Sense and signal

A person suffering from amyotrophic lateral sclerosis (ALS) endures the progressive loss of muscle function throughout their body. Eventually, they lose the ability to control their limbs, to swallow, and even to speak. Their inability to communicate becomes a particularly devastating symptom of the illness. Other diseases can cause similar, debilitating impairment.

Restoring functionality and well-being to these individuals requires an innovative and collaborative approach.

Carnegie Mellon University is leading a multidisciplinary consortium of researchers to develop and test a minimally invasive, brain-computer interface (BCI) in six patients with severe paralysis from ALS, stroke, and injury, among other causes. The system will enable these patients to operate computers and send digital communications, such as email and text messaging, by sensing and interpreting signals in the brain that express the user’s intent.

The human body is an amazing machine but it cannot heal itself from many diseases and injuries. This is where combining multidisciplinary expertise with emerging new technologies can make a significant impact.

Doug Weber, Professor, Mechanical Engineering and Neuroscience Institute

The $9.33M project, funded by the National Institutes of Health (NIH) Brain Research Through Advancing Innovative Neurotechnologies^® (BRAIN) Initiative, will evaluate the BCI’s safety and efficacy in providing a measurable improvement in independence and quality of life. Collaborators include Mount Sinai Health System (New York), Synchron, Inc. (New York), and the University of Pittsburgh Medical Center (Pennsylvania). The team combines expertise in engineering, medicine, neuroscience, and biomedical device technology.

The BCI, called the Stentrode^TM, is the only BCI system that can be implanted in the brain without opening the skull or penetrating brain tissue. Instead, it is implanted through blood vessels that provide a natural and safe passageway for accessing the motor cortex, the portion of the brain that controls movement in the body. It is being commercialized by the company Synchron, Inc.

Carnegie Mellon researchers bring additional expertise in brain-computer interface to the project. They will explore machine learning methods for processing and decoding brain signals to detect the user’s intended actions and a haptic feedback interface for improving speed and accuracy of BCI control.

“The human body is an amazing machine, but it cannot heal itself from many diseases and injuries. This is where combining multidisciplinary expertise with emerging new technologies can make a significant impact,” said Doug Weber, professor of mechanical engineering and neuroscience who is leading the collaboration. “Our team of engineers and neuroscientists will be working together with Synchron to evaluate and enhance capabilities of its BCI for restoring functionality in patients in this study and for future BCI applications.”

Detecting brain signals with a sensor placed inside a blood vessel represents an emerging new sub-discipline of medicine. “By using the blood vessels as the natural highway into the brain, we can access all areas, which traditionally required open surgery and removal of skull in multiple areas,” said Thomas Oxley, chief executive officer, Synchron. 

The system detects electrical signals generated by neurons in the motor cortex when the person thinks about moving their body, and these signals are transmitted wirelessly to an external interface connected to a computer. Users will be trained to perform computer-based tasks to control cursor position and BCI outputs to control discrete actions, such as letter or menu-item selection and zoom.

The technology will facilitate better communication between patients, caregivers, and medical professionals. In addition, it will empower these patients to experience functional independence in performing daily tasks like online shopping and banking.

“This technology has the potential to revolutionize our ability to care for patients by solving health challenges that have previously been insurmountable including communication with patients with certain types of paralysis,” said David Putrino, director of rehabilitation innovation for the Mount Sinai Health System (one of the sites involved in the trial) and associate professor of rehabilitation medicine at Icahn School of Medicine at Mount Sinai.

Another site, UPMC and the University of Pittsburgh’s Rehab Neural Engineering Labs (RNEL), will work together to recruit patients. RNEL will run tests and functional MRIs to determine which patients selected by a neuromuscular specialist and pulmonologist meet the entry criteria for implantation. A vascular neurologist will perform the BCI implantation surgery and physicians will monitor the subject’s clinical status.

BCIs have previously been limited to people involved in research studies, and only for the duration of their enrollment in the study. At the end of this trial, however, the six patients involved will retain use of the BCI technology. The aim is to make the technology broadly accessible.

In the future, those suffering from a range of medical conditions such as limb amputation, multiple sclerosis, and Parkinson’s disease might benefit from this research.

The project is funded by the NIH BRAIN Initiative (NS120191-01).