Medical errors in the operating room due to design, technological factors and poor human factors engineering are common. Determining the factors which facilitate or hinder successful performance during the use of medical systems is critical to the creation of standardized metrics for usability of medical devices in the operating room. Creation of a standardized evaluation for usability based on international standards and user-centered design principles can help determine what role these factors have in medical errors. In addition, device design can be evaluated to promote safety, measured objectively by metrics such as reduction in medical errors with a decrease in performance time.