ALBUQUERQUE, N.M. -- After the horrors of enduring a foot amputation due to disease, accident or landmine, one learns that a prosthesis -- say, an artificial foot and ankle -- doesn't flex with the intricacy of a natural limb and may be uncomfortable to use.
FANCY FOOTWORK -- Sandia liaison Mort Lieberman examines the latest version of a prosthetic foot created by U.S. private industry and checked by Russian nuclear weapons scientists -- a cooperative project originated by Mort. (Photo by Randy Montoya)
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Now, in an arrangement as complicated as a movie plot, an insight by a researcher at Sandia National Laboratories has resulted in funding for eight scientists at a top Russian nuclear weapons laboratory, Chelyabinsk-70, to divert their expertise in materials science, stress analysis, mechanical design, and computer simulation, to test and improve a new kind of artificial foot. The device, patented by a Tufts University professor in Boston, is licensed by a U.S. manufacturer of prosthetic devices, the Ohio Willow Wood Company, in Mount Sterling, Ohio.
The foot contains a rolling ball joint that offers a better approximation of the movement of the human foot as body weight passes over it.
"More technical work is being done to bring the best possible device to market," says Mort Lieberman, the Sandia researcher whose insight into the possibility of achieving funds from two government agencies made the international arrangement possible. Sandia is a laboratory of the U.S. Department of Energy (DOE).
While many improvements in prosthetic devices have been made, studies have shown that one-third of below-knee amputees and four-fifths of above-knee amputees choose not to wear prostheses. Another study indicated that 78 percent of all amputees never wear prostheses or use them no more than one hour per day.
Major issues are durability and comfort, says Lieberman.
In September, the Ohio Willow Wood Company sent plans for the design of the new prosthetic foot to the Russian scientists, who will develop and test components under stress, and use computer simulations to improve the foot's action.
"The company furnishes some of the parts for us to send to the Russians," says Lieberman. "The Russians develop other parts, and evaluations are performed by both [parties]." The Russians also will help in outcome determinations, such as gait testing.
"Obviously, we'd like to have the device out as soon a possible," says Jim Colvin, director of engineering for the Ohio Willow Wood Company. "A lot depends on how much the Russians help us, but our guesstimate is two years."
In the device, originated by Tufts professor Mark Pitkin, a rolling joint allows the artificial foot to offer little resistance at the beginning of its motion -- when an unimpaired person merely pushes his or her weight forward over the foot -- and more at its end, when a biological foot would aid in propelling its owner forward. The proposed artificial foot has the potential of causing less user discomfort because its action more closely corresponds to that previously experienced by the leg.
"This is the first rolling joint model of a human foot prosthesis," Pitkin says. "The rolling of bone heads is a major type of movement in the human body. There are no pin joints." Pitkin, himself a Russian emigre and a mechanical engineer, mathematically modeled the spring function of the human foot to receive a doctoral degree in 1975 from the St. Petersburg Institute in Prosthetics.
There are an estimated 260,000 lower limb amputees -- mostly elderly -- in the United States, with an occurrence rate of 40,000 per year at an estimated cost to society of $1 billion a year, says Lieberman.
"Internationally, the problem is worse," he says. "Landmines are a major cause of lower limb loss and amputation in Africa, the high rate of amputees due to mines in Bosnia is expected to continue, and in Vietnam, from 1967 to 1969, land mines accounted for 14 percent of U.S. casualties."
The international project originated when Lieberman, after spending six months at the National Institutes of Health's National Center for Medical Rehabilitation Research (NCMRR) as a technical expert, envisioned both a national defense and national medical reason for funding the arrangement and thus was able to leverage it into existence.
One funder is the DOE's Initiatives for Proliferation Prevention, charged with helping find peacetime employment for Russian nuclear weapons scientists, some of whom otherwise might be vulnerable to overtures from unfriendly national states or terrorist organizations.
Lieberman's idea of using Russian scientists to develop prosthetic devices -- solidified into a formal proposal -- drew DOE funding of $250,000.
For the DOE, "This is not a health care project," Lieberman says. "It is a nuclear nonproliferation project in prosthetics."
The second funder was NCMRR, where "the need for improved prosthetics and orthotics is well known and a subject of continuing research," says Lieberman.
The NIH agreed to contribute $100,000 a year for two years for the project.
Lieberman co-directs the program with co-founder Louis Quatrano, director of the Behavioral Science and Rehabilitation Engineering Program at NCMRR.
There will be no cost overruns because each stage of the project is contracted at a fixed cost.
"Anyone with a lower limb amputation is likely to need a foot. The device therefore will cover a large number of amputees," says Colvin.
According to Colvin, "We hope something good will come of it. We have expensive test facilities here -- one of the best equipped labs [in the industry] for testing prosthetic components -- but we're asking the Russians to look at the bands that hold everything together in an artificial foot -- the ankle, the keel or bottom portion, and the bumper portion, which sits on top of that. They're experts in materials, and it's our hope they'll identify an optimal material for the bands, and also a mechanism for adjusting the bands. They have the equipment to do that kind of testing. Then we'll test the entire foot from the components they send back."
Bands surround the foot like rubber bands around a cylinder. In addition to their binding properties, they are elastic elements that allow easy motion in early phases of a step and then, as stretched, provides stability, or resistance, just like a natural foot. " Right now, it's difficult to initiate the motion," says Colvin. "We want to make it easier."
"Currently, if you're seated in a chair and you're wearing a prosthetic device, that can be a problem," says Quatrano. "If you rolled back, your foot would come off the floor. This device permits a bit of flexibility in rotation."
"We're hoping we can develop other projects of mutual interest to work together in the future," says Quatrano. "The intent is to look at the area of assistive technology for an individual to move about in an environment. It could be something for an upper limb. or extended to a knee or an artificial skin covering. But we need to find more cofunding. We're hoping DOE and NIH might extend their support to do further development. NIH is a grant funding mechanism. We depend on investigator initiated ideas."
According to a letter from Jan Sokosa, president of the National Association for the Advancement of Orthotics and Prosthetics, "Prosthetic research is ideally suited for federal attention. Amputees are relatively few in number and rely on often costly lower limb prosthetic devices for mobility. . . . NAAOP enthusiastically supports the . . . collaborative project between the [DOE] and [NIH] that . . . addresses lower limb prosthetic research [and] could result in exponential progress in this area."
A letter from John Billock, president of the American Academy of Orthotists and Prosthetists, states: "The Academy board appreciates your efforts to expand needed research in the field and to team small companies with government to expedite development of needed products and international market growth. The approach you propose fills an important void by combining the technical resources of major U.S. and Russian laboratories with U.S. government support and input from U.S. prosthetists and orthotists."
A national committee set up by Quatrano has identified additional tasks related to lower limb prosthetics that may involve further Russian and U.S. cooperation.
Sandia is a multiprogram DOE laboratory, operated by a subsidiary of Lockheed Martin Corp. With main facilities in Albuquerque, N.M., and Livermore, Calif., Sandia has major research and development responsibilities in national security, energy, and environmental technologies and economic competitiveness.
Neal Singer, email@example.com, (505) 845-7078
Mort Lieberman, firstname.lastname@example.org, (505) 844-5458