Using the Propeller to improve you medical care and decrease the cost

rjo_

Howdy,

The demo board plus the assemblytoggle.spin is capable of measuring flicker fusion...
Flicker fusion changes in a variety of metabolic and ocular diseases... to use the Demo board to measure flicker fusion... you simply change the delay... start with a high value... around 1_500_000 and decrease it until you see the led as a constant light.·

That doesn't make the Propeller a medical device... but it does allow you to keep track of the condition of your own eyes.

In order for the numbers to make sense for general comparisons, we would need normals and there must be plenty on this forum...

But to take full advantage of the Propeller... you could periodically... at various times of day and month... find the range of flicker fusion· for your own eyes... (they should be the same)... then if you saw a change that seemed to be beyond your normal variations... you'd know something was going on.

I'm developing other public domain "home" monitoring tests... based on the propeller... and I would be interested in collecting individual statistics for this very simple flicker fusion test.

Rich

This application is perfect for personal use... a wide variety of conditions and·medications have an adverse effect on flicker fusion... and that fact would be useful to your doctor.

{{from AssemblyToggle.spin|}}
con
_clkmode = xtal1 +pll16x
_xinfreq = 5_000_000
Pub Main
{Launch cog to toggle pin 16 endlessly}
· cognew(@Toggle,0)
Dat
{toggle P16}
······· ORG 0
Toggle· mov dira, Pin
······· mov Time, cnt
······· add time, #9
·······
:loop·· waitcnt time, delay
······· xor outa,pin
······· 'sub delay, inc
······· jmp #:loop
Pin long |< 16
delay long 1_200_000
inc long 4_000
time··· res 1
inc2 long 9

Shane De Catania

Hi Rich,
I can't wait until I see my doctor next so I inform her that I am a self diagnosed autistic - She'll laugh! I won't when she tells me She already suspected so
The above sounds like an interesting idea in all seriousness though. There are a number of other interesting medical devices that could be made up with the demo board and a couple of external components... IR pulse and blood oxygen sensors for example...
Cheers,
Shane.

Leon

For this type of measurement it would be better to approach the threshold alternately from above and below, use several trials and average the results - the standard technique in psychophysics for determining perceptual thresholds.

Leon

rjo_

Leon,

Actually... there is an entire area of theory ... that will accomplish the task... in the minimum number of steps possible... right down to whatever accuracy is desired in the measurement.
In Chapter One of the E-Book... "Assembly language for Non-Programmers..." We start out with George Boole meeting Claude Shannon and Hans Selye.

Thanks for your input... the more you make me think... the better that book is going to be!!!!


Rich

rjo_

Shane,

I know that you were joking around in your first line... because you have a smiley face at the end of it[noparse]:)[/noparse]
But seriously, you would be classified as a diagnostic savant... not a diagnostic autistic...

I know because my son has an autism variant...

But back to your condition... which should probably be called polymorphoric savantism ... which is sometimes called genius... except in places of employment[noparse]:)[/noparse]

This public domain... home monitoring stuff is incredibly important. I'll be talking about it more as time goes along. Right now it is a little too early... and it a little off topic... so I don't want to glob up the forum with my personal interests... but I am very serious about it and I am moving along as fast as I can on that front.

Given the current structure of medical care... some move toward self monitoring is about the only way to make a quantum leap in the cost/quality ratio.

The idea isn't that a person would necessarily diagnosis himself... although I've met plenty of people who could if you gave them the right information[noparse]:)[/noparse]

The general idea is to monitor for change... then you could signal your docs that there is an important change...and the docs would know that you need to be looked at.

This particular example is perfect... because a change if flicker fusion could mean anything. Flicker fusion is sensitive to such a broad spectrum of conditions that a change doesn't have a specific meaning... it could mean anything... but it would always be medically significant.

The point of serious research would be to identify the threshold of change that is actually clinically significant... so that we wouldn't be creating a lot of anxious people going to their docs for nothing.

Serious work on flicker fusion goes back to the last century is already being looked at again for it's diagnostic potential... that doesn't interest me very much because most of the disease models are so screwed up that finding a cheap and easy way to filter through the diagnostic flow charts doesn't get you very far anyway.

Flicker fusion will be used ... and the one place for sure that it will be used is to monitor for adverse effects to powerful systemic medications.

Thanks for the humor... and the rest of your response.


Rich

potatohead

Hey, this is way off topic, but it could be done on the prop.

A while back, I had a very small blood vessel burst in my retina. This caused a tempoary loss of detail in one eye. I discovered it while looking at at white screen with too low of refresh. Another artifact was the halo that forms on a light in fog, was not uniform.

What happened was there was a color variation where the damage had occured. I did some investigation, and put patterns on the screen. A flickering bar graph, that is about two times absolute minimum that can be clearly resolved by the eye, revealed this variation quite clearly and consistantly, when viewed in a dim or really dark room. A normal eye would see a grey screen after a few cycles. An eye, with some variation in the retina, or perhaps other things too, would see this differently. The loss of detail, blends the pixels together, causing this portion of the visual image to stand out. A constant colored dot, or one that varies differently is ideal for tracking the center. We tend to move the eye toward detail, and in this case, that cannot be done. One must focus on one point, then internally focus ones attention to various parts of the visual field, in order to examine what might be happening.

Two alternating graphs, of different intensities and contrasting colors did the same thing. I also found that blue was the least effective at highlighting this percepual variance. Heh... turns out we only have a fraction of the blue cones that we do for the other two! No wonder blue is so annoying for detail! I never knew...

A trip to the eye doctor confirmed what I suspected that evening. The good news is that it cleared up, with both eyes running as they always have!

(the fix was as risky as just watching it to be sure it was healing. It was, by the time I had an exam. )

I never told the eye doctor what I saw, because I did not want to bias his examination. I had mapped out how an image hits the eye and located where I thought the trouble was. Doctor confirmed!

So, was this dumb luck, or would this be another potential self diagnosis tool for signs of macular damage / degeneration? I would worry about seisures with this method, but hey people play video games all the time right?

I strongly suspect this kind of thing happens to the average person and they have no idea. The variation I experienced does not manifest itself under normal viewing conditions, until you become aware of it.

Looking up at a clear sky, while rapidly blinking will reveal this to a degree as well.

Post Edited (potatohead) : 4/8/2007 5:00:49 PM GMT

rjo_

You've got the idea... Let me put it into "doctor speak"

There isn't enough info to know exactly what problem you had... but it was probably a posterior vitreous detachment(PVD). PVD's happen to everyone. A PVD usually doesn't cause bleeding but it can.

The docs want to see everyone that has a PVD... because under rare but real circumstances it can be associated with other sight threatening problems... Any time that it happens is a good time for a general eye exam... "because" sometimes a PVD happens at a moment when something else is changing inside of the eye. Usually not... but if so... that is when you want to find out.

A PVD will get you in the door and move you close to the front of the line[noparse]:)[/noparse]. A PVD is usually not much of a problem... but it can be. But as I said before... there won't be much that a person can do at home... this included... that will do anything but bring information to the attention of the person... and then his/her doc. The information itself won't be diagnostic.

But you do have to detect some kind of change before you can get to a diagnosis. Right now... detection alone is driving health care into the sewer.


Rich

potatohead

I'm on board with that. I suspect an increase in self-detection would also come with problems, but not so many problems as we have now, where detection is largely discouraged beyond the very elementary things we all know well.

Understood about the diagnostic. Knowing there is a problem is the key element. Actually, knowing more for some people may well be harmful! Self-treatment comes with significant bias = not good.

Anyway, I found it an interesting and informative experience, and thought I would share, that's all.

Getting back to your flicker test, does the size of the source matter? Lighting, etc...? A prop board LED has excellent characteristics for this kind of thing, but it's really tiny. Also, the center of ones vision is far less sensitive to this kind of thing than the perperial regions happen to be. My own, in the center lies somewhere between 60 and 65 Hz, in the center for high contrast sources. On the edges, it's more like 65 - 75hz before things blend. That's for a large source, such as a light or screen. a blinking LED is more difficult to discern, likely due to lack of resolution in the outer regions.

rjo_

Potatohead,

Size does matter... but we just need to know what we have. There is already work going on in places like Australia and Iowa to get data, which will allow for cross comparisons... so it will be possible to use other published data.

The key for the individual is to remember that what is most important is change. For example It takes a huge amount of effort to figure out what is normal for a 56 year old Swedish, male fisherman with diabetes.

But if he has Propeller on board... he can start out by measuring himself... figure out what is normal for him in his current condition... and then if THAT changes... he will know to point his ship at his doctors office... "What magnitude of change is significant." The published data will tell us that much for sure.

It takes forever to get research like this done in the usual way. And it usually costs the system megabucks for every bit of information generated.
Right now, I am trying to figure out the answer to your exact questions about the source... I have looked at the light coming out... projected it onto a screen about a meter away. There is no question it is bright enough and can be controlled well enough.

My mentor happened to have invented the automated visual field machine... and to make things very interesting... he called a young guy in, explained the whole thing to him... and that young guy went out... commercialized it and profited to the tune of about 30 million dollars. When my chief found out that the guy who stole from him was my wife's uncle... it was a very interesting moment.

The guy is now in jail... for something else.

What you are discussing in your last line... is an entire area of research that has gone on for about 50 years... there is a mountain of information about it.

Rich

potatohead

Yep.

I find that stuff very interesting. Our visual processing system is an amazing thing. Such bandwidth and ability to communicate detail. Lots of layers of processing going on, some starting right at the eye itself!

Well balanced machine actually. Where we have tradeoffs, they are good ones. The higher sensitivity to motion --flicker at the edges is just the thing for directing the slower, but higher detail and color region to the point of interest. On the whole, limiting the detail region allows for sophisticated image processing and mapping to occur in a layered approach that makes processing and acting on the information presented managable. It's almost like an index. Where ever the center of focus is, we are able to work with that at the highest level. The edges do, however map the entire scene to us, so we know right where to go when needing to change that focus. Buffers then hold the detail collected, transform it to account for motion, etc... thus delivering the perception of a full visual scene when the reality is actually far less at any one time.

This amount of processing is just HUGE, and it's as organic as the machine itself. IMHO, our visual systems self organize during early development, into this thing we take for granted. Ever look at something and not see it? On occasion, one will be presented with visual information that is not familiar. Like waking up on the wrong side of a room. We keep a whole lot more state information cached than we think, for this stuff to happen. Abstractions too. At that moment, you get a glimpse at raw data. It's similar to seeing a word and not reading it, or understanding what is a character and what is not, etc... You will blink once or twice, dart your eyes around and feel confusion, all the while the brain works hard on it's processing, then *snap*, it all maps in to place and things progress as normal.

Interesting stuff. Look forward to seeing more on this!

Post Edited (potatohead) : 4/8/2007 6:44:19 PM GMT

rjo_

AND... just the idea of being able to explore all of that... with a $12 chip... is a hoot[noparse]:)[/noparse]

rjo_

AND... if we all do it together... you guys get to go to your eye doctor... and make money off of your visit!!![noparse]:)[/noparse]

potatohead

I'm up for that!

In this regard, I'm stoked on the Prop. Fun chip. My available time is growing on a steady basis too. One of the best aspects of this thing is that learning just one new element opens up a lot of potential.

You mentioned projection. Did you do this, with just the demoboard LED? Thinking of something easily constructed, that makes use of a bright LED maybe? If so, papercraft models would suffice! Could sell a small kit for a few bucks and call it good.

rjo_

potatohead

Yep... just the demo board. And by playing with just one line in the "AssemblyToggle" example.
Right out of the box... the Propeller is capable of improving medical care and lowering costs.

Rich

rjo_

The only thing left to do is

1. make it easier and more reliable for a person to measure his Propeller flicker fusion frequence... There are two ways to do that. One example will be in Chapter 1... the other in Chapter 2.

2. provide general guidelines about how not to interpret the results.

3. make your eye doctor love you

4. develop a marketing strategy that won't fail... that is, figure out how a reader of the forum turns the
demo board into health care dollars... that they can put in their pockets.

Later...

Rich

rjo_

I missed the meeting... so I missed Al Gore's speech... so, I don't know exactly what he said.

But this sort of thing is what he was probably talking about.

Rich