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Robotic fingertips touch future of prosthetics

posted 9 Jul 2012, 13:28 by Mpelembe   [ updated 9 Jul 2012, 13:28 ]

Researchers in California are developing robotic fingers that can sense and identify different objects through touch alone. The fingers could one day be adapted to prosthetics to allow amputees a sense of touch that most people take for granted.

LOS ANGELES, CALIFORNIA, UNITED STATES  (REUTERS) - Dr. Gerald Loeb, a professor of biomedical engineering at the University of Southern California, has developed robotic finger tips with the ability to "feel" what they touch.

Loeb began working on the project seven years ago. He wanted to give robots the ability to judge textures and tell one material from another.

"People would like to have robots in the home to help people with disabilities but, in the home, the range of objects you might encounter and what you want to do with them is really indeterminate," said Loeb.

Loeb says the main challenge in creating the BioTac - tactile robot fingertips - was equipping robots with enough software to be able to distinguish different textures and objects and, consequently, store the information inside a library or memory bank, allowing robots to "remember" the objects they touch.

The robot finger tips are modeled after human fingertips, complete with a nail and finger prints. The tip of each finger is equipped with sensors that vibrate as the finger slides over a surface. The vibrations are stored inside the device, allowing the robot to identify the object it has just touched. According to Loeb, the sensors essentially mimic the interaction between the human finger, the nerves and the brain in identifying objects from touch.

"You have the most sophisticated muscles and tendons and actuators and things in your brain that allow you to make judgements but, without tactile sense you're almost paralyzed. So, even if we have really good robots with really good motors and really good linkages, if they don't have tactile sense they're never going to be any better than you are when your hands are numb," he said.

The robot has demonstrated it is capable of identifying 117 different materials using its finger. The process of identification is controlled by an algorith that takes a step-by-step approach to each material it encounters. Information gained from the intitial exploratory touch begins a process of narrowing down all the options until a final determination is made. Loeb says the robot has proven correct 95 percent of the time.

The BioTac finger tips are being marketed through a company called SynTouch LLC, founded by the University of California's Medical Device Development Facility. Loeb says he hopes future versions of the finger tips will eventually help amputees.

Vikram Pandit, a USC student and intern at the SynTouch lab, where Dr. Loeb works, is helping fulfil that goal. Pandit was born without his left forearm and has been using a conventional prosthetic most of his life.

"Everything I do with the prosthetic, I have to look at it while I'm using it. Say I'm picking up something, I have to actually look at me picking it up so I know I've grabbed it and as I'm picking it up making sure I'm applying the correct amount of force or making sure it's closed the entire time," he said. "The thing that I want most out of this technology is being able to hold something while the weight is changing without having to look at it and knowing how much force to apply without having it fall out of the prosthetic," said Pandit.

Loeb says the next step is to create fully tactile fingers that can not only identify objects by touch but also recognize temperature.