How do MRI Headphones work? (2022)(tomlingham.com) |
How do MRI Headphones work? (2022)(tomlingham.com) |
I guess I'm old now because this style of headphone was present on every model of passenger aircraft in the sky when I was a young adult.
It worked perfectly! Until a stewardess caught me and made me stop.
Pretty surprising to hear there's air/sound tubes rigged on to every seat on a plane.
Seems like the sound tubes ended in the 70's: https://apex.aero/articles/sound-tube-surprising-history-air...
Either because they didn’t want you to take their headphones from the plane, or so they could charge for use because you couldn’t just plug in your Walkman headphones.
Or both.
Either on the headphones themselves or in the little overwrap bag there was a note to leave them on the aircraft when you deplane, because they (obviously) wouldn’t work elsewhere.
I was still encountering them in the early '90s, although by that time they had become uncommon.
I'm 40-ish, and I remember them as a child, so they were definitely still kicking around in the mid to late 80s, most likely on KLM and Pan Am, that were the airlines of my childhood.
https://avidproducts.com/2023/12/08/celebrating-70-years-of-...
apparently the speaker was in the armrest.
Not sure if that was the backup plane or they were just desperately holding out to upgrade the fleet.
Having said that anyone that flew just over 30 years ago would have likely used pneumatic headphones and watched on a shared pulled down theatre screen. It was the norm not that long ago.
Edit:
From this URL: https://avidproducts.com/2023/12/08/celebrating-70-years-of-...
This type of headphones are called pneumatic headphones.
Cost: one speaker and tubes was probably cheaper than 200.
Weight: old headphones were chunky, see above.
Comfort: not wearing giant chunky headphones you weren't accustomed to might have been preferable
Breakability: pneumatic headphones were harder to break, cheaper to replace
Stealability: passengers would have no reason to steal the headphones, and if they did it was cheap to replace.
All of these go away as proper headphones get increasingly small and cheap.
[0] https://www.mriequip.com/store/pc/MRI-Non-Magnetic-Magnalarm...
https://tomlingham.com/articles/an-unfortunate-hierarchy-of-...
I found a bunch of posters here, but I could not find the exact one that you mentioned:
https://www.ismrm.org/19/program_files/DP02.htm
Maybe lost now? Or a different page?
[1]: https://www.audeze.com/blogs/audeze-journal/press-release-fo...
Very vague explanation of how they work, and that link in the middle - I suspect that is the entire point of the press release.
> The CRBN headphones are integrated into the Lumica AV system from SMRTImage that provides images and movies
Maybe you can get more info out of them: https://www.smrtimage.com/
Loose or easily dislodged materials. My belt buckle was ok to keep on. Had to empty my pockets, take off my ring, metal piercings are disallowed.
You don’t want gobs of belongings piling up on your magnet, and you don’t want something large enough to pin the human between it and the magnet. The first scenario is quite expensive to rectify. The second is quite expensive, quite painful, probably fatal, and certainly traumatic.
The American College of Radiology say the below [1].
‘it is advisable to require that the patients or research subjects wear site-supplied MR Safe scrubs or gowns in place of their own clothing and undergarments in the region undergoing direct RF irradiation.’
Slightly odd - this appears to be about burns rather than projectile risk. Anecdotally, sites that don’t change patients have more accidents.
[1] https://www.acr.org/-/media/ACR/Files/Radiology-Safety/MR-Sa...
I'd guess the tube is longer in an MRI, though.
I bought a kind of unusual type of headphone from aliexpress a little while ago, that essentially consists of an induction loop you wear round your neck and tiny magnets you put in your ear, I'm somewhat scared to try them out as I don't especially want them to get stuck in my ear.
There is the odd burn - rare, and mostly preventable. Burns are the most common class or MRI injury.
I’m an MR tech.
They were awful.
Would they sound better if they used a liquid instead of air for the conduction?
I did wonder on my last flight if I could use SDR & android to listen in.
I wouldn't be surprised if the channel selector wheel was a simple mechanical acoustic coupler rotating to connect or cap upstream source tubes. I remember it as well flying in the late 80s or early 90s.
I see it is simple, but I wonder, would it be possible to use different sound medium ("conductor")? Some liquid, water perhaps? Would elasticity of the tube eat more signal than is lost in the air? Too heavy? Leaky? Questions…
Even Andrew Huberman, one of the most popular health science podcasters, has dabbled into anti-EMF quackery. On one podcast he claimed that his Bluetooth headphones produced notable "heat effects", implying that the electromagnetic energy was enough to produce palpable heat in his body.
It's obviously placebo effect to the extreme (physically impossible given the amount of RF energy) but nevertheless he made the claim. Millions of people listen to that podcast.
Of course, people are catching on that Andrew Huberman isn't really a good source of scientific information (nor really a good person, given recent revelations) but the damage is done.
a) he's obviously done a LOT of steroids or something, which aren't really great for you
b) At least half of what he says appears to be made up woo-woo nonsense
And iPhone also had this in their Product Information Guide:
"When using iPhone near your body for voice calls or for wireless data transmission over a cellular network, keep iPhone at least 15 mm (5/8 inch) away from the body, and only use carrying cases , belt clips, or holders that do not have metal parts and that maintain at least 15 mm (5/8″) separation between iPhone and the body."
1. https://www.sciencedirect.com/science/article/abs/pii/S02697...
It it was at the speed of light we might have a problem.
In contrast, consider the glut of products involving magic nonsense about hematite beads or whatever.
I find the exact opposite problem, I go with old faithful over new.
It's for this reason that when I put my clothes away I simply take the stack of clothes in my dresser out, put all the fresh stuff on the bottom, then put the clothes that were in the drawer stuff on top.
I always grab the top sweater, t-shirt socks etc and I don't think about it at all.
Your linked article confirms the semi-humorous statement just a day later.
There was a YouTuber (WhiteBoy7thSt if anyone is familiar) I watched over ten years ago now that came from very humble beginnings, and when he started to make real money, his first splurge (and one he stuck with) was new socks. When I say new socks, I mean new socks most days, maybe even a new pair for every day of the year. These were normal white socks, not any nice wool socks, so it was still fairly cheap, but when he grew up, they always had beaten, old socks.
it seems 99% of gift clothing has some sort of special care requirements.
I’ve seen most these things play out. And as you say, it’s exactly what the call bell is for.
Even non-ferromagnetic materials react to the high field strength, and to show that, they let me hold a ring of aluminum just outside the bore. You can feel it "snap" to either parallel or perpendicular to the table when you try to turn it. It was a surreal experience.
I looked it up afterwards and tungsten apparently as little to no magnetic effects, but depending on the amount of carbon used in it, it can.
Oversimplification: Moving a conductor in a magnetic field or vice versa indices current in the conductor , resistance in the conductor results in heat.
The main field in an MRI is static but there are a lot of other fields moving around…
Similar happens on your body also (eddy currents) and deeper tissue gets energy which has to be controlled for - it can cause stimulation in peripheral nerves and heating .
Whether or not it’s a conductor is probably more of a concern. The loop likely wouldn’t be large enough to cause any drama though.
https://www.sciencedirect.com/science/article/pii/S193004331...
https://www.washingtonpost.com/wellness/2023/07/26/mri-yoga-...
Best practice for at least a decade is to always remove all rings and all jewelry and failure to detect rings or other jewelry is generally seen to indicate a problem in screening. That is... if a radiologist sees evidence of a ring on the images there better be an explanation. The reality is that particularly older people have not removed their rings in decades and their joint disease may have expanded so much that it simply cannot be removed and the risk/benefit doesn't justify damaging the ring nor denying them the benefits of a scan. But if the patient can't take the ring off, the magnet wont either.
Just for reference, people get head scans with braces pretty regularly and it's not considered a safety issue. Braces and rings can affect image quality though so that's usually the concern. So if the ring is near the body part being imaged you'd probably be asked to remove it because they'll easily cause undesired issues (in, say, roughly a 3-6inch radius) that can result in images that radiologists deem unusable for making a diagnosis.
So after the claustrophobic panic subsided and I realized I was left in there with nothing but the loud machine and my own thoughts, I decided to listen to the machine as if it were music.
I found it supremely hypnotic and trance-inducing, almost meditative. I'm a big fan of deep and hypnotic techno, so the rhythmic MRI sounds were right up my alley. I'd probably have enjoyed it more with earplugs though.
I haven't looked to see if anyone has actually tried to make music with the sound or not.
That was a golden opportunity to experience ambient music in the most historically authentic way possible!
Listen to Brian Eno's story of what inspired his 1978 album, "Ambient 1: Music for Airports":
https://www.synthtopia.com/content/2016/01/05/brian-eno-tell...
Some of the pulse sequences are rhythmic and I find the entire thing somewhat meditative, but there are many other places I'd rather be.
Most (all?) vendors suggest this - they get well over 100db and the vendor headphones are pretty crappy.
Source: Radiologist (and personal experience in the bore)
I thought they would do it all the way through, but then I suddenly heard the pump start halfway through the procedure and a slightly cooler fluid running up inside my arms.
Also, I accidentally left my wedding ring on (I informed them, they were not interested in the slightest). My right felt hot during the scans. Not painful burning hot, but warmer than body temp for sure.
I'm pretty sure there were 2 speakers in each arm rest. I think it's more about them being harder to break and cheaper to replace. When I flew on an airline that used them, they came clean in a sealed bag. They may have been brand new, or at least cleaned and sterilised. Electronic headphones are unlikely to be as cleanable.
I think it's not allowed to actually operate a radio receiver on an airplane in the us: https://travel.stackexchange.com/questions/2322/can-i-listen...
Some airlines might still have the "listen to ATC" feature available, but in my experience, it's the pilots' decision whether that's available or not, and I've only ever been able to use it on a United flight once.
Sirius XM on JetBlue also has an "ATC channel", but I've only ever heard silence there, and I'm not sure if that's a similar thing (i.e. sourced locally), or just a random ATC feed from somewhere in the country relayed via satellite.
https://whyy.org/segments/the-mri-is-a-source-of-anxiety-and...
You can also make music with the scanner:
I get what you're saying, and I think that's plausible. But as far as I'm concerned, an acoustic coupler is/was a type of modem, into which you plugged an ordinary telephone handset. You had to have a telephone that had hemispherical mike and earphone; it didn't work with e.g. a trimphone. Expected performance: 9,600 bits-per-second.
lemme see if I can dig up a patent number for the channel switcher wheel and put this pondering to rest.
seems the inventing corporation is still around haha
https://avidproducts.com/2023/12/08/celebrating-70-years-of-...
It is an in-cabinet trash can with a mechanism to compress the trash when you push the button. I don’t know how common they really are. I’ve only know a few people with them. I could see where they might be more popular in apartments where you can’t easily take your trash to an outside trash can. They do require special, heavy-duty trash bags to handle the pressure.
That was 20+ years ago, before flat panel screens in every headrest that could tune into one of a couple dozen looping channels, and long, long before you could watch anything at any time from a huge library.
"long, long before you could watch [Season 2, Episodes 4 - 6 of Comedy Central Roast]."
[0]: https://en.wikipedia.org/wiki/In-flight_entertainment#Histor...
That takes nothing away from his work in my point of view.
I don't understand why we hold impossible standards of perfection and sainthood to successful people.
He may be deeply flawed, he may not be at all. I have no opinion on it and lack the necessary information to form one, even if i wanted to.
NY mag’s reputation is the one damaged here in my eyes.
If this is true it take a lot away from his work in my point of view.
https://openlibrary.org/books/OL26809698M
(Reynolds' got enough books in his bibliography I don't feel like I'm spoiling anything by mentioning his name - I suspect I could come up with any random plot point and he's probably written it in somewhere)
https://www.forbes.com/sites/suzannerowankelleher/2019/10/13...
I have to add these were all international flights (this was mostly pre-Schengen, and in any case I don't believe I've taken a flight between Schengen Area countries until 2023), so I'm not sure if shorter distance flights would have been different. The mid-distance flights (> 2.5 hours) I've taken would generally have in-flight entertainment if it wasn't a budget option. Some of the cheaper flights had no screens (or maybe they had ones, but didn't want to pay for the movie) and still had earphones slots connect to a set of inflight radio stations (that were also available when there was a movie being played, as an alternative).
So yes, it was an arguably "superior" experience with selectable audio, volume buttons and rather crappy drivers directly inside the earphones.
I’m sort of joking, but if you aren’t ever getting PNS, the machine is not being run very hard.
However the sensation you get in the region being scanned feels more like heating than PNS to me. You notice it more on high SAR sequences, suggesting that might be the cause. PNS just feels like twitching you can’t control, but ones milage may vary as this is anecdotal.
Source: MR radiographer.
I also have some small ACL reconstruction hardware in the knee which might interact and predispose that leg to moving…
I am well acquainted with high SAR abdominal scans in a 3T from my time doing scan certification in a petmr. Even though I “know” that tissue heating from high SAR is a thing, it always surprises me when my abdomen gets warm.
I’ve had a little bit of PNS, but nothing that strong.
The SAR sensation of being heated from the inside is an unusual one, I’m not sure I’ve had anything else do that?
Is this the article everyone is referring to?
https://nymag.com/intelligencer/article/andrew-huberman-podc...
Scanning through it, the allegations I spotted are:
* He is flaky and often doesn't keep appointments. * One guy says he invited him to go camping but didn't turn up * Apparently he may have slightly misled his ex about where he lived in private messages * His ex says that he has anger (purely verbal) issues * Some other people all say he has anger issues * Some incredibly spurious allegations that he had an affair
I probably missed some. But notably, almost nowhere is there any attempt to tell Huberman's side or have any empathy for him as a human being. Hence, it's a hit piece.
I see no indication that they approached him for comment, fitting your ‘hit piece’ comment, but does that matter? Is he off limits for some reason?
I do not see his reputation as damaged, I just acknowledge that he is not perfect, something I was sure about beforehand.
Can I know whether the information presented in the article is factual ? Of course not. Is it single sided or even intentionally harming ? Could definitely be.
1. Buy ~15 copies of everything.
2. Not think about what to wear! Everything is roughly the same.
3. Throw out everything every ~3 years. A couple of months before that, start buying new models of clothes to find the best one.
4. Goto 1.
This is so important. You'd think that manufacturers would just keep the same stuff for sale all the time for all time but it doesn't work that way. Lands End comes close for button shirts and wool trousers, but that formality level is wasteful for work from home.
Edit: At first the 15 copies seemed excessive since only 7 are needed for weekly laundry, but basically you can get 2x longevity out of the stock based on laundry wear.
> Edit: At first the 15 copies seemed excessive since only 7 are needed for weekly laundry, but basically you can get 2x longevity out of the stock based on laundry wear.
1 week of clothes does not provide enough safety buffer for forgetfulness and procrastination. Also, travelling.
Do you not procure multiple copies of items that have a high value assessment?
There are a bunch of more expensive unique items too. I do actually find it a bit interesting to see which ones float to the top and which ones don’t.
Funny you mention Marie Kondo though. I do roll my clothes instead of folding them before putting them away into the cubes. I don’t entirely get it but it seems more space efficient that way.
I've been doing this for decades, but have never encountered this problem. I think because of a combination of the fact that I didn't buy my entire wardrobe all at once to begin with and that different clothes wear at different rates.
How do you approach this? Would it make sense to buy one of those shelf springs that grocery stores use to keep boxes towards the from of the shelf?
Edit: Regarding total stock of clothes: this is a tricky balance between storage and wash cycle. Ideally I would do laundry nightly for day clothes and daily for pajamas so that no storage was necessary. With ~7 days storage already seems excessive since most days of the week there is more dirty than clean. It also only requires one load of laundry. With ~14 days that is twice the storage and while there are fewer batch operations there doesn’t seem to be a time savings since it would require two loads . . . Wait, do you scale in parallel by using a laundromat?
If you pay for a premium plan then no multi-tenanting and only you get to wear any particular pair of socks.
On the other hand, if there is a "complete casual work from home uniform" service, that might be worth it as long as some VCs are subsidizing it like its 2019.