Design development completed with help of the EIC grant includes all components of the system: SmartFuse TLIF cage implant mechanical, electronics, and software as well as the ECAP external electronics unit with corresponding mechanical, electronics, and software. This work has culminated in a design freeze candidate system. The overall system design was intended to enable state-of-the-art function while maintaining manufacturability and cost-effectiveness. This system design will be tested in depth during the remainder of 2023 to verify its suitability for use in a FIH (first in human) clinical study in mid 2024.
The TLIF cage design developed during this process consists of a welded titanium hermetic capsule containing the control electronics. The enclosed electronics utilize flexible PCBs (printed circuit boards) folded to efficiently package the system in less than 1cc of volume. Power and data antenna as well as stimulation and measurement electrodes are contained in the TLIF cage body.
The TLIF cage body is constructed of PEEK and titanium components. While these materials are commonly used in spinal implants, the construction techniques are novel and were developed as part of the SmartFuse project to allow manufacturing of a high strength spinal fusion cage with embedded electrical structures in a cost effective manner. In addition, innovative thin film platinum electrodes were developed to provide stimulation and sensing as well as to not interfere with radiographic imaging or antenna performance. This is critical to ensure power and data transmission between the implant and the ECAP are possible across the expected patient population.
The ECAP developed during this project is a wireless “IOT” (internet of things) device combined with a wireless power and communication device all on one PCB. It consists of a housing, PCB, mobile data connection, implant communication electronics, battery system and software. The primary challenge developing this system was the filter circuit required to obtain reliable connection from the ECAP to the implant. This communication system and circuit design was a significant design challenge. The SmartFuse system requires reliable power and data transfer through an inductive link across a relatively long distance to a compact antenna embedded in the implant. This required careful circuit design by experts in the field to create a functional, reliable system.
The supply chain and quality system were developed parallel with the system design to support Intelligent Implants goals for the SmartFuse device. This supply chain is crucial to support a successful design verification / validation and FIH clinical study in 2024. As Intelligent Implants is a small start-up without internal manufacturing capabilities, a complete supply chain was developed. Vendors were selected based on their technical capabilities, responsiveness, cost-effectiveness, and appropriate quality certifications. In particular, thin-film platinum electrodes and cage body manufacturing with embedded active structures critically rely upon choosing the correct vendor. Finally, a range of quality systems were evaluated and one selected and implemented.
