An approved Department of Defense appropriations bill has allocated $1.6 million to the Center for Neuroprosthetics and BioMEMS (CNB). The center is part of Worcester Polytechnic Institute’s (WPI) Bioengineering Institute located in Worcester, Mass.
The allocation will fund research on neural control for advanced prosthetics. Researchers are working in three specific areas with the hopes of accomplishing two primary goals. The first goal is regenerating tissue to create a soft-tissue seal around an implanted limb. The second goal is to use engineered micro-wires for the recruitment of neural stem cells and the regeneration of nerves, according to a WPI press release.
Researchers will focus on tissue integration, regenerating neural tissues and signal processing that would control the prosthetic device.
“These specific areas will be enabling technologies for the eventual implementation of a prosthetic limb,” W. Grant McGimpsey, director of WPI’s Bioengineering Institute and professor of chemistry and biochemistry explained to O&P Business News.
In tissue integration, a titanium post would be implanted into the remaining bone in a lower-limb amputee. Soft tissue would then be sewn around the post. The prosthesis would be attached to the end of the post. The attachment of the post to the prosthesis would provide the patient with better feedback as to what type of surface they are walking on. The improved feedback would limit the patient’s ability to trip or fall, according to McGimpsey.
There are a number of challenges that would have to be met in order to enable this type of implant. One of the challenges would be the threat of infection. If the infection is in the bone, the implant must be removed and may take some bone along with it. According to McGimpsey, implant removal could compromise the patient’s ability to don a prosthesis in the future due to the lack of muscle in the leg.
“We can anticipate that the 20-year-old amputee will live to the age of 80 or 85,” McGimpsey said. “So they need that implant to be viable and infection free for 60 to 65 years. It is a huge issue that we are working on.”
WPI researchers are also trying to regenerate nerve tissue that provides sensory feedback and control the movement of the prosthetic limb. By regenerating nerves, it will be possible to connect the limb directly to the nervous system, enabling the device to receive commands from the brain, according to McGimpsey.
Researchers have also been working on more immediate and current prosthetic technology. WPI researchers are now trying to retrieve voluntary muscle signals from the pectoral muscle group and convert those to electrical signals that control the prosthetic device for the upper extremity amputee, McGimpsey said.
“We are trying to capture signals that the patient can generate by firing their pectoral muscle groups and converting that into a rotational movement of a wrist or a bending of an elbow,” McGimpsey said.
As the conflicts in Iraq and Afghanistan continue, more and more injured soldiers will be returning home, searching for the latest technological advances in prosthetics. The allocation of funds for implantable neuroprosthetic research has the potential to improve the quality of life of amputees, according to McGimpsey. — Anthony Calabro