A new study conducted by a research team in University of Minnesota recently showcased a new technique that can be used to control robotic arm with minds. It is an important breakthrough that can lead to a mind-controlled, practical formation of prosthetics for patients suffering with neurodegenerative diseases or paralysis. For mind control, the hardware needs a brain computer interface (BCI). There are several types of BCIs that are available in market these days and these can be categorized into two major categories: invasive and non-invasive. For this purpose, the team made use of non-invasive BCI that was based on electroencephalography (EEG). It makes use of electrodes at scalp’s surface to register all brain’s activities. For this study, thirteen test subjects were placed in a specialized EEG cap that had 64 electrodes lined over it.
When the patient wears this EEG cap, they need to learn how to control cursor over a computer screen by imagining wherever they wanted to go. The team directed them to imagine either their left or right or both hands or a relaxation in both hands.Whenever the body thinks of moving, the motor cortex of their brain sends electric currents. Just imagine a different kind of movement and a new set of neurons will be activated. With the help of this, the research team made use of signal processing as well as machine learning techniques that matched the EEG readings whenever the subject needed to move. Implied by just a few training sessions, the subjects could control the cursor effectively only through their thoughts.
The researcher then converted the 2D control of user into 3D control of a robotic arm with a two-phase approach. In the first phase, the participants were taught to pick up an object with that arm while in the next phase they directed the arm downwards in 3D to grasp an object. The patients were able to perform multiple things with this robotic arm. The lead researcher, Bin He, says, “This is exciting as all subjects accomplished the tasks using a completely non-invasive technique. We see a big potential for this research to help people who are paralyzed or have neurodegenerative diseases to become more independent without a need for surgical implants.”
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