(5 marks) Explain why the electrocution described in “In Search of the Lost Cord” could be considered a system accident.

In considering a system, one needs to look at the entire hospital room and the biology of the patient itself. The important points are

a. proximity between the devices, and in particular their cords.

b. tight coupling of the human patient with respect to electrical charge, i.e. it doesn’t take a lot of electrical charge to change patient state, for the worst.

c. non-linearities. Once connected there is a nonlinearity between the power source and the patient. Possibly a more robust argument are the nonlinearities inherent in biological systems.

d. common-mode interactions. There are many common mode connections in biological systems.

e. limited ability to isolate components in the patient

f. multiple unintended feedback loops in the patient.

g. tightly spaced organs, or proximate steps in organ systems.

h. not reversible

i. no buffer

There are easily 9 possible answers, 5 marks for any 5 of these.