Tutorial 2: Case Study

1
Tutorial 2Case Study

• Silent Warning
• Search of the Lost Cord
• SY DE 142 May 17, 2004
• Introduction to Human Systems Engineering
• Waterloo, Ontario, Canada

2
Outline

• Case Study Silent Warning
• Discussion on Silent Warning
• Case Study In Search for the Lost Cord
• Discussion on In Search for the Lost Cord

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Silent Warning Overview

• Time January, 1972
• Place Iraq
• Synopsis
• Pesticide treated grain is shipped to Iraq,
  labeled in English. Local farmers grind the grain
  to make bread, poisoning themselves.

4
Silent WarningEvents and their Cause

• Dry weather caused low supplies of grain for a
  couple of summers before 1971
• Imported grain was not distributed on time,
  caused a huge portion of the seeds to remain
  unused
• The shipment of grain was treated with
  alkylmercury fungicide to inhibit spoilage by the
  main distributors, caused (see next slide)

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Silent Warning Results

• Between January and the end of August, 1972
• 6530 admissions and 459 deaths from
  methylmercury (based on the record of the
  hospitals)
• 60,000 peasants have suffered neurological
  damage (based on expert opinion and general
  observations by tourists)

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Silent Warning Question

• Give examples of some factors contributing to
  this Accident.

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Silent Warning Analysis

• Factors contributing to this Accident
• Label in English
• Symbol not meaningful in their culture
• The alkylmercury was not physically bound with
  the dye
• Delayed effects, no immediate feedback
• No taste or smell to differentiate

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Silent Warning Discussion

• Based on your analysis
• What could have been done by Cargill Corporation
  of Minnesota to prevent this accident from
  happening?

9
In Search of the Lost Cord Overview

• Time December 1986
• Place Childrens Hospital, Seattle
• Synopsis
• Nurse plugged two connectors, one from the IV
  pump and other from EKG electrodes taped to the
  chest of a four-year-old girl and caused her
  electrocution.

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Question

• Use the Action Cycle to discuss what happened.
• Goal , (intention)
• Act (sequence, execution)
• World (what happened)
• Evaluate (perception, interpretation, evaluation)

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Action Cycle for The Lost Cord

• Goal Monitor girls condition
• Intention Monitor her heart/ Use the EKG
• Seq of Actions
• Tape electrodes to chest
• Run lead across mattress
• Plug into heart monitor machine
• Actions does the above but plugs into IV pump
  instead (Gulf of Execution)

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Action Cycle for The Lost Cord

• World girl connected to IV pump, flow of
  electricity running into girls body
• Perception seeing girl get electrocuted
• NOTE Always indicate HOW the world is
  perceived by indicating senses maybe (v. such as
  sees, hears, etc.)
• Interpretation Wrong amount of electricity into
  girl / wrong piece of equipment
• Evaluation could not monitor girls condition /
  girl died
• NOTE (you need to tie back to your goal)

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Use Action Cycle to discuss what happened

• A heart monitor machine was there to check the
  girls condition
• Nurse picked up the EKG lead, then bent over and
  grasped the end of the cord hanging down near the
  side of the bed
• The cord was from the IV pump and not the heart
  monitor machine, but the connectors had similar
  slots that matched