Researchers are bringing brain-computer interface capabilities from the laboratory into the home.
They have demonstrated that a small, portable system facilitates hand grasp of a patient paralyzed from a spinal cord injury, enabling the patient to pick up a toothbrush and other objects.
In addition, the system can be set up by a caregiver in a matter of minutes.
Kevin Davis
“That we got this into the home is very promising,” Kevin C. Davis, an MD and PhD student in the Department of Biomedical Engineering, University of Miami Miller School of Medicine, Miami, Florida, told Medscape Medical News.
If the investigators can continue to show that the technology improves independence and decreases costs of supportive care for patients with paralysis, “look out for these devices,” Davis said.
The findings were presented at the American Association of Neurological Surgeons (AANS) 2021 Annual Meeting.
Independence Improvement
Evidence suggests that about 54 million people in the United States live with paralysis. Most cases are caused by stroke (33.7%), followed by spinal cord injuries (27.3%) and multiple sclerosis (18.l6%), Davis reported.
Lifetime costs of spinal cord injuries can range from $1 million to $5 million, he noted. “Given the need for supportive care, any potential marginal improvement in independence could cut back on supportive care costs and improve quality of life,” he added.
There is currently no therapy for spinal cord injuries. Interventions aim to alleviate the primary injury and minimize secondary injury and to maximize any residual function. This is where a brain-computer interface system “can really come into play,” said Davis.
“Brain-computer interface” refers to “any system that takes neural data and translates it into something useful for the individual,” he reported.
Invasive and noninvasive neural signal recording methods have enabled patients to control computer cursors and to communicate through spellers, texting, and speech synthesis.
“But there still remains a translational problem of getting this technology from the laboratory into the clinic and the patient’s home,” said Davis.
Patients with quadriplegia report that the restoration of arm and hand function is the area they are most eager to have targeted. To provide this in the home, systems need to be simple to set up, intuitive to configure, and easy to maintain, Davis said.
Repurposed Technology
To address this challenge, his team partnered with Medtronic to initiate a clinical trial to deploy an electrocorticography-based brain-computer interface system that utilizes deep brain stimulation (DBS) technology.
“We have basically taken something that was designed for DBS in Parkinson’s disease and other movement disorders and repurposed it for a different patient population and for a different purpose,” Davis said.
The first patient to receive the system was a 21-year-old man who was paralyzed at age 17 when he suffered a C5 spinal cord injury. He could flex his biceps and had other limited movement in his arm, but he had no manual dexterity.
To enable use of the system, leads were placed over the surface of the motor hand region of the man’s brain, and wires connected to the DBS-sensing device were inserted under the skin just below his collarbone. This device collects neural data.
A mini-computer that converts the signal to a movement was then placed behind his wheelchair. A special glove that is connected to the computer with a Bluetooth signal allows him to open and close his hand.
Using the system, this patient is able to pick up a toothbrush, brush his teeth, and manipulate a fork and spoon, among other tasks.
The next step, said Davis, is to implant the system into additional patients and to eventually decode movements in both hands. In the future, the system may allow for more complex movements using other joints, such as the elbow and wrist, he added.
Proof of Concept
Commenting for Medscape Medical News, Angela M. Richardson, MD, PhD, assistant professor of neurologic surgery, Indiana University School of Medicine, Indianapolis, Indiana, noted that this is the first fully implanted device for home use and that this research represents “an important proof of concept.”
“It has the potential for increasing complexity with future generations of the device, both in terms of the type of information that could be sensed and decoded, as well as the types of movements the glove could be engineered to produce,” said Richardson, who was not involved with the research.
She noted the importance of providing patients with the ability to grasp with their hand.
“It’s significant for enabling more independence for a patient; for example, grasping and holding a spoon allows a person to feed himself or herself,” Richardson said.
The study was funded by the Miami Project to Cure Paralysis. Davis has reported no relevant financial relationships.
American Association of Neurological Surgeons (AANS) 2021 Annual Meeting: Plenary Session II. Presented August 24, 2021.
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