Stanford scientists develop brain-controlled sensor geared toward ALS patients

In the Stanford team's experiment, a brain-controlled sensor helped monkeys move a cursor over blinking dots on a computer screen.--Courtesy of Shenoy Lab

Brain-controlled prostheses are picking up steam within the industry, and a team of scientists from Stanford University is harnessing the technology to create a system that could help paralyzed patients carry out more precise movements.

Researchers led by Stanford engineering professor Krishna Shenoy are developing a technique that uses mind-controlled sensors to generate specific movements, potentially improving prostheses for patients with paralysis or Lou Gehrig's disease (ALS). The team created an algorithm that analyzes electrical signals sent to a mind-controlled prosthetic device, and tweaks them to so they resemble normal, baseline brain signals. The scientists tested the algorithm on two monkeys with full ranges of movement, training them to select the correct targets on a simplified keypad.

The team found that monkeys averaged about 29 correct finger taps in 30 seconds when they reached for the target with their finger instead of the brain-controlled cursor. When researchers altered the signals using a mind-controlled sensor, the monkeys scored 26 brain-controlled taps in 30 seconds--about 90% as quickly as when monkeys used their fingers, scientists said in a statement.

The Stanford team's research could have far-reaching implications, as scientists look for ways to advance thought-controlled prostheses for ALS patients. Most mind-controlled tracking systems for individuals with ALS rely on an eye-tracking system, which can be difficult to use. And the systems often do not take readings directly from the brain, further complicating movement for patients.

Stanford scientists' method relies on direct brain readings, combining years of neuroscience research with a mathematical algorithm to potentially improve patients' quality of life, Shenoy said in a statement. Eventually, the findings could lead to products such as a brain-powered electronic wheelchairs. The technology seems to be gaining traction, as the FDA recently gave the Stanford team a green light to kick off a pilot clinical trial of its mind-controlled sensor on people with spinal cord injuries.

"This is a fundamentally new approach that can be further refined and optimized to give brain-controlled prostheses greater performance and therefore greater clinical viability," Shenoy said in a statement.

- read the Stanford University statement