  Endovascular brain-computer interfaces (eBCIs) offer a minimally invasive way
to connect the brain to external devices, merging neuroscience, engineering,
and medical technology. Achieving wireless data and power transmission is
crucial for the clinical viability of these implantable devices. Typically,
solutions for endovascular electrocorticography (ECoG) include a sensing stent
with multiple electrodes (e.g. in the superior sagittal sinus) in the brain, a
subcutaneous chest implant for wireless energy harvesting and data telemetry,
and a long (tens of centimetres) cable with a set of wires in between. This
long cable presents risks and limitations, especially for younger patients or
those with fragile vasculature. This work introduces a wireless and leadless
telemetry and power transfer solution for endovascular ECoG. The proposed
solution includes an optical telemetry module and a focused ultrasound (FUS)
power transfer system. The proposed system can be miniaturised to fit in an
endovascular stent. Our solution uses optical telemetry for high-speed data
transmission (over 2 Mbit/s, capable of transmitting 41 ECoG channels at a 2
kHz sampling rate and 24-bit resolution) and the proposed power transferring
scheme provides up to 10mW power budget into the site of the endovascular
implants under the safety limit. Tests on bovine tissues confirmed the system's
effectiveness, suggesting that future custom circuit designs could further
enhance eBCI applications by removing wires and auxiliary implants, minimising
complications.
