[Doriana] Are scrunds still a thing?

[Doriana]

I used to have a scrund about a certain medical device. My scrund was corrected thanks to something I learnt as part of my PhD, but my PhD topic has nothing to do with the medical device. What's the scrund and how did I get rid of it?

There hasn't been a scrund puzzle in a while, so newer members might not be familiar with them. "Scrund" is just LTPF lingo for a false belief, and scrund puzzles used to be quite popular back when I first joined the forum (ten years ago!).

[wunderland]

Is it a diagnostic device? A therapeutic device?
Is it normally used by a doctor? A nurse? A surgeon? A patient?
Is it an outdated or historical device? Or one still in use today?
Did your scrund relate to how it functions? How it is used? How effective it is?

[Doriana]

Is it a diagnostic device? This A therapeutic device?
Is it normally used by a doctor? A nurse? This, I think A surgeon? A patient?
Is it an outdated or historical device? No Or one still in use today? So, yes
Did your scrund relate to how it functions? This How it is used? How effective it is?

[TDGperson]

Is the diagnostic device used to diagnose a specific kind of disease? If so, is it life-threatening usually?

Was the device invented after 1900?

Is your PhD topic related to science? If so, astronomy? chemistry? biology? physics? psychology? sociology?

[GalFisk]

Does the device use: sound? Pressure? Electricity? Mechanical force? Air? Liquid? Needle(s)? Radiation? Heat? Cold? Does it contain medication? Other relevant substances? Is it handheld? Is it a measuring device? Is it used on humans? Animals? Objects? Does it have uses besides medical diagnostics? Relevant what caused the scrund? Was the scrund about how it worked? How it was used? What it could diagnose? How it was made? Its cost? Is it costly? Difficult to make?

[Doriana]

TDGperson
Is the diagnostic device used to diagnose a specific kind of disease? No If so, is it life-threatening usually? But it can indicate something life-threatening

Was the device invented after 1900? Yes

Is your PhD topic related to science? Yes If so, astronomy? chemistry? biology? physics? psychology? This sociology?

GalFisk
Does the device use: sound? Pressure? Electricity? This, and something else Mechanical force? Air? Liquid? Needle(s)? Radiation? Heat? Cold? Does it contain medication? Other relevant substances? No to these Is it handheld? Yope Is it a measuring device? Yes Is it used on humans? Yes Animals? A similar device is also used on animals Objects? No Does it have uses besides medical diagnostics? Irrel / I don't know Relevant what caused the scrund? No Was the scrund about how it worked? Yes How it was used? What it could diagnose? How it was made? Its cost? No to rest Is it costly? Difficult to make? No (but largely irrel) to both

[GalFisk]

Does it, in addition to electricity, use: light? Sound? Ultrasound? Optics? Laser? Radio waves? Microwaves? Some other physics phenomenon?

[Doriana]

Does it, in addition to electricity, use: light? This Sound? Ultrasound? Optics? Laser? Radio waves? Microwaves? Some other physics phenomenon?

[GalFisk]

Does it use something relevant besides electricity and light? Does it measure something? Illuminate something? Shine through something? Heat something? Does the light hit a person? A surface? An eye? Is the device used on any part of the body? On a specific part? On the head? Eyes? Ears? Nose? Mouth?

[Doriana]

Does it use something relevant besides electricity and light? No Does it measure something? Yes Illuminate something? No Shine through something? Yesish Heat something? No Does the light hit a person? Yes A surface? A surface on a person, yes An eye? Is the device used on any part of the body? On a specific part? This On the head? Eyes? Ears? Nose? Mouth? But none of these

[GalFisk]

Is it used on the skin? Nails? Mucous membranes? Inside? Does it measure light absorption? Pigmentation? Blood flow? Pulse? Blood oxygen? Is it a pulse oximeter?

[Doriana]

Is it used on the skin? Nails? Mucous membranes? Inside? Does it measure light absorption? Pigmentation? Blood flow? Pulse? Blood oxygen? Skipping these because... Is it a pulse oximeter? ...it's this!

[GalFisk]

Did you have a scrund about: the way it uses electricity? The way it uses light? What it measures? How it measures?

[Doriana]

Did you have a scrund about: the way it uses electricity? The way it uses light? This What it measures? How it measures? and this

[GalFisk]

Did you think it didn't use light at all? Used a different light source than it did? Different wavelength(s)? That the light took a different path? That it was detected in a different way?

[TDGperson]

Is the "blood is blue" misconception relevant? Did you think blood was a different color than it usually is?

[Doriana]

Did you think it didn't use light at all? Yope Used a different light source than it did? No Different wavelength(s)? No That the light took a different path? No, potential FA That it was detected in a different way? Same FA

Is the "blood is blue" misconception relevant? Did you think blood was a different color than it usually is? No to both

[Doriana]

RECAP / HINT: I had a scrund about pulse oximeters and the way they use light. The scrund related to what the light does in a pulse oximeter. No detailed knowledge of pulse oximeters is needed to solve this puzzle.

[raevenclaw]

did you use a pulse oximeter when obtaining your PhD? and in doing so correct the scrund? or was the scrund corrected in another way?

did you think the light measures one thing, like pulse, when it in fact measures both? or think it measures one thing when it measures the other?
not entirely sure how pulse oximeters work myself, so maybe i’ll have the same scrund corrected!

[AlbatrossLover]

Did you think the light wasn't used for the measurements? That it was simply used to signal that the device works? To indicate the results?

[Doriana]

raevenclaw
did you use a pulse oximeter when obtaining your PhD? and in doing so correct the scrund? No to these or was the scrund corrected in another way? Yes

did you think the light measures one thing, like pulse, when it in fact measures both? or think it measures one thing when it measures the other? No to both, see below
not entirely sure how pulse oximeters work myself, so maybe i’ll have the same scrund corrected! Just one of the many perks of being on the LTPF

AlbatrossLover
Did you think the light wasn't used for the measurements? Yes That it was simply used to signal that the device works? Yes To indicate the results? No

RECAP / partial §poyler: I used to think that the light on a pulse oximeter merely signals that the device works / is on. My PhD did not involve using a pulse oximeter at any point, so how was my scrund corrected?

[GalFisk]

Did your PhD involve light? Blood? Pulse? Oxygen? Blood oxygen? Hemoglobin? Chemistry? Optics? Electronics? Did it require you to learn about pulse oximeters? Or lead you to learn it?

[Doriana]

Did your PhD involve light? Blood? Pulse? Oxygen? Blood oxygen? This, relevantly Hemoglobin? Chemistry? Optics? Electronics?
Did it require you to learn about pulse oximeters? Or lead you to learn it? Neither, really

[biograd]

Since you said your PhD was in psychology, is fMRI relevant? Blood oxygen as a proxy for brain activity?

If so, did someone make an analogy between this and a pulse oximeter, such as "fMRI is like a pulse oximeter for the brain" in that it measures oxygenation non-invasively using waves (though not light in this case)?

[Doriana]

Since you said your PhD was in psychology, is fMRI relevant? No Blood oxygen as a proxy for brain activity? Yes

If so, did someone make an analogy between this and a pulse oximeter, such as "fMRI is like a pulse oximeter for the brain" in that it measures oxygenation non-invasively using waves (though not light in this case)? Not quite, but close enough for the

********SPOILER********

I used to think that the light on a pulse oximeter merely indicated that the device was on / working. In a methods course I took for my PhD, we learnt about fNIRS, a method that measures blood oxygenation in the brain as a proxy for brain activity, using near-infrared light. It then dawned on me that a pulse oximeter works in a similar way, measuring the absorption of near-infrared light.