A team of researchers at Worcester Polytechnic Institute (WPI) will receive $1 million in federal and state grants to advance the critical development of neuroprosthetics—next-generation artificial limbs that could one day be permanently implanted and perform most of the movements and functions of natural limbs.
The majority of the funding comes through a two-year $860,000 grant awarded to WPI's Bioengineering Institute (BEI) by the U.S. Army's Military Amputee Research Program of the Telemedicine and Advanced Technology Research Center (TATRC). "There is a great human need for better, more functional prosthetic devices, especially for our soldiers who have been severely injured in Iraq and Afghanistan," says W. Grant McGimpsey, professor of chemistry and biochemistry, and director of the BEI. "So we are very pleased to receive this funding to enable our work. We are taking a comprehensive approach to this research, looking at how we can leverage our expertise at WPI to fill the gaps and advance the field."
In addition, WPI will receive a $150,000 grant from the John Adams Innovation Institute, the economic development division of the Massachusetts Technology Collaborative, to undertake market evaluation, strategic planning, and business development activities supporting the growth of the Center, and to help stage a national neuroprosthetics conference at WPI in 2009. "The collaborations and nexus of innovative activity created by the Center for Neuroprosthetics at WPI greatly improves conditions for growing the medical device industry in the region, throughout the Commonwealth, and beyond," said Pat Larkin, Director of the MTC's John Adams Innovation Institute.
The TARTC grant, funded through appropriations supported by U.S. Senators Edward M. Kennedy and John Kerry, as well as Congressman James P. McGovern, will cover three areas of prosthetics research at WPI: control signal processing, nervous system integration, and the tissue-interface between device and body.
Ted Clancy, associate professor of electrical and computer engineering at WPI, will lead the signal processing work. His lab will study the electrical signals that control normal muscle activity, to apply that knowledge for enhancing the control of prosthetic limbs. Using specialized technology and algorithms, Clancy will measure and analyze signals propagating along the forearm muscles of healthy volunteers, and record the associated movements and forces of the subjects' wrists and fingers. Current prosthetic limbs often rely on remnant musculature for control. Clancy's work may be able to enhance the control of current prosthetic technology, while also laying the foundation for signal processing for artificial limbs that are connected to the nervous system so they can be controlled directly by the brain and provide sensory feedback to the brain, such as limb orientation, temperature of surfaces, and so on.
Stephen Lambert, research associate professor with BEI, will direct basic science studies needed for eventually connecting external prosthetic devices with the nervous system. His team will try to direct the growth of neurons on artificial surfaces, such as glass, gold, or silicone, so their axons extend along channels etched in the materials. Axons are long, thin fibers that extend from neurons and carry electrical impulses across the nervous system. Bundles of axons form nerves. Fully developed axons are covered with a sheath of myelin, a fatty-like substance that insulates the axons and helps them work efficiently, much like the rubber or plastic coating that insulates electrical wires. Lambert's team will try to achieve predictable neuron growth and axon myelination on various surfaces in the laboratory.
Whether they are controlled by the nervous system or remnant muscle activity, the advanced prosthetics WPI researchers envision will have a permanent connection to the body. A fixed metal or composite post will be placed into bone, and then multiple layers of tissue will integrate around that post. Through the TATRC program, the WPI team will study the tissue interface at two levels. George Pins, associate professor of biomedical engineering, will focus on the top layer of skin, the epidermis, and study how those skin cells interact with a variety of post materials. Kristen Billiar, associate professor of biomedical engineering, will examine the deeper layer of skin tissue called the dermis, to analyze how it reacts to the stresses and movements associated with the integration of a prosthetic device. The idea is to coax the cells of the dermis to create a stronger bond around the implanted post to provide a foundation for the epidermis, which would then form a tight, yet flexible seal around the post to prevent infection.
"Our program has components that we hope will have an immediate impact on existing prosthetics technology, and will also address some of the fundamental research questions that must be answered if we are to achieve the goal of having advanced neuroprosthetics, fully integrated with bone and tissue and under the control of the nervous system," McGimpsey said.