[SystemSafety] Therac-25 redux

From: Les Chambers < >
Date: Sat, 16 Aug 2014 14:10:22 +1000

Just when you thought it was safe to be medicated by a machine ... read this from the Economist:


An excerpt:

"During the 1980s a bug in the software of Therac-25 radiotherapy machines
caused massive overdoses of radiation to be delivered to several patients, killing at least five. America's Food and Drug Administration (FDA) has linked problems with drug-infusion pumps to nearly 20,000 serious injuries and over 700 deaths between 2005 and 2009. Software errors were the most frequently cited problem. If buggy code causes a pump to interpret a single keystroke multiple times, for example, it could deliver an overdose.


Researchers at the University of Patras in Greece found that one in three of all software-based medical devices sold in America between 1999 and 2005 had been recalled for software failures. Kevin Fu, a computer science professor at the University of Massachusetts, calculates that such recalls have affected over 1.5m individual devices since 2002. In April researchers at McAfee, a computer-security firm, said they had found a way to get an implanted insulin pump to deliver 45 days' worth of insulin in one go. And in 2008 Dr Fu and his colleagues published a paper detailing the remote, wireless reprogramming of an implantable defibrillator."  

There is some good news however:

the article goes on:

"The Generic Infusion Pump project, a joint effort between the University of
Pennsylvania and the FDA, is taking these troublesome devices back to basics. The researchers began not by building a device or writing code but by imagining everything that could possibly go wrong with a drug-infusion pump. Manufacturers were asked to help, and several did so, including vTitan, a start-up based in America and India. "For a new manufacturer, it's a great head start," says Peri Kasthuri, vTitan's co-founder. By working together on an open-source platform, manufacturers can build safer products for everyone, while still retaining the ability to add extra features to differentiate themselves from their rivals."  

A quick search of the Internet did not reveal any publication of drug-infusion pump hazards. Is anyone aware of same?

This brings me to my point: wouldn't it be great if we had a readily accessible ontology of hazards for various application domains. It's an obvious idea. Is anyone aware of discussions along these lines? In my time in chemical processing this function was the role of company-internal technology centres that were the guardians of safety for various chemical processes. The information was heavily proprietary however.  

"Open source" hazard ontologies would solve the problem of corporate memory
loss, amnesia and denial. As a consultant running a hazard analysis you are always dependent on your subject matter experts to know what they're talking about, when it comes to predicting what could go wrong. I've seen situations where political machinations have actually prevented knowledgeable people from having a voice in this area.  

I am currently working on ontologies that inform software requirements specification
(http://www.chambers.com.au/glossary/requirements_patterns.php). It occurs to me though that they have a much broader application.  



Les Chambers
Chambers & Associates Pty Ltd
 <http://www.chambers.com.au> www.chambers.com.au

Blog: <http://www.systemsengineeringblog.com/> www.systemsengineeringblog.com

Twitter: <http://www.twitter.com/chambersles> _at_xxxxxx M: 0412 648 992
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systemsafety_at_xxxxxx Received on Sat Aug 16 2014 - 06:13:13 CEST

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