Stentrode

A device that mounts electrodes on a stent — a mesh tube used to hold blood vessels open — and delivers it through the neck to a vein near the brain, reading brain signals through the vessel wall.

Its defining feature is that it is placed by catheter through the blood vessels, without opening the skull. In 2016 Thomas Oxley and colleagues showed that a mesh electrode placed in a sheep's cerebral vein could record brain signals stably over long periods^[1].

Because the vessel wall sits in between, the signal is coarser than with electrodes inserted into the brain, and there are fewer electrodes. It is a design that puts safety ahead of resolution; Synchron is testing it in people.