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Dartmouth Engineer - The Magazine of Thayer School of EngineeringDartmouth Engineer - The Magazine of Thayer School of Engineering

Lab Reports

Wireless, Wearable Triage Gear

LIFELINE: Professor Sue McGrath’s remote triage information system will aid victims and rescuers. Photograph by Chris Milliman.
LIFELINE: Professor Sue McGrath’s remote triage information system will aid victims and rescuers. Photograph by Chris Milliman.

Associate Research Professor Sue McGrath, director of the Emergency Readiness and Response Research Center at Dartmouth’s Institute for Security Technology Studies, is developing a wearable, wireless, mobile communication system that will help medics and emergency teams conduct triage in high-risk situations.

Called Artemis (Automated Remote Triage and Emergency Management Information System), the system allows a team of hand-held computers to pass data wirelessly to one another and ultimately back to an emergency command center. Each Artemis unit can be worn on a belt and attached to GPS, vital-sign, or other monitors to gather and transmit critical data.

Last spring McGrath’s team tested a prototype in an emergency training exercise in which rescuers freed an “injured” construction worker from scaffolding beneath Cape Cod’s Bourne Bridge. The system outwitted interference from the concrete and metal in the bridge by bouncing signals between Artemis units, then back to the collector computer. The field trial led the team to improve the wireless networking, user interfaces, and software models. “Our experiments and exercises teach us a great deal about how the system could be used in actual emergency and battlefield conditions,” says McGrath. She predicts that a commercial system could be available in two to four years.

The research is sponsored by the Department of Homeland Security’s Office of Domestic Preparedness and by the U.S. Army Communications and Electronics Command Division.

Taking the Pain Out of Joint Replacements

Nearly half a million total hip and knee replacements are performed annually in the United States. Despite the high success rate of these procedures, an additional 60,000 surgeries are performed each year to replace failed prostheses. By analyzing failed prosthetic joints, the Dartmouth Biomedical Engineering Center for Orthopedics, headed by Professor John Collier, has greatly reduced the incidence of one cause of prosthetic failure, oxidation-related breakage of polyethylene bearings in artificial joints.

But many patients face another problem. The abrasive and adhesive wear of bearings in prostheses can cause microscopic particles of plastic and metal to migrate into the tissue surrounding artificial joints, causing an inflammatory, bone-resorbing reaction known as osteolysis. Collier and his colleagues are collaborating on a new research project to identify the factors that lead to this condition. Subjects will include both patients who have osteolysis and bone resorption and patients who are not experiencing resorption or infection despite loosened artificial joints.

After surgical removal of failed implants, samples of surrounding tissue are examined by pathologists, then sent to the Thayer School researchers to quantify and classify wear particles. By examining physical characteristics of the debris, patterns of wear on the removed prosthetic components, and tissue histology, the team hopes to identify conditions that lead to joint failure. Project goals are improved prosthetic joint design, better surgical techniques, and, ultimately, a decrease in the incidence of osteolysis-related joint failure.

Collier’s team includes pathologist Justin Cates, orthopedist Michael Mayor, Ph.D. candidate Doug Van Citters ’99, Th’03, medical student Derek Jenkins ’02, and undergraduate Katie Muse ’05.

Smart Football Helmets

A lightweight biofeedback system that measures the force of impact football players experience during head-on collisions is being field tested at three colleges this year. Thayer School Adjunct Professor Richard Greenwald, head of Simbex, the West Lebanon, N.H., company that is developing the Head Impact Telemetry System (HIT), says the patented invention can minimize the guesswork coaches apply every time a player goes down from a head-on collision.

HIT sensors embedded inside a football helmet continuously measure the force of blows to the head and wirelessly transmit the information to a compact console on the sidelines. Coaches can view images and graphs detailing the magnitude, location, direction, and duration of each impact.

Data gathered last year from 38 Virginia Tech players indicate that hits to the head have an average force of 40g — 40 times the force of gravity — and that impacts can reach as high as 180g, the kind of force involved in severe car crashes. Studies this year also include players from the University of North Carolina and University of Oklahoma.

While the National Football League has conducted lab research on concussions, Greenwald’s device is the first to measure on-field head impact for a large number of players. “The HIT System allows us to track players’ cumulative history over time,” he says. “And that is important because most researchers believe that cumulative impacts — not just one impact — may be significant in terms of sustaining more concussions and also long-term cognitive deficits.”

Research and development of the HIT System was funded by the National Center for Medical Rehabilitation at the National Institute for Child Health and Development at the National Institutes of Health.

Down Under for Nanotechnology

Two of Professor Ian Baker’s students, James Hanna ’02 and Johnathan Loudis ’05, traveled to Australia in March to use the University of Sydney’s Local Electrode Atom Probe (LEAP) to examine experimental nanostructured FE-NI-MN-AL alloys developed at Thayer School. The University of Sydney is the only university in the world with a LEAP machine. According to Baker, who visited the Sydney facility last year, the students obtained composition profiles of the alloys by stripping off atoms one layer at a time. Dartmouth has filed a patent on the alloys.

Pushing for Alternative Fuels

Professor Lee Lynd, whose research centers on developing biological alternatives to fossil fuels, is trying to rally support from the American public. In “Growing Energy (PDF),” an article published by the Natural Resources Defense Council, co-author Lynd argues that an aggressive plan for developing cellulose-based biofuels could end America’s dependence on foreign oil by 2025. Lynd also has initiated talks with the National Corn Growers Association, pointing out that corn and other sources of cellulose used in biomass conversion could provide a major new revenue stream for farmers.

Ice Engineer Aids NASA

Professor Erland Schulson, director of Thayer School’s ice research lab, is helping NASA’s Space Shuttle Return-to-Flight Program analyze the ice that builds up on the shuttle’s super-cooled external fuel tank. Because debris from Space Shuttle Columbia’s external tank resulted in the loss of the orbiter, NASA wants to know how much ice can accumulate on the tank without becoming a debris hazard.

ICEBREAKER Ph.D. candidate Andrew Fortt prepares to test ice strength with a multi-axial loading system in Professor Erland Schulson’s lab. Photograph by Douglas Fraser.
ICEBREAKER: Ph.D. candidate Andrew Fortt prepares to test ice strength with a multi-axial loading system in Professor Erland Schulson’s lab. Photograph by Douglas Fraser.

NASA is simulating the conditions typical of launch days to see how much ice and frost build up on the external tank. The agency sends the ice to Schulson for strength and structural analysis. Using a multi-axial loading system, Schulson measures the force required to crush the ice, then returns the samples to NASA for ballistic impact testing.

The NASA work has expanded Schulson’s research. “In our previous research we’d only ever tested poly-crystal ice samples,” he says. “For NASA, we’ve now tested a single crystal form of clear, hard ice and discovered that it is extraordinarily strong.”

Ph.D. candidate Andrew Fortt and engineering research associate Daniel Iliescu are assisting with the analysis.

For more photos, visit our Research and Innovations set on Flickr.

Categories: The Great Hall, Lab Reports

Tags: alumni, faculty, patent, projects, research, students

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