UNL, UNMC engineers, surgeons develop unique surgical tool

One of the problems with being an ergonomist is that one notices badly designed things and has an overwhelming urge to fix them.

At least, that's how Susan Hallbeck feels. An associate professor of industrial engineering at the University of Nebraska-Lincoln, Hallbeck is particularly interested in designing tools that perform tasks with the least amount of stress and trauma on the arms and hands of those using them.

A prototype surgical tool designed by Hallbeck and a team of undergraduate and graduate students in the UNL College of Engineering and Technology, in collaboration with physicians at the University of Nebraska Medical Center, promises to be better than current models.

The tool, trademarked under the name Intuitool, is an articulated grasping tool that can be used by surgeons performing minimally invasive surgeries. Often called laparoscopic or keyhole surgery, minimally invasive surgery is done through small incisions. Using specialized techniques and tools, miniature cameras with microscopes, tiny fiber-optic flashlights and high definition monitors, surgeons are able to perform a growing number of operations using the technique.

Laparoscopic surgery, the fastest growing surgical technique, was developed about 1990, said Dmitry Oleynikov, M.D., assistant professor of surgery at UNMC.

While this surgery has definite patient benefits -- including faster recovery and less risk of infection -- there are downsides for surgeons. Many are posed by the tools surgeons have to use.

"Current tools are essentially regular surgical tools on a long stick," Hallbeck said. The handles look like toy scissors and are "one size fits all," she said, meaning surgeons with unusually large or small hands are hampered. The tools also are usually to be used right-handed, forcing lefties to adapt.

"The current tools mean you are basically forced to perform complicated tasks with chopsticks," Oleynikov said. "They are rigid, unwieldy instruments."

Because the tools can grasp, but not rotate inside the body, the surgeon has to manipulate the tools outside the body, often using both hands. This forces the surgeon to hold the tools awkwardly, often causing stress and fatigue in the surgeon's hands, arms and shoulders.

Hallbeck said many surgeons report numbness, tingling, pain and other problems when doing these surgeries. Over time, this repetitive stress could shorten or end a career or cause permanent damage. And because of pain or fatigue, surgeons might have to stop during a surgery to rest before resuming the task, lengthening the surgery.

Training for minimally invasive surgery is also intensive, as surgeons must learn to work using the long tools inside the body while watching a video monitor that shows the procedure in two dimensions.

The breakthrough in the Intuitool is in the articulation function -- the grasper end rotates up to 120 degrees side to side using a roller ball the surgeon actuates using his or her thumb.

"Essentially, the Intuitool gives you a wrist on the tool," Hallbeck said.

"This is an unprecedented, even revolutionary breakthrough," Oleynikov said. "No one else has anything remotely similar. It absolutely excited the imagination of surgeons."

The Intuitool, patented and trademarked by UNL, has been licensed to Gyrus Medical, based in Minneapolis, to develop, manufacture and market the tool. It's yet to win approval by the Federal Drug Administration for use in humans, but Hallbeck said she is confident that will come once the design is finalized.

The device won an honorable mention in the Third Annual User-Centered Product Design Award from the Human Factors and Ergonomics Society in 2004. The work was funded through UNL's Layman Trust Fund grants and other internal funding sources.

Hallbeck's lab at UNL contains two surgical mock-ups she and her colleagues have made -- neoprene abdomens upon which researchers experimented with prototypes to look at how accurately users could aim and move the tool and also to study the stresses the tool put on users hands, arms and shoulders.

Among the questions Hallbeck and her team had to answer once they settled on the roller ball design was how the grasping end of the tool should respond to the ball. Do users expect the grasper to go up when the ball is pushed up, or down? There was no prior research in that, which surprised Hallbeck, but proved to be a valuable topic for her undergraduate and graduate students to study. Turns out folks expect the tool to go up when the ball is pushed up, down when pushed down and left or right when moved laterally left or right respectively. This is just one of the 19 publications with student co-authors that have arisen from this project.

"Good design should be user intuitive," Hallbeck said. "If I hand it to you, you ought to be able to figure it out intuitively."

Working on the project provided "an unbelievable real-world application" for the students, Hallbeck said. The undergraduates, now graduates, are in master's programs and the graduate students have completed their theses and have jobs. Five students' names are on the patent with Hallbeck and Oleynikov.

Hallbeck was drawn into the research in 2002 at a meeting coordinated by Prem Paul, UNL vice chancellor for research, where scientists from UNL and UNMC came together to look at possible collaborations. There, she met Oleynikov, co-director of UNMC's education and training efforts in minimally invasive and computer-assisted surgery.

Oleynikov described the collaboration between the physicians and engineers as uncommon and unusual. "I can't think of a precedent nationally for this type of collaboration," he said.

Rather than looking to modify existing inadequate tools, they looked to start fresh. "We designed this thing from the ground up," Oleynikov said,

An initial survey of 18 surgeons asked them to describe their concerns with current tools and their goals for a new tool. A later survey of 38 physicians asked their impressions of the latest model. In the latter study, the prototype tool was preferred. Some 92 percent of those surveyed indicated they thought the articulated tool would be somewhat or very useful and 89 percent said they would try the prototype once commercially available.

Hallbeck said that while an articulated tool was a high priority for surgeons, the "holy grail" for laparoscopy tools would allow the ability to distinguish tissue textures.

Oleynikov agreed. "The ultimate tool for surgeons is our hands. Laparoscopic surgery took our hands out of the mix. A surgeon really feels the most comfortable with his or her own hands doing the work on tissues. We are as close as we can get with current technology and a tool with tactile sensation would be extremely important," he said.

Tactile feedback would help surgeons determine what they are grasping, confirming what they are seeing on two-dimensional video monitors.

"We want to determine how squishy is squishy," Hallbeck said.

Hallbeck said she has been interested in ergonomic design as long as she can remember and she continues to be enthusiastic about her work. "I really had a ball doing this project," she said of the Intuitool.

Oleynikov and Hallbeck are pursuing development of a proposed Center for Advance Surgical Technologies.

"I'm really excited and proud that these kind of innovations are happening at UNMC and the university in Lincoln," Oleynikov said. "It's really a very unique thing."

Hallbeck is looking at the tasks in the operating room to examine the stresses on the health professionals. In addition, her group -- the Innovative Design and Ergonomic Analysis Laboratory -- is working on a piano keyboard design that would accommodate pianists with smaller than usual hands. She is the coordinator of a group of engineers (materials, electrical, mechanical and industrial), chemists and physicists who are creating a neutron detector for homeland security. With a faculty member in biological systems engineering, she has just completed a study funded by the National Institute for Occupational Safety and Health on the reduction of wrist motion while grasping at various strength levels. She also is interested in comparing and perhaps improving on the keyboards in various personal digital assistant devices like Blackberries and Treos in the near future.

"That's the pitfall of being an ergonomist. I see everything that's wrong with tools in my world, and I want to make them better," she said.

The links below are to color JPEG images of Hallbeck, Oleynikov and the Intuitool. The first image is of Hallbeck holding a prototype Intuitool, with a currently available laparoscopic tool that can cause surgeon fatigue lying on the desk. The second image is of a current laparascopic tool (top) and the Intuitool. The third is a head-and-shoulders photo of Oleynikov.

CONTACTS: Susan Hallbeck, Assoc. Prof., Industrial & Management Systems Engineering, (402) 472-2394; and
Dmitry Oleynikov, Asst. Professor, Surgery, UNMC, (402) 559-4518