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Electrical and Computer Engineering |
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Hagness is working with Associate Professor of Radiology Frederick Kelcz (right) to develop a low-cost, computer-based microwave tumor-detection system that could improve early detection and eliminate the trauma of unnecessary biopsies. The planned microwave sensor will include a small flat panel containing an array of miniature antennas placed gently on the surface of the breast. The devices are inexpensive enough to make them widely accessible in health care. In addition, microwave imaging carries no danger of ionizing radiation exposure. Microwaves interact with human tissues primarily according to water content. Because malignant tumors have a much higher water content and more vascularization than normal breast tissue, microwaves can provide the basis for a highly sensitive detection system. In Hagness's research, low-power microwave pulses are used to interrogate the tissue. Cancerous lesions back-scatter the pulses, producing a microwave echo. The measurements of those echoes enable Hagness to develop a 3-D image of malignant tumors. Graduate student Kristen Leininger (left), Hagness and Kelcz collect data on breast tissue removed through hundreds of excisional biopsies at UW Hospitals and Clinics. The information will be used to develop a microwave sensor capable of detecting very small lesions and discriminating between malignant and benign cases.
After eight years, more than 100,000 hours of effort, $7.5 million, and an incredibly complex design and fabrication process, the 14-member team of the Helically Symmetric Experiment (HSX) created the first plasma in the program's new stellarator. Associate Professor David Anderson and co-investigators Simon Anderson and Joseph Talmadge are now measuring the device's attained magnetic field structure through electron beam mapping techniques. A stellarator is a "magnetic bottle." Fusion plasma research has the goal of making a miniature star by heating heavy isotopes of hydrogen to ignition. Plasmas are achieved by heating matter to intensely high temperatures, creating a glowing, gas-like state that can conduct electricity. Magnetic fields constrain the high-temperature plasma. In the presence of magnetic fields, charged particles orbit around the magnetic lines. With the proper orientation of the magnetic lines of force, a "bottle" is formed and the particles can be prevented from touching material walls and losing energy. HSX combines the best attributes of tokamaks and stellarators. Tokamaks require a strong current in the plasma itself. Stellarators don't need that current, but generally don't produce the high-quality magnetic field required to confine plasmas at higher temperatures. HSX solves that problem by achieving symmetry in the magnetic field through its oddly-shaped magnet coils.
The gene chip, which permits scientists to analyze thousands of genes at once, may soon come within easy reach of researchers. Writing in the October issue of the journal Nature Biotechnology, UW-Madison scientists described a new way to inexpensively and simply manufacture the customized chips capable of deconstructing long segments of DNA. The technique enables scientists to study human, animal and plant genomes. "The recently announced mapping of the human genome opens incredible possibilities for this type of chip," says Professor Franco Cerrina . "It's an ideal tool for making use of the genetic map in discovering gene variations." The interdisciplinary team includes ECE's Cerrina; visiting scientist Yongjian Yue; Roland Green, environmental toxicology program, now at NimbleGen Systems; physicist Sangeet Singh-Gasson, now at Motorola; Clark Nelson, Biotechnology Center; Professor Fred Blattner, genetics; and Professor Michael Sussman, horticulture and genetics. The Wisconsin team capitalizes on display projection technology involving 780,000 micro-mirrors arranged on a computer chip, eliminating the need for the complex mask process used in previous high-density DNA chip technology. In addition, the technology reduces fabrication time to only a few hours.
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raditional X-ray mammography creates a breast image by passing
high-energy ionizing radiation through a highly compressed breast to
film on the other side. Though this process has warned thousands of
cancer, it is far from perfect, notes Assistant Professor Copyright 2000 University System Board of Regents
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Published: September 2000 |
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