h a l f b a k e r yBirth of a Notion.
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Many you will have had the inestimable pleasure of not
meeting
my great-aunt Halva recently.
She seldom travels these days, not least because of her
need to
remain within 28 yards of a loo at all times.
This, it seems, is a common complaint amongst those of
advanced years. The problem
is that the elderly bladder
is less
like a balloon and more like a polythene bag - it has lost
its
resilience. As a result, it goes from being almost-full to
get-out-
of-my way! in a very short space of time. In short, the
curve of
pressure versus volume is almost step-like rather than
the
smooth rise of the younger bladderial organ.
Great-aunt Halva has shortly to travel overseas to a
reunion of
the Two Pins Club (those of you in the Network will
doubtless
know it). This seems, therefore, the ideal opportunity
to field-
test the Buchanan Bladderloon.
The Bladderloon is simply a silicone balloon, imperviable
to
liquids and gasses. It is inserted (uninflated) into the
bladder, by
means of a catheter under sedation (gin, usually), and
then
inflated with about 50cc of air.
Once in place, the Bladderloon will float at the top of
the
bladder, thereby not obstructing the urethra.
As the bladder fills, the Bladderloon does nothing.
However, as
soon as the bladder is actually full, the rising pressure
will cause
the Bladderloon to be compressed.
Consequently, the Bladderloon restores an element of
compliance to the elderly bladder, so that the internal
pressure
rises only gradually (rather than suddenly) as the bladder
fills.
This, in turn, gives Great Aunt Halva some degree of
forewarning.
[link]
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Bladder pressure is in the realm of 10 kPa, which is about 10% off atmospheric. So for a 10% change in balloon pressure, you'd get a 10% volume reduction (assuming it's filled with an ideal gas), which is not a lot. The cost would be 10% of capacity. |
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Also, I'm not sure it would float unless a substantial amount of urine was present. An empty bladder collapses and the balloon would risk blocking one of the inlets. |
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Well, it's too late now - she's probably half way to
Tobruk by now. |
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However, thanks to some ingenious non-linearity
in the walls of the Bladderloon, I can report that it
collapses from 50cc down to about 10cc under an
external pressure of about 10kPa. |
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If we encounter difficulties, we plan instead to fill
it with a small amount of volatile liquid whose
boiling point is close to body temperature. This
should ensure that it collapses a little more
readily as the pressure increases moderately. |
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A thought just occurs to me - I wonder if I made it
clear to her that she shouldn't travel by air? |
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//fill it with a small amount of volatile liquid whose boiling point is close to body temperature// |
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I thought this was that village that appeared every hundred years. Some sort of loon. Goon? There was a B in it, for sure. |
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You'd be thinking of Brigadoon. |
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There's a significant chance that this could
obstruct a
ureter causing reflux which can be a Very Bad
Thing.
There's also a non-trivial risk of this becoming a
site
for encrustation and stone formation. |
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Urge incontinence is usually cause by a bladder
that's
over active and spasms rather than one that is all
saggy and non-compliant. |
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Also, having something free roaming in your
bladder is really uncomfortable |
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Listen, I said it was an idea. I said nothing about its
being a good idea. |
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//having something free roaming in your bladder is really uncomfortable// A small urine consuming bladder eel would be an option worth exploring, would it not? |
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// having something free roaming in your bladder is really
uncomfortable // |
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Please, reassure everyone that you're not speaking from personal
experience... |
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