Retention of surgical instruments occurs when a surgical item is inadvertently left inside a sealed patient at the end of surgery. Current practice is to have a circulating operating room nurse make manual counts of all instruments, but this takes time and is prone to error. This clinic team has been tasked by City of Hope Hospital to create an automated system to count with 100% accuracy all instruments in the operating room. The design uses a combination of metal detection, radio frequency identification, and fluorescent barcodes to achieve this goal.