Background

Philip R. Kennedy is a neuroscientist and entrepreneur who pioneered chronic intracortical brain-computer interface research through his invention of the neurotrophic electrode. While at the Georgia Institute of Technology in the 1980s, Kennedy developed a novel electrode design intended to achieve long-term stable recordings from the brain. His goal was to restore communication and control to people with severe paralysis, including locked-in syndrome. He founded Neural Signals, Inc. in 1987 to translate his electrode technology into clinical practice.

The neurotrophic electrode

Kennedy invented the neurotrophic electrode: a pair of gold wires encased in a glass cone filled with growth factors designed to attract nearby neurons to grow into the electrode tip. The architecture was intended to promote tissue integration, in contrast to the rigid penetrating-array approaches that followed.

In 1996, after the FDA agreed to allow implants in locked-in patients, Kennedy and neurosurgeon Roy Bakay implanted the electrode in a patient with ALS (Marjory, known as MH), who died 76 days later. In 1998, Kennedy’s second patient, Johnny Ray, a Vietnam veteran in a locked-in state following a brainstem stroke, learned to move a computer cursor and spell words using signals from the implanted electrodes.

Legacy

Kennedy’s work established the proof-of-concept for chronic intracortical BCI use in humans and demonstrated that long-term, stable neural interfaces were technically feasible. His human implants began eight years before the first BrainGate Utah Array implant in 2004. Kennedy himself underwent a controversial self-implantation in 2014 to study chronic electrode performance in a non-paralysed brain.