$100 for a somewhat specialized, durable medical device that has to meet regulatory standards and will be used daily, possibly for years, by healthcare providers to do patient assessments?
A 3D printed option is going to require a 3D printer, appropriate filament and should be unit tested to ensure it's within spec. The durability is going to be suspect no matter what. It's an awesome project and I'm sure would be a welcome addition to the 'boostrap humanity' catalog of 3D printed parts, but for everyday doctors plunking a hundo on a good tool is going to be a no-brainer.
A commercially sold hospital stethoscope is a legally marketed medical device made under a manufacturer quality system, with labeling/instructions, device listing/registration obligations, adverse-event/complaint processes, cleanability expectations, liability, warranty, consistent materials, and repeatable acoustic performance.
An open-source 3D-printed stethoscope is a cool project, but unless it is produced and controlled as a medical device, it is not equivalent to what hospitals are buying for daily patient care.
Personally, if I was a hospital or a doctor, it would be a no-brainer for me to go with the commercially sold stethoscopes. All those factors I listed above, if neglected, can end up costing a lot more in terms of consequences. I would rather pay a fixed extra overhead price per unit to sleep well, knowing I don't have to worry or think about those factors at all. And, I would assume, most of the patients would be in favor of that as well.
> $100 for a somewhat specialized, durable medical device...
And one which is treated as a status symbol, at that. Part of the reason a good stethoscope costs more is because it looks nicer, not just because it works better.
There are cheap, generic scopes (Sprague-Rappaport types) that are very sensitive but the double tube also causes a lot of noise. There are knock-offs of the Littmann scopes in the market. Then there are the scopes doctors usually buy, which are Littmann, Harvey (made by Welch-Allyn) and Heine, and a few smaller makers. No marketer of a high-quality scope wants to sell it at a $30 or less price point, and if you're going to go higher, might as well place it in the same market as the Littmann ($115+). I'll be honest, for emergency medicine use, the Littmann lightweight scope is good enough and cost about $45 when I bought it. But if I actually want to hear the subtleties in a chest, I'll use my personal scope (a Littmann Cardiology IV). Why choose this one? I already know it and they are very consistent. It doesn't feel cold to the patient and it has the right level of sensitivity without much noise. It is a little heavy. If a dog is bucking around, it can go flying and hurt if it hits someone.
I have a littmann cardiology 3 I bought in 2010 and the diaphragms wore out in 2019. By that time, they stopped selling official kits for the 3, so I repaired it with an off brand kit and was given a 4 for Christmas. The off brand diaphragm lasted only a couple years. My colleague has had the rubber tubing wear out. They say if you wear a collared shirt it lasts forever hanging on your neck but if it sits on your skin it wears out, and she always wears scrubs.
Years ago I had my blood pressure taken by a nurse; this was when they did it manually, squeezing the pressure cuff bulb by hand and listening with a stethoscope. The doctor came in later, saw the numbers and frowned, and took my pressure again. She (both were women) ended up with a reading much more within my normal range.
I asked, joking, “So are you just better than her?” “No,” my doctor replied, “She’s better. She gets more practice. I have a better stethoscope.”
The pressure cuff + stethoscope combo is called a sphygmomanometer. It's a pretty fascinating piece of technology: A heartbeat is only audible in the earpiece when the cuff is compressing between someone's systolic and diastolic pressure.
To use it, you get the cuff pressure high enough that you stop hearing a heartbeat in the earpiece. Start releasing pressure slowly. As it comes down, take note of where on the dial you start hearing the heartbeat. That's systolic pressure. Keep listening, and take note of where you stop hearing the heartbeat. That's diastolic pressure.
And if you use a mercury sphygmomanometer, you can actually see those pulses appear and then disappear. (It's harder to see them with a gauge-based one.)
I have a much higher BP when I first go to the office than after I'm sitting in the exam room for a bit.
Usually they call me back to the hallway where they check my weight, then have me sit in a chair and check my temperature, pulse ox and BP, with maybe only a minute sitting down before they do the BP check. My BP is usually in the "hypertension" range there.
But, if they come back to the exam room after I've been sitting in that quiet room for 5 or 10 minutes and check my BP , it's almost always in the "normal" BP range (same as what I see when I check it at home).
Doctor calls it "white coat hypertension", I call it "rushed BP check in the hallway".
If the nurse got a reading well outside normal range she should have repeated it to confirm, especially if it was inconsistent with your overall presentation.
Then you will notice when your HCP ignores those instructions, like wrapping the cuff around your shirt-sleeve, or prompting you to talk while the measurement is taken, or allowing you sit with your legs crossed.
BP monitors are often poorly calibrated. The instructions for my home monitors suggest bringing the device into the clinic for calibration, and then the clinician says "we don't do that!"
Manual sphygmomanometer readings won't have an automatic digital readout, and require the human HCP to interpret, announce and record the numbers.
People buying stethoscopes tend to be reasonably affluent. Some of the pricier ones just look better and people usually buy them when you get into med school (at least this was the case for me), it's somewhat symbolic so why not splurge.
There does seem to be a difference in quality though. It's much easier to hear the important things with my littman than with the cheap generic stethoscopes I usually find lying around in clinics.
It’s funny, most physicians agree that the cheap disposable stethoscopes in isolation rooms are the best, mostly because they are so loud it’s difficult miss anything with them. However, I am not a cardiologist so they may have a different opinion.
I've actually found them pretty terrible. I can't hear subtle findings at all with those. My usual stethoscope is an older-model Littman Cardiology III with stiff rubber and a dual pediatric-adult head. I've had it for over 25 years.
I would really disagree as a physician that's used a lot of random crap stethoscopes when I don't have one or in an iso room. Those disposable ones are different in what they pick up, some findings are louder others not detectable. Sure I can pick up some stuff like rubs and systolic murmurs but you aren't going to get more subtle findings like diastolic murmurs and fine crackles. Probably a combination of certain frequencies responding and also me being used to mine.
I'm shocked that you're shocked lol.
$100 for a somewhat specialized, durable medical device that has to meet regulatory standards and will be used daily, possibly for years, by healthcare providers to do patient assessments?
A 3D printed option is going to require a 3D printer, appropriate filament and should be unit tested to ensure it's within spec. The durability is going to be suspect no matter what. It's an awesome project and I'm sure would be a welcome addition to the 'boostrap humanity' catalog of 3D printed parts, but for everyday doctors plunking a hundo on a good tool is going to be a no-brainer.
> has to meet regulatory standards
Genuinely curious, what standards exactly, for a stethoscope?
A commercially sold hospital stethoscope is a legally marketed medical device made under a manufacturer quality system, with labeling/instructions, device listing/registration obligations, adverse-event/complaint processes, cleanability expectations, liability, warranty, consistent materials, and repeatable acoustic performance.
An open-source 3D-printed stethoscope is a cool project, but unless it is produced and controlled as a medical device, it is not equivalent to what hospitals are buying for daily patient care.
Personally, if I was a hospital or a doctor, it would be a no-brainer for me to go with the commercially sold stethoscopes. All those factors I listed above, if neglected, can end up costing a lot more in terms of consequences. I would rather pay a fixed extra overhead price per unit to sleep well, knowing I don't have to worry or think about those factors at all. And, I would assume, most of the patients would be in favor of that as well.
4 replies →
In the UK it would be Class Im - so low risk device that sits outside the body, with a measuring functionality.
1 reply →
> $100 for a somewhat specialized, durable medical device...
And one which is treated as a status symbol, at that. Part of the reason a good stethoscope costs more is because it looks nicer, not just because it works better.
You can get a basic littman for not much. I could afford one when I was a rookie EMT and I've still got the same one many years later.
There are cheap, generic scopes (Sprague-Rappaport types) that are very sensitive but the double tube also causes a lot of noise. There are knock-offs of the Littmann scopes in the market. Then there are the scopes doctors usually buy, which are Littmann, Harvey (made by Welch-Allyn) and Heine, and a few smaller makers. No marketer of a high-quality scope wants to sell it at a $30 or less price point, and if you're going to go higher, might as well place it in the same market as the Littmann ($115+). I'll be honest, for emergency medicine use, the Littmann lightweight scope is good enough and cost about $45 when I bought it. But if I actually want to hear the subtleties in a chest, I'll use my personal scope (a Littmann Cardiology IV). Why choose this one? I already know it and they are very consistent. It doesn't feel cold to the patient and it has the right level of sensitivity without much noise. It is a little heavy. If a dog is bucking around, it can go flying and hurt if it hits someone.
This part stood out to me. Do they use a special material? This sounds interesting.
How long do they last? Looks like pretty solid piece of equipment, but are they damaged easily or simply clap out after few years?
I have a littmann cardiology 3 I bought in 2010 and the diaphragms wore out in 2019. By that time, they stopped selling official kits for the 3, so I repaired it with an off brand kit and was given a 4 for Christmas. The off brand diaphragm lasted only a couple years. My colleague has had the rubber tubing wear out. They say if you wear a collared shirt it lasts forever hanging on your neck but if it sits on your skin it wears out, and she always wears scrubs.
I still use one I got in 1994. Replaced the earpieces and diaphragm a few times, but the chestpiece and tubing are original
That's like a little over $3/yr. Can't complain
> How long do they last? Looks like pretty solid piece of equipment, but are they damaged easily or simply clap out after few years?
They last forever. Why would they break? This is like asking how long floor speakers last.
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Years ago I had my blood pressure taken by a nurse; this was when they did it manually, squeezing the pressure cuff bulb by hand and listening with a stethoscope. The doctor came in later, saw the numbers and frowned, and took my pressure again. She (both were women) ended up with a reading much more within my normal range.
I asked, joking, “So are you just better than her?” “No,” my doctor replied, “She’s better. She gets more practice. I have a better stethoscope.”
The pressure cuff + stethoscope combo is called a sphygmomanometer. It's a pretty fascinating piece of technology: A heartbeat is only audible in the earpiece when the cuff is compressing between someone's systolic and diastolic pressure.
To use it, you get the cuff pressure high enough that you stop hearing a heartbeat in the earpiece. Start releasing pressure slowly. As it comes down, take note of where on the dial you start hearing the heartbeat. That's systolic pressure. Keep listening, and take note of where you stop hearing the heartbeat. That's diastolic pressure.
Using one feels kind of magic.
And if you use a mercury sphygmomanometer, you can actually see those pulses appear and then disappear. (It's harder to see them with a gauge-based one.)
4 replies →
It does feel magical, especially when the first sound comes in. More details here [0].
[0] https://en.wikipedia.org/wiki/Korotkoff_sounds
I have a much higher BP when I first go to the office than after I'm sitting in the exam room for a bit.
Usually they call me back to the hallway where they check my weight, then have me sit in a chair and check my temperature, pulse ox and BP, with maybe only a minute sitting down before they do the BP check. My BP is usually in the "hypertension" range there.
But, if they come back to the exam room after I've been sitting in that quiet room for 5 or 10 minutes and check my BP , it's almost always in the "normal" BP range (same as what I see when I check it at home).
Doctor calls it "white coat hypertension", I call it "rushed BP check in the hallway".
Same. I measure at home and my relaxed systolic is 30-40 lower than the first measurement in their office.
Or, maybe you have "white coat syndrome" [1]. This is closely related to "pretty lady syndrome".
[1] https://en.wikipedia.org/wiki/White_coat_hypertension
If the nurse got a reading well outside normal range she should have repeated it to confirm, especially if it was inconsistent with your overall presentation.
If you purchase a home BP monitor, it will include instructions on how to take readings, like these:
https://www.heart.org/en/health-topics/high-blood-pressure/u...
Then you will notice when your HCP ignores those instructions, like wrapping the cuff around your shirt-sleeve, or prompting you to talk while the measurement is taken, or allowing you sit with your legs crossed.
BP monitors are often poorly calibrated. The instructions for my home monitors suggest bringing the device into the clinic for calibration, and then the clinician says "we don't do that!"
Manual sphygmomanometer readings won't have an automatic digital readout, and require the human HCP to interpret, announce and record the numbers.
They can become a lot more expensive than $100, but the difference between a Littman Cardiology and the $15 EMT student stethoscope is night and day.
> Currently, the stethoscope resulting from this project functions as well as the market gold standard, the Littmann Cardiology III
If this is true, it's a major achievement.
My daughter's toy stethoscope has actual tubing, some sort of diaphragm, and that seems to work reasonably well!
I'm not surprised good results are available for a few dollars.
People buying stethoscopes tend to be reasonably affluent. Some of the pricier ones just look better and people usually buy them when you get into med school (at least this was the case for me), it's somewhat symbolic so why not splurge.
There does seem to be a difference in quality though. It's much easier to hear the important things with my littman than with the cheap generic stethoscopes I usually find lying around in clinics.
You probably pay for tests and that the company has to be audited for medical diagnostics standards
It is somewhat of a critical tool, so you don't wanna be checked by a doctor who made their own stethoscope or got one for 3 USD on AliExpress.
It’s funny, most physicians agree that the cheap disposable stethoscopes in isolation rooms are the best, mostly because they are so loud it’s difficult miss anything with them. However, I am not a cardiologist so they may have a different opinion.
I've actually found them pretty terrible. I can't hear subtle findings at all with those. My usual stethoscope is an older-model Littman Cardiology III with stiff rubber and a dual pediatric-adult head. I've had it for over 25 years.
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I would really disagree as a physician that's used a lot of random crap stethoscopes when I don't have one or in an iso room. Those disposable ones are different in what they pick up, some findings are louder others not detectable. Sure I can pick up some stuff like rubs and systolic murmurs but you aren't going to get more subtle findings like diastolic murmurs and fine crackles. Probably a combination of certain frequencies responding and also me being used to mine.
Our one that DIY'd one like one would do a dosing rod in their garage.
Well-formed sentence one dosed for make benefit understandability not garage DIY'd one?
Written on ether?
How shocked are you, in comparison, that a Claude code subscription is $200/month?
If it’s your everyday carry used in your profession, just pay for a nice one. It’s really not that much.
If someone showed you how to create a functional $30 monitor, you’d still pay more for a nicer commercial one
Is that a lot or a little?
This "recipe" produces them for $5 ... that's 5% of the market price.
Assuming equivalent capabilities and longevity.. I know physicians who have used their "20x too expensive" Littmann for 30 years.
À lot