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Re: [IP] Millenium bug

> > It's a nasty thought. There could be a lot of DKA on New Years Day.
> > 
> > My Minimed507 doesn't hold the date, just the day of the week, so
> > presumably this isn't an issue. But I know nothing about the Disetronic.
> > Do any of the older models hold the full date?
> I doubt it very highly, there's no reason at all to put it in there.
> The thing about turning the clocks to 2000 is based on financial considerations, 
> such as interest rates and how long ago they date from so your bank can
> figure out your balance. Nowhere have I seen anything saying ANY machine 
> will stop working from it, it's what it figures that's the problem.

Well, that's not entirely true. First, it's not a financial consideration. It's
an issue of comparison. The problem shows up in financial issues very
frequently, but it's not the only place that the date change is a problem.

Date becomes an issue when you have to compare two dates with an intervening
"roll-over" (i.e. 1999-2000, Dec. 31 - Jan 1). Consider comparing two dates
with substantial time between them, say Jun 5, 1960 and Sept 19, 2001 (nothing
significant about those two dates). All you want to know is "How many days
elapsed between the two dates 6/5/60 and 9/19/01 (or 6/5/1960 and 9/19/2001
to be Y2K compliant). 
Without going into the messy details, the easiest way to do that is to convert
everything to days then add them all together for each date. Subtract
the first date from the second date giving the total number of days between
the two. But if all you have are the last two digits of the year, you can't
safely assume which century the year occurred. Any assumption you make is 
probably going to get you in trouble.

Now normally this probably won't affect hardware devices because they don't
do comparisons across large amounts of time (i.e. several months or years). 
But some devices do. Your car may be an example. Some of the recent diagnostic
systems monitor how long the device has been in operation and how
long it is before some required service must be performed. Should the
programmer have been dumb enough and the quality checks non-existant or very
poor, the device COULD become confused at the millenium changeover, assuming
that the device was bright enough to even recognize the roll-over.

As far as the pump is concerned, the only possible area that would be
at issue would be in calculating the time for the next basal dose. If that
were calculated from when the last dose was given and that calculation
included the year of the last dose, you MAY have a problem. That said, it
would only be a problem for the first basal dose on Jan 1, 2000 and it would
immediately clear itself after that.

But in almost ten years of programming real-time devices, I can't think of
anyone who uses a human-readable date type of calculation for calculating 
cyclic events. They would keep track of internal "cycles" to determine 
the time for the next basal dose. In short, this doesn't look like a problem 
for pump wearers.

> > My GP and some colleagues are publishing a book on medical equipment and
> > the millenium bug. He had heard a rumour that some infusion pumps do
> > fail at the turn of the century.
> As above, I think he's getting strange and silly information from somewhere!

Yeah, but it would probably count as a publication. Publish or perish!

> > And then of course there are the blood glucose meters that hold the
> > date.
> Yes, but what's the effect on the machine's operation? 

Meter users don't need to worry either, for that matter. Meter readings don't
involve time/date comparisons, so there shouldn't anything to worry about. The 
meter's calendar is either built in (hardcoded), or uses an algorithm that 
should handle the millenium roll-over. If it can't handle something that simple
I sure as heck wouldn't trust the bg readings I got from it.

Look, the fact of the matter is that most governments (most notably the government
of the US) are just now beginning to recognize that the problem exists. The
problems created by huge stupid government bureaucracys moving a glacial speeds
will dwarf any problems your insulin pump or meter might present. Except maybe
that you won't be able to get suppplies because the government doesn't think you'll
be born for another 50 years or so ;-{)>.

Insulin-Pumpers website http://www.bizsystems.com/Diabetes/
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