Tuesday, March 1, 2011

Dangerous by Design

I recently read this article, which describes hundreds of infants (and adults) mistakenly being over-radiated in hospitals.

Like others who were interviewed in the article and those who commented on it, I too am shocked and outraged. But not for the reasons you might think.

The problem is the manufacturers of this machine violated one of the most central tenants of systems design, and that is:
The system should be designed to help the user prevent errors
These CT scanners are clearly not well-designed to help radiology technicians avoid making mistakes. It should be difficult, not easy, to overdose an infant. There should be a scale on the exam table - if the patient is below a certain weight the radiation level will be limited, and only by entering an override code can that the dose be increased.

The system should run through a step-by-step procedure with the technician, requiring them to verbally say, "Yes, I have properly positioned the infant." "Yes, I have shielded them." etc.

Really, very simple stuff - but could help prevent an avalanche of errors.

I agree that increased licensing / re-certification of techs is also a good idea, but they still need to be using  systems designed to help them make fewer errors in the first place.


  1. This is a great point. I had not been able to express it so clearly, but I really wonder why the folks that made the machine didn't realize this.

  2. I used to work in IT making medical stuff. Our first tenet was "If a user can do it, they will." In other words... make it as idiot-proof as possible, or someone will crash it, or press that button just to see what happens. Yeah.

    On a related note, I once clicked the "write-in" button at the polls just to see what would happen. (Answer: nothing good.)

  3. This is why I will not allow the TSA to irradiate me. TSA + "turn this knob to make it clearer" = cancer.