The next-to-last place any farmer should visit is here
By Larry Dreiling
If a farmer is injured in an on-farm accident, the last place any farmer wants to visit is a funeral home because that means he’s dead. Even worse, it’s the last place when someone the farmer loves dies a premature accidental death.
About the next-to-last place any farmers should visit is a prosthetics lab because it means they’ve lost a limb.
According to the Amputee Coalition, there are about 2 million people in the U.S. living with limb loss. While about 54 percent of those losses are due to vascular disease such as complications from diabetes and peripheral arterial disease and less than 2 percent are due to cancer, about 45 percent are attributable to industrial accidents. About one-third of those industrial accidents happen on the farm.
Farmers in accidents are twice as likely to lose a limb than any other injury. According to the University of Georgia Extension’s Farm Again program, which assists farmers with disabilities, on-farm amputation accidents generally fall into four categories.
1. Entanglement. This is when clothes, jacket or shoestrings, gloves, or long hair, get caught in moving parts (such as PTO shafts, belts, pulleys, balers and combines). The best way to prevent entanglement is to completely shut down and disable machinery prior to working or moving next to the equipment.
2. Entrapment. Combine heads and augers would be an example because they are designed to trap and pull. Augers should always have guards on them. Producers should remember to turn off the machine before working on it.
3. Crushing. Usually this occurs from post drivers or heavy equipment pinning certain body parts. This type of injury usually causes internal damage to the arm or leg and eventually ends in amputation.
4. Infection. This is usually due to a dirty wound. The limb may survive initial trauma, but amputation is eventually required following days or weeks of intensive therapy.
From this loss of limb comes new hope through research.
In the crowded Biomechatronics Developmental Research Laboratory at the Department of Bioengineering, College of Engineering and Applied Science, University of Colorado Denver/Anschutz Medical Campus and the Department of Physical Medicine and Rehabilitation, School of Medicine, University of Colorado Anschutz Medical Campus, researchers are developing prosthetic hands and fingers that provide a full range of movement from muscle signals, as well as a sense of touch for persons with arm amputations.
Walk into the laboratory located deep inside the basement of Children’s Hospital Colorado on the Anschutz Medical Campus, and you may see a hand in the making.
Richard Weir, Ph.D., research associate professor, along with professional research assistant Stephen Huddle and a bevy of graduate students from a host of universities along the Front Range of the Rockies, are focused on developing prosthetic hands and fingers that provide a full range of movement as well as a sense of touch for persons with arm amputations below the elbow.
Weir, the son of a professor of medicine at Trinity College Dublin, Ireland, comes to this research personally, as his twin sister lost her hand in a lawn mower accident when she was 5 years old.
Weir and his team have been working on these sophisticated prostheses for over a decade. According to a CU release, they previously worked with a team at the Rehabilitation Institute of Chicago on a neurally controlled hand, which was part of a project to develop a physiological replacement for the human arm.
The Defense Advanced Research Projects Agency initiative assigned different teams to various parts of the arm, such as the elbow, shoulder and hand. Weir was the architect of the hand, and the team’s prototype was featured in a 2010 National Geographic cover story on advances in prosthetics.
DARPA ultimately moved its focus on developing a brain-machine interface to help patients with high-level spinal cord injuries.
Still, Weir continued with the neural and muscle interfaces in the arm because a brain-machine interface has a risk-benefit ratio that’s not necessarily justified for people with amputations. Also, he said, amputees already have been through trauma and are resistant to more invasive surgery than is required for brain machine interfaces.
The key to these interfaces is the development of Implantable MyoElectric Sensors (IMES—pronounced “eye-me’s”), metal capsules about the size of a plump rice kernel that can be implanted into muscles in the forearm.
The IMES match with a socket equipped with a coil that transmits information from each implant and sends back a sensed muscle signal back to the prosthesis that can be used to control hand and finger movement.
IMES research is being supported by a grant from the National Institutes of Health from the National Institute on Bioimaging and Bioengineering.
The goal is to give the prosthesis the full 22 degrees of movement articulated in a human hand and wrist. Current technology provides a control interface that only allows two commands to be delivered to the prosthetic hand—to open and close, Weir said.
“Recently, we had been working with the Alfred Mann Foundation in California and translated that technology to them,” Weir said. “They began a clinical trial with these sensors at Walter Reed Army Medical Center in Bethesda, Maryland, in July of last year. The head of physical medicine and rehabilitation there said he wanted it for his guys.”
While 3-D plastic printers have been available for many years, metal printing is still “a very nascent technology,” Weir said. He estimates that only a couple dozen of the devices are being used in the U.S., mostly for biomedical and aeronautical applications.
In 2011, the Department of Veterans Affairs, thinking Weir’s pioneering research could benefit veteran amputees, funded through a $600,000 capital equipment grant, the purchase a direct metal laser-sintering machine. Weir and the team in the lab already had been using a 3-D plastic printer, but a metal prototyping machine dramatically expanded the horizons for their prosthetic designs, such as the product now being tested by an Army veteran in that clinical trial.
“The results have been encouraging. We have a soldier with eight implants in his arm for the control of two degrees of finger, hand and wrist. The first batch of implants was egregiously expensive, but they will get cheaper as we are able to produce more of them.”
Weir produced a video showing an Army veteran, Staff Sgt. James Sides, with a right arm prosthesis that allows him to open and close his hand, rotate his wrist and independently move his thumb. The veteran said the device has opened up a whole new world for him.
“It’s very challenging to build something that can articulate like your natural hand,” Weir said. “To fit the motors into the fingers and into the palm in the forces and speeds your natural hands do. It’s applied engineering. The challenge is to get a user to communicate with these mechanisms.
“So many people take their fingers, hands and wrists for granted. We now can fit a hand for anybody and they would be able to control it. When we used to use surface electrodes, they could do sequential, tedious, movements. Now they can do multiple, simultaneous, movements, and the hand will be there for that gentleman where and when he wants it.”
What’s truly gratifying for Weir is seeing the confidence with which the veteran is using his hand.
“He cannot just handle a cup, but a hot saucepan and do it with confidence. The implanted sensors won’t do anything funky on him like a surface electrode,” Weir said. “With a fixed location, he has a constant, stable signal. It’s not very sexy, but to have a user be confident that all these degrees of motion can work for him in parallel.”
Weir believes if this passes muster with the Food and Drug Administration, it will, indeed, open a whole new world for amputees. Currently, the IMES are implanted using a small incision into the arm. Weir thinks that with time, the process can be accomplished via injection with a large needle.
The hope remains for Weir that the work he does will benefit as many people who need help as possible.
“The numbers of people who’ve come back from Iraq and Afghanistan who could benefit is relatively small, about 2,000 individuals in the last 10 years,” Weir said. “That’s compared with the 10,000 people a year who lose upper limbs in the U.S. About 30 percent of those are injured in farm accidents. There are 60,000 people who lose fingertips.
“It’s far more exotic and sexy to say we’re fitting our soldiers at Walter Reed, when there are far more people injured in industrial and, especially, farm accidents annually who need help.”
What Weir would really like is for farmers not to need his help, since they know they ought to practice good farm safety habits, since the vast majority of people who come into the lab for help have seen limb loss via farm accidents.
“They need to not take the shields off their stupid PTO drives to remove some weed or something while that drive is running or to lean in with a hand to clear a running grain auger,” Weir passionately said to this reporter. “PTOs are the banes of my existence.
“Or how about having a shirttail out, or their pants hanging down while clearing a cutting bar on a combine, and that shirttail or pant leg gets caught in the cutter and you try to grab onto it to get it out, they’ll see their hand go through the machine. Everyone complains about OSHA, but in industry, where OSHA works, accidents are down. On the farm where OSHA’s not around, accidents are up.
“What would I say to farmers? Let them know I don’t want them here in the lab, and I hope if they’ll never need me, the better, and to not forget what can happen in a split second when they’re not safe. Tell them that.”
Larry Dreiling can be reached by phone at 785-628-1117 or by email at firstname.lastname@example.org.