Think, and a prosthetic arm moves
Toni Björninen develops antennas that receive and transmit brain signals within the framework of a project funded by the Academy of Finland.
Eye-tracking technology that allows hands-free writing on a computer screen is no longer science fiction. Researchers are now developing a mind-controlled, wireless brain-machine interface that improves the quality of life for people living with severe disabilities.
Tampere University of Technology (TUT) is participating in a project that explores the utilization of wireless radio frequency identification (RFID) technologies in implantable medical devices.
“Our research is a continuation of the widely publicized recent advances in brain-machine interfaces, which establish an electrical connection between a computer and the human brain,” says Postdoctoral Researcher Toni Björninen.
Brain-machine interfaces are already helping patients who are severely paralyzed, for example due to the locked-in syndrome, to communicate with those around them.
“Brain signals are recorded using electrodes that are either embedded into a cap or attached to the patient’s scalp. However, the applications of brain-machine interfaces require a precision that can only be achieved by recording brain activity directly from the cortical surface. Fully wireless interfaces have not yet been developed anywhere in the world.”
The project seeks to determine whether the implanted subdural electrodes could be connected to a central processing unit that resembles an RFID tag. The tag would receive all the energy it needs via a transmitter outside the body.
“The recorded brain signals will be wirelessly transmitted to an external system that, for example, translates the data into control signals for a prosthetic limb. So we’ll also need an external antenna that receives the signals,” he adds.
Wearable antenna captures brain data
Toni Björninen’s postdoctoral research project is sponsored by the Academy of Finland and focuses on the development of antennas that receive and transmit brain signals. The project is a joint effort between multiple international partners.
“The antenna placed outside the human body could be made of conductive thread or fabric and sewn directly onto clothes. It would be easy to carry around,” explains Björninen.
Scientists are already using brain implants, among others, to monitor the neural activity of people with severe epilepsy. Electrodes are surgically implanted in the brains of epileptic patients on a temporary basis to localize the source of seizures.
“A wireless and fully implantable brain-machine interface would have the advantage of ultimate portability and convenience.”
“Of course the central processing unit that is implanted in the brain for an extended period of time must meet strict safety standards. The unit could be made of certain polymers that remain nonreactive within the body. The electrodes that are in direct contact with brain tissue could be made of precious metals, such as platinum,” says Björninen.
Hot research topic brings together international partners
To make wireless brain-machine interfaces a reality, TUT has joined forces with the University of California at Berkeley, UCLA, and the Tsinghua University in Beijing that all enjoy an international reputation for research excellence. In Berkeley, close collaboration is maintained with several laboratories: Berkeley Wireless Research Center (BWRC), the Brain-Machine Interface Systems Laboratory and Berkeley Sensor & Actuator Center. Wearable antennas are developed in collaboration with UCLA and Tsinghua University.
“I spent a research period at UC Berkeley while I was pursuing my doctorate. It turned out that BWRC was looking for an expert in antenna design,” says Björninen.
“Brain-machine interfaces have sparked worldwide interest among scientists, but we’re on the front lines due to our comprehensive and multidisciplinary approach. We have every opportunity to succeed in developing a functional system that brings all the bits and pieces together,” he believes.
The image below illustrates the wireless brain-machine interface.