title: Designing devices with the task in mind: which numbers are really used in hospitals?
abstract: OBJECTIVE
  We studied the patterns of digits and numbers used when programming infusion pumps with the aim of informing the design of number entry interfaces.
  
  
  BACKGROUND
  Number entry systems on medical devices are designed with little thought given to the numbers that will be entered. In other fields, text and number entry interfaces are designed specifically for the task that they will be used for. Doing so allows for faster and more accurate interaction.
  
  
  METHODS
  In Study 1, logs were taken from infusion pumps used in a hospital. Information about the numbers being typed was extracted. For Study 2, three common number entry interfaces were evaluated in light of these results to determine which were best suited to the task of programming infusions.
  
  
  RESULTS
  There are clear patterns in the numbers being used in hospitals. The digit 0 is used far more frequently than any other digit. The numbers 1,000, 100, and 50 are used in nearly half of all infusions. Study 2 demonstrates that interfaces are not optimized for entering such data.
  
  
  CONCLUSIONS
  Changes could be made to the design of the number entry interface on infusion pumps, leading to a reduction in the number of key presses necessary to program a device. We offer a set of four heuristics to guide the design of number entry interfaces on infusion devices.
  
  
  CONCLUSIONS
  Improving the design of the number entry interface of medical devices, such as infusion pumps, would lead to improved efficiency and a reduction in the likelihood of errors.
authors.affiliation: University College London, Interaction Centre, 8th Floor, Malet Place Engineering Building, London WC1E 6BT, UK. sarah.wiseman@cs.ucl.ac.uk
authors.forename: Sarah
authors.initials: S
authors.lastname: Wiseman
authors.forename: Anna L
authors.initials: AL
authors.lastname: Cox
authors.forename: Duncan P
authors.initials: DP
authors.lastname: Brumby
mesh_terms: D004867:Equipment Design / Q000379:methods*; D006804:Ergonomics / Q000379:methods*; D006801:Humans; D007260:Infusion Pumps; D013647:Task Performance and Analysis