A novel ultrasonic device for monitoring implant condition

Every year more than 2.3 million joint replacement is performed worldwide. Around 10% of these replacements fail those results in revisions at a cost of $8 billion per year. In particular patients younger than 55 years of age face higher risks of failure due to greater demand on their joints. The long-term failure of joint replacement such as implant loosening significantly decreases the life expectancy of replacement. One of the main challenges in understanding and treatment of implant loosening is lack of a low-cost screening device that can detect or predict loosening at very early stages. In this work we are proposing a novel method of screening implant condition via ultrasonic signals. In this method we are applying ultrasonic signals to the joint via several piezoresistive discs while reading signals with several other piezoresistive sensors. We are introducing a new approachin interpreting ultrasonic signals and we prove in a finite element environment that our method can be used to assess replacement condition. We show how our new concept can detect and distinguish between different implant fixation failure types sizes and even locate the position of the failure. We believe this work can be a foundation for development of a new generation of ultrasonic diagnosis wearable devices.