Custom-made Implants for Chronic In Vivo Electrophysiological Recording From Primate's Brain Based on the Reconstructed Skull Model.

Introduction: In vivo neural recordings from primates require the installation of implants on the skull of the animal. Despite some improvements, current routines risk predisposition to infection and failure or impose constant discomfort by placing heaviness on the top of the head.

Methods: A custom-designed imaging adapter was obtained by magnetic resonance and computerized tomography (CT) imaging of the head region. Then, based on a reconstructed skull model, the implants were designed and constructed using a computer numerical control (CNC) machine. During the surgical operation, the position of each implant was sketched on the skull, and implants were slipped onto their predicted site, following their sketched boundaries without any manual reshaping.

Results: We have performed this procedure on two monkeys. After surgery, the location of the implants has been verified by CT imaging. The recovery period was without significant complications with minimal infection.

Conclusion: Our experiment showed that applying an image-guided design makes it possible to utilize the skull area better and gain access to brain regions. At the same time, our method reduced the possibility of gap formation between the implant and skull open skin margins. It reduces the time and cost of operation, resulting in a reduced chance of infection and failure, and provides animal-friendly operational surgery procedures. Despite some improvements, more refinements of methodology are still required. Here, we propose and report an improvement in the design and installation of low-cost biocompatible implants providing access to at least three brain regions.