Robotic Device Powered by Patients’ Own Brains Helps Improve Stroke Rehabilitation

Upper-limb motor weakness occurs in 77% of first time and 55-75% chronic stroke survivors and significantly affects their quality of life. Stroke survivors who had ceased to benefit from conventional rehabilitation gained clinically significant arm movement and control by using an external robotic device powered by the patients' own brains.

 

Brain-Machine Interface (BMI)

A brain-machine interface (BMI) is a computer program that captures brain activity to determine the subject's intentions and then triggers an exoskeleton, or robotic device affixed to the affected arm, to move in response to those intentions. However, the efficacy of BMI enabled robotic training for upper-limb recovery is seldom quantified in clinical use because robot-assisted exercise doesn't generally engage the user. Furthermore, a movement-related neural correlate that can predict the extent of motor recovery remains elusive, which impedes the clinical translation of BMI-based stroke rehabilitation.

 

The Trial Across 5 Years

The trial conducted by the group of researchers spanned from 2013 to 2018, partly because it took time to find subjects who met the criteria and were both interested in participating and able to make the required time commitment. Ultimately, 10 subjects between the ages of 41 and 71 were enrolled.

 

The trial involved training stroke survivors with limited movement in one arm to use a BMI. The device wouldn't move if the intention wasn't detected, ensuring subjects remained engaged in the exercise. The therapy took place 3 times a week for 4 weeks. The average prediction accuracy was consistently greater than 50% across sessions. During the last 5 therapy sessions, 4 participants achieved greater than 90% accuracy. The results showed that most patients retained the benefits for at least two months after the therapy sessions ended, suggesting the potential for long-lasting gains.

 

A Future Project

However, it is still unclear if the benefits will persist long-term, which leads to an ongoing project of designing a low-cost system that would allow people to continue the treatments at home. "If we are able to send them home with a device, they can use it for life," said Jose Luis Contreras-Vidal, director of the Non-Invasive Brain Machine Interface Systems Laboratory at the University of Houston.

 

References:

Bhagat, Nikunj A., et al. “Neural Activity Modulations and Motor Recovery Following Brain-Exoskeleton Interface Mediated Stroke Rehabilitation.” NeuroImage: Clinical, vol. 28, 2020, p. 102502. Crossref, doi:10.1016/j.nicl.2020.102502.

 

Henderson, Emily B. Sc. “Robotic Device Powered by Patients’ Own Brains Helps Improve Stroke Rehabilitation.” News-Medical.Net, 13 Jan. 2021, www.news-medical.net/news/20210112/Robotic-device-powered-by-patientse28099-own-brains-helps-improve-stroke-rehabilitation.aspx.

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Image: Pattyl. “Neuralink - Merging Humans with AI.” Pinngle Blog, 24 July 2019, pinngle.me/blog/neuralink-merging-humans-with-ai.

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Resources by Judy Zhu