Galvanic-coupled Trans-dural Data Transfer for High-bandwidth Intra-cortical Neural Sensing

Area of Science:

• Biomedical Engineering
• Neurotechnology
• Wireless Communication

Background:

• Traditional brain implants rely on tethered wires, limiting mobility and potentially causing tissue damage.
• High-speed, minimally invasive wireless telemetry is crucial for advanced neural interfaces.

Purpose of the Study:

• To introduce a novel digital-impulse galvanic coupling for high-speed trans-dural data transmission.
• To enable a "free-floating" brain implant, reducing brain tissue damage.

Main Methods:

• Developed a finite element model for channel propagation analysis.
• Characterized the trans-dural channel using a liquid phantom and porcine tissue.
• Designed and validated a pulse-based transmitter ASIC and miniature PCB module ex-vivo.

Main Results:

• The trans-dural channel exhibits a wide frequency response up to 250 MHz.
• The transmission method is robust to misalignment, with only 1 dB loss at 1mm horizontal misalignment.
• Achieved a data rate of 250 Mbps with 2 pJ/bit energy efficiency and a 26 mm² module area.

Conclusions:

• Digital-impulse galvanic coupling offers a viable high-speed, low-power wireless communication method for brain implants.
• The developed system is miniature, energy-efficient, and minimally invasive.
• This technology paves the way for advanced, free-floating neural devices.