A customized model for 3D human segmental kinematic coupling analysis by optoelectronic stereophotogrammetry

The study of three-dimensional human kinematics has significant impacts on medical and healthcare technology innovations. As a non-invasive technology, optoelectronic stereophotogrammetry is widely used for in-vivo locomotor evaluations. However, relatively high testing difficulties, poor testing accuracies, and high analysis complexities prohibit its further employment. The objective of this study is to explore an improved modeling technique for quantitative measurement and analysis of human locomotion. Firstly, a 3D whole body model of 17 rigid segments was developed to describe human locomotion. Subsequently, a novel infrared reflective marker cluster for 17 body segments was constructed to calibrate and record the 3D segmental position and orientation of each functional body region simultaneously with high spatial accuracy. In addition, the novel calibration procedure and the conception of kinematic coupling of human locomotion were proposed to investigate the segmental functional characteristics of human motion. Eight healthy male subjects were evaluated with walking and running experiments using the Qualisys motion capture system. The experimental results demonstrated the followings: (i) The kinematic coupling of the upper limbs and the lower limbs both showed the significant characteristics of joint motion, while the torso motion of human possessed remarkable features of segmental motion; (ii) flexion/extension was the main motion feature in sagittal plane, while the lateral bending in coronal plane and the axial rotation in transverse plane were subsidiary motions during an entire walking cycle regarding to all the segments of the human body; (iii) compared with conventional methods, the improved techniques have a competitive advantage in the convenient measurement and accurate analysis of the segmental dynamic functional characteristics during human locomotion. The modeling technique proposed in this paper has great potentials in rehabilitation engineering as well as ergonomics and biomimetic engineering.

Mixed reality emergency management:bringing virtual evacuation simulations into real-world built environments

Computer-based evacuation simulations are important tools for emergency managers.These simulations vary in complexity and include 2D and 3D GIS-based network analyses,agent-based models,and sophisticated models built on documented human behaviour and particle dynamics.Despite the influential role of built environments in determining human movement,a disconnect often exists between the features of the real world and the way they are represented within these simulation environments.The proliferation of emergency management location-aware mobile devices,along with a recent infatuation for augmented reality(AR),has resulted in new wayfinding and hazard assessment tools that bridge this gap,allowing users to visualize geospatial information superimposed on the real world.In this paper,we report research and development that has produced AR geovisual analytical systems,enabling visual analysis of human dynamics in multilevel built environments with complex thoroughfare network infrastructure.We demonstrate prototypes that show how mixed reality visual analysis of intelligent human movement simulations built in virtual spaces can become part of real space.This research introduces a fundamentally new way to view and link simulations of people with the real-world context of the built environment:mixed reality crowd simulation in real space.