LJ Anderson's column in the
Palo Alto Daily News in Calif.:
Research scientist Richard Weir (pictured) likes to build things — including artificial hands and arms — and if he succeeds over time, those who have lost a limb will have a better quality of life because of his efforts. Some of those who may benefit include the more than 1,000 U.S. soldiers who have lost one or more limbs as a result of their service in the Iraq and Afghanistan wars.
There was a large effort, notes Weir, in the 1960s to pursue prosthetic research due to the effects of thalidomide and casualties of the Vietnam War, and the VA has always funded prosthetic research. But right now attention and an escalation of VA-funded amputation and prosthetic research is again being driven by an increasing number of returning amputee soldiers.
Trying to mimic capabilities of the human arm and hand, in particular, is challenging, and researchers such as Weir are at work designing and developing sensors, external control devices, cable-powered systems and other components that will make it worthwhile for an amputee to use the device and be able to perform everyday functions such as reaching back to pull out one's wallet.
Close to 50 percent of upper-extremity amputees in the U.S. use a prosthetic device, notes Weir, although use is highly dependent on the level of the amputation. Worldwide, there are an estimated 650,000 upper-extremity amputees, according to the Open Prosthetics Project (www.openprosthetics.org), or about 10 percent of all amputees.
Nationwide, there are over 1.7 million people who live with the loss of a limb, according to the National Limb Loss Center (www.amputee-coalition.org). Most are lower-limb amputations, and the loss is often related to vascular complications such as from diabetes. Other causes of limb loss include trauma, typically occurring in men and in the upper body; or from cancer and congenital reasons. Trauma, cancer and congenital causes are on the decline, while amputations due to vascular complications are on the rise.
Richard Weir, Ph.D., is director of the Biomechatronics Development Laboratory at the Rehabilitation Institute of Chicago at Northwestern University in Chicago. Biomechatronics is an interdisciplinary science using mechanics, electronics and biology. The focus of Weir's research has a long-term goal, as he describes, of "achieving meaningful, simultaneous, multi-functional control of prosthetic arms and/or hands." His Ph.D. is in biomedical engineering from Northwestern University.
Q: What are the challenges of "recreating" limbs of the human body?
A: The main issues are comfort, and the limited power, space, and ability of the user to communicate with their device, i.e. user interface. We are constrained to anthropomorphic size and shape and less than anthropomorphic weight — because we must suspend our systems on an individual's soft tissue as opposed to their skeleton.
Q: How has research progressed in this area over time?
A: The device of choice for many upper-limb users seeking function over cosmesis (making artificial limbs look life-like) is a hook-and-cable system based on technology from 1945. The technology using motors and robotics — the cool bionic stuff — is still too heavy and we don't have a meaningful way to control it yet. We are working on different methods, but these will involve the use of surgically implanted devices or surgical modification of tissue and bon — both of which users tend to be resistant to. I believe we will get there, but the bar to acceptance is very high because most people have unilateral loss — so they still have a good hand and can function adequately with just one hand. Consequently, if a device is a hassle, or burdensome, or confers little advantage, these devices tend to be rejected.
Q: What does it take for a person to adapt well to a prosthesis?
A: They have to want it. There are various stages of recovery associated with limb loss. The user has to be beyond the point where they are looking for "the cure" — a complete replacement for their lost limb. They have to be at a point where they know what technology is "really" out there — not what the media says is out there — and they have come to accept the reality of what these devices can offer and whether wearing an arm is for them.
Q: How are your research efforts involved with returning soldiers from Iraq and Afghanistan?
A: Much of our advanced research effort is driven by the conflicts in Iraq and Afghanistan. We have been involved in projects funded by the Defense Advanced Research Projects Agency (DARPA) to develop advanced arm systems. The DARPA project was initiated due to perceived shortcomings in the existing prosthetic systems available for returning soldiers. The same issue of how to interface these systems to the user arises, and this is what much of our research is focused on.
Q: What drew you to this area of research?
A: I have a twin sister who lost her hand when she was 5. Also, I come from a medical family on my father's side and an engineering family on my mother's side, and I have always liked science fiction, making things, and been intrigued by robots and the like. So I would say it is an amalgam of all these things.
LJ Anderson's column in the Palo Alto Daily News in Calif.: