Understanding how the brain works and transmits thought into movement or words is critical to advancing prosthetic technology, particularly developing a wireless, brain-controlled prosthesis. It would be a game-changer for many living with limb loss, limb difference, or paralysis.
For the past 18 years, Stanford researchers sought to understand how the brain transmits thoughts to other parts of the body, like the feet or fingertips. A team of researchers, led by neuroscientists Krishna Shenoy, Ph.D., Boris Murmann, Ph.D., and Jamie Henderson, MD, have been working to advance a brain-computer interface (BCI)—a device implanted beneath the skull on the surface of the brain. Shenoy and Murmann are also electrical engineers, while Henderson is also a neurosurgeon.
The implant is designed to connect the nervous system to an electronic device. It is designed to enable individuals to use their thoughts to control prosthetic devices and interact with computers.
The journey to wireless
One of the research team's chief concerns is how to create an implant that would be safe for the user. The existing, wire-enabled versions of these devices can record vast amounts of neural activity and then transmit them to a computer. When the researchers created a wireless BCI to do the same, they found that it required so much power to share the data, the implants would generate too much heat.
Recently, the Stanford team developed a method that would create safer implants that require only a tenth of the power used by wire-enabled systems. Their methodology is detailed in a paper published in the Nature Biomedical Engineering journal.
In a nutshell, the team's neuroscientists were able to identify the exact neural signals needed to control a prosthetic. The electrical engineers then designed the circuitry that would enable a wireless BCI to process and transmit these isolated signals, using less power, thus making it safe to implant the device on the brain's surface.
The researchers previously tested wired BCIs and how fast and accurate participants with paralysis could type by using their thoughts. In a recent study, the team sought to understand the trade-offs between signal quality and decoding performance of wired and wireless BCIs.
The researchers tested their wireless BCI by collecting neuronal data from three nonhuman primates, particularly the rhesus macaque. They also collected data from one human participant who had a 96-channel Utah microelectrode arrays implanted.
The team measured as the subjects performed tasks, like positioning a cursor on a monitor. Their findings validated their hypothesis. They found that a wireless interface could control an individual's movement by recording a subset of action-specific brain signals, instead of copying the wired device by collecting vast amounts of brain signals.
After the recent study confirmed the researchers' hypothesis, the next step is to build an implant based on the new method and proceed with a series of tests.What do you think about this development?