Background

David Brandman is a neurosurgeon at UC Davis Health and co-director of the UC Davis Neuroprosthetics Lab alongside neuroscientist Sergey Stavisky, both Brown University alumni. The laboratory bridges surgical expertise with advanced signal processing and machine learning approaches to neural decoding for paralyzed patients.

Speech Decoding Breakthrough

Brandman performed the implant surgery in July 2023 on ALS patient Casey Harrell. He placed four microelectrode arrays (256 cortical electrodes in total) into the left precentral gyrus, the brain region responsible for coordinating speech. The system uses high-density intracortical recording, not surface ECoG.

In the first session, the system achieved 99.6% word accuracy on a 50-word vocabulary in just 30 minutes. In a subsequent session with a 125,000-word vocabulary, the system reached 90.2% accuracy after an additional 1.4 hours of training. After continued data collection, the BCI has maintained 97.5% accuracy, the most accurate speech-from-brain decoding system reported to date. The work was published in the New England Journal of Medicine on 14 August 2024.

BrainGate2 Clinical Trial

Brandman participates in the BrainGate2 consortium as a clinical investigator, contributing to multi-institutional evaluation of intracortical electrode BCIs. His involvement bridges academic research infrastructure with clinical trial conduct in a university medical center setting.

Recognition and Impact

In 2025, the Brandman / Stavisky UC Davis speech BCI work received a Top Ten Clinical Research Achievement Award and the Herbert Pardes Clinical Research Excellence Award, recognising the significance of the high-density intracortical speech decoding result. The awards reflect growing clinical acceptance and validation of intracortical BCI approaches for communication restoration.

Speech Focus

By emphasising speech restoration rather than limb control, Brandman addresses a distinct patient population with distinct neurological needs. The UC Davis approach (256 high-density intracortical electrodes targeting the precentral gyrus) sits structurally between BrainGate’s earlier 96-electrode Utah Array work and the higher-channel-count systems being pursued commercially by Neuralink and Paradromics.