Design and evaluation of a safety-centered user interface for radiation therapy.

Purpose: As radiation therapy treatment grows more complex over time, treatment delivery has become more susceptible to adverse events and patient safety risks from use error. The radiation therapy monitoring and treatment delivery user interface explored in this study was redesigned using ecological interface design, a human factors engineering method, and evaluated to improve treatment safety.

Methods And Materials: An initial design concept was created based on previously completed analysis and informally evaluated in focus groups with radiation therapists. Sixteen newly graduated radiation therapists used both the redesigned and current system in a usability test to determine if the redesigned system better supported detection of errors.

Results: The redesigned system successfully improved the error detection rate of 2 errors: wrong treatment volume and wrong treatment site (P < .03 and P < .01, respectively). It also improved level 2 and level 3 situation awareness (ie, comprehension of the meaning of the information and the projection of the behavior of the technology: P < .01 and P < .01, respectively) and achieved a higher user satisfaction.

Conclusions: The ecological interface design approach was found to be effective in redesigning a radiation therapy treatment delivery interface. Radiation therapists were able to deliver simulated radiation therapy with a higher rate of error detection and improved higher-level situation awareness, and participants preferred the redesigned interface to the current interface. Overall, the redesigned interface improved the radiation therapists' system understanding and ability to detect errors that affect patient safety.