Contact-Free Magnetoelastic Smart Microsensors With Stochastic Noise Filtering for Diagnosing Orthopedic Implant Failures

A novel contact-free magnetoelastic microsensor for diagnosing failing orthopedic implants is introduced. It uses an implant-embedded 30-mu m-thick MetGlas-2826 film and a sensing coil placed 30 mm away from the film. Implant loading generates thin-film magnetoelastic response, passively (contact-free) detected as voltage by the coil. A specific integrated stochastic nonlinear filter performs data denoising, and a decision-making module concludes (via data assessment) on the health state of the implants. The sensor is successfully validated in vitro on an external fixation system and a hip prosthesis implant, respectively.