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An open-source stethoscope that costs between $2.5 and $5 to produce
- colinbartlett 5mo agoI was shocked to see that a "brand name" stethoscope is $100+ and even generic ones are $30.
- unsupp0rted 5mo agoIs that a lot or a little?
- hungryhobbit 5mo agoThis "recipe" produces them for $5 ... that's 5% of the market price.
- mikeyouse 5mo agoAssuming equivalent capabilities and longevity.. I know physicians who have used their "20x too expensive" Littmann for 30 years.
- Agingcoder 5mo agoÀ lot
- donaltroddyn 5mo agoThey 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.
- elAhmo 5mo agoIt 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.
- recursivegirth 5mo agoOur one that DIY'd one like one would do a dosing rod in their garage.
- DoctorOetker 5mo agoWell-formed sentence one dosed for make benefit understandability not garage DIY'd one? Written on ether?
- NewsaHackO 5mo agoIt’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.
- classichasclass 5mo agoI'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.
- NewsaHackO 5mo agoI guess it's different strokes, because I can definitely hear subtle sounds much easier with them. In fact normal sounds sound like it is going to blow out my ears. The only issue I have is consistency; it's difficult to gauge how much something has changed over time with different stethoscopes, especially pulmonary edema and wheezing.
- zeagle 5mo agoI 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.
- deknos 5mo agoYou probably pay for tests and that the company has to be audited for medical diagnostics standards
- jcims 5mo agoI'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.
- nomel 5mo ago> has to meet regulatory standards Genuinely curious, what standards exactly, for a stethoscope?
- filoleg 5mo agoA 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.
- nomel 5mo agoWhat standard exactly, for a stethoscope? I know nothing of this, but it looks like stethoscopes are Class 1 medical devices with 501(k) exemption, and fall under the "Good manufacturing practices" guidelines of Quality System Regulation (21 CFR 820), but that seems pretty squishy.
- sonofhans 5mo agoYears 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.”
- Lalabadie 5mo agoThe 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.
- devilbunny 5mo agoAnd 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.)
- boelboel 5mo agoPeople 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.
- matheusmoreira 5mo agoThere 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.
- Lalabadie 5mo agoMy 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.
- conductr 5mo agoIf 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
- projektfu 5mo agoThere 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.
- dzhiurgis 5mo agoHow long do they last? Looks like pretty solid piece of equipment, but are they damaged easily or simply clap out after few years?
- bonsai_spool 5mo ago> 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.
- ssl-3 5mo agoSpeakers sometimes die while sitting unused in their original shipping carton in a dry, climate-controlled room. The adhesives can age. Foam surrounds can disintegrate. (Ask a Bose 901 owner about foam rot.) They also can also die from use, and abuse. And finger-poking. And environmental conditions like moisture and UV light. I know enough enough about old speakers to know that lasting forever isn't one of their usual traits. Are stethoscopes really as bad as that?
- 5mo ago
- copperx 5mo agoHow shocked are you, in comparison, that a Claude code subscription is $200/month?
- mythrwy 5mo ago$100? So, like 4 aspirin tablets US hospital billing prices?
- samantha_greene 5mo agoNo pictures? Missed opportunity. Seems cool though!
- bradrn 5mo agoThe linked paper has some pictures: https://doi.org/10.1371/journal.pone.0193087 https://doi.org/10.1371/journal.pone.0193087
- esc861 5mo agohttps://journals.plos.org/plosone/article/figure?id=10.1371/journal.pone.0193087.g001 https://journals.plos.org/plosone/article/figure?id=10.1371/...
- duskwuff 5mo agoThe Y piece (part C in the photos) seems a little silly. Surely there are commercially available hose fittings which would be suitable - possibly even ones which a hospital would have on hand?
- brcmthrowaway 5mo agoAre sthethoscopes passive or active devices?
- kfarr 5mo agopassive
- matheusmoreira 5mo agoIt's basically a tube that transmits sound waves from a diaphragm to your ears. Pretty much an extension of your own ears. Nowadays they do make electronic models. Active enough, I suppose. Can even record sounds.
- Modified3019 5mo agoDo the design and materials take into account how well it can be sterilized?
- zabzonk 5mo agoNever seen a UK doctor or nurse attempt to clean, much les sterilize, one.
- jwcacces 5mo agoThere are disposable, single-patient stethoscopes, but I've seen my Dr do a casual wipe with an alcohol swab often enough...
- xyzzy_plugh 5mo agoI think this is a good point, insofar that how bacterial resistant the stethoscope is relevant. Stethoscopes made of stainless steel are going to beat anything 3d printed by a significant margin.
- bsza 5mo agoIt definitely doesn’t help that prints from filament printers are very porous, 100% infill or not. Maybe sealing it with epoxy after printing would help?
- bluGill 5mo agoThis seems like another case where the hobby has discovered the 3d printer hammer and forgot that cnc tools (lathe, milling machines) are often better and faster for the job. Or if plastic is what you want injection molding is something you can do on a hobby scale and it is much better (but unlike the others this isn't something you can go from CAD to widget)
- jstanley 5mo agoIn my experience it is very rarely the case that setting up machine tools is faster than 3d printing. And even when it's faster, it's not less trouble. And you have to go and acquire materials in suitable shapes and sizes, and deal with cleaning up chips and offcuts, and deal with deburring and cleaning the part after it's finished. The 3d printer is always ready and always has material in the right shape. It doesn't make a lot of noise, it doesn't make a lot of waste, the parts come off the machine clean and dry and ready to use. It's really hard to overstate the convenience of 3d printing.
- jader201 5mo agoInstructional video: https://youtu.be/u-KNTc0POLA https://youtu.be/u-KNTc0POLA
- stronglikedan 5mo agoThe thing is that I can get just as good if not better ones (metal) for $7 all day long, and not have to spend time sourcing and assembling materials, and I don't even have to leave my house to do it.
- bluGill 5mo agoI'm not sure what you are buying, but it wouldn't surprise me if they were done in a factory that does medical grade quality control. While the odds are a medical problem from a non-medical grade stethoscope seem low, it still seems a couple bucks is worth the price. (if we are talking thousands I'd ask for a deeper drive into what that really gets you)
- deleted 5mo ago[deleted]
- throwaway2037 5mo agoHow much do you think doctor's spend on their stethoscope when they live in a developing country? My guess: About 10 USD. Think about the global demand for stethoscopes for countries where GDP per capita is below 4000 USD. It must be enormous.
- dieselgate 5mo agoRespectfully, as this is HN, I do not believe that is the purpose of the posted Github repository.
- andrewla 5mo agoWhen my kids were little they had a toy doctors set and the fake wooden stethoscope broke; replacing it with a real one was significantly cheaper than paying Melissa and Doug for a new one.
- throwaway2037 5mo agoHat tip. I never heard of "Melissa and Doug" before this post. I found the doctor's kit here on Amazon: https://www.amazon.com/Melissa-Doug-Doctors-Original-Pieces/dp/B07VNB8BV9?th=1 https://www.amazon.com/Melissa-Doug-Doctors-Original-Pieces/... It is adorable!
- abdullahkhalids 5mo agoWhat's the price per use compared to a standard industrial metal one?
- onetokeoverthe 5mo ago[dead]
- sandworm101 5mo agoI seem to remember a major issue re 3d-printing medical things. Early in the pandemic LTT organied an effort to print some PPE face shields for hospitals. It was all rejected. The microscopic holes left in the print material meant it could not be properly sanitized. A stethoscope touches both patients and providers. This may be a place where smooth non-printed material may be the only sanitary choice.
- krispykrem 5mo agoHere is an interview with one of the researchers behind this project: https://logicmag.io/bodies/tarek-loubani-on-3d-printing-in-gaza/ https://logicmag.io/bodies/tarek-loubani-on-3d-printing-in-g... It explains the project and its motivations. It's been a while since I read it (2019), but at the time I found it really fascinating and inspiring.
- martinwright 5mo agoReally eye-opening to my western-brain that agreed with higher comments simply comparing the process with ordering a unit off Alibaba and having it delivered. Truth is, there's often a million other parameters that could come up and make a project like this really useful & practical to someone.
- shimman 5mo agoYes, this group had a great interview on The Majority Report w/ Sam Seder. Really both inspiring and infuriating. Inspiring in that human ingenuity to preserve and help others truly knows no limits; infuriating because these are a people having a genocide committed against them and are forced to do such things for basic medical care. One day everyone will truly be against this.
- ErroneousBosh 5mo agohttps://www.ebay.co.uk/itm/264691582901 https://www.ebay.co.uk/itm/264691582901 (if eBay kills that link, then for future HNers it's a link to an inexpensive bright yellow single-use plastic stethoscope by a company called Valuemed, which have been available basically forever and are for when you cannot risk getting something nasty on your good Littman) £1.99 in single unit quantities from a dude on eBay. These things are so cheap in bulk that they'd ship two in every box of Orthogon Gemini microwave links that I used to fit something like 20 years ago before VDSL was a thing to link fast sites to places that'd otherwise be on dialup. They emitted a quiet beeping to help you align them when they were in aiming mode; the cheap plastic stethoscope made it possible to hear that over wind noise, air handling units, and other such clatter. I still have a box full of them, despite giving a bunch to the nursery my son went a couple of years ago. What's the point in 3D printing something for $3 when you can buy them in a bulk box for a tenth of that?
- Animats 5mo agoRight. There are plenty of cheap plastic stethoscopes on Alibaba. There are even metal ones in the $2 range. If you want to bang out simple parts in quantity, 3D printing is not the way to go.
- throwaway2037 5mo agoUp next: 3D metal printed version!
- Animats 5mo agoSomething I'd like to see from the hobbyist community: DIY injection molding. Injection molding is a process where the first one is a huge amount of work, and then you just bang them out for a few cents each. Which is why most of the world's cheap stuff is injection molded. TechShop used to have the machine for it, but it was very rarely used. The injection molding machine was about the size of a benchtop drill press. It had fixtures to hold two dies, a pressure pump, and a guard around the molding area in case something went wrong. There's an automated one coming out as a kickstarter. Pre-order for $6500.[1] Now you need to make injection molding dies. This requires a milling machine, and is much easier with software support. The commercial software for planning injection molding is Autodesk Moldflow, but that's overkill for simpler projects. TechShop had that on their computers, but nobody ever used it. There's something called OpenFOAM, but it's not a nice GUI program. [1] https://www.micro-molder.com/product-page/micromolder https://www.micro-molder.com/product-page/micromolder
- hex4def6 5mo agoHmmm. Looking at: https://journals.plos.org/plosone/article/figure?id=10.1371/journal.pone.0193087.g001 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-Littmann-3200s-bell-mode-vs-Eko-Cores-cardiac-mode-and_fig3_368568555 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.
- rustyhancock 5mo agoIt'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!
- KnuthIsGod 5mo agoI can buy cheap ones online from Temu for $3. However I am comfortable with my Littmann. Littmann's last for 20 plus years.
- aaron695 5mo ago[dead]
- hereme888 5mo agoWhat we need now is open-source ultrasound devices.
- dogmatism 5mo agoAs an early-adopter of POCUS, I can't quite believe we actually still use stethoscopes
- KnuthIsGod 5mo agoAmazon in India will sell you a pretty reasonable stethoscope for for $3. Assuming the usual Amazon, distributor and retailer markups, these probably cost around 50 cents to make in China. https://www.amazon.in/BPL-Medical-Technologies-ST-01-Stethoscope/dp/B0D5MM9SQB?pd_rd_w=0vK1G&content-id=amzn1.sym.173983d0-d713-4684-a64b-0ce5fd9d608b&pf_rd_p=173983d0-d713-4684-a64b-0ce5fd9d608b&pf_rd_r=RW435N0EJGG7QJJMQN9A&pd_rd_wg=a4aDH&pd_rd_r=edc09c64-eef1-4fc5-8840-d3c874b1baff&pd_rd_i=B0D5MM9SQB https://www.amazon.in/BPL-Medical-Technologies-ST-01-Stethos... Many poor countries are perfectly capable of manufacturing their own medical equipment Background: I have worked in hospitals in Bihar & Vellore Tamilnadu, and have university mates, friends and family who worked in hospitals in Mizoram, PNG, Libya, Nepal, Uganda and even South Sudan. Even the doctors who worked in South Sudan had no difficulty sourcing basic equipment. They did however, have enormous trouble sourcing funding and trained personnel who were willing to work in a potentially lethal situation.
- zawaideh 5mo agoThis has been used in Gaza to make their own due to Israel’s blockade. https://logicmag.io/bodies/tarek-loubani-on-3d-printing-in-gaza/ https://logicmag.io/bodies/tarek-loubani-on-3d-printing-in-g...
- surajguptayc 5mo agoInteresting project. Feels like the real value here is not beating commercial stethoscopes, but accessibility and local manufacturing. even if performance is slightly worse, being able to produce something “good enough at scale in low-resource environments could still have huge impact. Curious though has anyone tested consistency across multiple prints? I’d expect variation in material + print quality to affect acoustic performance quite a bit.
- mfgadv99 5mo ago[flagged]
- Cryptoclidus 5mo agohttps://github.com/Gliax https://github.com/Gliax
- bombcar 5mo agoPart of it is this - you get hired by Anthropic making $250k a year. They give you the latest MacBook Pro, a nice office, and a $5 Walmart mouse. It works. Probably fine. But it’s weird.