Stanford Today Edition: November/December, 1996 Section: On Campus WWW: Science & Medicine News
Science & Medicine News
Nearsighted No More Trials of a new outpatient laser surgery to correct nearsightedness combined with astigmatism are under way on campus. If approved by the FDA, the procedure is expected to benefit many of the 10 million to 20 million people nationally who have compound myopic astigmatism, said Dr. Edward E. Manche, the ophthalmologist who heads the program. "For most patients, a few painless minutes with the laser procedure provide the potential for permanent correction of their [vision problem], enabling the majority of patients to see well without dependence on glasses or contact lenses," said Manche, acting assistant professor of ophthalmology and newly appointed director of refractive surgery. The computer-controlled laser system for treating simple myopia and compound myopic astigmatism gives physicians greater precision and more versatility than the traditional vision correction surgery, radial keratotomy, which has been available for more than 15 years.
New Cancer Drug An experimental cancer drug developed at Stanford is being tested to determine whether it might eliminate the need for debilitating surgery while improving treatment for head and neck cancer. The new drug, tirapazamine, attacks cancer cells that radiation and chemotherapy often miss, said Dr. Harlan A. Pinto, assistant professor of medicine (oncology). These tough-to-kill cancer cells usually resist chemotherapy because they lie farthest from the blood vessels that deliver the tumor-destroying drugs. They also resist radiation because they are low in oxygen, Pinto said. Although the current round of testing focuses on head and neck cancer, tirapazamine also offers promise for treating other soft-tissue tumors, including tumors of the breast, brain, cervix and colorectal region. The final word on whether the drug will be effective in combination with radiation should be available within two years.
Better Ways to Test Chips As computer chips grow larger and more complex and are driven at ever higher speeds, manufacturers face increasing difficulty in identifying defective chips. Now, Stanford's Center for Reliable Computing and the specialty chip maker LSI Logic Corp. have embarked on a three-year, $400,000 effort to improve chip testing methods. In the past, manufacturers have approached the test problem by building bigger and faster electronic testers. But this strategy is becoming prohibitively expensive, says E. J. McCluskey, director of the reliable computing center and professor of electrical engineering and computer science. McCluskey and his colleagues have opted instead to develop improved testing methods, and will evaluate the effectiveness of more than two dozen test techniques. "We have designed and built an integrated circuit whose only point in life is to be tested. We will test it in lots of different ways," McCluskey said. The study will evaluate methods that test all aspects of state-of-the-art integrated circuit performance including logic, memory and other mixed signal circuits.
Novel 3-D Display Elizabeth Downing, a graduate student working with electrical engineering Professor Lambertus Hesselink, has developed a prototype video display that can produce 3-D images in a whole new way - by creating actual three-dimensional color images inside a solid cube of fluorescent glass. The technology, although still rudimentary, has a number of potential applications, including medical imaging and air traffic control. The technology is unique in that "it doesn't create an image that appears to be three dimensional, it actually produces an image that is drawn in three dimensions," Downing says. "As a result, there are few restrictions on the viewing angle and a number of people can view the images at the same time Also, the images are emissive - they glow - rather than reflective, so they can be seen easily in ordinary room light." The technology also has limitations. The objects that it forms are transparent, not opaque, so additional processing would be required before it would be suitable for entertainment purposes. It also takes 500 times as much data to construct a three-dimensional object as it does to draw the same object in only two dimensions. The research is reported in the Aug. 30 issue of the journal Science. ST