rusty0101's Journal: bad design common to consumer electronics...

As a starting point, I heard from my sister recently about a problem that my niece encountered with something a bit more vital than what would be considered "consumer electronics".

My niece is diabetic. Type 1, taking insulin. This last year she went onto an insulin pump in an attempt to stabalize her blood sugar levels. She is now on her second pump as the first one was not working as expected. In fact she ended up in ICU as a result of it. With the pump she is on now, her blood sugar levels are significantly improved.

She has run into a problem with this pump however that should never have come up. It is a problem that people have encountered with just about every form of portable consumer electronics however, from watches through walkman's, remote controls through flashlights. The problem is Battery polarity.

A week or so ago at about three in the morning, the alarm on her pump went off telling her that she needed to replace the battery. If you carry a pager, you have probably gotten a similar alert. However you were probably comfortable waiting till 8 in the morning, or some later time to replace the battery. Life is a bit different with an insulin pump. You pretty much do not want to let the battery die, else you encounter problems of your own. So a very groggy niece of mine, at 3 in the morning, replaced the battery in her pump.

Backwards.

Scott Adams noted in one of his books, the title elludes me at the moment, that one day his pager stopped functioning. He took it to the local pager support tech, who took the pager, and all with one hand, poped the battery compartment open, dropped out the battery into his palm, flipped the battery around, slipped it back into the pager, closed the pager door, and handed the now functioning pager back to Scott. Scott is not stupid by any means. I will personally attest that I have had the same problem with other electronic devices myself. Fourtunatly for me, my very life does not rely upon these devices functioning, and I can usually figure out what has happened, as I am often awake enough to remember to check these things shortly after I have swapped batteries in them.

My brother-in-law was made aware of the fact that there was a problem later the same morning. I suspect that what happened is that her blood sugar levels did not go down, and the pump appeared to be out of order. He was on the phone with tech support for the pump for quite some time, and they eventually realized that the problem was the battery was installed backwards.

There is a very small, very simple, very effective, user proof solution to this type of a problem. Actually two such solutions, one of which can would give the user feedback that the battery was backwards, the other would not care if the battery was backwards or not.

The solution that would provide feedback that the battery was backwards would simply add a circuit in parallel to the electronics that ran on the same voltage, reversed as the primary circuit. It could be simply an LED and a resistor set up to light if the batteries are backwards.

The solution that would be battery polarity agnostic would put a bridge rectifier across the battery compartment and so long as all the batteries were connected positive to negative, would provide the correct polarity to the primary electronics.

It would even be possible to bridge rectify every battery so it would not matter if one battery was installed backwards.

Yes there would be added drain on the batteries as a result of these additional components. In fact it would cost extra money to add these components which would drive the cost up by a couple of pennies per device. In the cut-throat consumer electronics industry, it probably would not fly. I can not think of one good argument against this in the medical and military markets however.

The last thing I want a soldier to have to do is try to figure out what orientation his night sight batteries are and should be. Likewise medics in ambulances, or other people in life threatening situations.

Agrivating this situation is the fact there are a number of AAA batteries on the market these days where you have to search for the (+) indicator to know which end is which.

I honestly think that there are a large number of people who would be a lot happier with their electronics if they knew that all they had to do was swap the batteries, and it did not matter how they were installed. I personally think that a lot of parents of type 1 diabetics, with pumps would sleep a lot better if they did not have to worry about their kid putting the batteries in backwards at some time during the night.

Then again, that's just my opinion. Anyone with a better idea?