A clinical research paper led by Stanford University investigators has demonstrated that a
The report involved three study participants with severe limb weakness — two from amyotrophic lateral sclerosis, also called Lou Gehrig’s disease, and one from a spinal cord injury. They each had one or two
Each participant, after minimal training, mastered the technique sufficiently to outperform the results of any previous test of
One participant, Dennis Degray of Menlo Park, California, was able to type 39 correct characters per minute, equivalent to about eight words per minute.
‘A major milestone’
This
«Our study’s success marks a major milestone on the road to improving quality of life for people with paralysis," said Jaimie Henderson, MD, professor of neurosurgery, who performed two of the three
Henderson and Krishna Shenoy, PhD, professor of electrical engineering, are
«This study reports the highest speed and accuracy, by a factor of three, over what’s been shown before," said Shenoy, a Howard Hughes Medical Institute investigator who’s been pursuing BCI development for 15 years and working with Henderson since 2009. «We’re approaching the speed at which you can type text on your cellphone.»
«The performance is really exciting," said Pandarinath, who now has a joint appointment at Emory University and the Georgia Institute of Technology as an assistant professor of biomedical engineering. «We’re achieving communication rates that many people with arm and hand paralysis would find useful. That’s a critical step for making devices that could be suitable for
Shenoy’s lab pioneered the algorithms used to decode the complex volleys of electrical signals fired by nerve cells in the motor cortex, the brain’s command center for movement, and convert them in real time into actions ordinarily executed by spinal cord and muscles.
«These
Millions of people with paralysis reside in the United States. Sometimes their paralysis comes gradually, as occurs in ALS. Sometimes it arrives suddenly, as in Degray’s case.
Now 64, Degray became quadriplegic on Oct. 10, 2007, when he fell and sustained a
«I’ve got nothing going on below the collarbones," he said.
Degray received two device implants at Henderson’s hands in August 2016. In several ensuing research sessions, he and the other two study participants, who underwent similar surgeries, were encouraged to attempt or visualize patterns of desired arm, hand and finger movements. Resulting neural signals from the motor cortex were electronically extracted by the embedded recording devices, transmitted to a computer and translated by Shenoy’s algorithms into commands directing a cursor on an onscreen keyboard to
The researchers gauged the speeds at which the patients were able to correctly copy phrases and sentences — for example, «The quick brown fox jumped over the lazy dog." Average rates were 7.8 words per minute for Degray and 6.3 and 2.7 words per minute, respectively, for the other two participants.
A tiny silicon chip
The investigational system used in the study, an intracortical
An intracortical BCI uses a tiny silicon chip, just over
Henderson likened the resulting improved resolution of neural sensing, compared with that of
Shenoy said the day will come — closer to five than 10 years from now, he predicted -when a
«I don’t see any insurmountable challenges." he said. «We know the steps we have to take to get there.»
Degray, who continues to participate actively in the research, knew how to type before his accident but was no expert at it. He described his newly revealed prowess in the language of a video game aficionado.
«This is like one of the coolest video games I’ve ever gotten to play with," he said. «And I don’t even have to put a quarter in it.»
The study’s results are the culmination of a
«This incredible collaboration continues to break new ground in developing powerful, intuitive, flexible neural interfaces that we all hope will one day restore communication, mobility and independence for people with neurologic disease or injury," said Hochberg.
Stanford research assistant Christine Blabe was also a study
The study was funded by the National Institutes of Health (grants R01DC014034, R011NS066311, R01DC009899, N01HD53404 and N01HD10018), the Stanford Office of Postdoctoral Affairs, the Craig H. Neilsen Foundation, the Stanford Medical Scientist Training Program, Stanford
Stanford’s Office of Technology Licensing holds intellectual property on the intercortical
Stanford’s departments of Neurosurgery and of Electrical Engineering also supported the work. Shenoy and Henderson are members of