STTR Phase I: Investigating Self-powered Health Monitoring of Orthopedic Implants and Data Retrieval Using Diagnostic Ultrasound

The broader impact/commercial potential of this Small Business Technology Transfer (STTR) Phase I project will be a significant transformation-changing reactive orthopedic surgery into proactive, preventive and cost-effective surgery. The project will have a direct positive impact on the quality of orthopedic surgery practice while reducing significant social costs. According to 2013 national survey, 25% of the patients who underwent orthopedic surgery reported dissatisfaction with their orthopedic surgical outcomes. Even worse, patients suffered great pain if the orthopedic implants experienced catastrophic failures and extensive costs have been spent on the recall of the defective implants and complex revision surgeries. The lack of a data- driven, decision-making tool available to surgeons during and after orthopedic surgery is created by the current inability to continuously monitor ?physical health? of orthopedic implants. Creation of this missing tool will empower surgeons to make reasonable judgment as to when trauma fixation devices can be optimally removed or when revision surgery can be optimally timed. The key impacts of the project will be: 1. Reduction of patients discomfort; 2. Reduction of orthopedic healthcare costs; 3. Reduction of social costs due to delayed revision surgery and endured long hospital stays; 4. Improvement of post orthopedic surgery rehabilitation. The proposed project will develop a health monitoring sensing system for orthopedic implants using a patented self-powered piezo-floating-gate (PFG) sensing technology. This proposal tackles a long-standing technical challenge in orthopedic surgery to create a proactive and preventive orthopedic surgery experience. A key question often asked of surgeons after trauma surgery is an inquiry on the patients bone healing progress - a common question that is nearly unknowable today. X-rays generally do not give surgeons a full, accurate and continuous assessment of the extent of healing of bone fractures. A key feature of the PFG sensor is the use of floating-gate sensing circuits that compute and store cumulative statistics of the strain- rates and stresses while achieving operational power limits not possible with any competing health and usage sensing technologies. The sensor requires less than one microwatt of power that can be easily harvested from a miniature piezoelectric transducer operating in strain-mode (not vibration-mode). This will enable batteryless, self-powered PFG sensors to be implanted inside the body or attached to orthopedic implants. This PFG sensor would empower trauma surgeons with quantitative information to enable actionable decisions regarding bone-healing progress, and to plan timely revision surgery if needed.