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In <4epq35$…@sun.sirius.com> "Raymond A. Chamberlin"
<ra…@sirius.com> writes:
(…)
>No, you don’t have the concept of "digitality" down right at all.
(…)
I use the term digital to refer to anything which can be or is best
expressed in digits, integers or whole numbers as opposed to real
numbers (with decimal points).
Most things that I consider to have a digital nature are not ‘purely’
digital, but are predominantly so, like the human pulse. If that’s not
acceptible in the halls of electrical engineering, oh well…
Sorry I couldn’t follow your discussion well enough to be of any use.
Bill
w…@ix.netcom.com(William Stacy ) wrote:
>In <4e1rv0$…@sun.sirius.com> "Raymond A. Chamberlin"
><ra…@sirius.com> writes:
>(…)
>>Well, there seems to be also, but only on rare occasions, a
>>fluidic wetware (circulatory) analog of this action going on in
>>the cornea
>An avascular (hopefully), so you don’t mean cornea…
Yeah, not cornea, I guess.
>> of my good (non-glaucomatous) eye, or nearby,
>Which could mean iris, conjunctiva, lid, what-have-you…
Not iris or lid; I suppose, conjunctiva.
>> which
>>changes the lens power
>What lens power? Your spectacle Rx? What?…
Just a tiny portion of the cornea a tiny bit, I guess (two
slightly different sets of ray traces, sequentially, in a tiny
area).
>>slightly over a small area at the top of
>>that eye
>The *top* of the eye? Way up under the upper lid???
At the top of my field of vision (subjectively).
>–from one of two fixed values to the other–upon each
>>pulse of blood in a small vessel at that location.
>This is a blood vessel you can see directly, as in mirror assisted
>self-examination, or are you visualizing it entopically?
Cannot compute ‘entopically’. Subjective experience of
just-noticeable change of image in small portion of field.
> The
>>puzzlement is: What physiology could possibly perform this
>>toggling action? Why wouldn’t the optical modulation simply
>>roughly follow the pulse pressure, rather than be toggled that
>>way?
>I’m not totally sure what the heck you’re talking about, but it sounds
>like variations in your blood pressure are causing you subjective
>visual changes in your one good eye.
I believe you could call it a non-nervous nervous tic
(neurally something less than a reflex) triggered by local blood
pulsation.
Since the other is blind from
>glaucoma, my first suggestion is to keep careful watch on that good eye
>and consider agressive anti-glaucoma therapy at the first sign of
>trouble (I know you disagree with that, but I gotta say it to keep my
>malpractice insurance in force).
Yeah, I got a squad of ex-OJ attorneys monitoring this newsgroup
every night. ;-) This has nothing to do with glaucoma. I
believe it existed considerably prior to any of my glaucoma and
hasn’t changed. It is quite infrequent. Stick to the question.
>Getting back to the contest question, blood pressure is more digital
>than analog in nature. The systolic spike is more a sudden change of
>state (due to the similarly digital ‘open/close’ action of the heart
>valves) than a sinusoidal increase in pressure. If that were not true,
>we would not have pulses that you can hear via auscultation.
No, you don’t have the concept of "digitality" down right at all.
(We’ll skip the biologists’ and physicians’ grandfathered view
that it has something to do with fingers and toes, and that
mathematicians and engineers who had lost their calculators
/ slide rules stole it from them in order to figure.) Digitality
requires more than nonlinearity! The shape of blood-pressure
pulsation only determines the rate=frequency-harmonic content
present, the higher-frequency contribution of a spike
creating a less time-ambiguous trigger action for what I’m
describing. A sine wave would also trigger it. Abstractly,
digitality involves quantization (setting to only one value of a
range of values within two or more ranges to produce two or more
values) plus, if more than such number of values are to be
represented, a modulus-determined representational schema, where
the modulus is normally equal to the number of values (quanta).
(Probably Alex could state that much better.)
From a hardware/physical standpoint, a gain (amplification) of an
energy parameter plus positive feedback, together with some
decoupling from the analog source are necessary to achieve
digitalization. This is arranged differently for parallel and
serial digitalization.
In the instant case, we are concerned only with two output
values, in which case, there is no parallel/serial distinction
(only one "digit position"); however, in the instant case, we
deal with a toggle, so, in respect to a count of the pulses of
blood, the blood pulses and toggled light-refraction states
relate as adjacent digit positions, a given state of the latter
having twice the value of the occurrance of the former, or a rate
of occurrance of half that of the former. A mechanical toggle is
the clunkiest version of a toggle around and may fit your
intuition well, but to me it’s rather mystical analytically. An
electronic toggle flip-flop can be analyzed well in terms of
electrical parameters.
>We know that the eye pressure varies with the pulse, a variation that’s
>always seen during Goldmann tonometry. This variation of intraocular
>pressure may be changing an optical component slightly (cornea
>probably) or somehow affecting a neurovascular component in your eye or
>brain, or even modulating the chorio-retinal structure itself.
I don’t know of any physio/biological things (on the cell-level
or above, at least) that can toggle other than neural systems;
and I would agree that, in this case, the blood-flow variation in
an arteriole or capillary, or whatever, is probably nudging some
little autonomic vessel-wall neural arrangement–except that I
don’t know what I’m talking about.
>Whatever it is, it’s going to be more digital than analog, since the
>proximal cause presumably is the spike of systole.
No, it would work with a sine wave also, just not as cohered to
its trigger (more jittery occurrance).
>>(Sorry, the winning answerer does not get a free autorefractor.)
>Darn! I was counting on it…
>Bill
Well, this way, you’re not losing any prize. I was just curious
as to whether anyone ever observes such things, or do they just
sit around watching floaters. I have no trouble from them.
Another such curiosity, which is off-topic here, is what is
apparently an extraneous pacemaker that, on a very few occasions
of semi-wakefulness, does the opposite–"counts up", i.e., runs
at a rate either 2 or 4 times my heart rate (but doesn’t affect
my pulse, at least outside my heart). I wonder how that works;
apparently the main pacemaker or resultant heart action
sychronously triggers its every second or fourth pulse.
Ray: Is ’1′ better, or ’0′?
"Raymond A. Chamberlin" <ra…@sirius.com> wrote:
……
It’s
>sharp waveshape? It’s periodicity? It’s zero-crossings (or
….
Ma’n, I h’ate pe’opl’e who use apost’rophe’s whe’re t’hey don’t
b’elong– even when it’s (that’s one’s (oops, two’re (oops, …ad
infinitum) OK, right?) me.
Ray
In <4esjv2$…@sun.sirius.com> "Raymond A. Chamberlin"
<ra…@sirius.com> writes:
>Ma’n, I h’ate pe’opl’e who use apost’rophe’s whe’re t’hey don’t
>b’elong– even when it’s (that’s one’s (oops, two’re (oops, …ad
>infinitum) OK, right?) me.
>Ray
I admit to overuse and misuse of the single quote ‘ character. It’s a
habit that comes from the fact that in my database programming
language, textual variables are distinguished from numeric variables by
enclosing the text within two of the critters, so I am constantly using
them. (Yes, I *do* use my PCs for something other than this!).
I’ll try to cut back.
Bil’
w…@ix.netcom.com(William Stacy ) wrote:
>In <4epq35$…@sun.sirius.com> "Raymond A. Chamberlin"
><ra…@sirius.com> writes:
>(…)
>>No, you don’t have the concept of "digitality" down right at all.
>(…)
>I use the term digital to refer to anything which can be or is best
>expressed in digits, integers or whole numbers as opposed to real
>numbers (with decimal points).
OK, but that doesn’t explain why you would describe a waveform as
digital simply because it’s far from a sine wave–or whatever
other reason.
>Most things that I consider to have a digital nature are not ‘purely’
>digital, but are predominantly so, like the human pulse. If that’s not
>acceptible in the halls of electrical engineering, oh well…
That’s not acceptable in all of science or any respectable arts
which apply it. If you go around making up your own definitions,
you can’t very well complain about what a lot of other people in
this newsgroup do. I’ve never heard anyone in any line of work
use the word in that manner! The purpose of using words is
communication. It doesn’t come across to me (or probably to
anyone here) what you want to point out specifically about the
"human (only human?) pulse" by using the term ‘digital’. It’s
sharp waveshape? It’s periodicity? It’s zero-crossings (or
other phase points) as discrete events? These periodic points
can be counted up digitally, but the waveform is basically
continuous ("analog"), though it can be digitized in either
amplitude or phase (time) or both, as can any "analog" function.
I can’t figure out what aspect of a "human pulse" you wish to
label "predominantly digital" but not "purely digital".
‘Digital’ refers to functionality, and you either see something
as functioning that way or you don’t; it doesn’t describe
squared-off corners, which can be part of a waveform that can be
analytically described and thus regarded as analog. Do we have
here the medical human model that says, "I’m in charge here; you
figure out what I mean."?
Does anyone else here make anything out of his terminology?
>Sorry I couldn’t follow your discussion well enough to be of any use.
>Bill
Well, I wasn’t seeking anything of *practical* use, of course; I
was just curious whether the innocuous effect I described was
commonly known and if there existed at least a sort of
explanation of how the subjective optical effect could occur at a
rate *half* that of the triggering blood pulse.
Ray
In <4eshp8$…@sun.sirius.com> "Raymond A. Chamberlin"
- Hide quoted text — Show quoted text -
<ra…@sirius.com> writes:
>w…@ix.netcom.com(William Stacy ) wrote:
>>In <4epq35$…@sun.sirius.com> "Raymond A. Chamberlin"
>><ra…@sirius.com> writes:
>>(…)
>>>No, you don’t have the concept of "digitality" down right at all.
>>(…)
>>I use the term digital to refer to anything which can be or is best
>>expressed in digits, integers or whole numbers as opposed to real
>>numbers (with decimal points).
>OK, but that doesn’t explain why you would describe a waveform as
>digital simply because it’s far from a sine wave–or whatever
>other reason.
Because a waveform that exhibits relatively sharp extremes is acting
more digitally than analogously (there I go again, inventing new uses
for words).
- Hide quoted text — Show quoted text -
>>Most things that I consider to have a digital nature are not ‘purely’
>>digital, but are predominantly so, like the human pulse. If that’s
not
>>acceptible in the halls of electrical engineering, oh well…
>That’s not acceptable in all of science or any respectable arts
>which apply it. If you go around making up your own definitions,
>you can’t very well complain about what a lot of other people in
>this newsgroup do. I’ve never heard anyone in any line of work
>use the word in that manner! The purpose of using words is
>communication. It doesn’t come across to me (or probably to
>anyone here) what you want to point out specifically about the
>"human (only human?) pulse" by using the term ‘digital’. It’s
>sharp waveshape? It’s periodicity? It’s zero-crossings (or
>other phase points) as discrete events?
Yes, yes, and yes. So I *did* get my point across after all?
These periodic points
>can be counted up digitally, but the waveform is basically
>continuous ("analog"), though it can be digitized in either
>amplitude or phase (time) or both, as can any "analog" function.
Thank you.
> I can’t figure out what aspect of a "human pulse" you wish to
>label "predominantly digital" but not "purely digital".
>’Digital’ refers to functionality, and you either see something
>as functioning that way or you don’t; it doesn’t describe
>squared-off corners, which can be part of a waveform that can be
>analytically described and thus regarded as analog. Do we have
>here the medical human model that says, "I’m in charge here; you
>figure out what I mean."?
Tsk tsk.
>Does anyone else here make anything out of his terminology?
>>Sorry I couldn’t follow your discussion well enough to be of any use.
>>Bill
>Well, I wasn’t seeking anything of *practical* use, of course; I
>was just curious whether the innocuous effect I described was
>commonly known and if there existed at least a sort of
>explanation of how the subjective optical effect could occur at a
>rate *half* that of the triggering blood pulse.
Your description *was* pretty obtuse. Maybe that’s one reason I’m the
only one who answered.
It sure sounded ‘digital’ to me.
Bill
w…@ix.netcom.com(William Stacy ) wrote:
…..
>Your description *was* pretty obtuse. Maybe that’s one reason I’m the
>only one who answered.
>It sure sounded ‘digital’ to me.
>Bill
Know anyone that can handle obtuse-angle glaucoma?
Ray