Philip Kennedy
Pioneering neuroscientist who implanted the first long-term intracortical brain-computer interface electrode in a human patient in 1996, establishing the feasibility of chronic neural interfaces and the foundational case for long-term BCI use.
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 rather than displace it, in contrast to the rigid penetrating-array approaches that followed.
On 24 June 1996, Kennedy and neurosurgeon Roy Bakay performed the first FDA-approved human implantation of an intracortical BCI electrode in a patient with ALS (Marjorie), the first time a chronic intracortical neural interface had been authorised for human use. In 1998, Kennedy’s second patient — Johnny Ray, a Vietnam veteran in a locked-in state following a brainstem stroke — became the first BCI user to control a computer cursor and spell with thought alone. Johnny Ray lived for approximately four years post-implantation with the device continuously functional, becoming the first long-term BCI user.
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 patient outcomes and electrode-tissue integration data influenced the subsequent design choices of intracortical BCI programmes at BrainGate, Neuralink, Paradromics, and other contemporary clinical-stage companies. Kennedy himself underwent a controversial self-implantation in 2014 to study chronic electrode performance in a non-paralysed brain.