Hong Chen (Tsinghua University, China)
As the average age of the population goes higher, the number of people suffering severe pain in their damaged hip and knee joints caused by a variety of human diseases and activities has increased steadily. The last resort to regain full mobility and alleviate the pain is total hip replacement (THR) and total knee replacement (TKR) surgeries. According to the Agency for Healthcare Research and Quality (AHRQ), almost 500,000 THRs and 700,000 TKRs are performed annually in the US in 2011. However, both THR and TKR surgery still have a failure rate of about 10%, leading to serious complications such as dislocation, prosthetic impingement, intraoperative fracture, infection, and leg length discrepancy along with the long-term complications of wear and loosening. The failure rate will increase to 20% of the revision surgeries. Many efforts have been made to improve the success rate of the surgeries with microelectronics technologies. In this tutorial, two novel monitoring systems during TKR and THR surgeries, which have been verified by clinic experiments, are discussed in detail. The low-power circuits design for smart medical devices will be described, including power harvesting from PZT elements inside the knees, ultra-low-power design of microelectronics control units, asynchronous circuits design, etc.. Recent development on low-power circuits design technologies are summarized and future research directions are discussed.