A Novel Wireless Health Orthopedic System Integrating Motion and Acoustic Emission Monitoring

Cost effective, wireless, wearable and robust systems are imperative for allowing us to shift our focus from the traditional event-driven healthcare model to a pervasive health awareness model where we are continuously monitoring a person's well-being. This capability will not only prove essential for timely diagnostics and early treatments, but will enable an array of tools for furthering scientific knowledge. Bringing these benefits to the orthopedic applications is of great important, since degeneration of joins is known to be a leading cause of chronic disability in the United States [1]. Monitoring acoustic emissions from joints has been previously studied to demonstrate that via quantization, clinically healthy and osteoarthritic joints can be distinguished. In the trials, piezoelectric transducers were used to detect sound waves emitted from knee joints during sit-stand-sit movements [5]. Such systems have previous been limited by the size and complexity of the acquisition unit, thus only a very limited range of activities have been monitored. In this thesis, we present the novel Wireless Health Orthopedics (WHO) system, the developed hardware, as well as the accompanying software architecture. The specifics of the acoustic emissions (AE) system are shown in detail. We then explain how it interacts with the joint angle monitoring (JAM) measurements. We discuss the implementation of the holistic WHO system in healthy subject trials, which include sit-stand-sit, leg-extensions, walking and climbing stairs as movement sets. We further describe data post processing algorithms and techniques for synchronizing and visualizing the acquired measurements. Preliminary results indicate a quantitative difference between healthy young knee joints and healthy older knee joints. Further analysis allows for the discovery of distinct wave characteristics unique to certain movements and certain participant profiles. Finally, synchronized and superimposed acoustic emission and joint angle monitoring data is presented