Technology Bulletin 408

No big, scary needles

James W. Winkelman may soon qualify as a hero among the many adults and children who don't like big, scary needles. Winkelman, a professor of pathology at Harvard Medical School, pioneered development of a device that allows physicians to conduct many common blood tests without drawing blood. "Results are available in about 10 seconds," he notes. One area where the need for speed is especially important is in emergency applications. "Speed is a factor in emergency rooms and intensive care units," says Winkelman. "The other area where this device is important is in applications where drawing a blood sample is difficult, such as with patients in neonatal intensive care units or geriatrics," he says. The enabling technology is called reflectance spectroscopy. It analyzes red and white blood cells and platelets using visible and ultraviolet images. When inserted under the patient's tongue, the reflectance spectroscopy probe captures reflected spectral images of blood cells flowing in capillaries in the mouth's mucous membrane. A computer analyzes the images captured by the probe. Results are printed and placed in the patient charts. The new medical device provides information needed for diagnosing anemia, infections, and other diseases that are currently diagnosed with CBC (complete blood count) tests. More than 1.5 billion CBC tests are performed annually in the U.S. A modified version of the probe, called the Cytoscan, is expected to serve as an early warning system for cardiovascular disease. The reflectance spectroscopy device is currently in clinical trials. Call (215) 574-7000.

Avoiding medical device recalls

A National Institute of Standards and Technology (NIST) report on heart monitors, ventilators, and other medical devices indicates that 6% of equipment failures were related to the software programs that run the devices. "Logic errors were the number one reason for software failures, and math errors were the number two reason," says Richard Kuhn, a computer scientist at NIST. "Ninety percent of failures were caused by a single condition," he says. Although none of the failures cited in the study resulted in death or injury, all prompted costly recalls. Kuhn believes that many of the failures were unnecessary and could have been avoided with improved testing and quality assurance. "Instead of testing a device under a single set of conditions, companies should test multiple conditions under which the device might operate," he says. The report also indicates that if software programmers had been familiar with the medical devices, and not just the associated software, failures might have been avoided. He notes that the vast majority of medical devices are safe, but some could be improved. Contact Kuhn at kuhn@ nist.gov or call (301) 975-3337.

Device detects cancer in seconds

The "biological microcavity laser" is a dime-sized surgical device that identifies abnormal protein content found in tumor cells. A vertical microlaser beam enters individual cells as they are pushed by a micropump through tiny channels cut into the glass surface of the surgical device. Cancerous cells contain more protein than normal cells. The protein's additional density changes the speed of the laser light passing through the cancerous cells. The change registers as a difference in output frequency by a receiver and is then transmitted by optical fiber to a laptop computer where an algorithm translates the data into a graph. The graph changes as the surgeon cuts through tissues. Peaks and valleys in the graph determine when the scalpel is in cancerous tissue. "Unlike cell cytometers that require staining tissues with dye and then waiting up to an hour for results, the biological microcavity laser produces feedback in seconds," says Paul Gourley, the project leader at Sandia National Labs. "Initially, people didn't think we could make a laser one-tenth the width of a human hair, but we proved otherwise," he says. The device should help surgeons accurately cut away malignant growths and minimize damage to healthy tissue. Other possible applications include the monitoring of lymphocytes and the measurement of hemoglobin in blood. Contact Gourley at (505) 844-5806 or send e-mail to [email protected] .

Micromirrors target tumors

Tumor detection may soon take place inside the body with a microscope that fits on the end of an endoscopic instrument. Researchers at three German Institutes-Fraunhofer Institute for Silicon Technology (Itzehoe), Laser-Medizin und Technologie GmbH (Berlin), and the Centre for Minimally Invasive Surgery (Tubingen)-built the miniaturized confocal laser scanning microscope. They say the small microscope gives high-resolution images of tissue samples because it suppresses interference from scattered light in the tissue. Normally, a physician removes several tissue samples and then analyzes them outside of the body, which requires at least 30 minutes and possibly several hours. The new device uses micromirrors that are etched on silicon and electroplated with nickel. Mirrors are suspended on springs and electrostatically controlled for horizontal and vertical movement. The microscope's resolution is two micrometers-good enough to visualize cellular nuclei. At that level, it is possible to distinguish between cancerous and "normal" tissue. Practical applications of the device will detect fluorescence from the nuclei. The team is looking for industrial partners to help develop the technology further. Contact: Fraunhofer Institute USA at (734) 354-9700, fax (734) 354-9711, or e-mail: [email protected] .

Software helps paralyzed do math

Henry Gray is helping engineers, paralyzed students, and others save countless computer keystrokes. His new software, called MathTalk, converts voice commands to mathematical expressions. Gray is the C.F. Frensley Professor of Mathematics and Statistics in Southern Methodist University's Dedam College of Humanities and Sciences. He developed the software to help himself and his colleagues save time. The software recognizes all mathematical symbols and equations, according to Gray. "Instead of punching in 55 keystrokes to do one equation, you just say a few words and it does the calculations," says Mike McClellan, Gray's partner. "Right now, MathTalk will work with AutoCAD versions 13 and 14. We're working on the 2000 version for AutoCAD," says McClellan. The software is especially important to paralyzed students and professionals who cannot use their hands to manually keystroke mathematical symbols and other information into a computer. Gray has also developed a version of the software for visually impaired students. Called MathBrailleTalk, this version translates mathematical formulas into Braille, which is then output using an embossing machine. Gray taught himself Braille to develop MathBrailleTalk. The software will be commercialized through Metroplex Voice Computing of Arlington, TX. For information, fax (817) 543-1103.

Lab on a chip

Researchers at the Lawrence Livermore National Laboratory (LLNL) are demonstrating a new chemical analysis device that fits in the palm of a hand. "It's not the tricorder you've seen Spock carrying around on Star Trek, but our approach to chemical analysis, the miniaturization of chromatography, is different from anything out there," says Duane Lindner, a chemist at LLNL. "Why go small? Because when you get small, things move a lot faster," he says. This device produces results in roughly one minute, about a half hour faster than many of today's bench-top chromatograph units. "You also don't need as much material at this small scale. And many of the standard protocols developed for large chromatographs can be used on our micro scale," he says. Potential applications for the "lab on a chip" include performing medical diagnostics at the patient's bedside, screening pharmaceuticals, optimizing industrial processes, locating land mines, and sniffing out chemical and biological hazards. "One of the things we wanted to do with the device was to get it into the hands of first responders, primarily the police and firefighters who might be first on the scene at a chemical spill or biological terrorist attack," says Lindner. The device moves fluids on a chip with electro-kinetic pumping. Pumping channels 10 to 100 microns wide are packed with silica. The surfaces of the particles and channel walls drive buffered solutions forward when high voltage is applied. This pump creates pressures up to 9,000 psi. The device is also capable of hydraulically actuating a host of microsystems, such as microsurgical tools. Contact Lindner at (925) 294-3306.

Nano-particles for high-density storage and medical apps

Microscopic nanoparticles possess magnetic properties. The means of controlling these magnetic properties for computer and medical applications is being uncovered by Dr. John Zhang, a professor of chemistry and biochemistry at the Georgia Institute of Technology in Atlanta. "We are understanding the fundamental ways to control the properties of these small particles as well as chemically manipulating their magnetic interactions," he says. Potential applications that would utilize this type of information include the precise delivery of drugs to specific areas of the body. In this application, the magnetic nanoparticles containing drugs are attracted to specific areas of the body by applying a magnetic field. Concentrating the drug particles in one area where they are needed most enhances the therapeutic benefit while reducing side effects on other areas of the patient's body. Zhang's team is learning the surface characteristics of particles that help nanoparticles get past the body's defense mechanisms. Another potential application for Zhang's research includes magnetic data storage devices. Magnetic digital data bits in a computer hard disk have magnetic states similar to the nanoparticles. His research is beginning to provide insight into high-density information storage. Contact the Georgia Institute of Technology Public Affairs Office at (404) 984-6986.