theories, algorithms and applications. Mechanical models are able to predict bone remodeling through direct relationships between mechanical stimulus and bone structures, but no actual biological processes are considered. According to different remodeling stimuli, mechanical models mainly include mechanostat models and maintenance models. Physiological models try to unravel the role of the mechanical environment in the biological mechanisms involved in bone remodeling. Different types of cells are involved in bone remodeling process; osteoclasts, which resorb bone, and osteoblasts, which deposit bone. Based on different hypotheses, these cells are thought to work separately or as basic multicellular units. Remodeling models are normally implemented in finite element programs to enable numerical solution of problems related to bone remodeling. Based on several application examples, parametric investigation of remodeling equations is discussed as well. Source


Yang Z.Z.,China Astronaut Training and Research Center | Yu X.J.,China Astronaut Training and Research Center | Fei J.X.,China Astronaut Training and Research Center | Song D.,China Astronaut Training and Research Center | And 2 more authors.
7th International Symposium on Heating, Ventilating and Air Conditioning - Proceedings of ISHVAC 2011 | Year: 2011

To investigate the effects of dynamic airflow on body temperature during 30d -6°head-down bed rest (HDBR). Seven males took part in the three arranged sessions on the 10 th day, 20 th day and 29 th day during 30d HDBR. Artificial airflow environment was varied in control state (C), constant airflow (CON) and dynamic airflow (DYN) in the three sessions respectively. Air temperature was 23°C. Subjective perception of general thermal sensation, rectal (T r,), skin temperature and skin blood flow (SkBF) were measured. Compared with under C, the T r (p<0.01), average skin temperature (T̄ s) and SkBF (p<0.05) under CON and DYN were significantly decreased, subjective perception increased under DYN (p=0.038). The T r under DYN was significantly higher than that under CON. No differences were found in T̄ r, SkBF and subjective perception between under CON and DYN. Dynamic airflow can inhibit the decrease of core temperature compared under constant airflow and there was no significant difference in general thermal sensation between the two environments. Therefore, dynamic airflow was more helpful to thermoregulation than constant airflow in 23°C during HDBR. Source


Fu Y.,Huazhong University of Science and Technology | Wang C.,China Astronaut Training and Research Center | Li S.,Huazhong University of Science and Technology | Chen W.,Huazhong University of Science and Technology | And 2 more authors.
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2014

Six-dimensional tracking and control task within an Integrated Cognitive Architecture, as a makeup for automated Six-dimensional tracking and control task default. is a common yet highly complex space operation, challenging the human workload. For space exploration system safety, workload is a critical factor in task design and implementation. This research integrates two cognitive architectures: Queuing Network (QN) & Adaptive Control of Thought-Rational (ACT-R) to develop a rigorous computational model for Six-dimensional tracking and control task cognition process. ACT-R represents the human mind as a production rule system. Experiments are set up to build Six-dimensional tracking and control task cognition model and afterwards to validate feasibility of the proposed integrated cognition architecture. Ten subjects of similar training level are chosen to finish manual Six-dimensional tracking and control task with three task difficulty level: one only with displacement margin, one only with posture margin and one with displacement and posture margin. Cognition task analysis is firstly conducted on task performance of subjects. Cognition model of manual Six-dimensional tracking and control task is then built up based on the proposed integration architecture. The proposed integration model developed in the ACTR-QN describes component processes of tracking, decision making and controlling in a 3D environment by ACT-R production rules within QN network. Workload index for each cognition module is calculated based on sector utility throughout the whole task. Human results are compared with the modeled results in the dimension of task time and displacement/posture control trajectory deviation. Workload index is calculated based on the percentage of each module in the time dimension. © 2014 Springer International Publishing. Source

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