RFID technology is well known in the retail industry, which uses tags to track inventory because individual items can be quickly counted with scanners. Some hospitals use the tags or bar codes to track other gear such as wheelchairs and beds, and some use technology to show when crash cart trays have been opened. And while hospitals have been focusing more on reducing human error, University of Maryland Medical Center appears to be the first to use the high-tech markers to track all its emergency medications.