Something I sent in to the RISKS Forum:
Yesterday I took a CPR class that featured training in the use of
Automated External Defibrillators, or AEDs.
AEDs are truly remarkable devices. Early defibrillation raises the
probability of survival about an order of magnitude over CPR alone, and AEDs
are - supposedly - designed to be so easy to use that even child can
operate them. Watching the training video brought to mind memories of
science-fiction stories where the hero hooks his wounded buddy up to an
"autodoc" unit that monitors and medicates him, acting like a cybernetic
paramedic until their spaceship makes it back to base.
User interface confusion was never a problem in those stories.
The unit we were using has only two buttons: one to turn the thing on
and off, one to deliver the shock. Guess which button the woman taking the
test in front of me pressed when the voice prompt said "Shock advised"?
Part of the problem is that the on/off button was clearly a button, a
good old fashioned push button of the type my grandfather would recognize,
and it was right in the front of the control panel. But the shock "button"
was one of those almost-flush, slightly-raised, continous-with-the-surface
sort of things, that you might not know was a button, especially under
stress. And it was in the center of the unit - a place that, with the voice
prompts, you might not look.
I understand that some models power on when opened, eliminating the
two-button problem. If I'm ever in the market for one of these things, I'll
look for one where the remaining button is big and shiny and red and says
"Push Here to Deliver Shock" in large friendly letters; a button that looks
like a button.
-Tom Swiss / email@example.com