Safety-Critical Computing

Jonathan Jacky discusses Safety-Critical Computing: Hazards, Practices, Standards, and Regulation and discovers why several people were killed by radiation therapy machines.

There is a less innocent reason why clinics continued to use their machines after injuries and deaths occurred: they were driven by what accident researcher Charles Perrow calls production pressures. In his classic study of high-technology mishaps [27], Perrow describes how plant operators, under pressure to keep production lines running, will sometimes tolerate unsafe conditions--until an accident occurs. Today's cancer clinic is hardly less driven by economics than a power plant or chemical refinery; an idle clinic must still pay for the million-dollar machines and the staff that operate them. Pressures may be most acutely felt in the for-profit "free-standing" clinics that only provide radiation therapy, which have burgeoned in recent years and are actively competing with hospitals and with each other [18]. The FDA was sensitive to the clinics' plight. Asked after the fifth accident whether the FDA was considering a total ban, Edwin Miller of the Office of Compliance in the agency's Division of Radiological Products replied, "No such action is planned at this time. A complete ban would require an extensive study of risk assessment" [4].

Production pressures bear most heavily on the therapy technologists who actually administer the daily treatments (usually in the absence of a physician). The working world is largely divided between people whose job it is to track down problems and others who are supposed to get on with production. Many technologists find themselves in the latter category, and can become inured to 40 dose rate faults a day, routinely pressing the "P" key rather than interrupting treatments for the hours or days required to get the machine back in tune. When Cox was hurt at Tyler, he was at first unable to communicate with the technologist outside the heavily shielded treatment room because the intercom and closed-circuit TV were not working that day [2, 5].

Some clinics resist the pressure. The Hamilton, Ontario, clinic kept its machine out of service for months following their accident, until the fault was positively identified and repaired [3]. Recently, a prominent radiation therapy journal felt it necessary to remind readers, "Remove the patient from the treatment room as a first step when uncertainty in normal treatment unit operation occurs; err on the side of safety rather than staying on schedule" [28].

Emphasis Mine
Footnotes are in original

The thing about Capitalism is that life and death decisions are cost-benefit ones. How many people can we kill without impacting profits?

This is also the result of the proletarisation of the medical profession. Medical staff act and think like factory workers. This is the way to extract profits from their work.

Read more!