Orthopedic Implants Integrating Fluidic Pumps and Smart Sensors

Abstract

This thesis presents the development of miniature fluidic pumps and biosensors integrated into smart bone implants for post-operative infection monitoring and on demand drug delivery. First, a modular, magnetically actuated screw-based pump and a lockable flexible magnetic valve are proposed to enable controlled drug release. These components are demonstrated in a dental implant platform, whose structure is optimized to ensure effective drug distribution under varying gap sizes and surface geometries, simulating the progression of peri-implant diseases. Second, to enable closed-loop drug delivery in orthopedic implants, a pH-responsive hydrogel sensor, comprising poly[2-(diisopropylamino)ethyl methacrylate] and poly(ethylene glycol)diacrylate (PDPAEMA- PEGDA) blocks and paired with an optical readout system, is developed to reliably detect synovial fluid pH changes under physiological conditions. This sensing system is integrated into a knee implant. Modular pumps are coupled with microfluidic channels to enable repeatable, non-invasive biofluid sampling and therapeutic delivery. To optimize implant design, two decoupled control strategies are introduced for spatial configuration of the integrated components. Additionally, remote charging and Bluetooth Low Energy (BLE) modules are embedded to support long-term operation and real-time data transmission. A wearable magnetic actuation system is developed to wirelessly control two pumps within the knee implant for fluid sampling and drug ejection. Closed-loop sensing and therapy for infection detection and treatment in knee implants is demonstrated. The system is further validated in a porcine tibial bone model using X-ray imaging to visualize drug delivery. Mechanical testing confirms that the integration of sensors and pumps does not compromise the implant's structural integrity. Overall, this thesis demonstrates multi-functional smart orthopedic implants capable of real-time biosensing and closed-loop therapy. The proposed platform offers a promising approach for long-term monitoring and autonomous therapeutic intervention in orthopedic applications.