@@NineEyeRon Ain't got time for that. Sideways or toe method is quick and usually available. Sometimes the toe is not available, but that's why the EMT is there.
Good solution as well as clipping the sensor to an earlobe. However, in 30 years as an anesthesiologist I can't remember a single case of nail polish causing an oximeter failure. Cold fingers or hypotension - yes, nail polish - no.
As an academic in this exact technology, with a PhD and journal publications in pulse oximetry and it's fundamental technology of photoplethysmography, I personally applaud this video. It is to the point, and with all the jargon free facts about how it works and brief history that anyone curious needs. I do teach about this technology (as a biomedical engineering academic and researcher) and I think this presentation is by far one of the best I have ever seen by a self professed non-professional in the subject. As a spring-board to further teaching in this area I may be using this in my future lectures. Thank you! As a side note, I would like to add that I have had personal contact and albeit brief correspondence with the inventor, Dr. Aoyagi. And sadly report that he sadly passed away earlier this year in April. To Dr. Aoyagi, thank you for what you have given the world. A truly remarkable piece of technology!
How is the perfusion index derived from a pulse ox ? -70s / 80s rock music superstar, astrophysicist- international superstar auto review TV presenter, journalist, notorious Casanova with the ladies, AND a medical doctor specializing in biomedical engineering! Is there anything you CAN'T do? (I always mix up James and Brian May) ;)
Couldn't agree more. When I heard his disclaimers I was waiting for the let down, thinking he may not be able to really dive into the most significant caveats such as CO poisoning and the need for specialized devices. Was so impressed to hear all of the high points nailed. The entire video is elegant from a teaching perspective.
I love how supposed subject matter experts with lots of pieces of paper declaring their worth use a completely random source of information to teach their students. Academics are such a scam.
My pulse oximeter saved my life. I'm a pilot, which is the primary reason I owned one. But a few months ago, and about 4 months after I had an Achilles tendon surgery, I was feeling woozy when I stood up from working on something on the ground, and it didn't resolve like "orthostatic hypotension" (BP drop from standing). When I got home, amongst other things like checking my BP, I put on the pulse oximeter. When it showed 84%, I knew something was very wrong. Turned out I had a bilateral pulmonary embolism, probably from the surgery. Walked into the ER and they went nuts when they saw my CT scan...people don't walk in with that size clot, they arrive mostly (or totally) dead. I caught it before the last bit of blood was blocked from my lungs, and that was completely because I saw my SPO2 as way lower than it usually is for me. Yes, the devices are cheap...and boy am I glad I had one.
This sort of thing is why the Blood Oxygen app needs to be reinstated internationally on Apple Watches. Regardless of ownership, that sort of info can be the tipping point for an emergency situation
"If you know a thing or two about blood, You'll probably know that in general it should be inside your body and not outside of it" Don't you give me medical advice regarding where I position my blood Mr. Not a Doctor.
As a transfusion scientist, I'm glad that not all blood is inside people and I would encourage more people to get their blood out from inside, in a controlled setting of course.
Good lord man I am in love with this production quality. You could make a 50 minute video on the history of power strip design, and as long as you put the time and effort you put into these I'd be there for the full 50.
Anesthesiologist (MD) here; great video, also wanted to input that the Pulse Ox is probably 80% responsible for bringing surgical anesthesia from one of the riskiest medical specialties in the 1970's to arguably the safest (by a few metrics), today. In other words, the POx has more than any other technology, resulted in fewer deadly and injurious complications from surgery since it's widespread acceptance in the 1980's. It's also brought our malpractice insurance premiums down to amongst the lowest in all of medicine :). Thanks again for the vid
@@kichapps Not a doctor, but I imagine using a pulse oximeter would allow you to check whether or not you should stop giving them anesthesia, instead of being based on guessing.
Because prior to its development, the oxygen saturation of the blood of anaesthetised patients couldn’t be measured or monitored in real time. It’s critical to know this in order to titrate the correct amount of anaesthetic agents, the amount of oxygen to give, and to know whether the patients CO 2 levels are in order . Interestingly the basic technology was first developed as long ago as the 1930’s
As an EMT, I appreciate and like this video. I especially like the idea that you reinforced, which is often stated as "Treat the patient, not the numbers." The note about the false reading in a case of CO poisoning is especially good as an example of that. Well done, and well prepared. I would echo your advice to get trained and get the knowledge you need to know what you're doing.
So anyone living or working in a potentially high CO area, enclosed usually, should be using a standalone High CO Warning Device. I’m not an expert, but say, using combustion device heaters, is a most common need. RVs typically use propane heaters so they have CO Monitoring.
@@BoneBurglar The Learning never Ends, so wonder: May i recommend anyone some nice science-channel and education-channel one may not yet know? Yes, a very random question, sure, but why not? I think Science-Fans should more often recommend each other more stuff, so an Echo-Chamber is never created.
I remember back in the late 80's the inventor of the first portable version of this device used our fire department rescue squad in western NY to test the utility of the device for emergency care. The unit was the size of a briefcase. Now it fits entirely inside the finger sensor.
Measure o2 before you smoke your cigarette if you are a smoker then at the end of your cigarette you willl see a difference it will help you stop smoking
"Quite useful"! Dude you are slightly underselling the impact of these things! I'm a doctor, and pulse oximetry has been massive. We are probably talking millions of lives saved. It has really changed patient care and is a major part of the reason surgery is a lot safer than it was 40 years ago. This little device isn't quite at "penicillin" level of big, but it is pretty darn close.
@Phil Olivetti ...and I'm a lawyer and I advise the OP to sew you in court 'cause of defamation & slander & stuff! (I get not more than a weeny 60%!! (Only this month!!))
anon video If you already have a catheter in the artery, maybe. But we usually use a BP cuff in the OR to keep things simple. ABGs are technically difficult, painful, and if you mess up, there’s only one more artery supplying that hand. No thanks. Pulse Ox every time. Also an MD (oncologist) and wanted to say this is without a doubt the best explanation of the pulse is I’ve ever heard. Do venous mappers next! I’m sure they work similarly and they’re fun to play with.
@@anonvideo738 No, and for two reasons. First a pulse-ox gives you beat by beat values of SpO2 where a full blood gas analysis takes time to obtain the blood and more time for the lab to process it. Second, with a blood gas, you have to obtain arterial blood which means sticking a needle or sometimes an cannula (think an I.V. but in an artery). While the complications of this are low they are certainly not as low as shining a light through a finger.
Hahaha I had no idea this was a thing. Thanks for letting me know to turn on CC for the credits, now I have to go back and rewatch the other episodes :)
This is easily one of the best channels on UA-cam. Edit: Also, we should be more grateful to the Phoenicians. They gave us so many wonderful things and we hardly mention them in History class.
The fact that our writing system that we use right now is literally a heavily modified version of Phoenician alphabet already should tell that they were hella important. But despite this, in my history class at school they were barely mentioned, as well as the fact that the roots of our writing system lies in the Phoenician alphabet
As a biomedical engineer and a long term fan, I applaud your simple but great explanation. I think, I'll link my students to this video. Also, looking forward to an fMRI machine explanation :-D
Medical Assistant here. I use one of these nearly everyday when preparing patients for their visit with the healthcare provider. Thank you so much for this video as I can now more clearly explain how the device works for the occasional curious patient.
I saw the title of the video and happily reported out loud to no one, 'I think they're super cool, too! I like this guy!' It makes me smile to know there are others of us who feel this way. Thanks for bringing us together with videos!
A lot of the COPD/respiratory patients I've worked with are absolutely OBSESSED with their O2 saturation. Like, they check it every 30 seconds. EXCELLENT disclaimer that it's an extremely useful tool but not for everyone. Thank you, Alec for your thoroughness!
Ah, the PulseOxy, one of my favorite tools as an ER nurse. Thanks for the explanation how it works, I knew already that its an optical method, but the exact method was news to me. Oh, and the info that CO also makes nice red Hemoglobin is way more advanced knowledge than your humble disclaimers indicate. How many in my field simply don't know that, to predictably bad outcomes. BTW one of the (many) reasons you shouldn't smoke before operations; it makes this method of monitoring unreliable...
fascinating. someone i know has a smartwatch with spo2 and they insist the readings prove their smoking isn't affecting their oxygen intake ... now i have a new piece of knowledge lol, it can't actually tell CO from O2
@@kaitlyn__L It can't tell it apart AND CO hangs on MUCH longer on the Hb, so the reading will be higher. That's a common way to find out if someone has an sub-acute CO poisoning in persons without hobbies like deep-diving or mountaineering: Usually they will show a constant 100% SpO2 without breathing heavy or fast and without obvious problems in consciousness. This should always ring the alarm bell in experienced ER personnel resulting in a Blood-Gas Analysis to measure the severity.
@@kaitlyn__L Someone's not doing his/her homework. Any smoker knows of the substantial increase in CO and its high affinity for Hb. I just hope Apple doesn't get sued because of this particular misunderstanding, e.g. someone's CO alarm is not working properly, they think their respiration is working fine because of how they interpret an oximeter reading, and then perish from CO poisoning. Hint - why not call the reading bound Hb % instead of oxygenated Hb %, at least for the cheap ones that can't tell CO from O2?
@@coopergates9680 bound Hb% would unfourtunatly also be misleading, as there is also MetHb, HHb and simply CO2Hb, all of them stuff bounded to Hb. But you are right, the term oxygenated Hb is more highly misleading, gives false confidence and should be avoided when you use the optical measurement.
7:37 Thank you so much for this video. I work for OSHA and have developed a mathematical model for predicting exposure to carbon monoxide based and data from devices like this and/or blood lab results but I never knew how they worked. Thanks again.
That sound's interesting! Is this mathematical model applicable to a sequence of SpO2 readings for a single person? To have that estimated from data we already have would be a nice addition to those of use who like to track our health with smartwatches and other wearables!
Actually, @@crispy9175, he creates mathematical models based off *data* from the device, which in no way requires he understand the function of the device, simply mathematics and data modelling. I'm sure there are *plenty* of medical professionals who can perfectly operate machinery of which they do not fully understand the internal mechanics, yet I don't see you calling for the mass re-consideration of the medical field's standards. In fact, I imagine you likely drive a car, but don't understand how it works in its entirety. Should we revoke your license until you can prove 100% knowledge of a car's functions? It's almost like you didn't actually read what Phillip wrote, and instead knee-jerk reacted to the mere acronym "OSHA" because your conservative overlords have convinced you if the government does it, then it must be bad. Maybe take some reading comprehension classes and try again. ^.^
Some manufacturers of pulse oximeters use different parameters like measuring 3 signals at once or using the entire color spectrum, aside from red and white.
I'm a phonetician and I was SO stoked by your t-shirt and that you were talking about the way we interpret speech. Then I reread it and realized no one ever thanks the phonetician.
I'm a hospice nurse and I use that exact pulse oximeter everyday. One thing that doesn't get brought up often is that they can read 1-2% higher on darker skin tones because they were calibrated on light skinned people and melanin will absorb some amount of light, tricking the sensor into believing there's more hemoglobin. This is rarely an issue that would affect a clinical decision, but it is one way that technology can be designed to accidentally overlook people who are non-white.
That's a really interesting thing I'd never considered! Does that mean there are fancier ones that look at skin color and take that into account, or something like that?
@@KevinCrouch0 Unfortunately no, but there are some universities working on it. The problem is that these would require more sensors and more light which could cause them to be very expensive. Even if one is created and is economical, knowing the medical industry it will be 15-20 years before they're widely adopted lol
Ah, nothing says we’re still living in a world with glaring blindspots in medicine like neglecting to study any people other than white men. Classic humanity. Making wonderful things, but never questioning our biases.
I took a class this semester where we designed a very rudimentary pulse oximeter using some fancy analog circuitry, and for the final write up we had to talk about some ethical considerations, and I actually chose to write about this. There are some decently disturbing studies about this--I believe there was some evidence that this discrepancy was enough to disqualify some people with darker skin tone from receiving the care they needed during the pandemic, and thus they incurred higher causalities.
It was because of a pulse oximeter that we knew to send my Aunt to the hospital while she had COVID. Her's was at 75% one night and a nurse told us it may come up and to keep an eye on her. The next day it was 47. We took her straight to the ER and she was put on a ventilator.
What kind of nurse was that? I seriously hope you remembering wrong. If you read 74% on the pulse oximeter your next course of action should be dialling 991. When mine was 84% the doc immediately called EMS and rushed me to the hospital.
For my entire childhood, (every year from birth until my late teens), I was admitted to hospital at least once a year after an asthma attack. I had to wear a Pulse Oximeter the whole time and became fascinated by it's red glow. They were often the arbiter on whether I was allowed to go home even after I felt fine and my breathing was normal: so many times I remember being told "It hasn't been above 95 for long enough today, so you have to stay another night"... I have an oddly bittersweet love of them to this day. Thanks for the video.
your friendly neighborhood Respiratory Therapist could come in every 4 hours and draw an ABG instead. ( That said, depending on a lot of other factors, I'd have sent you packing with 95%!)
This man knows humor. He is not hillarious but he does not try to be. Yet he knows how to slip in thr perfect joke and more importanly knows how much time to spend on it. Also none of his jokes are edgy, or memes. Which is surprisingly refreshing.
I’m an electrical engineer. I still find this channel on everyday sort of items (if everyday can mean decades ago) very interesting. Keep up the good work!
As a mountain First responder (Ski patron and mountain guide), these devices sometimes don't like the cold. This is generaly solved by putting the victims glove back on (a bit) over the device, or putting hand inside jacket. A warmer device (and warmer hand) give a more accurate reading. And as you say they are an excellent device.
I am pleased and not at all surprised to find that Technology Connections, with his low-key excellent comedic delivery, also has hilarious closed captions. Too bad I usually just listen to videos and don't watch much, if at all, but that just means there's replay value!
You know, the blooper reel at the end makes the videos that much better. You really get to see all the effort you put in, and they're usually good for a few laughs. Keep it up, I love all the unique, obscure, and random topics I get to learn about!
congratulations for your channel, the detail of the content, editing and strong effort you put into each chapter, makes this channel a must for retro and electronic enthusiast
Software dev here, greatly appreciate the video and the qualifiers about pulse ox's not being perfect sensor solutions. I've been working on an experimental medical monitor trying to get decent HR, SpO2, respiration, etc outputs. This video was helpful in breaking down how the majority of sensor's I've handled work, while I'm trying to replicate their outputs. At one point I had a pulse ox with bluetooth that I could communicate with to compare signal quality, but those are hard to come by and harder to write software around, from what I've gathered. The one in my Nintendo Switch's Joycon IR sensor tends to reads my heartrate maybe ~10-20 bpm higher than the medical device pulse ox, so I've been anxiously pondering the degree to which other monitors handle unexpected/noisy Red + IR input.
“When demand hasn’t peaked”... you ain’t lyin’! I bought this exact same Oxymeter on Amazon last year for about $12. It now sells for more than three times as much - thanks to this pandemic thing that’s going around I guess.
People pay way too much for electronic trinkets (ie. smartphones, ipads, etc) compared to medical equipment. It's a thankless job designing medical equipment. I wish I could put a credit card reader on all the medical devices I've designed, especially with covid! I've been working for charity and been trying to find "greener pastures". But like actors in Hollywood, one gets typecast and I cannot get out of this socialized field. I am back with my decades of expertise in oximetry working in a startup, dozens of patents where I don't get a dime of royalty, yet making a mediocre salary for this expertise. All the while Google, Facebook, etc employees rake in the bucks for pushing money around. So with Covid needs, ventilators, respiratory, and ICU equipment, don't expect them because the scientists and engineers have gone into the much more profitable realm of Google, Facebook, and other tech. Thank Obama for destroying many medical devices and promoting the profiteering likes of silicon valley and pharma. I truly wish I didn't go into the field and help save billions of lives (yes billions) as I am now struggling to pay mortgage & bills.
@@rchn1315 Did you just claim to be a specialist in the field of oximetry that can't get a job in a different field, blamed Obama for it, and then said you saved billions (with a B) of lives? Bruh, you're one "kiddo" away from being a copypasta
@@rchn1315 Who are you? What is your name - if you have "decades of expertise in oximetry", I may remember you. I began working on pulse oximetry technology - both design development and manufacturing - back in 1983. Although this video explains some of the underlying technology, it is not quite accurate in its description of the function of the two LEDs. But, at least it attempts to provide some pretty useful information on its application. Before our oximeter, blood would have to be drawn for analysis. There was a critical need for "real-time" blood gas monitoring - especially in the OR. We were the first to provide this capability. If you are interested in making a better paycheck, get out of product development engineering, and work in sales/marketing - that's where the money is. Throughout most of my career, I have rarely ever been "recognized" or compensated for my contributions - now, in retirement, at least I can look back and feel a strong sense of professional accomplishment - even if only known to myself and my wife. I never made a lot of money, but certainly enough to pay the rent. There are other personal satisfactions to be earned through a successful career besides the money.
I am a copd patient, and since I've gotten one of these it has been a godsend. It helps keep me aware when I'm exerting myself, and can help me catch respiratory illness or an asthma flare before they become acute, which decreases the potential for hospitalization.
I am a techy (at least I thought so before watching your channel) and I am totally enjoying watching you refreshing my thinking cap. Keep going!! You're doing great!! And the bloopers at the end of each video are so funny it makes all these videos down to our level. I really appreciate you making the point that it takes a lot, LOTS, of goof-offs before you get awesomeness. Cheers!!
I broke my hip three weeks ago - I've had scores of different versions of these hanging off my various digits since then. So, this video is nicely timed.
@@randombloke82 Excuse my ignoramce but isn't that somewhat true? Dont we have some sort of mechanisms that translate these external inputs into chemical reactions that derive to the information our brains get? And can't those be refered to as "sensors" or "receptors"?
Thank you so much for such a concise and coherent explanation of pulse oximeters. I've always wondered how they work. It's amazing to think that this everyday piece of technology applies the same leap of logic that allowed humans to figure out what the stars are made of.
I’m a recently retired respiratory therapist, and I remember when pulse oximeters came out and they were HUGE! (About the size of the first VCRs 1’ high, 2’ wide, 2’ deep). Now look at them! I believe that they could be made smaller, but they’re easy enough to lose the way they are. Additionally, I think that they were first developed for the Air Force as they’re planes were flying higher and higher and they were having difficulties with pilots passing out from low oxygen levels.
I really love this channel. If all of UA-cam were to fall apart and I could pick only one, you bet it would be technology connections. It's the stuff I live for. Just getting to know how everyday tech we take for granted has had a lot of ingenuity put behind it tickles some sweet spot in my brain.
Oh, so that's how they work. As I'm doing a Chemistry PhD in organometallic chemistry, I know all about the theory but I hadn't realised that's how it does it. Cool.
I had the same reaction, except it was "I did a home sleep study and had to put my finger into one of those, and didn't understand what it could possibly be doing with just a little red light" i mean aside from gently cutting off my circulation. I bet it was reading pretty poor oxygenation by morning.
I love hiking in Colorado so I definitely want one. Going from sea level in Louisiana to 14k feet (Mt. Elbert for instance) takes one HELL of a toll on your breathing and oxygen levels 🥴
Finally a very clear lesson about this device. Never knew how it worked. As a former Air Force and commercial pilot, this would be helpful in determining hypoxia.
I've been working in the healthcare field for a couple of years now, and I've always been a little curious as to how pulse oximeters actually work. Also, yes it's very true that nail polish can interrupt the reading, it's a pretty common trick at my workplace that if someone has nail polish, you actually put the oxmiter on sideways on the finger so the polish doesn't change the reading.
"Now I am not a healthcare professional of any sort and have no qualifications to be giving medical advice whatsoever." Shame more people can't seem to grasp this basic concept, especially given the current circumstances.
I was about to point out the same thing. At no point when I saw this video in my feed I thought, "Oh I can't wait till he tells me how to medically use this device!" Instead my thought process was,"Oh! New TC! It's something about a light doohikie! Can't wait to see how it works from an engineering prospective." I mean if you think you might need one medically... you might want to go see your local doctor, not your local Tech Y0utuber heh.
@white ehhh gonna have to hard disagree. the difference to use your analogy is in someone who spent 8 years studying and working on your exact model car. And then you expecting to be better than them at fixing it
Aw. I was *_so_* looking forward to watching you hold your breath, to demonstrate the coolness of the device, that I watched all the way to the very end. Something I rarely do. And then you went right ahead and... *_...DIDN'T DO IT !_* >
I have a cheap pulseox. Have had it for well over a year now (cheap one from Lidl, but still having a fun oled screen with choice of display modes). How come I've never tried this, until just now?!
@@MattFowlerBTR AND?!?! I wouldn't think it'd register much, actually. It's not the oxygen level that gets you, rather it's the buildup of CO2 in your bloodstream that triggers the urge to breathe. Unless you've trained yourself to hold your breath for extended periods, which I'd think, logically, is training yourself to suppress the urge to breathe because of to CO2 elevation, as simultaneously your blood oxygen level also will obviously fall.
@@mlindholm yep, healthy adults deoxygenate fairly slowly (relative to your urge to breathe). On top of that, most healthy adults oxygen saturation sits a decent amount above the level where you feel effects to start with (aka become hypoxic)
I just tried it with my Samsung phone that has an Oximeter built in. Breathing like normal I had a score of 99% (did the test 5 times just to make sure, and it was always within 98-99%), but breathing poorly and then holding my breath for half a minute it took the score down to 87%
I was wondering how my Fitbit knows my heart rate (accurately enough to match what's measured at my doctor office, give or take a couple bpm). I figured it had to do with the weird flashing light on the bottom but other than that, it just seemed to be magic. I'm guessing it's a variant on this tech! Thank you!
It's very similar to these but instead of measuring the light passing through, it measures the light reflected back. I believe that's part of why they're not quite as accurate
This is awesome but I have 1 tiny pedantic point. The pulse oximeter is NOT "telling you the heart rate". As you say, we want the saturation of the blood that is in the artery i.e the pulsing part, but other things can pulse (e.g. veins if you have some forms of heart disease, tissues for various reasons etc) and we need to make sure that the pulse ox is looking in the correct place. The reason it displays the heart rate is so that you can manually check the pulse and make sure it correlates with the pulse ox i.e. make sure that it seems to be looking at the right place to tell you the saturation. So it's not TELLING you the heart rate, it is actually ASKING if what it thinks is the heart rate actually IS. (Though of course, if you have checked it a few times and it is always correct then you can go on to use the displayed heart rate instead of taking the pulse.)
Keep in mind this remark of Newton’s is a barbed insult aimed at Robert Hooke, a competing physicist of short stature, thus not a Giant. inversesquare.wordpress.com/2008/03/07/friday-isaac-newton-blogging-on-the-shoulders-of-giants-or-revenge-is-a-dish-best-eaten-cold-edition/
About ten years ago, I observed to my mother that while we don't have the flying cars we were promised, I had just spent two hours' pay to buy a device that measured the oxygen in my blood by shining a laser through my fingernail. And it runs on a AAA battery. "How Buck Rogers is that?"
wow, simply wow, i've been years taking care of my mother and use one of this pulse oximeters pretty much a lot through the day and night (she usually has normal readings below 85%spO2 and sometime lower than 65%, so i apply medical oxigen to her to even the oxigen levels as she has pulmonary fibrosis acompanied by other medical illnesses) i always knew what this devices do, but now i know how it does the readings, so thanks a lot this helped me comprehend more about it.
My son was born with a heart defect and pulse oximeters are now part of our daily life. I've since wondered how on earth a light tells us such important information. Thank you for such a brilliant and to the point video!
TC: "Look at this graph!" Me (a Physician Assistant): Oh no, not the oxyhemoglobin dissociation curve! (It wasn't thank goodness) Also: Fun fact! Carbon monoxide has approximately 50x the affinity for hemoglobin as does oxygen. That's why relatively small amounts of it is so lethal, because it will continuously build up with minimal ability for your body to dispose of it through respiration. Also see the oxyhemoglobin/carboxyhemoglobin dissociation curves. *shudder*
ummmmmm it's the other way around: hemoglobin has a greater affinity for CO. And are you scared of the OD Curve? it's ok. Fortunately there are Respiratory Therapists at your back.
I was so amazed when i learned how they work several years ago that since then i wanted to habe one for me, but they were very expensive and soecialized. Now that they become mainstrean (basic but mainstream) i got one for me and i really consider that they should be in a lot of homes with special needs (like elder people, asthma patients etc). The more information the healthcare professionals at the other end of the call have about the patients, the better.
In this case, I'd agree. But there _is_ such a thing as too much information-check out MedLife Crisis's video titled "Why Don't We Test for Everything".
One week ago I was planning on buying a pulse oxymeter. It comes as an option with my 3 month OTC health insurance kit. Now, you upload a video about pulse oxymeters. Your timing is impeccable, sir.
The Learning never Ends, so wonder: May i recommend anyone some nice science-channel and education-channel one may not yet know? Yes, a very random question, sure, but why not?
Anaesthesiologist here. Excellent video and factually almost perfect, unlike some textbooks, so kudos!! The one error is the reference to carboxy-Hb and how its absorption 'appears' the same to the pulse oximeter as oxy-Hb. Of course this isn't true as the only thing that matters is the *ratio* of absorption at the two wavelengths - carboxy-Hb absorbs slightly less than oxy-Hb at the red wavelength and virtually nothing at the infrared wavelength - hence the ratio is actually more like deoxy-Hb (which has a higher red:infrared absorption ratio). The pulse oximeter has no idea how much of what is there, simply the absorption ratio at two wavelengths of the pulsatile component. So, despite being rosy red with CO poisoning, a PULSE oximeter (functional saturation - ie. the assumption is that all blood is either oxy- or deoxy-Hb) will read *lower* than normal if there is carboxy-Hb present, but a co-oximeter will read even lower still (fractional saturation - it measures all types of Hb variants) and only then will you see the true impact of the carboxy-Hb. It's the human eye that 'sees' carboxy-Hb like oxy-Hb - the pulse oximeter doesn't! So while the text books say it 'reads higher', this is only true in relation to the fractional saturation,, but in actual fact your *functional saturation* may well be 100% (ie. all the non-carboxy-Hb is in oxy-Hb) but it will read *lower*. Hypothetical 1 ie. 50% carboxy-Hb blood and 50% oxy-Hb - Functional saturation (pulse oximeter), might read 90-95% when the TRUE functional saturation (ie. that percentage of normal Hb available) is technically 100% - Fractional saturation (ie. what REALLY matters) is 50% (co-oximeter in a lab) Hypothetical 2 ie. 50% carboxy-Hb blood and 45% oxy-Hb and 5% deoxy-Hb - Functional saturation (pulse oximeter), might read 80-85% when the TRUE functional saturation (ie. that percentage of normal Hb available) is technically 90% - Fractional saturation is 45% (co-oximeter in a lab) This is why it's often stated that a pulse oximeter 'over-reads' in carbon monoxide poisoning... but only with respect to true, fractional saturations. Most textbooks get this wrong! Interestingly, when the absorption of red & infrared is the same (ie. the ration is 1:1) the pulse oximeter will read 85%. It's one reason why this is a number that often appears when the signal is weak, particularly on cheaper devices. As for nail polish - almost never an issue and on those rare occasions where it is (very black acrylic nails), simply turn the sats probe sideways and shine though the fingertip that way - easy! And why at those two perfect wavelengths? It was pure luck as those were the available red & infrared LED frequencies and it just so happens that the absorption at those two wavelengths is not just wide, but opposite, as you so correctly pointed out. That's the critical thing that makes this all work!
It’s kinda nerdy but also kinda respectable that you take the time to make it clear people shouldn’t take what you say as medical advise, epilepsy warnings, etc.
Modern medicine and the tech it uses are the biggest achievements in the history of humanity, and my respect for the people working in all areas of both is immeasurable.
Excellent job! I really appreciate explaining the weakness in a two-wavelength oximeter. There are many others but that is a big one depending on the circumstances.
i really appreciate the blooper real. it shows that even well spoken and intelligent people trip up on words and sentences. coming from a person that gets ignored because my brain go brrrr but my mouth doesn't, makes me stammer. you helped my self esteem a little today and I thank you for that. also thank you for teaching me something new.
I was just wondering the other day why the finger oximeters could measure blood oxygen but phone cameras can't... I swear you read my mind sometimes! Thanks lol
Phone cameras have an IR filter. Well MOST EVERY digital camera has an IR filter. There's a One Plus one that deliberately doesn't, and it's somewhat notoriously in the news for it right now.
Posted to it's own comment, but responding to your question I saw afterwards. If you have a Samsung phone, many of them have had this ability built in, with sensors next to the camera flash. The Samsung Health app has a function to measure Heart Rate, and used to have an obvious option for Blood Oxygen. That's been moved/renamed to the Stress function, which records both, and optionally asks you to indicate your felt stress level. The hardware exists in the Samsung Galaxy S5 / S5 Neo / S6 / S7 / S8 / S9 / S10 and Edge versions as well as Galaxy Note 4 / 5 / 7 / FE / 8, but isn't in the cheaper S10E, and was no longer included as of the Note 10 and Galaxy S20 models.
@@mlindholm Cool, I didn't know about that! I suppose it really is just down to what technology the manufacturers want to put in, and it's certainly possible to have, just not standard.
@@mlindholm It works a bit differently too, which I find interesting, because many smart watches and phones obviously cannot wrap around your finger. So instead of reading the light as it passes through your finger, it's looking at the reflection of light from inside your finger. You can find some 3rd party apps that give extremely detailed information on just how the sensors are being used to determine the oxygen saturation, plus some other interesting metrics, such as arterial stiffness, something I had never considered as a measurable thing before. Edit: I did some research earlier too, and I found a lot of people said that Samsung's sensor gave pretty much identical readings to one of those dedicated sensors that clip onto your finger.
Great video, as always. As someone who's had a heart and lungs transplant i've tons of experience with this. But i've also had arterial blood taken from my wrist and the pain was incredible! And ached for a good half hour later. Something to be avoided if you can :-)
My wife and I LOVE you. So common sense. Thanks for what you do, taking time to give some clarity to us Not so able to comprehend the issue. Great Job.
These devices have saved my, my parents, and may people's asses many times. One of the biggest under rated tools on the market. PS: Dad had failing lungs, and my mother has a failing heart. Both where easily picked up by it.
Very interesting and well-made video! I am not super familiar with the technical side but have used these extensively as a nurse, so I can confirm related info from that POV. Little titbit about ABGs (Arterial Blood Gas): the analysis actually doesn't need a lab, there are specialised machines which can analyse a blood sample within minutes (maybe you can do a video about those? I have no idea how they work, but would be interested to know some basics :) but you'd probably need to find a suitable medical professional to help with a video on those, maybe get in touch with medlife crisis). Especially on ICUs ABGs are taken quite often and doing the analysis through a lab would be too timeconsuming. Also: when you are on ICU it is not uncommon for you to have invasive blood pressure monitoring via a catheter in an artery (somewhat akin to what is put in your vein, when you get some intravenous fluids or meds), from those the ABGs can be drawn without you being perforated again and again ;)
One of these saved my life. I have two now and always check my self. 8 hours home from surgery a PT came to my house. Checking me my O2 was only 64. I was rushed to the hospital where I only thought I was tired. I had a horrible case of pneumonia. I remained in the hospital for 14 days, almost died.. blah blah blah. Keep one all the time now.
You state that you're not a medical professional- yet you know the proper location of blood. Such a humble chap.
XD
for a second i thought he was going to explain the circulatory system and how capillaries work or something, but what i got was far more insightful
So wise in the ways of science
Hahah
Honestly he could make a video that's 100% BS and we'd believe him.
8:05: I was an EMT. If someone is wearing fingernail polish you have to perform a secret medical procedure called "turning the clip sideways".
Y no carry acetone?
@@NineEyeRon Ain't got time for that. Sideways or toe method is quick and usually available. Sometimes the toe is not available, but that's why the EMT is there.
Good solution as well as clipping the sensor to an earlobe. However, in 30 years as an anesthesiologist I can't remember a single case of nail polish causing an oximeter failure. Cold fingers or hypotension - yes, nail polish - no.
You can also use what my hospital calls a sticker. I’ll stick it right to you.
That sounds so painful.
I'm never getting sick ever again.
As an academic in this exact technology, with a PhD and journal publications in pulse oximetry and it's fundamental technology of photoplethysmography, I personally applaud this video. It is to the point, and with all the jargon free facts about how it works and brief history that anyone curious needs. I do teach about this technology (as a biomedical engineering academic and researcher) and I think this presentation is by far one of the best I have ever seen by a self professed non-professional in the subject. As a spring-board to further teaching in this area I may be using this in my future lectures. Thank you!
As a side note, I would like to add that I have had personal contact and albeit brief correspondence with the inventor, Dr. Aoyagi. And sadly report that he sadly passed away earlier this year in April. To Dr. Aoyagi, thank you for what you have given the world. A truly remarkable piece of technology!
How is the perfusion index derived from a pulse ox ?
-70s / 80s rock music superstar, astrophysicist- international superstar auto review TV presenter, journalist, notorious Casanova with the ladies, AND a medical doctor specializing in biomedical engineering! Is there anything you CAN'T do?
(I always mix up James and Brian May) ;)
Brian May is the rock guitarist/astrophisicist
James May is the TV show presenter.
Couldn't agree more. When I heard his disclaimers I was waiting for the let down, thinking he may not be able to really dive into the most significant caveats such as CO poisoning and the need for specialized devices. Was so impressed to hear all of the high points nailed. The entire video is elegant from a teaching perspective.
I love how supposed subject matter experts with lots of pieces of paper declaring their worth use a completely random source of information to teach their students. Academics are such a scam.
Jon G sounds like you’re bitter
I love how this channel feels like something you’d watch as a kid on PBS
Maybe he is on PBS(idk what PBS is exactly, sounds like a public broadcast channel like here in Germany with ZDF and ARD)
@@Tobi_DarkKnight yup. It literally means Public Broadcasting Service. I remember it having lots of educational content
His fashion (Which I love) is a contributing factor, but yes he has a PBS tone overall .
@@Car_D_Board Also the name of the channel, to be honest
1000%
My pulse oximeter saved my life. I'm a pilot, which is the primary reason I owned one. But a few months ago, and about 4 months after I had an Achilles tendon surgery, I was feeling woozy when I stood up from working on something on the ground, and it didn't resolve like "orthostatic hypotension" (BP drop from standing). When I got home, amongst other things like checking my BP, I put on the pulse oximeter. When it showed 84%, I knew something was very wrong. Turned out I had a bilateral pulmonary embolism, probably from the surgery. Walked into the ER and they went nuts when they saw my CT scan...people don't walk in with that size clot, they arrive mostly (or totally) dead. I caught it before the last bit of blood was blocked from my lungs, and that was completely because I saw my SPO2 as way lower than it usually is for me.
Yes, the devices are cheap...and boy am I glad I had one.
You are very,very lucky.And strong too.
Thats an amazing story. How are you holding up now?
Really hard to overstate just how lucky you are. Many PE cases are dead within half an hour.
This sort of thing is why the Blood Oxygen app needs to be reinstated internationally on Apple Watches. Regardless of ownership, that sort of info can be the tipping point for an emergency situation
The problem is that those apps were never actually approved for official medical use and are not very reliable. @@houserhouse
"If you know a thing or two about blood, You'll probably know that in general it should be inside your body and not outside of it"
Don't you give me medical advice regarding where I position my blood Mr. Not a Doctor.
Yeah, no one can tell me whether I can take a blood bath or not!
Dr. Goor
I am reminded of a rooster teeth animated adventure about blood outside the body
Alec is also not a bricklayer, nor an escalator, nor a coal miner, nor a Vulcan...
As a transfusion scientist, I'm glad that not all blood is inside people and I would encourage more people to get their blood out from inside, in a controlled setting of course.
Good lord man I am in love with this production quality.
You could make a 50 minute video on the history of power strip design, and as long as you put the time and effort you put into these I'd be there for the full 50.
We need more toaster videos!
I would watch the bejeezus out of a video about power strip design! Just sayin’.
Did you tune in to the CED series?
Check out his laserdisc series.
@@tjbautista01 Yes, that series was brillant.
And Greggory, I wouldn't be surprised if there is one on power stripe design in his back catalog. :-D
Anesthesiologist (MD) here; great video, also wanted to input that the Pulse Ox is probably 80% responsible for bringing surgical anesthesia from one of the riskiest medical specialties in the 1970's to arguably the safest (by a few metrics), today. In other words, the POx has more than any other technology, resulted in fewer deadly and injurious complications from surgery since it's widespread acceptance in the 1980's. It's also brought our malpractice insurance premiums down to amongst the lowest in all of medicine :).
Thanks again for the vid
But how?
@@kichapps Not a doctor, but I imagine using a pulse oximeter would allow you to check whether or not you should stop giving them anesthesia, instead of being based on guessing.
@@nerd_nato564 ah, I see. I didn't know that giving anesthesia required them to know the blood oxygen saturation
@@kichapps Idk, I'm just guessing that too much anesthesia might make your blood oxygen drop, I'm very likely wrong.
Because prior to its development, the oxygen saturation of the blood of anaesthetised patients couldn’t be measured or monitored in real time. It’s critical to know this in order to titrate the correct amount of anaesthetic agents, the amount of oxygen to give, and to know whether the patients CO 2 levels are in order . Interestingly the basic technology was first developed as long ago as the 1930’s
As an EMT, I appreciate and like this video. I especially like the idea that you reinforced, which is often stated as "Treat the patient, not the numbers." The note about the false reading in a case of CO poisoning is especially good as an example of that. Well done, and well prepared. I would echo your advice to get trained and get the knowledge you need to know what you're doing.
Good word
So anyone living or working in a potentially high CO area, enclosed usually, should be using a standalone High CO Warning Device.
I’m not an expert, but say, using combustion device heaters, is a most common need. RVs typically use propane heaters so they have CO Monitoring.
@@BoneBurglar The Learning never Ends,
so wonder:
May i recommend anyone some nice science-channel
and education-channel one may not yet know?
Yes, a very random question, sure, but why not?
I think Science-Fans should more often recommend each other more stuff,
so an Echo-Chamber is never created.
@@stephenpowstinger733 yes
Yessir EMT here too. Treat the patient
I remember back in the late 80's the inventor of the first portable version of this device used our fire department rescue squad in western NY to test the utility of the device for emergency care. The unit was the size of a briefcase. Now it fits entirely inside the finger sensor.
Measure o2 before you smoke your cigarette if you are a smoker then at the end of your cigarette you willl see a difference it will help you stop smoking
"Quite useful"! Dude you are slightly underselling the impact of these things! I'm a doctor, and pulse oximetry has been massive. We are probably talking millions of lives saved. It has really changed patient care and is a major part of the reason surgery is a lot safer than it was 40 years ago. This little device isn't quite at "penicillin" level of big, but it is pretty darn close.
Wouldnt using arterial blood monitoring be pretty easy if you have someone in an operation room anyway?
@Phil Olivetti ...and I'm a lawyer and I advise the OP to sew you in court 'cause of defamation & slander & stuff!
(I get not more than a weeny 60%!! (Only this month!!))
anon video If you already have a catheter in the artery, maybe. But we usually use a BP cuff in the OR to keep things simple.
ABGs are technically difficult, painful, and if you mess up, there’s only one more artery supplying that hand. No thanks. Pulse Ox every time.
Also an MD (oncologist) and wanted to say this is without a doubt the best explanation of the pulse is I’ve ever heard. Do venous mappers next! I’m sure they work similarly and they’re fun to play with.
Pulse Oximeters are probably going to be medical useful for longer that penicillin ever was.
@@anonvideo738 No, and for two reasons. First a pulse-ox gives you beat by beat values of SpO2 where a full blood gas analysis takes time to obtain the blood and more time for the lab to process it. Second, with a blood gas, you have to obtain arterial blood which means sticking a needle or sometimes an cannula (think an I.V. but in an artery). While the complications of this are low they are certainly not as low as shining a light through a finger.
“Heart thing” seems an imprecise term... I recommend the term “thumping squish”. Also see “thinking squish” for describing the mind organ.
@Page Fault self-regulating chemo-electric moderated positive displacement pump
And the thumping squish pumps life juice to all of your existence goo.
squishy thinking machine
666Tomato666 self regulating chemo-electric moderated positive displacement haematic transport device
And "squishy squish" for the fun times organs
I'm always glad to see Closed Captioning Alex enjoying himself in the credits.
boopy doopy
@@dgpsf every time. it's worth it
Hahaha I had no idea this was a thing. Thanks for letting me know to turn on CC for the credits, now I have to go back and rewatch the other episodes :)
bah DAAAAAAAAAH
Don't write that word
This is easily one of the best channels on UA-cam.
Edit: Also, we should be more grateful to the Phoenicians. They gave us so many wonderful things and we hardly mention them in History class.
The fact that our writing system that we use right now is literally a heavily modified version of Phoenician alphabet already should tell that they were hella important. But despite this, in my history class at school they were barely mentioned, as well as the fact that the roots of our writing system lies in the Phoenician alphabet
4:54 "Look at this Graph" - Nickelback, 2015
ua-cam.com/video/sIlNIVXpIns/v-deo.html
Takes some damn skill to fit an awkward pause into a six-second video, lemme tell ya.
I'm so happy I'm not the only one who immediately thought about that. The only question is: Was it intentionally?
Lmaoo
First thing that came to mind when he said it. Glad I'm not the only one
As a biomedical engineer and a long term fan, I applaud your simple but great explanation. I think, I'll link my students to this video.
Also, looking forward to an fMRI machine explanation :-D
The MRI is quiet simply powered by black magic. Any professional in the field worth their salt ougth to know this.
Medical Assistant here. I use one of these nearly everyday when preparing patients for their visit with the healthcare provider. Thank you so much for this video as I can now more clearly explain how the device works for the occasional curious patient.
Just send em over to this video
If you sold this show on VHS I would buy it. So interesting
I'm more of a LaserDisc guy myself
Making VHS is very time consuming. Especially today when VHS is deprecated.
@@james.lambert i would prefer a CED version
Betamax would be better
Mr. Plinket?
I saw the title of the video and happily reported out loud to no one, 'I think they're super cool, too! I like this guy!' It makes me smile to know there are others of us who feel this way. Thanks for bringing us together with videos!
A lot of the COPD/respiratory patients I've worked with are absolutely OBSESSED with their O2 saturation. Like, they check it every 30 seconds. EXCELLENT disclaimer that it's an extremely useful tool but not for everyone. Thank you, Alec for your thoroughness!
Ah, the PulseOxy, one of my favorite tools as an ER nurse. Thanks for the explanation how it works, I knew already that its an optical method, but the exact method was news to me.
Oh, and the info that CO also makes nice red Hemoglobin is way more advanced knowledge than your humble disclaimers indicate. How many in my field simply don't know that, to predictably bad outcomes. BTW one of the (many) reasons you shouldn't smoke before operations; it makes this method of monitoring unreliable...
Those of us old enough to remember the movie Coma, know that CO poisoning keeps blood nice and red looking.
fascinating. someone i know has a smartwatch with spo2 and they insist the readings prove their smoking isn't affecting their oxygen intake ... now i have a new piece of knowledge lol, it can't actually tell CO from O2
@@kaitlyn__L It can't tell it apart AND CO hangs on MUCH longer on the Hb, so the reading will be higher. That's a common way to find out if someone has an sub-acute CO poisoning in persons without hobbies like deep-diving or mountaineering: Usually they will show a constant 100% SpO2 without breathing heavy or fast and without obvious problems in consciousness. This should always ring the alarm bell in experienced ER personnel resulting in a Blood-Gas Analysis to measure the severity.
@@kaitlyn__L Someone's not doing his/her homework. Any smoker knows of the substantial increase in CO and its high affinity for Hb.
I just hope Apple doesn't get sued because of this particular misunderstanding, e.g. someone's CO alarm is not working properly, they think their respiration is working fine because of how they interpret an oximeter reading, and then perish from CO poisoning.
Hint - why not call the reading bound Hb % instead of oxygenated Hb %, at least for the cheap ones that can't tell CO from O2?
@@coopergates9680 bound Hb% would unfourtunatly also be misleading, as there is also MetHb, HHb and simply CO2Hb, all of them stuff bounded to Hb. But you are right, the term oxygenated Hb is more highly misleading, gives false confidence and should be avoided when you use the optical measurement.
7:37 Thank you so much for this video. I work for OSHA and have developed a mathematical model for predicting exposure to carbon monoxide based and data from devices like this and/or blood lab results but I never knew how they worked. Thanks again.
That sound's interesting! Is this mathematical model applicable to a sequence of SpO2 readings for a single person? To have that estimated from data we already have would be a nice addition to those of use who like to track our health with smartwatches and other wearables!
bless you, OSHA worker phillip. truly one of the best parts of the government
Lol. This guy writes regulations on things for OSHA that he doesn't know about.... this is a problem.
Actually, @@crispy9175, he creates mathematical models based off *data* from the device, which in no way requires he understand the function of the device, simply mathematics and data modelling. I'm sure there are *plenty* of medical professionals who can perfectly operate machinery of which they do not fully understand the internal mechanics, yet I don't see you calling for the mass re-consideration of the medical field's standards. In fact, I imagine you likely drive a car, but don't understand how it works in its entirety. Should we revoke your license until you can prove 100% knowledge of a car's functions? It's almost like you didn't actually read what Phillip wrote, and instead knee-jerk reacted to the mere acronym "OSHA" because your conservative overlords have convinced you if the government does it, then it must be bad. Maybe take some reading comprehension classes and try again. ^.^
Some manufacturers of pulse oximeters use different parameters like measuring 3 signals at once or using the entire color spectrum, aside from red and white.
I'm a phonetician and I was SO stoked by your t-shirt and that you were talking about the way we interpret speech. Then I reread it and realized no one ever thanks the phonetician.
I'm a hospice nurse and I use that exact pulse oximeter everyday. One thing that doesn't get brought up often is that they can read 1-2% higher on darker skin tones because they were calibrated on light skinned people and melanin will absorb some amount of light, tricking the sensor into believing there's more hemoglobin. This is rarely an issue that would affect a clinical decision, but it is one way that technology can be designed to accidentally overlook people who are non-white.
That's a really interesting thing I'd never considered! Does that mean there are fancier ones that look at skin color and take that into account, or something like that?
@@KevinCrouch0 Unfortunately no, but there are some universities working on it. The problem is that these would require more sensors and more light which could cause them to be very expensive. Even if one is created and is economical, knowing the medical industry it will be 15-20 years before they're widely adopted lol
Could is just be as simple as training on deployment - -3% for dark skin? The human element is the most important tool@@RogueAstro85
Ah, nothing says we’re still living in a world with glaring blindspots in medicine like neglecting to study any people other than white men. Classic humanity. Making wonderful things, but never questioning our biases.
I took a class this semester where we designed a very rudimentary pulse oximeter using some fancy analog circuitry, and for the final write up we had to talk about some ethical considerations, and I actually chose to write about this. There are some decently disturbing studies about this--I believe there was some evidence that this discrepancy was enough to disqualify some people with darker skin tone from receiving the care they needed during the pandemic, and thus they incurred higher causalities.
It was because of a pulse oximeter that we knew to send my Aunt to the hospital while she had COVID. Her's was at 75% one night and a nurse told us it may come up and to keep an eye on her. The next day it was 47. We took her straight to the ER and she was put on a ventilator.
Then what happened?
Scary. I hope she's ok.
She should have been sent to the hospital at 75 percent. Damn I hope she recovered
Yea she should have gone when it read 75... I get worried when my patients are reading at 90.
What kind of nurse was that? I seriously hope you remembering wrong. If you read 74% on the pulse oximeter your next course of action should be dialling 991. When mine was 84% the doc immediately called EMS and rushed me to the hospital.
"You can shine light through your fingers."
Glad to hear childhood me wasn't the only one who made that observation.
i do it almost once a week just for fun, and i'm 31
my tool of choice was laser pointers
Who didn't stand in front of a mirror with a flashlight in his mouth, shiny end inwards. :-D
I used to do the finger thing at 3:44 and pretend to be E.T.!
@@misophoniq tonight i will
For my entire childhood, (every year from birth until my late teens), I was admitted to hospital at least once a year after an asthma attack. I had to wear a Pulse Oximeter the whole time and became fascinated by it's red glow. They were often the arbiter on whether I was allowed to go home even after I felt fine and my breathing was normal: so many times I remember being told "It hasn't been above 95 for long enough today, so you have to stay another night"... I have an oddly bittersweet love of them to this day. Thanks for the video.
your friendly neighborhood Respiratory Therapist could come in every 4 hours and draw an ABG instead. ( That said, depending on a lot of other factors, I'd have sent you packing with 95%!)
“He was upset with himself” 😂🤣💀 always love the outtakes
And check that part with subtitles, it's even better.
hi there hi there hi there hi there hi there hi there hi there hi there hi there hi there hi there hi there
@@RobCamp-rmc_0 I was having flashbacks from "The Critic" BUY MY BOOK BUY MY BOOK BUY MY BOOK
This man knows humor. He is not hillarious but he does not try to be. Yet he knows how to slip in thr perfect joke and more importanly knows how much time to spend on it.
Also none of his jokes are edgy, or memes. Which is surprisingly refreshing.
I’m an electrical engineer. I still find this channel on everyday sort of items (if everyday can mean decades ago) very interesting. Keep up the good work!
As a mountain First responder (Ski patron and mountain guide), these devices sometimes don't like the cold. This is generaly solved by putting the victims glove back on (a bit) over the device, or putting hand inside jacket. A warmer device (and warmer hand) give a more accurate reading. And as you say they are an excellent device.
"oxygenatedly smooth jazz"
i love the CC
me too, it makes me that is not a native english speaker understand better the video, this is more helpfull than it seems...
I agree, the Closed Captioning is the best I've seen on UA-cam ever.
Also boopydoopy :)
actually it is not jazz
Not only are the captions helpful, but there are some real hidden gems in some videos closed caption haha
I am pleased and not at all surprised to find that Technology Connections, with his low-key excellent comedic delivery, also has hilarious closed captions. Too bad I usually just listen to videos and don't watch much, if at all, but that just means there's replay value!
“All my bleeding was internal. That's where the blood's supposed to be!”
I always keep a couple of litres in a bucket, in the fridge, next to the heads.
@@davelordy Bloody Mary, much?
@@philipcooper8297 I didn't catch her first name.
Jake Peralta
One of my favourite quotes from that show.
"Various unpleasantness" is such a useful phrase nowadays.
I read that with a lisp
4:54 "look at this graph" *gets blinded*
You know, the blooper reel at the end makes the videos that much better. You really get to see all the effort you put in, and they're usually good for a few laughs. Keep it up, I love all the unique, obscure, and random topics I get to learn about!
10:20 Damn I was sure this was going to turn into a skillshare ad.
Me too. After a dramatic pause there is always a Skillshare or Foursquare ad.
I’m glad he doesn’t do those kinda sponsors
Or Brilliant, when he mentioned applied knowledge!
Probably was then he lost the sponsorship
@@jacksong6226 yeah no why? Im with Sid
I'm somewhere in the middle of nowhere with a limited data cap, but when I see a Tech Connections video, I click.
F
Just use wi-fi then, if you have a data cap
Make sure to screen record that
@@dkt6408 I can't tell if you're joking, or if you read that wrong
Say hi to Courage for me.
11:26 When the cd starts skipping
So annoying!
I was thinking a vinyl record personally, but that could be showing my age 😆
The picture skips as well, so it was most likely a CED
I think Max Headroom has more panache. ;)
congratulations for your channel, the detail of the content, editing and strong effort you put into each chapter, makes this channel a must for retro and electronic enthusiast
Software dev here, greatly appreciate the video and the qualifiers about pulse ox's not being perfect sensor solutions. I've been working on an experimental medical monitor trying to get decent HR, SpO2, respiration, etc outputs. This video was helpful in breaking down how the majority of sensor's I've handled work, while I'm trying to replicate their outputs. At one point I had a pulse ox with bluetooth that I could communicate with to compare signal quality, but those are hard to come by and harder to write software around, from what I've gathered. The one in my Nintendo Switch's Joycon IR sensor tends to reads my heartrate maybe ~10-20 bpm higher than the medical device pulse ox, so I've been anxiously pondering the degree to which other monitors handle unexpected/noisy Red + IR input.
*sensors
Stop apostrophe abuse today. They’re almost never correct to put into plurals.
“When demand hasn’t peaked”... you ain’t lyin’! I bought this exact same Oxymeter on Amazon last year for about $12. It now sells for more than three times as much - thanks to this pandemic thing that’s going around I guess.
People pay way too much for electronic trinkets (ie. smartphones, ipads, etc) compared to medical equipment. It's a thankless job designing medical equipment. I wish I could put a credit card reader on all the medical devices I've designed, especially with covid! I've been working for charity and been trying to find "greener pastures". But like actors in Hollywood, one gets typecast and I cannot get out of this socialized field. I am back with my decades of expertise in oximetry working in a startup, dozens of patents where I don't get a dime of royalty, yet making a mediocre salary for this expertise. All the while Google, Facebook, etc employees rake in the bucks for pushing money around. So with Covid needs, ventilators, respiratory, and ICU equipment, don't expect them because the scientists and engineers have gone into the much more profitable realm of Google, Facebook, and other tech. Thank Obama for destroying many medical devices and promoting the profiteering likes of silicon valley and pharma. I truly wish I didn't go into the field and help save billions of lives (yes billions) as I am now struggling to pay mortgage & bills.
@@rchn1315 Did you just claim to be a specialist in the field of oximetry that can't get a job in a different field, blamed Obama for it, and then said you saved billions (with a B) of lives?
Bruh, you're one "kiddo" away from being a copypasta
@@rchn1315 Who are you? What is your name - if you have "decades of expertise in oximetry", I may remember you. I began working on pulse oximetry technology - both design development and manufacturing - back in 1983. Although this video explains some of the underlying technology, it is not quite accurate in its description of the function of the two LEDs. But, at least it attempts to provide some pretty useful information on its application. Before our oximeter, blood would have to be drawn for analysis. There was a critical need for "real-time" blood gas monitoring - especially in the OR. We were the first to provide this capability. If you are interested in making a better paycheck, get out of product development engineering, and work in sales/marketing - that's where the money is. Throughout most of my career, I have rarely ever been "recognized" or compensated for my contributions - now, in retirement, at least I can look back and feel a strong sense of professional accomplishment - even if only known to myself and my wife. I never made a lot of money, but certainly enough to pay the rent. There are other personal satisfactions to be earned through a successful career besides the money.
@@wyleyg as a useless human being myself I thank you for your time and hard work to make life better.
@@rchn1315 cap
I am a copd patient, and since I've gotten one of these it has been a godsend. It helps keep me aware when I'm exerting myself, and can help me catch respiratory illness or an asthma flare before they become acute, which decreases the potential for hospitalization.
The “Star Trek: The Motion Picture” reference was beautiful
Yup, here for this. Set phasers to stunning.
“Sen-sores” -Spock
Not to be confused with a censor, scents or, censer.
make it so. engage. elementary.
🤔Fascinating!
I am a techy (at least I thought so before watching your channel) and I am totally enjoying watching you refreshing my thinking cap. Keep going!! You're doing great!! And the bloopers at the end of each video are so funny it makes all these videos down to our level. I really appreciate you making the point that it takes a lot, LOTS, of goof-offs before you get awesomeness. Cheers!!
3:47 Cracked me up really hard... BLOOD
Same lmaoooooo, the delivery is perfect. "It comes out red on the other side because... BLOOD"
@@thunder____ so unexpected 😂👌
I had to watch it a few times because I kept laughing out loud by myself!
I broke my hip three weeks ago - I've had scores of different versions of these hanging off my various digits since then. So, this video is nicely timed.
I especially hate the one with the sticky tape.
Tell me more of your... various digits.
That sucks! Hope your recovery goes smoothly!
Hope you heal quickly!
"Our body is filled with sensors!"
*cries in first year of med school*
TheMrFabian1 so, so many.
Dunno about you but phisiology is a second year subject here.
@@randombloke82 Excuse my ignoramce but isn't that somewhat true? Dont we have some sort of mechanisms that translate these external inputs into chemical reactions that derive to the information our brains get? And can't those be refered to as "sensors" or "receptors"?
@@Vits2001 The word you are thinking of is transducer.
@@Vits2001 Yes, but receptors are only a part of that operation.
This is the channel I never knew I needed but now I can't live without!
Welcome to the club!
Thank you so much for such a concise and coherent explanation of pulse oximeters. I've always wondered how they work. It's amazing to think that this everyday piece of technology applies the same leap of logic that allowed humans to figure out what the stars are made of.
I’m a recently retired respiratory therapist, and I remember when pulse oximeters came out and they were HUGE! (About the size of the first VCRs 1’ high, 2’ wide, 2’ deep). Now look at them! I believe that they could be made smaller, but they’re easy enough to lose the way they are. Additionally, I think that they were first developed for the Air Force as they’re planes were flying higher and higher and they were having difficulties with pilots passing out from low oxygen levels.
I like the "boopydoopy" and the "be bah da daaaahhh" etc. in the subtitles at the end!
Oxygenatedly smooth jazz
I really love this channel. If all of UA-cam were to fall apart and I could pick only one, you bet it would be technology connections. It's the stuff I live for. Just getting to know how everyday tech we take for granted has had a lot of ingenuity put behind it tickles some sweet spot in my brain.
Oh, so that's how they work. As I'm doing a Chemistry PhD in organometallic chemistry, I know all about the theory but I hadn't realised that's how it does it. Cool.
I had the same reaction, except it was "I did a home sleep study and had to put my finger into one of those, and didn't understand what it could possibly be doing with just a little red light"
i mean aside from gently cutting off my circulation. I bet it was reading pretty poor oxygenation by morning.
i've been binging your videos lately, they are just so good! i appreciate the genuine passion and love for technology
I love hiking in Colorado so I definitely want one. Going from sea level in Louisiana to 14k feet (Mt. Elbert for instance) takes one HELL of a toll on your breathing and oxygen levels 🥴
♫ "Last Christmas I gave you that heart-thing in my chest cavity." ♫
Literally in the movie
I just want to say, for all the retakes you have to do, I really appreciate how professional the end result comes across.
Finally a very clear lesson about this device. Never knew how it worked. As a former Air Force and commercial pilot, this would be helpful in determining hypoxia.
I've been working in the healthcare field for a couple of years now, and I've always been a little curious as to how pulse oximeters actually work. Also, yes it's very true that nail polish can interrupt the reading, it's a pretty common trick at my workplace that if someone has nail polish, you actually put the oxmiter on sideways on the finger so the polish doesn't change the reading.
"Now I am not a healthcare professional of any sort and have no qualifications to be giving medical advice whatsoever." Shame more people can't seem to grasp this basic concept, especially given the current circumstances.
I was about to point out the same thing. At no point when I saw this video in my feed I thought, "Oh I can't wait till he tells me how to medically use this device!" Instead my thought process was,"Oh! New TC! It's something about a light doohikie! Can't wait to see how it works from an engineering prospective."
I mean if you think you might need one medically... you might want to go see your local doctor, not your local Tech Y0utuber heh.
@white ehhh gonna have to hard disagree.
the difference to use your analogy is in someone who spent 8 years studying and working on your exact model car. And then you expecting to be better than them at fixing it
Your comment is unfortunately relevant.
@white either you're trolling, or you need to be restrained.
@white Dear god, I hope you just forgot a "".
Aw.
I was *_so_* looking forward to watching you hold your breath, to demonstrate the coolness of the device, that I watched all the way to the very end.
Something I rarely do.
And then you went right ahead and...
*_...DIDN'T DO IT !_*
>
I have a cheap pulseox. Have had it for well over a year now (cheap one from Lidl, but still having a fun oled screen with choice of display modes). How come I've never tried this, until just now?!
@@MattFowlerBTR AND?!?!
I wouldn't think it'd register much, actually. It's not the oxygen level that gets you, rather it's the buildup of CO2 in your bloodstream that triggers the urge to breathe. Unless you've trained yourself to hold your breath for extended periods, which I'd think, logically, is training yourself to suppress the urge to breathe because of to CO2 elevation, as simultaneously your blood oxygen level also will obviously fall.
@@mlindholm yep, healthy adults deoxygenate fairly slowly (relative to your urge to breathe). On top of that, most healthy adults oxygen saturation sits a decent amount above the level where you feel effects to start with (aka become hypoxic)
I just tried it with my Samsung phone that has an Oximeter built in. Breathing like normal I had a score of 99% (did the test 5 times just to make sure, and it was always within 98-99%), but breathing poorly and then holding my breath for half a minute it took the score down to 87%
mlindholm hint- when your kid’s pulse ox level drops to the low 80s, the ambulance driver drives faster. 🙁
Hey try to tone down the whole "one of the best channels on youtube" thing. You're making everything else on the internet look bad by comparison.
Yee, I agree
Yes, lets move him to sandford Gloucestershire.
I swear
Hey! Don't passively "quality shame"; we want to encourage this sort of thing.
TheCrazyCrewNL : But isn’t Sandford a chemical contamination hotspot and at risk of Severn floods?
I was wondering how my Fitbit knows my heart rate (accurately enough to match what's measured at my doctor office, give or take a couple bpm). I figured it had to do with the weird flashing light on the bottom but other than that, it just seemed to be magic. I'm guessing it's a variant on this tech! Thank you!
It's very similar to these but instead of measuring the light passing through, it measures the light reflected back. I believe that's part of why they're not quite as accurate
@@sheafromME explains why it's green
This is awesome but I have 1 tiny pedantic point. The pulse oximeter is NOT "telling you the heart rate". As you say, we want the saturation of the blood that is in the artery i.e the pulsing part, but other things can pulse (e.g. veins if you have some forms of heart disease, tissues for various reasons etc) and we need to make sure that the pulse ox is looking in the correct place. The reason it displays the heart rate is so that you can manually check the pulse and make sure it correlates with the pulse ox i.e. make sure that it seems to be looking at the right place to tell you the saturation. So it's not TELLING you the heart rate, it is actually ASKING if what it thinks is the heart rate actually IS. (Though of course, if you have checked it a few times and it is always correct then you can go on to use the displayed heart rate instead of taking the pulse.)
“If I have seen further it is by standing on the shoulders of Giants." - Sir Issac Newton
Keep in mind this remark of Newton’s is a barbed insult aimed at Robert Hooke, a competing physicist of short stature, thus not a Giant.
inversesquare.wordpress.com/2008/03/07/friday-isaac-newton-blogging-on-the-shoulders-of-giants-or-revenge-is-a-dish-best-eaten-cold-edition/
"Isaac," I bear his name and hardly none of y'all can spell it right.
@@IsYitzach "Ice Ache"
About ten years ago, I observed to my mother that while we don't have the flying cars we were promised, I had just spent two hours' pay to buy a device that measured the oxygen in my blood by shining a laser through my fingernail. And it runs on a AAA battery. "How Buck Rogers is that?"
It's... not really a laser.
@@Sakkura1 Shhhhhhhh
@@Sakkura1 If those kids could read, they would be very upset.
We do have flying cars... just not that many yet... anyway we now have electric cars.... that should count for something...
@@PR-fk5yb isn't it technically possible to make flying cars, but just that it'd be very inefficient and expensive or something
I was a child and I did shine a flashlight on my fingers... well played sir.
wow, simply wow, i've been years taking care of my mother and use one of this pulse oximeters pretty much a lot through the day and night (she usually has normal readings below 85%spO2 and sometime lower than 65%, so i apply medical oxigen to her to even the oxigen levels as she has
pulmonary fibrosis acompanied by other medical illnesses) i always knew what this devices do, but now i know how it does the readings, so thanks a lot this helped me comprehend more about it.
My son was born with a heart defect and pulse oximeters are now part of our daily life. I've since wondered how on earth a light tells us such important information. Thank you for such a brilliant and to the point video!
TC: "Look at this graph!"
Me (a Physician Assistant): Oh no, not the oxyhemoglobin dissociation curve! (It wasn't thank goodness)
Also: Fun fact! Carbon monoxide has approximately 50x the affinity for hemoglobin as does oxygen. That's why relatively small amounts of it is so lethal, because it will continuously build up with minimal ability for your body to dispose of it through respiration. Also see the oxyhemoglobin/carboxyhemoglobin dissociation curves. *shudder*
Isn't CO also very lethal because people don't notice the effects until it's too late?
mel816 also, it tends to make people sleepy. Sleepy people have a hard time getting out of the area.
I appreciate this comment because I too, know the feeling of just HAVING to say something technical.
@SHAHZEB MIR if it's irreversible... Until your red cells are reknewd
ummmmmm it's the other way around: hemoglobin has a greater affinity for CO. And are you scared of the OD Curve? it's ok. Fortunately there are Respiratory Therapists at your back.
I was so amazed when i learned how they work several years ago that since then i wanted to habe one for me, but they were very expensive and soecialized. Now that they become mainstrean (basic but mainstream) i got one for me and i really consider that they should be in a lot of homes with special needs (like elder people, asthma patients etc). The more information the healthcare professionals at the other end of the call have about the patients, the better.
In this case, I'd agree. But there _is_ such a thing as too much information-check out MedLife Crisis's video titled "Why Don't We Test for Everything".
Thanks Technology Connections, very cool!
One week ago I was planning on buying a pulse oxymeter. It comes as an option with my 3 month OTC health insurance kit. Now, you upload a video about pulse oxymeters. Your timing is impeccable, sir.
I am a healthcare career student and your explanations are well informed and very well explanied.
Here here for the Phoenicians!! Also, you never explicitly point out that it is a real time continuous reading, where as drawing blood would not be.
"Thanks to that heart thing in your chest cavity"
- Technology Connections 2020
The Learning never Ends,
so wonder:
May i recommend anyone some nice science-channel
and education-channel one may not yet know?
Yes, a very random question, sure, but why not?
"I wasn't hurt that badly. The doctor said all my bleeding was internal, that's where the blood's supposed to be!"
funny show
Anaesthesiologist here. Excellent video and factually almost perfect, unlike some textbooks, so kudos!! The one error is the reference to carboxy-Hb and how its absorption 'appears' the same to the pulse oximeter as oxy-Hb. Of course this isn't true as the only thing that matters is the *ratio* of absorption at the two wavelengths - carboxy-Hb absorbs slightly less than oxy-Hb at the red wavelength and virtually nothing at the infrared wavelength - hence the ratio is actually more like deoxy-Hb (which has a higher red:infrared absorption ratio). The pulse oximeter has no idea how much of what is there, simply the absorption ratio at two wavelengths of the pulsatile component.
So, despite being rosy red with CO poisoning, a PULSE oximeter (functional saturation - ie. the assumption is that all blood is either oxy- or deoxy-Hb) will read *lower* than normal if there is carboxy-Hb present, but a co-oximeter will read even lower still (fractional saturation - it measures all types of Hb variants) and only then will you see the true impact of the carboxy-Hb. It's the human eye that 'sees' carboxy-Hb like oxy-Hb - the pulse oximeter doesn't! So while the text books say it 'reads higher', this is only true in relation to the fractional saturation,, but in actual fact your *functional saturation* may well be 100% (ie. all the non-carboxy-Hb is in oxy-Hb) but it will read *lower*.
Hypothetical 1
ie. 50% carboxy-Hb blood and 50% oxy-Hb
- Functional saturation (pulse oximeter), might read 90-95% when the TRUE functional saturation (ie. that percentage of normal Hb available) is technically 100%
- Fractional saturation (ie. what REALLY matters) is 50% (co-oximeter in a lab)
Hypothetical 2
ie. 50% carboxy-Hb blood and 45% oxy-Hb and 5% deoxy-Hb
- Functional saturation (pulse oximeter), might read 80-85% when the TRUE functional saturation (ie. that percentage of normal Hb available) is technically 90%
- Fractional saturation is 45% (co-oximeter in a lab)
This is why it's often stated that a pulse oximeter 'over-reads' in carbon monoxide poisoning... but only with respect to true, fractional saturations. Most textbooks get this wrong!
Interestingly, when the absorption of red & infrared is the same (ie. the ration is 1:1) the pulse oximeter will read 85%. It's one reason why this is a number that often appears when the signal is weak, particularly on cheaper devices.
As for nail polish - almost never an issue and on those rare occasions where it is (very black acrylic nails), simply turn the sats probe sideways and shine though the fingertip that way - easy!
And why at those two perfect wavelengths? It was pure luck as those were the available red & infrared LED frequencies and it just so happens that the absorption at those two wavelengths is not just wide, but opposite, as you so correctly pointed out. That's the critical thing that makes this all work!
It’s kinda nerdy but also kinda respectable that you take the time to make it clear people shouldn’t take what you say as medical advise, epilepsy warnings, etc.
This is one of the best channels or places to "surf" the 'net.
11:26 HI THERE!
Hi there!
Hi there!
Hi there!
Hi there!
Hi There!
As a pilot, I can confirm that hypoxia is bad for you.
Hahahaha 😂😂
Good to know.
As an hypoxic person, I can confirm that airplanes are imaginary.
Same with diving and flying in the same day.
As a person who can read (and enjoys living), I too can confirm that hypoxia is bad for you.
As a Biomed Tech I would say that you hit the nail on the head. Great explanation, thank you Sir.
Modern medicine and the tech it uses are the biggest achievements in the history of humanity, and my respect for the people working in all areas of both is immeasurable.
"Blood belongs inside your body"
- okay slow down a bit web MD
Lol
Nah medscape is better imo
No the Earth is not Flat.
AAAAAAAAAAAAAAAnd now you have cancer.
Excellent job! I really appreciate explaining the weakness in a two-wavelength oximeter. There are many others but that is a big one depending on the circumstances.
I'm a long time EMT, and i approve this message. Great job!
i really appreciate the blooper real. it shows that even well spoken and intelligent people trip up on words and sentences.
coming from a person that gets ignored because my brain go brrrr but my mouth doesn't, makes me stammer. you helped my self esteem a little today and I thank you for that.
also thank you for teaching me something new.
The scatting at the end was priceless. Captions are just as good as the audio.
I was just wondering the other day why the finger oximeters could measure blood oxygen but phone cameras can't... I swear you read my mind sometimes! Thanks lol
Phone cameras have an IR filter. Well MOST EVERY digital camera has an IR filter. There's a One Plus one that deliberately doesn't, and it's somewhat notoriously in the news for it right now.
Posted to it's own comment, but responding to your question I saw afterwards. If you have a Samsung phone, many of them have had this ability built in, with sensors next to the camera flash. The Samsung Health app has a function to measure Heart Rate, and used to have an obvious option for Blood Oxygen. That's been moved/renamed to the Stress function, which records both, and optionally asks you to indicate your felt stress level.
The hardware exists in the Samsung Galaxy S5 / S5 Neo / S6 / S7 / S8 / S9 / S10 and Edge versions as well as Galaxy Note 4 / 5 / 7 / FE / 8, but isn't in the cheaper S10E, and was no longer included as of the Note 10 and Galaxy S20 models.
@@mlindholm Cool, I didn't know about that! I suppose it really is just down to what technology the manufacturers want to put in, and it's certainly possible to have, just not standard.
@@mlindholm It works a bit differently too, which I find interesting, because many smart watches and phones obviously cannot wrap around your finger. So instead of reading the light as it passes through your finger, it's looking at the reflection of light from inside your finger. You can find some 3rd party apps that give extremely detailed information on just how the sensors are being used to determine the oxygen saturation, plus some other interesting metrics, such as arterial stiffness, something I had never considered as a measurable thing before.
Edit: I did some research earlier too, and I found a lot of people said that Samsung's sensor gave pretty much identical readings to one of those dedicated sensors that clip onto your finger.
The Raspberry Pi has a cheap IR camera attachment you can buy. I’ve considered getting one, because IR photography is freaky cool
I work in the medical field, and I always call these the "finger thingy."
...does it go to the machine that goes "ping"...? :P
As a biomed (repairer of medical equipment), I know what you meant. :p
@@AttilaAsztalos no that's on the boomers (ballistic missile submarines hehe). In a hospital you find the machine that goes 'beep'.
@@AttilaAsztalos That is quietest of the annoying beepy machines, thankfully.
@@xmlthegreat And sometimes you also have the wosh wooosh.
Great video, as always. As someone who's had a heart and lungs transplant i've tons of experience with this. But i've also had arterial blood taken from my wrist and the pain was incredible! And ached for a good half hour later. Something to be avoided if you can :-)
My wife and I LOVE you. So common sense. Thanks for what you do, taking time to give some clarity to us Not so able to comprehend the issue. Great Job.
These devices have saved my, my parents, and may people's asses many times. One of the biggest under rated tools on the market.
PS:
Dad had failing lungs, and my mother has a failing heart. Both where easily picked up by it.
11:10 ♫ oxygenatedly smooth jazz ♫
Best tech channel on UA-cam
Change my mind
We cannot.
Very interesting and well-made video! I am not super familiar with the technical side but have used these extensively as a nurse, so I can confirm related info from that POV.
Little titbit about ABGs (Arterial Blood Gas): the analysis actually doesn't need a lab, there are specialised machines which can analyse a blood sample within minutes (maybe you can do a video about those? I have no idea how they work, but would be interested to know some basics :) but you'd probably need to find a suitable medical professional to help with a video on those, maybe get in touch with medlife crisis).
Especially on ICUs ABGs are taken quite often and doing the analysis through a lab would be too timeconsuming. Also: when you are on ICU it is not uncommon for you to have invasive blood pressure monitoring via a catheter in an artery (somewhat akin to what is put in your vein, when you get some intravenous fluids or meds), from those the ABGs can be drawn without you being perforated again and again ;)
I just want you to know that I appreciate the crispness and accuracy of your captioning of the end song. Sublime.
One of these saved my life. I have two now and always check my self. 8 hours home from surgery a PT came to my house. Checking me my O2 was only 64. I was rushed to the hospital where I only thought I was tired. I had a horrible case of pneumonia. I remained in the hospital for 14 days, almost died.. blah blah blah. Keep one all the time now.
Oof, 64 is really bad. Your heart can spontaneously stop when you're in the 60s.
I wish I could ever say "Look at this chart!" with such excitement