Neural Signals Moves from BCI Pioneer to Commercial Vendor

by David Pope, editorial director

Neural Signals, Inc. of Atlanta, GA, was founded in 1987 by neurologist Philip R. Kennedy to develop a brain-computer interface that would give a paralyzed patients the ability to communicate with the external world and to control external devices. Kennedy, who holds both an M.D. and a Ph.D., personally funded the company’s initial development of a novel implantable device for detecting and transmitting signals from the cerebral cortex.

Kennedy’s research gained support in the form of research grants, and successful animal tests led to FDA approval of human clinical trials. In 1998, the first patient, who was totally paralyzed by a brain stem stroke, had the device implanted and after months of training was able to control a computer cursor by focused thinking.

Kennedy’s patented device consists of glass cones with microelectrodes that have been coated with neurotrophic proteins to promote binding of the electrodes to the extracellular matrix of the cerebral cortex. The neurotrophic electrode tip is implanted 2 mm under the surface of the cortex and the outer end is attached to an amplifier and radio transmitter on the skull under the scalp.

Kennedy and his team have pioneered techniques for implanting the neurotrophic electrodes in the cerebral cortex of human patients. Power is provided by an induction system. A computer analyzes the neural signals and detects those deliberately intended to move a cursor or activate a switch. Kennedy notes that implanted patients have been able to improve performance with training, apparently by fine-tuning the small number of cortical neurons in contact with the electrodes.

Neural Signals has developed two basic types of communicators for paralyzed patients: The Brain Communicator, which is specifically for ALS, brain stroke, or traumatic injury patients who are locked-in or nearly locked-in but still retain normal cognitive function (determined by MRI), and have no history of seizures or epilepsy; and the Muscle Communicator, which is for moderately to severely paralyzed patients (ALS, brain stem damage, muscular dystrophy, quadriplegia) who still have the ability for intentional muscle movement in the jaw, eye, or any part of the body.

Both the Brain and the Muscle Communicators are designed for use with computer software such as EZ Keys and Reach Interface Author, which have been specifically developed for handicapped users. Neural Signals also has worked with Prentke Romich Co. of Wooster, OH, to develop an iconic based neural language as an alternative for the typing computer interface.

The Brain Communicator uses either an implanted neurotrophic electrode or new, patented conductive screws implanted in the skull without entering the brain. The conductive screws detect cortical local field potentials (LFPs) more reliably than conventional scalp electrodes can. In a clinical trial, an ALS patient who was almost locked-in successfully activated a switch using LFPs picked up by the conductive screws. Time domain or frequency domain analysis was used to determine which signals represented intention switch activation.

The Muscle Communicator is available in three versions: EMG, which uses a removable skin-surface electrode to detect any slight muscle movement and uses the signals to activate a switch, EOG, which uses a removable surface electrode to detect movement of eye muscles and uses the signals to activate a switch or move a cursor on a computer screen, and a piezoelectric switch (P-switch) that can be turned on or off by slight movement of jaw, hand, or foot muscle.

The entire line of communicators developed by Neural Signals is being marketed through its subsidiary, Emerge Medical LLC, which was co-founded by Kennedy and Paul Freet, BSEE, who serves as CEO. Emerge Medical has opted to sell its products directly to end users, and on its website encourages caretakers of paralyzed persons to apply for an evaluation of eligibility. For ALS patients and other patients on social security, Medicare will pay 80 percent of the cost and private insurance usually picks up the remaining amount. Payment assistance also is available from the Muscular Dystrophy Association.

Emerge Medical offers medical billing assistance to its customers.
The company has developed a free web portal called Emerge Club that users can access with a single switch input. The browser-based product allows users to write notes, read books, play games, and access email and instant messages.

Neural Signals has received more than $2.5 million in research grants. Support has come from the National Institutes of Health’s Neural Prosthesis Program, the National Institute of Neurological Disorders and Stroke, ALS Association of Georgia, and the American Paralysis Association. The company has worked closely with Emory University, Georgia Institute of Technology, and Georgia State University. The Alfred Mann Foundation presented its scientific achievement award to Kennedy for his pioneering work.

Although Neural Signals’ initial focus is on helping ALS and other patients who are cognitively aware but locked in, the company is looking ahead at other applications for its cortical control device. It is developing a six-electrode version that could provide multi-dimensional control. Neural Signals also is interested in partnering with a manufacturer of motor prostheses to develop cortical control of artificial limb movement.