Topic 4- ergonomics

• ergonomics


  • about the ways that people interact with their environment, the study of designing equipment and devices that fit the human body, its movement and cognitive abilities
  • physical- looks at ensuring that the user does not experience any physical discomfort
  • cognitive- this is focused on designing machinery to fit with how we think
• cognitive overload


  • suggests that there are limits to the amount of stimuli that people can handle at any one point in time
• Brown and Poulton


  • participants drove in either a residential area or a crowded car park
  • while doing this they were played a tape containing lists of numbers. they had to identify what numbers changed from one sequence to the next
  • participants made more errors in the shopping car park than the residential area
  • participants needed to give more attention to the stimuli associated with the primary task of driving so had less mental capacity left over for the stimuli associated with the less important task
  • this is an example of secondary task performance
• Miller- chunking

  • understanding how our memory works might help to reduce the dangers of cognitive overload
  • it has been suggested that we have different parts to our memory, short term and long term
  • miller suggested that there are limits to our short term memory
  • he proposed the magic number 7 plus or minus 2
  • the digit span technique
• Hawthorne studies

  • research was investigating light levels on productivity in an electric company
  • there was an experiment group- a small group of of women had to continue their regular job of assembling relays, the lighting conditions varied across different trials
  • there was a control group- other workers with consistent lighting
  • when lighting was dim, productivity increased, when lighting was constant productivity increased, when lighting was bright productivity increased
  • it was not lighting that increased productivity, but rather the fact they were being watched
• Higuera-Trujillo


  • a virtual reality study was carried out with 80 Spanish university students
  • participants completed 2 cognitive tasks while wearing VR headsets which simulated their university classroom
  • colour was manipulated by changing the hue of the headsets
  • memory task- participants given 30 seconds to recall 15 words
  • attention task- seeing how quickly participants could react to specific audio stimuli
  • both cognitive tasks were performed best when the VR room was either purple or blue-purple hue
• Drews and Doig- background


  • nurses and doctors who work in ICUs have to be able to monitor their patients' heart rate, blood pressure and oxygen saturation effectively
  • monitoring displays show all of this information to staff
  • the problem with these displays is that all the data is displayed numerically, and trends in data is not available on the main screen
  • reading many of these displays can be mentally demanding, increasing the chances of missing important information
• Drews and Doig- aim


  • the aim of this study was to compare a new monitoring system called configure vital signs display (CVS) with older displays
  • this display presented information graphically instead of just in numerical form
  • the CVS was designed to help nurses in rapid detection and identification if there is any deterioration in patients
• Drews and Doig- sample


  • 42 registered nurses with experience of ICU
  • split into 2 groups of 21
  • group 1- monitored patients using the new CVS
  • group 2- monitored patients using old displays
• Drews and Doig- procedure


  • each nurse was given 4 hypothetical patients: septic shock, early sepsis, pulmonary embolus and stable scenario
  • nurses were given 5 minutes with each 'patient'
  • the nurses had to verbally evaluate the status of each patient, interpret the data and recommend interventions
  • the nurses were assessed in accuracy and speed
  • after the nurse had completed each patient, they were given a questionnaire on the tasks and the level of mental demand associated with each task
• Drews and Doig- results


  • nurses identified the patients state 48% quicker with the CVS compared to the numerical display
  • the accuracy of nurses improved by 1/3 or more when using the CVS for certain hypothetical patients
  • nurses reported significantly lower mental demand in the CVS condition
• Drews and Doig- conclusions 


  • providing hospitals with the CVS can make hospital staff quicker and more accurate when assessing patients
  • CVS allows nurses to detect subtle changes in vital signs quicker than traditional monitoring, potentially avoiding harm
  • displays that integrates visual data can enhance nurses assessment of a patients state