
Operations, machine learning and premature babies - ColinWright
http://radar.oreilly.com/2012/04/operations-machine-learning-data.html
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streptomycin
_the telltale signal wasn’t spikes or irregularities, but the opposite. ...
Their heart rate was too normal; it didn’t change throughout the day as much
as it should. That observation strikes me as revolutionary._

It was revolutionary... like 30 years ago when people first noticed that
decreased heart rate variability is a marker for bad events, obviously without
"a machine learning system that can sift through gigabytes of data".

Not that I disagree with the rest of the article, but the anecdotal example is
poor, and it just wouldn't be Hacker News if somebody didn't pedantically
point that out.

Also, FWIW, in the field of predicting bad things in premature babies based on
patterns in heart beats, these guys are a bit ahead of IBM, having recently
completed a multicenter randomized controlled trial:
<http://www.heroscore.com/>

~~~
ars
I came here to say the exact same thing. During fetal monitoring the #1 thing
they are looking for is heart rate variability. If the heart rare is constant
that is very dangerous sign for the fetus.

The reason is simple: If the fetus has the oxygen it needs then the heart rate
will constantly change, low during rest and high during activity. But if there
is a shortage of oxygen the heart will run at the highest it can manage with
the oxygen available.

This is also true for adults: The military figured out that the best soldiers
for special forces training had a constant heart rate - their hart rate
doesn't spike during times of stress, making them very good as resisting
interrogation.

But it has a downside: They don't live as long as people with constantly
changing heart rates.

~~~
streptomycin
_The reason is simple_

In your example it may be (I don't know much about fetuses), but in general it
isn't. The reasons for changes in heart rate variability (HRV) are generally
unknown, although there are various hypotheses and theories. If you read the
papers by the company I linked to above that does HRV monitoring for neonatal
sepsis, they freely admit that they don't know the mechanism behind the signal
they detect.

 _The military figured out that the best soldiers for special forces training
had a constant heart rate_

Interesting. Do you have any links about that?

~~~
ars
[http://www.thedailybeast.com/newsweek/2009/02/13/lessons-
in-...](http://www.thedailybeast.com/newsweek/2009/02/13/lessons-in-
survival.html)

~~~
hcrisp
Fascinating article.

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pjscott
I was hoping for more than speculation. Sadly, this article didn't contain it,
but a bit of googling turned up this paper:

[http://static.usenix.org/events/sysml08/tech/full_papers/xu/...](http://static.usenix.org/events/sysml08/tech/full_papers/xu/xu.pdf)

These guys wrote some software that looks through the logs from a Hadoop
cluster and identifies patterns of anomalies. If a cluster of a few exceptions
tend to be spammed in the logs at the same time, it identifies this as a
single problem. If a scary-looking "error message" is actually normal, it says
that this is normal.

As someone who has spent too much time doing that kind of thing manually, the
idea of automating this sounds _very_ appealing.

------
ars
This makes sense for machines - if your server is always running at a constant
rate then it's probably maxed out. If the rate changes, and has no "clipping"
(flat areas at the top of the peaks) then it has the headroom it needs.

