Tufts physicist Austin Napier uses the university's new "VisWall" to show the workings of high-energy particle research at Europe-s CERN particle collider. (Tufts University Photo / Joanie Tobin)
By Colin Nickerson
Globe Staff / March 31, 2008http://www.boston.com/news/science/articles/2008/03/31/plasma_tv_has_nothing_on_this_visionary_virtual_device/
MEDFORD - At first glance, the screen dominating a front room at the Tufts University School of Engineering seems nothing more than an out-sized version of the high-definition TVs found in any sports bar or airport lounge. But when Lionel Zupan, the school's associate director for research technology, fires up the new "VisWall," you get more than close-ups of some sweaty-browed pitcher pondering whether to hurl a sizzler or a sinker.
The $350,000 scientific display device and its twin backscreen projectors are packed with software designed to impart three-dimensional form and even "feel" to virtual objects, whether a string of molecules seeming to swirl in mid-air, a hovering swath of DNA, or a simulated diseased organ about to be removed.
The 3D objects - which leap off the screen with such forcefulness that first-time observers often flinch or hop backward - can be manipulated to perform flip-flops and other twists and turns. It's illusion, sure, but not just the scientific version of a parlor trick. The virtual forms enable researchers to scrutinize things they would not be able to easily view or handle otherwise.
"You can go deep into the structure of a chemical, an organism, or even a natural event," said Zupan. "It is getting interest from researchers into everything from particle physics to how a caterpillar locomotes."
The 8-foot high by 14-foot wide screen at the Tufts Center for Scientific Visualization, funded by a grant from the National Science Foundation and built by the Illinois firm Visbox Inc, is among the most sophisticated such devices in use on any US campus. Boston University and Brown University also have visualization systems, but the Tufts model uses an advanced German-designed filter to sift out "ghost" images and is equipped with twin projectors - as opposed to multiple projectors - for smoother images.
"You feel like you are entering another world," said Bruce M. Boghosian, chair of the Tufts mathematics department and adjunct professor of computer science, who uses the VisWall to enrich his studies of fluid dynamics, or how liquids flow under a range of conditions.
"With such powerful visualization, you can immerse yourself in the data," he said. "You can go right up to streamlines in a fluid or dig into a reservoir to see which way it's flowing."
Scientific visualization refers to computer-linked technology that enables researchers to "see" objects, processes, or raw information that may be too small, too distant, or - in many cases - too abstract to scrutinize with the unaided eye. The VisWall, for example, can lead a medical student on a highly-detailed journey through the colon or create a virtual tornado that uses computer models to show how the collision of winds and thermal currents quickly builds into one of nature's most brutish forces.
"The brain has a large region devoted to processing visual images, it's very powerful, and often under-utilized in processing data," said Robert J. K. Jacob, professor of computer science. "We hardly think about it because it is so easy, natural, almost unconscious, but it really does a lot. A key idea behind visualization is to harness all that brainpower to help understand our data."
According to Tufts, most visualization systems use several projectors or multiple "tiled" screens to produce images based on data entered by scientists or mathematical models produced by computers. The VisWall uses a single screen and two projectors to produce nearly 9 megapixels of resolution. In flatscreen mode, it boasts twice the sharpness of high-definition televisions.
For Caroline G. L. Cao, assistant professor of mechanical engineering, a big attraction of the VisWall is its "haptic" capability - that is, the unit's ability to use computer-generated feedback to impart a sense of feel or touch to someone using the remote controls. This allows senses in the fingertips to guide the manipulation of virtual scalpels or surgical tweezers onscreen.
"You aren't just seeing, you are feeling," said Cao, whose focus is making more tactile surgical training systems. "This is critical, for example, in training or designing tools for laparoscopic surgery," or for surgery performed with devices manipulated by tubes inserted through tiny incisions in the skin.
Someone wielding a scalpel, for example, can sense the yield of the skin and the controlled slice of blade through soft tissue, said engineering student Kyle Maxwell, a Tufts senior and member of Cao's surgical simulation team.
Such refined haptic technology is not employed on most laparoscopic training systems, so research using the VisWall could eventually boost the quality of medical training as well as assist in the designing new surgical tools.
"The texture of the skin or the organ changes and deforms according to how you use your device," Maxwell said. "You use 'feel' to figure out the right pressure for cutting away a tumor, say, and removing it with a grabbing tool."