Comment by hex4def6
16 hours ago
Hmmm.
Looking at: https://journals.plos.org/plosone/article/figure?id=10.1371/...
I'm not sure I believe the graphs.
For example, here's another frequency response chart of some stethoscopes: https://www.researchgate.net/figure/a-Frequency-response-of-...
How is it that professional stethoscopes can be that different, and yet this 3D printed one can match a gold-standard one almost exactly?
From what I can tell there's no audio engineering / modelling that's been done here -- It's just some crude openSCAD tubes. And it's not even optimized for 3D printing; a 3D printed tube with a circular cross-section is going to have bridging issues at the top which will result in internal roughness. I have to imagine that results in attenuation. (A better internal shape for a tube is something that looks like "ô". The ^ will print much better)
The type of plastic used and its frequency response, the thickness / stiffness of the silicone tubing, the height / width of the bell... There are so many variables that I think would make significant differences in performance. The fact that they see basically no difference is highly suspect.
This feels like one of those "3D-print everything" fads that was popular a few years ago. Yes, you can make a 3D-printed adjustable wrench, but even the most miserable dollar-tree metal version will beat it in every possible metric.
Likewise, on Alibaba, if you order 200 pieces, I'm seeing metal ones as low as $1.22/pc. I don't believe that this 3D printed one will even be as good as those.
You can measure all the parameters you want. The question is: does it really matter? I know many doctors, and one of my favorite questions is about stethoscopes: I have unanimously the answer "I could just roll a piece of paper and if the room is quiet enough, I can do my work". My grandpa used one made out of wood, just a cone. Once, I was fascinated by a Littmann, with bluetooth audio, I told a friend doctor, that would be great (thinking about a present) the answer was "That is all hype, I can do with a $2 piece exactly the same". I pointed out the possibility to record the sound, to possibly defense in case of being sued: she laughed out loud, said is unpractical to record everything, would take too much time, and again, just a toy.
Lots of nurses and EMTs swear by the amplified Bluetooth stethoscopes but unlike a Dr working in a nice quiet office, they're often in much noisier conditions.
The difference between a $100 mic and one that costs ten to a hundred times as much is not how well they work in perfect conditions, but how well they work in the worst conditions imaginable.
Doctors often have the seniority and authority to make the room quiet; nurses and EMTs are often working in much different conditions.
It's a bit of a head scratcher.
It would require abject incompetence on the part of jellybean stephoscope manufactorers for this to make sense.
On the other hand the reason Litmann stephoscopes are expensive is target market (doctors), build quality and amortization of cost over probably a decade of use. Stephoscopes are a metanym for doctor, and doctors don't want cheap stephoscopes.
It reminds me of the product to make budget incubators for developing markets. I can't find a link but it failed for two reasons, if you can't afford medical grade systems. You probably don't have the highly trained teams needed anyways.
Medicine is in large part a trust based endeavour you need to trust the system you are putting your life at the hands of.
Long story short, this solves an imagined problem. When you consider why X doesn't have Y medical system. It's not because of the price of the kit. It's the entire system that is too expensive. If you can't afford a brand incubator you probably can't afford the it intense cleaning regime needed for the room to put that incubator in!
There is something about using quality tools that goes beyond practical.
For example, I like coding on a nice keyboard, and I think I am not the only one here. But realistically, the cheap keyboards that litter offices everywhere work just as well. Simply, I don't enjoy using them, and when it is something you work with every day on a job that pays well, you can afford a few hundred dollars worth of luxury once in a decade.
As someone said, there is also the question of image. If you are a professional, your customers (/patients if you are a doctor) expect you to have professional tools. For example, a contractor arriving with that $10 Ikea toolbox may rise a few eyebrows. Maybe that's all he needs and he can do a terrific job with it, but he may not be taken seriously.
That is also my productivity hack. It reminds me of video games that gives you reward cues for doing something. Psychological tricks to massage your brain and get you hooked. That's why also like to buy nice stationary. I always look forward to use my notebooks and pens.
And the $10 toolbox needs to only be insufficient once or twice and suddenly the $200 packout makes sense.
For you or I who use the box once a year? The savings are worth the minor hassle - but if you’re using it everyday it only takes once or twice to outweigh the costs.
And patients. What would you think if the doctor in front of use is using a plastic thingy that seems more come from a doctor-toy-set?
steThoscope
I normally wouldn't comment just to correct a misspelling, but it's pretty consistent and it's an entirely different sound, as well as being what the thread is about.
To some percentage of the British population, I fink you'll find it's exactly the same sound.
1 reply →
Thanks!
Yes, if you're going to be using it for the next 10 years, it is worth going for the more expensive Littman if you can. However, I've heard that there are decent Chinese clones, and honestly I've used those $1 stethoscopes in isolation units and they're not terrible for basic pulmonary auscultation.
But where do they fail? What does a good stethoscope bring? better and clearer amplification?
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metanym
(taxonomy) A name that is rejected because a valid name (based on another member) already exists for the same group.
https://en.wiktionary.org/wiki/metonymy#English
That label the graph "log dB" which seems a very odd choice if you wanted to show differences