Paralysed Woman Moves Robot With Her Mind

 Brain-Machine Interfaces

A new study in Nature reports that two people with tetraplegia were able to reach for and grasp objects in three-dimensional space using robotic arms that they controlled directly with brain activity. They used the BrainGate neural interface system, an investigational device currently being studied under an Investigational Device Exemption. One participant used the system to serve herself coffee for the first time since becoming paralyzed nearly 15 years ago.

Aparalyzed patient equipped with an implanted brain chip has used a robotic arm to reach for and pick up a bottle of coffee, bring it close enough to her face so she could drink from a straw, and then place the bottle back on the table.

Cathy Hutchinson has been unable to move her own arms or legs for 15 years. But using the most advanced brain-machine interface ever developed, she can steer a robotic arm towards a bottle, pick it up, and drink her morning coffee. The interface includes a sensor implanted in Cathy's brain, which 'reads' her thoughts, and a decoder, which turns her thoughts into instructions for the robotic arm. In the video below, watch Cathy control the arm and hear from the team behind the pioneering study.

A study published in the journal Nature shows that people with the brain chips can use the devices to perform complex three-dimensional tasks that could be helpful in daily life. Furthermore, the implanted electrodes can record neuronal signals for as long as five years—longer than had been suspected. In previous studies, patients using brain implants have been able to move a cursor on a screen, but not perform complicated movements with objects in the real world.

The results are the latest announcements from a team led by John Donoghue, a neuroscientist at Brown University. Donoghue and collaborators had reported in 2006 that patients paralyzed by spinal-cord injuries could use brain-machine interfaces to drive the movement of cursors on a screen and do simple open-and-close movements with a robotic hand. Now the researchers have shown that a brain-machine interface can direct more complicated tasks. "Not only can people control a computer cursor, they can control really complex devices like a robotic arm that can carry out the functions that our own arm can do," says Donoghue.

The brain implant is a small array that's four millimeters on each side ("about the size of a baby aspirin," says Donoghue) with 96 hairlike electrodes extending from one side. The device sits on the surface of the brain, and the electrodes penetrate the arm-controlling region of the motor cortex by one millimeter. The implant records the impulses of dozens of neurons. A patient's intent to move generates these impulses, which are then transmitted to a computer that translates the patterns of electrical activity into commands that can control a robotic arm.

"What's striking to me about this study is that it's nicely showing, for the first time in human patients, that you can use these signals to control a robot of importance for activities of daily living for a patient," says Andrew Jackson, a neuroscientist at Newcastle University. The researchers say that algorithmic improvements in picking up patterns of activity in the brain and interpreting those patterns were key to the advance.

The goal of the pilot clinical trial is to develop technologies that can restore the ability to communicate and move and to give independence to people with neurological disease or injury. So far, seven patients have enrolled in the trial. The two participants in this latest work both suffered from brain-stem strokes that left them unable to speak or move their limbs. At the time of the study, one patient had the implant for five months, the other for more than five years.

For now, the implant must be plugged into an external setup, but the Brown researchers and researchers at Blackrock Microsystems in Utah (which manufactures the implants) are working on wireless versions that are being tested in animals. Donoghue hopes that the implants can eventually drive electrical stimulation of a patient's own muscles, circumventing the need for robotic arms. Such experiments have shown promise in nonhuman primates (for example, see a recent study from Northwestern University).

SOURCE  Technology Review, Brown University

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