The question is about pain in the human body: Are there any
"objective" measures of it, besides the explanations provided by the
patient herself?

I am thinking in any form of technological device that could detect
pain and automatically release medication. Or even more, a device that
would provide the doctor with an exact picture of where and how is the
pain perceived by the patient to aid in diagnosis.

Is this possible? How far are we from it?

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Clarification of Question by angelf-ga on 12 Aug 2005 03:57 PDT

I was thinking along EEG/CAT/MRI/... analysis or maybe measuring some
form of body response (hormonal, muscular, whatever). There has to be
some form of physical indication of pain, and this physical reaction
has to be measurable.

A good explanation of why my expectations are wrong would be fine as an answer.

This is a well-known conundrum.  Pain is one of the "realest" things
we can experience, yet it has totally eluded any sort of physical
measurement.  The only way I know of to 'measure' pain is to ask a
person "On a scale of 1 to 10..." sorts of questions, or to gauge
intensity by facial expressions, etc.

This is one reason why worker compensation cases and injury lawsuits
are so tricky -- a guy shows up in court grimacing something fierce,
wearing a neck brace, but the question remains:  Is he really in pain?
 He's the only one who knows for sure!

Funnily enough, there is a validated clinical instrument in
wide-spread use today that allows doctors and allied health
professionals both to determine pain levels and to assess response to
treatment.  It's known as a the 1-10 pain scale.  The doctor or nurse
asks you how your pain is on a 1-10 scale, or shows you (if you are a
child, or do not speak English well) a series of cartoons of heads
from smiling to crying (think of smiley-faces with various states of
emotions).

Perhaps surprisingly, this tool has been validated in clinical trials
to have very good interobserver reliability and repeatability.  In
other words, people give consistent answers regardless of who asks
them and when.  Likewise, there is repeatability in use of the scale
to determine effectiveness of pain control.

What the scale lacks is any consistency between patients: there is no
way to compare one person's 6 out of 10 to another person's 6 out of
10.  This points to the very subjective nature of pain itself: pain is
situational as well as individual.  There are many anecdotes about
people not having significant pain from a significant injury until
they become aware of the significance of their injury.  Soldiers with
severe battlefield injuries are well known to describe their pain as
not being severe, whereas civilians with similar injuries tend to
suffer agonizing pain.

Thus in answer to your question: we are infinitely far away from any
technological device that could detect pain: likely this is
impossible.  And we already have a decent (if imperfect) instrument
for communicating with health-care professionals the degree of our
pain.

Cheers.

Several years ago I read an account of a South American dissident who
was tortured while hooked up to a polygraph. Apparently his torturers
believed that by observing the polygraph results, they could get an
indication not only of the possible truthfulness or deceit in the
answers, but also of the amount of pain the victim was feeling, and
they fine-tuned their grim procedures accordingly.

While it seems plausible, I don't know of any scientific research that
backs up the theory that a polygraph (or similar device) offers any
useful measure of pain.

Linezolid is refering to this:  http://painsourcebook.ca/docs/pps92.html

"It shows a close linear relationship with visual analog pain scales
across the age range 4 through 16 years."

"Visual analog pain scale" is the expression (as I learned here a few
days ago from a question asking who originated the term).  Here is one
site on the subject:

http://www.rasch.org/rmt/rmt122s.htm

As Linezolid explained, it is a relative measure, fairly accurate for
that individual, but not objective in a more general sense.
Myoarin

Read THE BODY IN PAIN for a detailed discussion of this topic.

http://www.amazon.com/exec/obidos/tg/detail/-/0195049969/qid=1125686274/sr=8-1/ref=pd_bbs_1/104-5783129-4087969?v=glance&s=books&n=507846