At-home stroke rehab one step closer with portable EEG headset design

In the foreseeable future, at-home stroke rehabilitation could become a reality, thanks to a novel portable brain-computer interface (BCI). The user-friendly and cost-effective BCI was devised by researchers at the University of Houston. This innovation involves a portable electroencephalography (EEG) headset, which establishes a non-invasive connection between the patient’s brain and powered exoskeletons, aiding in their rehabilitation process. The non-invasive device was validated and tested by the researchers, demonstrating promising outcomes for a future of stroke rehabilitation at home.

The study, published in Sensors, presents an EEG-based BCI system that acts as an intermediary between the brain and external devices by interpreting EEG patterns. In other words, the device deciphers brain activity to initiate robotic movements, effectively translating thoughts into actions. In addition, this prototype also has the potential to promote cortical plasticity following stroke, which has been shown to improve motor recovery outcomes. The added benefit lies in the adjustable headset, designed from commercial readily available components, catering to a wide 90 percent of the population.

Leading the way in non-invasive brain-machine interfaces and robotic device innovations, Jose Luis Contreras-Vidal, an author of the paper, explains the challenges with existing commercial EEG amplifiers and BCI headsets. He highlights the current limitations include high cost, limited interoperability, and insufficient signal quality or closed-loop functionality.
To bridge this gap in affordable and accessible EEG-based BCIs, the researchers describe in the paper how they, “Designed and validated a wireless, easy-to-use, mobile, dry-electrode headset for scalp EEG recordings for closed-loop BCI and internet-of-things (IoT) applications”.
“We used a multi-pronged approach that balanced interoperability, cost, portability, usability, form factor, reliability and closed-loop operation,” says Contreras-Vidal.

The new prototype integrates five EEG electrodes into the bracket, covering the sensorimotor cortices, and introduces three skin sensors to track eye movement and blinks. With the addition of an inertial movement unit to gauge head motion, a portable brain-body imaging arrangement is established for BCI usage.

“Most commercial EEG-based BCI systems are tethered to immobile processing hardware or require complex programming or set-up, making them difficult to deploy outside of the clinic or laboratory without technical assistance or extensive training. A portable and wireless BCI system is highly preferred so it can be used outside lab in clinical and non-clinical mobile applications at home, work, or play,” says Contreras-Vidal.
A patent-pending status covers both the BCI algorithm and the self-positioning dry electrode bracket, which optimises scalp contact by parting the user’s hair. The researchers explain how ensuring a snug headset fit is crucial for system performance, usability, and comfort—all aspects that they have prioritised in their prototype.

Additionally, the study highlights a critical requirement in designing mobile devices is the ability for one-handed interaction, given that the headset's users often have limited attention spans and upper-limb or hand impairments, including reduced mobility and hand dexterity.
The design of this custom EEG-based closed-loop BCI headset, blending affordability and ease-of-use, marks a significant stride towards enabling stroke patients to undergo rehabilitation in the comfort of their homes. The National Science Foundation (NSF) provided support for this groundbreaking research.