Virtual hand is an important medium for implementation of human-computer interaction in the process of virtual assembly. And the comparability between the action of virtual hand and real man-hand has always been regar...Virtual hand is an important medium for implementation of human-computer interaction in the process of virtual assembly. And the comparability between the action of virtual hand and real man-hand has always been regarded as one of the important criteria to judge whether the virtual environment has the property of immersion. On the basis of analyzing the relative position,posture,and motion behavior relationship between virtual hand and the object to be operated during virtual assembly,this paper proposed an implementation method of combining grasp index with collision detecting technology for identifying grasp action of virtual hand. The method is to identify grasp/quit using grasp index and to implement joint angle adjustment through simulation cyclic iteration and joint angle interpolation calculation. Although some traditional method identifying the grasp action on the basis of the shape of the object is operated,the simulation result getting from virtual environment created by EON STUDIO shows that it has good features of serviceability and fidelity to realize operation control of virtual hand.展开更多
Glaucoma, the world's leading cause of irreversible blindness, is a condition for which elevated intraocular pressure is currently the only modifiable risk factor. However, the disorder can continue to progress ev...Glaucoma, the world's leading cause of irreversible blindness, is a condition for which elevated intraocular pressure is currently the only modifiable risk factor. However, the disorder can continue to progress even at reduced intraocular pressure. This indicates additional key factors that contribute to the etiopathogenesis. There has been a growing amount of literature suggesting glaucoma as a neurodegenerative disease of the visual system. However, it remains debatable whether the observed pathophysiological conditions are causes or consequences. This review summarizes recent in vivo imaging studies that helped advance the understanding of early glaucoma involvements and disease progression in the brains of humans and experimental animal models. In particular, we focused on the non-invasive detection of early structural and functional brain changes before substantial clinical visual field loss in glaucoma patients; the eye-brain interactions across disease severity; the metabolic changes occurring in the brain's visual system in glaucoma; and, the widespread brain involvements beyond the visual pathway as well as the potential behavioral relevance. If the mechanisms of glaucomatous brain changes are reliably identified, novel neurotherapeutics that target parameters beyond intraocular pressure lowering can be the promise of the near future, which would lead to reduced prevalence of this irreversible but preventable disease.展开更多
基金Sponsored by the Heilongjiang Science and Technology Program ( Grant No GC02A125)
文摘Virtual hand is an important medium for implementation of human-computer interaction in the process of virtual assembly. And the comparability between the action of virtual hand and real man-hand has always been regarded as one of the important criteria to judge whether the virtual environment has the property of immersion. On the basis of analyzing the relative position,posture,and motion behavior relationship between virtual hand and the object to be operated during virtual assembly,this paper proposed an implementation method of combining grasp index with collision detecting technology for identifying grasp action of virtual hand. The method is to identify grasp/quit using grasp index and to implement joint angle adjustment through simulation cyclic iteration and joint angle interpolation calculation. Although some traditional method identifying the grasp action on the basis of the shape of the object is operated,the simulation result getting from virtual environment created by EON STUDIO shows that it has good features of serviceability and fidelity to realize operation control of virtual hand.
基金supported by the National Institutes of Health R01-EY028125(Bethesda,MD,USA)(to KCC)BrightFocus Foundation G2013077 and G2016030(Clarksburg,MD,USA)(to KCC)Research to Prevent Blindness/Stavros Niarchos Foundation International Research Collaborators Award(New York,NY,USA)(to KCC)
文摘Glaucoma, the world's leading cause of irreversible blindness, is a condition for which elevated intraocular pressure is currently the only modifiable risk factor. However, the disorder can continue to progress even at reduced intraocular pressure. This indicates additional key factors that contribute to the etiopathogenesis. There has been a growing amount of literature suggesting glaucoma as a neurodegenerative disease of the visual system. However, it remains debatable whether the observed pathophysiological conditions are causes or consequences. This review summarizes recent in vivo imaging studies that helped advance the understanding of early glaucoma involvements and disease progression in the brains of humans and experimental animal models. In particular, we focused on the non-invasive detection of early structural and functional brain changes before substantial clinical visual field loss in glaucoma patients; the eye-brain interactions across disease severity; the metabolic changes occurring in the brain's visual system in glaucoma; and, the widespread brain involvements beyond the visual pathway as well as the potential behavioral relevance. If the mechanisms of glaucomatous brain changes are reliably identified, novel neurotherapeutics that target parameters beyond intraocular pressure lowering can be the promise of the near future, which would lead to reduced prevalence of this irreversible but preventable disease.
