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Biomedical Engineering

Carmalyn Lubawy, Nimmi Ramanujam, and Changfang Zhu

From left: Graduate student Carmalyn Lubawy, Assistant Professor Nimmi Ramanujam and graduate student Changfang Zhu developed a technology that helps doctors take more accurate breast biopsies. (20K JPG)

Viewing breast biopsy in a new light

New technology developed by Assistant Professor Nimmi Ramanujam's research group will be a "third eye" during breast biopsies and can increase the chance for an accurate clinical diagnosis of breast cancer.

Currently, doctors use X-ray or ultrasound — two-dimensional pictures — to guide the biopsy needle into a three-dimensional region. To ensure they biopsy the right spot, they take up to a dozen tissue samples.

Now Ramanujam and graduate students Carmalyn Lubawy and Changfang Zhu are harnessing the power of light to add another dimension of information about tissue properties at the tip of the needle. Light can provide structural information such as cell or nuclear size, as well as measurements of hemoglobin oxygenation, vascularity and cellular metabolic rate — all of which are hallmarks of carcinogenesis and can indicate the needle has hit the mark, she says.


This fiber-optic probe may help identify cancerous tissue. (11K JPG)

Her group has built fiber-optic probes that doctors can thread down the existing hollow biopsy needle to the tip to help them find the right area to sample. The researchers are testing probes in both the near-infrared wavelength, which allows light to go deeper but probes fewer molecules, and in the UV-visible wavelength range, which allows them to probe a large number of molecules but with limited depth. With two grants totaling more than $1.2 million from the National Cancer Institute and National Institute of Biomedical Imaging and Bioengineering, the researchers will recruit about 250 patients for in vivo studies.

Although current needle-biopsies are minimally invasive, an additional benefit of the fiber-optic probe is that it can be made thin enough to fit through an even smaller needle than the standard quarter-inch size, making an emotionally draining procedure even less physically traumatic.

Quick, custom-built labs that fit in the palm of your hand

Associate Professor David Beebe's palm-sized "laboratories" require no assembly, contain no electronics and are powerful enough to detect botulinum toxin in a tiny drop of blood. With University of Illinois Urbana-Champaign Chemistry Professor Jeff Moore, Beebe's group developed a new way to make the microfluidic devices easily and quickly. They bond polycarbonate top and bottom layers and fill the gap between them with a photo-polymerizable polymer. Using masks, they shine light on selective areas of the device to form a channel network, then remove the excess polymer. They can make multiple layers and, to add pumps, filters, valves and other components, flow a different polymer into the channels and repeat the process. In addition, the group was first to incorporate materials that respond to environmental stimuli such as temperature, light, pH or a biological agent and react according to conditions in the channel.

Building the devices, which are easily customized for many applications, can take less than an hour and doesn’t require a clean room. Although Beebe's group collaborated with Food Microbiology and Toxicology Professor Eric Johnson to develop a system specifically to detect botulinum toxin, the applications are far reaching. His group currently is working with Pediatrics Professor Mike MacDonald on a microfluidic insulin delivery patch for diabetic children and an environment that enables cells to behave as though they were in vivo to facilitate basic cell-behavior studies. Grants of approximately $7 million over the past six years from the Defense Advanced Research Projects Agency supported the research.

"Failing" to learn: Engineering design for the disabled

The idea of arthritis is largely incomprehensible to 18-year-old freshman engineering students — until they enter the Trace Research and Development Center, don a glove with knarled fingers, attempt to press tiny buttons on a cell phone, and fail.

The exercise is one of many they undergo to raise their awareness of how a product's design and interface can make it difficult or impossible for a person with physical or cognitive limitations to use that product. Last fall, student Bern Jordan (now a graduate student with Trace) began offering the exercises as part of the college's Introduction to Engineering course, in which students learn about various engineering disciplines and, in teams, solve a design problem.

At Trace, the students' challenges include everything from using a mouth stick to open a laptop computer fitted with two front latches and discerning color-coded information on a web page while wearing goggles that simulate color-blindness to trying to understand the functions of buttons on an unmarked stereo control panel. After they fail at all of the activities, the students reattempt them with the same limitations, but on products with simple design changes, such as arrow-shaped buttons to indicate forward or reverse, or a single latch that opens the laptop.

The center offers the exercises to other classes, including "Design and Human Disability and Aging" (IE/BME 662), at conferences, and at the student-run Engineering EXPO. With funding primarily from the National Institute of Disability and Rehabilitation Research, Trace is a research leader in accessibility of standard information and telecommunications technologies. Its director is Professor Gregg Vanderheiden (also Industrial Engineering).


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Copyright 2004 The Board of Regents of the University of Wisconsin System
Date last modified: Thursday, 17-Feb-2005 14:09:29 CST
Date created: 17-Feb-2005