New Diffusers Tame Unruly Light Waves
Whether the source is a table lamp, a flashlight or the backlight on a portable computer, light tends to scatter randomly, causing strange shadows and flickering. A new type of light-diffusing technology, developed by Torrance-based Physical Optics Corp., promises to improve lighting in a wide range of applications, from flat-panel computer screens and projection systems to specialized flashlights used for aircraft inspection.
Called a light-shaping diffuser, it provides a way to shape those normally unruly light waves by bending off-target rays in the right direction while smoothing out differences in intensity.
Diffusers are already used with the fluorescent backlight on liquid crystal displays to produce a uniform light source. But the combination dramatically reduces the light’s intensity. Physical Optics’ LSD, which is based on a patterned holographic impression molded onto one surface of a thin, transparent material, retains close to 90% of the light, compared with 30% to 50% for conventional diffusers.
Thus, a notebook computer screen fitted with an LSD would be up to 15 times brighter, allowing both better viewing and longer battery life. Physical Optics’ LSDs have also found their way into a depth finder for fishermen.
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Custom-Made Bones: Currently, when surgeons need to replace a joint that has broken or worn out, they order prosthetic devices from manufacturers. But these typically aren’t manufactured to fit a specific individual. Replacement of a bone segment, meanwhile, requires surgeons to manually reshape one of the patient’s less critical bones, or one from a cadaver. In either case, the manufacture of bone and joint replacements is time-consuming and expensive.
A collaborative research project hopes to develop new methods for producing ceramic prostheses tailored to individuals. The project involves Zimmer Inc., owned by Bristol-Myers Squibb and a leader in the design and manufacture of orthopedic implants; Midwest Orthopedics, an orthopedic surgical group; and the Energy Department’s Argonne National Laboratory.
The process begins by taking a 3-D X-ray image using a scanning technology developed by Argonne. To create a replacement bone segment for a patient’s left foot, for example, an X-ray image of the right foot would be digitized and entered into a computer. Using special software, the computer can flip the right foot’s 3-D X-ray image to produce a mirror image for the left foot.
This file is then read directly by a rapid-prototyping machine that builds the ceramic part using a process called “fused deposition.” The machine oozes ceramic material out a nozzle and builds the part layer by layer. A series of heat-treatment steps follow to harden the material.
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Melts in Your Brain: Of the 20,000 primary brain tumors diagnosed in the U.S. each year, the most common--and one of the most deadly of all cancers--is glioblastoma multiforme, or GBM. When GBM strikes, it progresses rapidly and often kills a patient within a year.
Recently, the Food and Drug Administration approved the first treatment ever to deliver chemotherapy directly to the tumor site--and the first new major brain cancer treatment to be approved in more than two decades. Called Gliadel, the product is a dime-sized plastic wafer that dissolves slowly when placed in the brain.
By delivering chemicals directly to the tumors, the wafers could prevent them from recurring. Gliadel, made by Guilford Pharmaceuticals Inc., a Baltimore biotechnology company, is based on a plastic technology developed at MIT.
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Healthy Skepticism: Credit card companies have long used sophisticated software to look for suspicious patterns that might signal that while your credit card was in Los Angles lunching at Spago, you were still shoveling snow in Minneapolis. Now a Los Angeles-based company, Integrated HealthCare Inc., is using these same pattern-detection techniques to ferret out fraud in another arena: health care.
Health-care fraud, which costs government and private insurance plans at least $44 billion a year, is believed to be the fastest-growing criminal enterprise in the U.S. Integrated HealthCare, which provides its services to insurance companies, self-insured employers and medical providers, uses a combination of mathematical pattern-detection techniques such as regression analysis and rule induction, as well as neural networks and genetic algorithms, to analyze claims data.
Freelance writer Kathleen Wiegner can be reached at kkwrite@aol.com
