A new implant aims to rewire the brains of stroke patients

One stroke It is a leading cause of long-term disability, with approximately two-thirds of survivors having significant disabilities in their hands and arms. While some people eventually regain this function, many live with persistent paralysis or weakness. Epia Neuro, a newly launched San Francisco startup, wants to help more stroke patients regain hand function with a brain implant and robotic gloves.

It is among a growing number of companies developing brain-computer interfaces, devices that read neural signals from the brain and translate them into specific actions. The space has seen a massive influx of investment in recent years, with Elon Musk’s Neuralink raising $500 million last year and Sam Altman’s Merge Labs coming out of stealth in January with $252 million in funding.

Neuralink and others build devices that give people with severe motor disabilities the ability to control a computer or speak with a digital voice. Epia’s technology aims to help people move their hands again.

“These patients have a very weak grip. It’s a very common problem,” says Michel Maharbez, CEO of Epia and a professor of electrical engineering and computer science at UC Berkeley. “If you can reliably put them back in control, a huge number of things will open up in their daily lives.”

Improvements in hand function can mean the difference between being able to dress or eat independently and relying on ongoing care.

The disc-shaped Epia implant is inserted into the skull and detects brain signals associated with a person’s intention to move their hand. The implant will be used in conjunction with robotic grip-assist gloves that patients will wear during rehabilitation or at home. Neural signals are translated by artificial intelligence algorithms and combined with data from external sensors on the glove to predict and drive the grasping motion. The system learns to associate certain brain signals and contextual data with a person’s desire to open and close their hand.

The device is based on the idea of ​​neuroplasticity, which is the brain’s ability to change and make new connections. During a stroke, blood flow to part of the brain is cut off, starving cells of oxygen and damaging precious tissue. Damage to the motor area of ​​the brain can lead to paralysis and muscle weakness. When a person with paralysis tries to move, their brain continues to generate signals related to movement, but the injury means that these signals are prevented from reaching the muscles. The Epia implant collects nerve signals from the unaffected part of the brain, determines the intention to move, and converts this intention into hand movement through the glove.

“We can train the system to know the user’s intent regarding the function they are trying to compensate for,” Maharabez says.

Repeated use of the system can strengthen the neural pathways associated with movement, reducing a person’s dependence on the glove.

“Many brain-computer interfaces allow a person to type on a computer screen or move a robotic arm to accomplish a task,” says David Lin, a critical care neurologist and director of the Neurological Recovery Clinic at Massachusetts General Hospital who advises the company. “This is different from the rehabilitative solution, where using this device itself causes brain plasticity, or changes the brain and the connections to the spinal cord, so that once the glove is removed, the original function of the arm and hand improves.”

One obstacle to brain-computer interfaces is scalability. These devices need to be relatively easy to implant with little risk for people to want them. Neuralink is trying to overcome this problem by developing its own BCI insertion robot. Another company, Synchron, has a stent-like implant that is inserted into blood vessels instead of requiring brain surgery.