UMaine Researcher Building Novel Prosthetic Hand
Contact: Ashish Deshpande, (207) 581-2180; George Manlove, (207) 581-3756
ORONO – Medical science and engineering technology have taken great strides toward the development of prosthetic hands since the implementation of steel hooks, and a University of Maine researcher in the College of Engineering is pushing the envelope revolutionizing hand prosthetics with novel robotics technology.
Mechanical engineering professor Ashish Deshpande, who directs UMaine’s Rehabilitation & Neuromuscular (ReNeu) Robotics Lab, has received a five-year research grant from the National Science Foundation for more than $512,000 to develop a functional robotic hand.
“It’s exciting, even for younger students who come to visit our lab,” says Deshpande, who came to the College of Engineering in September 2009 with a background in robotics, bioengineering and a prototype artificial human hand. “This is working closely with the human body … but is sort of pushing the envelope, and we’re at the edge of the field. That’s the dream. That’s where we are going.”
Deshpande and his students are working on the design of a state-of-the-art robotic hand with tiny links, cables, motors and sensors that, for the first time, can swivel, rotate and pinch, replicating the movement of the human thumb, fingers and wrist.
What is unique about Deshpande’s artificial hand is that it has built in passive properties like a human hand.
“The current robotic hands are ‘clunky,’ but if you explore your own hand you notice that it has a lot of give,” Deshpande explains. “The joints in the human hand are springy because of the muscles, tendons, tissues and ligaments. This is critical for us to achieve versatile manipulation.”
That provides, for example, the flexibility to grasp an egg firmly but without crushing it. “I strongly believe that we need ‘passive’ features in the robotic hand and we are developing those,” he says. “We make mathematical models to describe the behavior. How does it change from person to person? We want to mimic and incorporate it in a robotic hand. This will drive the design of a much-improved prosthetic hand.”
Sensors and an advanced camera system in the ReNeu Robotics lab can record and analyze human movements. Recently, Deshpande and his students conducted experiments with 20 UMaine male and female volunteers to study hand biomechanics during hand and finger motion. In the past, he has studied the human hand and forearm through the biomechanical models using cadavers with small motors attached to forearm tendons.
Once a robotic hand is built to more precisely replicate the human hand, he says, the next step is to tap into brain signals to control it.
“The ultimate goal is to design a prosthetic hand that a user can easily control by ‘thinking about it,'” he says. “But, before we get there, we have to address a number of questions. How will the prosthetic hand connect to the neural control system? What is the interface of connection between the human intent and the robot action, and robot sensors and human sensing?”
The research has a vast number of applications, from medicine to military and fitness to entertainment, says Deshpande, who notes interest in his work from the hand therapist at the U.S. Department of Defense and also the Disney Research Lab.
The advancing field also needs new scientists and researchers, which is why he sometimes shows his students parts of The Terminator movie starring Arnold Schwarzenegger as a human-like cyborg, or other films that highlight futuristic robotics.
“My goal is to get the students and the general public excited about robotics, but also to educate them to realize that the field of robotics is still in its infancy,” he says. “We need more scientists to come in and help us solve the big problems in prosthetics and rehabilitation.”
Apart from the robotic hand, Deshpande is building robotic assistive devices for the disabled and elderly. He is building an assistive exoskeleton for upper body fitness activities for people with severe disability and a ‘ServiceBot’ to assist people with disabilities to carry food in a cafeteria. He is collaborating on those projects with Elizabeth DePoy, a faculty researcher at UMaine’s Center for Community Inclusion and Disability Studies.
“I am designing robots that work very closely with the human body,” he says. “So I study the human body and then come up with unique designs that lead to comfortable and safe interactions between the users and the robots.”