Development of a Wireless Telemetry Load and Displacement Sensor for Orthopaedic Applications
Abstract
Due to sensor size and supporting circuitry, in vivo load and deformation measurements are currently restricted to applications within larger orthopaedic implants. The objective of this thesis is to repurpose a commercially available low-power, miniature, wireless, telemetric, tire-pressure sensor (FXTH87) to measure load and deformation for future use in biomechanical applications. The capacitive transducer membrane of the FXTH87 was modified, and a relationship was reported between applied compressive deformation and sensor signal value. The sensor package was embedded within a deformable enclosure to illustrate potential applications of the sensor for monitoring load. Finite element analysis was an effective tool to predict the fatigue life and failure location of 3D-printed Ti-6Al-4V and PLA load cells. Finite element models of fracture fixation loading scenarios were developed to evaluate the feasibility of internal sensing components. The proposed device presents a sensitive and precise means to monitor high-capacity loads within small-scale, deformable enclosures.