Proper pumping

Humans are imperfect. There are some things we always find difficult, and there’s no way to change it. Interaction designers need to accept those things, and then design ways around them. For example, humans are not that great at doing many jobs at the same time. Sure, we can multitask if we really have to, but it often takes longer and we are prone to making more mistakes. One place that mistakes can be really dangerous is a hospital. Which means that it’s probably better for doctors and nurses to do one thing at a time.

One thing at a time

How do you make that happen? This is where designers can almost be like clever tricksters. People will often choose the path of least resistance, so if you can find a way to make your desired method the easiest method, you’re ahead of the game. That was the idea behind a study by Jonathan Back, Anna Cox and Duncan Brumby at University College London. They work on a project called CHI+MED, which is trying to find ways to design safer medical devices. They were working on the pumps that deliver medicine into patients’ bodies through an intravenous drip. They believed that it was safer for nurses to program those pumps one at a time: they make fewer mistakes that way, and mistakes with medicine can be fatal. But could the researchers find a way to coax nurses into programming them in sequence rather than all together?

Design detectives

They found a clue in the way nurses get their dosage information. They read the dosage off of a prescription form, then program it into the machine. Another clue came from the design of many pumps in hospitals. They are designed to stack one on top of another, to save space. What would happen is that nurses would bring their prescription form right next to the stack of pumps, and program the machines all together. Once they did a bit of programming on the first pump they would have to wait for it to do some work before the second step. So the nurses would go on to program a bit of the second pump, then come back to finish the first pump later. It seems more efficient, but it meant more mistakes. Sometimes nurses would get mixed up and forget steps, like opening the clamps that allow the medication to flow.

Improving nurses’ form

The CHI+MED team wondered if the solution was to do what seems less efficient and move the prescription form away from the stack of pumps. That way, the nurses would have to remember the information they were reading from the forms. Suddenly it was easier to program one pump at a time than to do them together. Their test subjects looked at the form, memorised the information, programmed the pump, released the clamp, and went back to the form to memorise the information for the next pump. Fewer mistakes!

In the real world, you can’t really force nurses to keep their forms on the other side of the room from the pumps. But the experiment gave designers an important clue to reducing mistakes. If they make it easier to program one pump at a time, patients will be safer. And it goes to show that good design is about knowing how people work – especially when we’re not perfect.