Seattle Team Implants German BCI for Stroke Rehabilitation

by James Cavuoto, editor

July 2025 issue

The neurotechnology market for stroke rehabilitation suffered a serious setback in 2008 when Northstar Neuroscience, the Seattle, WA developer of cortical stimulation systems, failed its EVEREST trial, which led to the demise of the firm a year later. The company’s therapeutic approach relied on epidural cortical stimulation to promote neuroplasticity to improve motor function,

For nearly a decade following that event, startup firms seeking to commercialize neurotech device therapies for treating stroke found it difficult to attract funding. That blockage was partially overcome in 2021 when MicroTransponder received FDA approval for its ViviStim implanted VNS stroke therapy, which also exploits concepts of cortical plasticity. Subsequently, Reach Neuro has received funding and recognition for its spinal cord stimulation approach to upper extremity motor recovery post stroke. But there has been little commercial effort to return to the brain with an implanted device for stroke rehabilitation.

Earlier this month, German firm CorTec GmbH, announced the first human implantation of its brain computer interface system, Brain Interchange, in an effort to exploit cortical plasticity for stroke rehabilitation. Ironically, the procedure took place in Northstar’s birthplace, Seattle, at Harborview Medical Center under an FDA investigational device exemption. Led by principal investigator Jeffrey Ojemann, from the University of Washington School of Medicine and co PI Steven Cramer from UCLA, this trial will gather initial safety data and evaluate whether direct cortical electrical stimulation can enhance upper-limb motor recovery in stroke patients. The study is funded by the National Institutes of Health.

The device was implanted July 22 in a 52-year-old man who over the past years had several strokes that severely affected his ability to use his arm and leg. The patient recovered partial use of the limbs with rehabilitation, but the improvement was limited.

“We’re thrilled to share that the implantation procedure was a success and, most importantly, the patient is in good condition and recovering well from the surgery. We’re incredibly grateful for this initial outcome in our first study participant. Both the therapeutic strategy and the technology we are using are entirely novel. While we proceed with careful optimism, the potential benefits for patients are promising,” said Ojemann, who is vice chair and professor of neurological surgery at UW.

This novel approach offers highly precise and personalized treatment for neurological conditions. The implant system continuously records brain activity, instantly interpreting signals and delivering targeted electrical stimulation in real time to enhance neuroplasticity. The study explores whether this can help the brain relearn lost functions, thereby accelerating and improving rehabilitation of patients.

“The first implantation of our BCI marks a milestone for European medical neurotechnology and underscores CorTec’s emergence as Germany’s first implantable BCI developer, ready to compete on the global stage,” said Frank Desiere, CEO of CorTec. “Building on our extensive experience in developing advanced components and active implantable systems, our proprietary cutting-edge BCI system is now entering human clinical testing, aiming to help people affected by neurological diseases recover lost function and enhance their quality of life. We are proud of this new era of innovation and are committed to expanding the possibilities of neurotechnology to improve outcomes for patients.”

Today in the U.S. and Europe alone, 1.7 million people annually have a stroke that frequently involves loss of upper limb function. While physical therapy alone can help many patients regain function, it is sometimes not sufficient. Patients with a BCI may benefit from neuroplasticity-inducing stimulation during their rehabilitation. Regaining control of their upper limbs would enable patients to be more independent and have a better quality of life.

“This breakthrough opens the door to therapies that were once unimaginable,” added Martin Schuettler, CTO of CorTec. “For the first time, our BCI system connects wirelessly to external hardware—no cables, no physical links. This approach is part of the transformation of neurological therapies worldwide, built on a technology platform that can be tailored to multiple neurological conditions, delivering real-time, patient-specific treatment.”

Movement of the muscles—such as those that move the arms and legs—is controlled by a strip of interconnected neurons that runs over the top of the brain in the motor cortex. Thousands to tens of thousands of neurons may contribute to a neural circuit controlling a single movement.

These brain regions receive signals from many other parts of the brain and spinal cord. These regions then send the spinal cord signals that control the contraction of muscles. Some regions are primarily dedicated to the performance of a specific movement, whereas others may be dedicated to other contexts.

Strokes cause physical disability by destroying brain regions and connections involved in specific movements. Depending on the extent and location of the damage, the disability can be severe. In many cases, functional use of the affected body part (such as the hand) can be lost.

But if enough brain regions survive and remain connected, they can strengthen their existing connections and form new ones to help restore function, at least in part. In addition, brain regions that were not directly involved can be induced to contribute more to the circuit’s activity. Rehabilitation exercises help promote this rewiring by activating damaged circuits.

The study team is seeking to enlist this effect by using electrical impulses from the device to induce neurons to fire together when the patient tries to perform certain movements during rehabilitation sessions. The simultaneous firing of the neurons is thought to promote stronger connections between surviving regions.

Timing is crucial, said Ojemann “You want to activate the neurons when the brain is doing something you want to improve. The real power of this method is that it gets the two areas of the brain to train together.”

The implant consists of two soft, thin silicon sheets embedded with tiny electrodes. The sheets are placed on the surface of the brain over the area affected by the stroke. The electrodes can detect brain waves and emit electrical impulses to stimulate the brain.

The electrodes are connected to a small device implanted in the skull. This device wirelessly relays information through the skin to a computer that can analyze changes in brain waves and adjust the electrical impulses for maximum effect.

The study will include both rehabilitation sessions and extended monitoring of the patient’s neural signals, said Jeffrey Herron, an associate professor of neurological surgery at the UW School of Medicine who holds a Ph.D. in electrical engineering. He is an expert in brain-computer interfaces and will lead the study’s engineering aspects. The device will be removed after about nine months.

“It’s a rehab enhancement device, not a treatment,” Herron said. “The idea is to implant the device, have the patient go through rehab while receiving stimulation, hopefully acquire long-lasting improvements, and then remove the device.”