Microelectrode Array Insertion System using Ultrasonic Vibration to Improve Insertion Mechanics, Reduce Tissue Dimpling and Trauma, and Improve Placement Precision in the Neocortex

This Phase II SBIR further develops and tests a system that employs ultrasonic vibration to improve the insertion mechanics for multichannel penetrating electrode arrays. This proposal is in response to PA-18-871 BRAIN Initiative: Development, Optimization, and Validation of Novel Tools and Technologies for Neuroscience Research – including ‘Iterative refinement of such tools and technologies with the end-user community’. The long-term goal of Actuated Medical, Inc. is to develop technology enabling accurate placement of penetrating neural electrode arrays at target locations with minimal tissue trauma and displacement, ultimately paving the way for clinical use of neural implants. Penetrating neural implants provide direct access to extracellular neural signals across the central and peripheral nervous systems with both high temporal and spatial resolution. Unfortunately, the implantation of neural electrode arrays, commonly comprised of numerous closely spaced shanks, applies forces to neural tissue resulting in significant compression (dimpling), prohibiting uniform shank insertion, and increasing the risk of trauma, bleeding and inflammation at the implant site. These issues can increase the chronic foreign body response (FBR) leading to neural cell death, glial scaring, and device failure. Phase I demonstrated the ability to releasably grip and deliver ultrasonic vibration to a range of commercially available implant types, including floating-style arrays, resulting in reductions of insertion force and surface dimpling in bench studies of up to 80-90% for most implants tested. In vivo, ultrasonic vibration significantly reduced brain surface dimpling (~50%, pandlt;0.01) and exhibited evidence of reduced bleeding, while preserving device function as evidenced by post implant neural recordings. Furthermore, preliminary work suggests significant potential for the ultrasonic vibration to improve insertion of ultrafine (8-15 µm) microwire arrays, as well as NeuroNexus’ Matrix platform arrays, one of the most delicate and complicated commercially-available implants. This Phase II SBIR expands use of the NeuralGlider inserter for inserting complex, fragile, and flexible penetrating neural electrode arrays using ultrasonic vibration to reduce insertion force, brain surface dimpling, tissue damage, and bleeding. The project uses a unique multi-institutional collaboration to obtain scientific data, supporting the benefits of the NeuralGlider insertion technology. Phase II hypothesis: Ultrasonic micro-vibration improves insertion accuracy and success, reduces insertion trauma, and improves recording outcomes for penetrating neural electrode arrays. Specific Aims: Aim 1 - Evaluate implantation trauma and inflammation response through 2-photon imaging and magnetic resonance imaging. Aim 2 - Demonstrate efficacy of NeuralGlider insertion approach for ultra-fine, ultra-high-density electrode array designs. Aim 3 - Integrate end user feedback, design upgrades for coupling options, and conduct Verification and Validation. Aim 4 - Demonstrate improved outcomes with micro-vibrated insertion.Project Narrative: Relevance – Penetrating electrode implants could revolutionize treatments of neurological problems: restoring sensory function, enabling direct control of prosthesis, and providing brain-machine interface communication. Unfortunately, device implantation applies forces to the neural tissue resulting in significant neural tissue strain (dimpling) at the implant site, increasing risk of implantation trauma, bleeding and inflammation, limiting device function. Flexible and/or thinner devices minimize the foreign body response, yet these properties make successful insertion more challenging. This project will further develop the NeuralGlider insertion system, which utilizes ultrasonic energy to insert penetrating implants with lower force and strain on the implant and surrounding tissues.