A Johns Hopkins team has published the first peer-reviewed clinical results for Precision Neuroscience’s Layer 7 cortical interface, reporting that the 1,024-channel thin-film array decoded speech and motor commands in real time during awake brain surgery. The study, published in Neurosurgical Focus in February, tested the device in four patients undergoing tumour resection near eloquent cortex.
A four-word speech classification model hit 77.5 per cent accuracy, while a real-time synthesis model reliably distinguished speech from silence across roughly 20 minutes of intraoperative recording. In the motor task, three patients used a joystick paradigm: a convolutional recurrent neural network decoded four-direction movement at 78 to 84 per cent accuracy. All four patients, aged 23 to 43, tolerated the device without adverse events.
A different kind of BCI
The Layer 7 is a micro-electrocorticography (μECoG) device — it sits on the brain’s surface rather than penetrating tissue. The polyimide film substrate is 5 micrometres thick, roughly one-fifth the width of a human hair, and carries platinum electrodes in a 400-micrometre hexagonal grid at approximately 683 electrodes per square centimetre — some 600 times the spatial density of conventional electrocorticography strips.
Surgical placement uses Precision’s cranial micro-slit technique: a slit smaller than one millimetre, with the array deployed using endoscopic tools in under a minute. Multiple arrays can be tiled to exceed 2,000 channels without additional surgical burden. Penetrating arrays like Blackrock Neurotech’s Utah array and Neuralink’s N1 achieve higher decoding resolution by reading individual neurons, but they carry greater surgical risk and face long-term stability challenges from tissue scarring. The Layer 7’s surface approach trades some signal fidelity for a lighter footprint and potentially better chronic stability — a trade-off that longer implant durations will need to validate.
From operating room to chronic implant
The study was intraoperative: arrays were placed and removed during a single surgical session. But Precision’s FDA 510(k) clearance, granted in April 2025, already permits diagnostic implantation for up to 30 days. Preclinical minipig studies showed stable impedance within 10 per cent of baseline over that window, with no bleeding or structural damage.
In January 2026, Precision announced a partnership with Medtronic to integrate the Layer 7 with Medtronic’s StealthStation surgical navigation platform — standard equipment in neurosurgery suites worldwide — signalling a path toward routine clinical deployment.
The study was led by Nathan Crone at Johns Hopkins. The full paper is available at DOI 10.3171/2025.11.FOCUS25908.