Technically, we are making progress towards a first short-term human test in Q3 2026, and a 6 months long test in a blind volunteer starting in 2027.
Activities Performed:
1) Device Design and Scaling: To transition from animal models to human applications, the team redesigned the implant to handle an extended 12 cm distance between the pedestal connector and electrode arrays. We developed a wire-bonding concept utilizing thin, individually insulated gold wires and modified the fabrication process to optimize wire bondability and long-term polymer encapsulation adhesion under physiological conditions.
2) Anatomical Mapping: An anatomical study was conducted using Human Brain Project MRI data from eight subjects to delineate the V1 visual cortex, allowing the team to establish safe insertion trajectories that avoid crossing sulci containing major blood vessels.
3) Surgical Procedure Development: The team constructed mechanical 1024-electrode prototypes, a phantom head, and implant holders for surgical usability testing. They also designed and iteratively refined a specialized tunneling shuttle, testing it on sheep cadavers, a human corpse, and mock skulls to facilitate surgical routing.
4) Precision Insertion Systems: To ensure accurate placement of long, flexible shafts, an insertor device was designed to couple with existing stereotactic frames or robots and integrate directly with camera-based neuronavigation tracking systems.
5) Electronics and Packaging Integration: The team integrated a 256-channel stimulation ASIC onto flexible substrates featuring iridium oxide electrodes. Peripheral electronics were consolidated onto a miniature system PCB controlled via Bluetooth Low Energy (BLE) through a custom mobile application. Additionally, the fabrication process was adapted to support multiple metal interconnect layers and vias to maximize functional channels.
Main Achievements:
1) Fabrication of Human Study Implants: A series of 256-electrode implants—comprising three arrays attached to a single pedestal connector—was successfully fabricated and sent for final assembly.
2)Functional Miniaturized Proof-of-Concept: The team successfully delivered the first functional, and miniaturized standalone prototype system of the future implant.
3)Encapsulation & Biocompatibility Milestones: Long-term encapsulation adhesion was validated via accelerated aging tests in phosphate-buffered saline (PBS). Furthermore, a multilayer thin-film encapsulation strategy (utilizing ALD, Parylene-C, and biocompatible epoxy) demonstrated a proven equivalent lifetime of approximately two years in vivo.
4) Regulatory Progress: Technical and safety files were finalized, securing formal approvals from both the hospital ethical committee and the Hungarian government for acute human insertion tests during brain surgery. Regulatory documentation was also fully prepared for submission to Spanish health authorities as well.
5) Project partner ReVision obtained FDA Breakthrough Device Designation status and was able to close a 4 M€ capital round, thanks to the support by the project.
