Lost in menuspace: user interactions with complex medical devices

The advent of fast-acting drugs has made the infusion pump the most pervasive electronic medical device in the acute care (hospital) environment. Despite the importance of its correct operation, incident reports in the US Food and Drug Administration (FDA) database implicate interface programming as a significant aspect of adverse outcomes. This article describes a study of infusion pump-programming performance by experienced healthcare professionals in a major urban teaching hospital. Early findings indicate that practitioner experience with device programming does not increase proficiency. This suggests that a complex menu structure ("menuspace") makes programming difficult and inefficient in ways that impede practitioner development of mental models that are sufficient for reliable device operation. This causes operators to become disoriented in the interface structure, or "lost in menuspace." We relate these findings to the current study of the USFDA adverse events reports and indicate directions for further research.