The ability to noninvasively acquire longitudinal sensing information (e.g., strain, force, pressure) could enhance TJA outcomes by enabling (1) the optimization of TJA placement and component selection during the surgery, (2) postoperative rehabilitation and monitoring of TJA integrity over time and (3) acquisition of data to improve future designs. Despite advancements in microelectronics, the development of TJA with integrated sensors has so far been primarily limited to a few biomechanical studies with experimental patient cohorts. The fundamental barriers to clinical adoption lie in the significant increase in risks associated with the following: First, conventionally fabricated electronics (e.g., chipset, batteries) typically contain toxic chemicals and have rigid geometry that would cause cell toxicity, immune responses or served as a nidus for infection into the human body. Second, current electronics integration strategies require significant structural modification on a clinically proven TJA design, which introduces uncertainty in its long-term safety. Third, the geometrical and mechanical dichotomies between the planar, rigid nature of a microfabricated electronics and an anatomically designed three-dimensional TJA causes significant design constraint that limits the performances of the device. Finally, due to the customization required, a significant cost increase is associated with the current electronics integration strategy as the economy of scale is no longer applicable. Indeed, despite the potential of electronics to transform arthritis treatment with TJA and decades of advancement, there has yet to be a viable strategy that can overcome the barrier of clinical adoption. The proposed research will overcome these barriers by seamlessly integrating a resonance-enhanced wireless sensing platform with existing TJA systems via a multi-material, multi-scale 3D printing strategy. This research leverages the PI?s expertise in creating entirely 3D printable electronics and the advancement of wireless sensing technologies. Specifically, 3D printed resonant-enhanced sensors (PRES) can be directly printed on existing arthroplasty components, eliminating the need to modify the implant for the purpose of sensor integration. Second, the freeform digital fabrication approach enables customization of sensors for various implant designs. Finally, the sensors can be robustly and wirelessly interrogated with high sensitivity using readout techniques that leverage the enhanced sensitivity of systems at special degeneracies (e.g., diabolic points, exceptional points). The R21 Trailblazer will initiate the development of the proposed 3D printed resonant-enhanced sensor technology that can overcome the clinical barrier for electronics integration in TJA. Upon completion of the proposed research, the validated PRES is readily applicable to other joint arthroplasty systems as it is printed on the non-contact faces of TJA. The foundation established by this proposed work is also applicable to a wide range of inductance/capacitance-based sensors (temperature, biochemical, bacterial) enabling multivariate longitudinal sensing that can better-understand and ultimately enhance TJA outcomes.
This proposal is to establish a fundamentally new, general approach to integrating electronic functionality and a robust wireless response on existing, nonplanar medical devices, all without compromising their underlying mechanical function. This is in contrast with existing solutions that requires significant modification to joint prosthetics, which we believe is the core barrier that prevents the adaption of electronics. The proposed research will overcome these barriers by seamlessly integrating a resonance-enhanced wireless sensing platform with existing total joint arthroplasty (TJA) systems via a multi-material, multi-scale 3D printing strategy.