Electronic Measurement Systems for Osteosynthesis Implants and External Fixators

In this dissertation an electronic osteosynthesis implant and an electronic hexapod fixator are presented, which utilize strain gauges for measurements of the mechanical loading of bone fractures. The load measurements can be used to monitor the fracture healing process more reliably than with conventional radiography. Moreover, they provide a continuous overload detection and warning of the patients to avoid damage to the fracture or the osteosynthesis device. For the electronic osteosynthesis implant, this is enabled by an autonomous operation, in which the electronics module is powered from rechargeable batteries. Wireless power transfer and Bluetooth Low Energy are implemented as interfaces to external devices. The implant contains an application-specific integrated circuit, which was designed to optimize the sensor interface. In addition to the mechanical load measurements, the electronic hexapod fixator also optically measures the length of six length-adjustable distractors.