[HN Gopher] Oura Ring 2 Teardown
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Oura Ring 2 Teardown
Author : zdw
Score : 108 points
Date : 2020-07-10 14:40 UTC (1 days ago)
(HTM) web link (www.ifixit.com)
(TXT) w3m dump (www.ifixit.com)
| Erlich_Bachman wrote:
| Before buying one I tried to make research about its
| effectiveness and there are some very alarming reports, coming,
| of all places, from the research published by the same company.
| So this isn't even biased... "From EBE
| analysis, OURA ring had a 96% sensitivity to detect sleep, and
| agreement of 65%, 51%, and 61%, in detecting "light sleep" (N1),
| "deep sleep" (N2 + N3), and REM sleep, respectively. Specificity
| in detecting wake was 48%." Specificity in detecting
| wake was 48%! If this was a medical test, it would never be
| approved by FDA. A specificity of 48% means that
| there is a 48% chance that someone is awake when the device says
| they are asleep. That is horrible.
|
| This is very surprising and alarming. As the author later goes on
| to describe, this has real implications and possible negative
| effects, this is not just a benign error here and there. Users
| are apparently supposed to use the Oura data to change or at
| least adjust and improve their sleep habits, and of course if
| they will do it based on faulty information, the adjustments
| themselves are going to be faulty and it can lead to worse or
| sub-optimal sleep!
|
| Apparently you can still use Oura to track heart rate and HRV,
| but their own proprietary markers like "readiness" are probably
| based on all of their data including sleep, so they are not going
| be that accurate either.
| wvl wrote:
| This matches my experience having received one Nov 2018 (and
| returning it a few weeks later). It was constantly getting my
| actual sleep times wrong, more often than not marking me as
| being asleep while watching tv in the evening.
|
| After contacting support, their solution was an upcoming update
| to their app where I'd be able to edit the data so that I could
| override the app whenever I knew it was wrong. Which completely
| invalidates the primary reason to own this product. I mean, if
| I knew when I was asleep, why would I need a ring to track it?!
|
| So given that it couldn't properly track sleep, doesn't track
| activity (by design), the only other purpose in my mind was to
| track HRV. And count me as skeptical of the accuracy of that
| data as well.
| sadfasdfsad wrote:
| It's a great device.
|
| If there is a primary flaw, it's that it can't be resized. If you
| are sufficiently motivated to become more active, the ring
| becomes too loose over time.
|
| Not the worst problem, but it ends up in caught in the drain more
| than I'd like.
| z3ugma wrote:
| I saw a talk on consumer wearables in sleep at the Sleep Trends
| conference this spring. There was a great presentation comparing
| consumer sleep trackers, and how their advertised reporting of
| "accuracy" can be misleading.
|
| If you do a thought experiment: let's say I make a "sleep
| tracker" that is just a piece of plastic, no sensor, and write an
| algorithm that always presumes the wearer is in stage N2 sleep.
| Since we spend around 50% of our night in N2 sleep, this
| algorithm would start with a fairly high baseline accuracy of
| 50%.
|
| Sensitivity and specificity are much better measurements of
| accuracy, because they measure the false positive and false
| negative rates. A comparison of Oura against a medical
| polysomnogram showed that while it's very good at detecting
| sleep, it's very bad at detecting _not_ sleep:
|
| From https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6095823/: "OURA
| ring had a 96% sensitivity to detect sleep, and agreement of 65%,
| 51%, and 61%, in detecting "light sleep" (N1+N2), "deep sleep"
| (N3),and REM sleep, respectively. Specificity in detecting wake
| was 48%"
|
| The current state of the art in sleep measurement really requires
| some sort of EEG measurement beyond just PPG and HR, what Oura
| uses. The Dreem headband is a good example (https://dreem.com/),
| but it's definitely more cumbersome than a ring. It's tailored
| more like a medical service for insomnia than for the average
| consumer interested in quantified self.
| sradman wrote:
| Garmin acquired FirstBeat Analytics less than two weeks ago
| [1]. According to DC Rainmaker, "They power the vast majority
| of Garmin's fitness and outdoor training-focused algorithms"
| but they are also used by other manufacturers. The Garmin's
| Sleep Stage tracking, powered by FirstBeat Analytics [2], use
| higher power red LEDs at night. I wonder if OURA uses a
| separate technique, maybe even transmissive PPG.
|
| [1] https://www.dcrainmaker.com/2020/06/garmin-acquires-
| firstbea...
|
| [2]
| https://assets.firstbeat.com/firstbeat/uploads/2019/11/First...
| jerlam wrote:
| The red LEDs on Garmin watches are used for SpO2 (Pulse
| Oximeter) tracking, not sleep tracking. They are also
| generally regarded as terrible[1].
|
| [1] https://www.dcrainmaker.com/2018/06/garmin-
| fenix5-plus-5s-5x...
| Youden wrote:
| I own a Dreem V2 headband and though it's more cumbersome than
| a ring, it's really not a problem. It takes me less than a
| minute to put it on and activate it each night and though it's
| a little uncomfortable at first, I got used to it quite
| quickly.
|
| I disagree that it's "more like a medical service for
| insomnia". The app does have some of your standard CBT stuff in
| it if you choose to use it but there's also a lot for people
| without major sleep problems as well. For example there's a
| sleep schedule function that will give you bedtime reminders
| and automatically wake you in the morning when you're in a
| light stage of sleep.
|
| As far as data, I'd say that's one of the major focuses of the
| app. "Sleep reports" (weekly summaries of your sleep habits)
| are made very prominent in the main screen of the app and
| contain reasonably comprehensive but very approachable pieces
| of data.
|
| As for accuracy, I've compared various products of various
| kinds such as under bed, apps and wristbands (though not Oura)
| and found basically everything but Dreem to be pretty garbage
| at doing anything more than detecting that I'm laying in a bed.
| I'm not convinced it's possible to detect that I'm awake but
| lazily delaying leaving the bed with anything but an EEG.
| marcinzm wrote:
| >It's tailored more like a medical service for insomnia than
| for the average consumer interested in quantified self.
|
| There used to be a EEG headband aimed at the quantified self
| group (cost $100 or $150) but they went out of business.
| Probably because for that group a fitbit like tracker was good
| enough. So I'm guessing the medical side and higher price point
| is seen as a better business model.
| scrollaway wrote:
| Last time this came up I mentioned the Dreem headband which
| is still actively produced.
| marcinzm wrote:
| The post I replied to mentioned Dreem but they're at a $500
| price point from what I can tell which is beyond the usual
| non-medical need consumer.
| etrautmann wrote:
| The Zeo headband fits this description?
| oneplane wrote:
| I wonder if it's currently technically feasible to make a version
| with swappable batteries while maintaining the same form factor,
| functionality and other properties the product has as-is.
|
| I know a lot of other products could have better serviceability
| and repairability if one were to sacrifice form factor,
| dimensions or aesthetics, but for a product like this it doesn't
| seem obvious to me how one would go about that, but it'd be very
| interesting to speculate on.
| theshrike79 wrote:
| Not really no, the whole package is encased in a completely
| waterproof way.
|
| Any kind of swappability would require connections, which in
| turn would compromise the IP rating.
| amacbride wrote:
| Ultra-low power indeed: I often get 6+ days of use before having
| to recharge. I've been very happy with mine; the sleep tracking
| seems quite consistent with my subjective experience, and the
| activity/exercise detection matches closely with the data from my
| Apple Watch.
| gregwebs wrote:
| I love the aura ring. AFAIK it is clearly the best non-
| intrusive sleep tracker and I would recommend it to anyone for
| _sleep_ tracking. But in my experience the activity tracking is
| horrible because the ring achieves low power consumption by
| being off most of the time. I would suggest using a different
| device for daytime activity tracking.
| gambiting wrote:
| Serious question - what is sleep tracking useful for? While I
| can see the benefit of tracing activity, I have no idea why
| would I want to track my sleep. I fall asleep, I wake up,
| what is there to track? Or rather, even if it tells me that I
| had a period of less/more movement during the night, what
| kind of actionable information can you possibly get out of
| it?
| greghausheer wrote:
| So many ways it's useful.
|
| Wether you have trouble sleeping or not, it allows you to
| measure what "good" and "bad" is for you.
|
| If I have alcohol before I sleep and don't use a sleep
| tracker, I generally assume I have a bad nights sleep. But
| my interpretation is all anecdotal. A sleep tracker can
| tell me though that I get up X more times when I have
| alcohol, I sleep Y less hours in each stage, I have a
| higher heart rate by Z much, have a lower heart rate
| variability, etc.
|
| And you may think "so what?" We'll, that's the whole point.
| Now you know...not just "kind of know" that alcohol is bad
| for you.
|
| It allows you to confirm what you think may be true, but
| can't prove.
| sprucely wrote:
| It allowed me to identify food intolerances that had a
| significant impact on my sleep.
| Tronno wrote:
| I am struggling with a similar problem (food, and gas in
| particular, affecting my sleep) and was wondering if
| you'd be willing to share more about your experience.
| hkeide wrote:
| Very cool, mind sharing some? Others may have the same.
| FPGAhacker wrote:
| > I fall asleep, I wake up, what is there to track?
|
| Oh man, I remember those days. Enjoy them while you have
| them.
| oneplane wrote:
| If you wake up happy, energised in a consistent manner then
| there isn't much to get out of sleep data. But a lot of
| people don't sleep consistent times with consistent results
| and not knowing why that happens leaves you with little
| control on how to improve your sleeping.
|
| Without proper sleep, life loses a lot of its value.
| jmcgough wrote:
| I'm building some unobtrusive alerting with mine (they have
| a public API). I'm bipolar, and less sleep is often
| correlated with a hypomanic episode. My oura helps me track
| my overall sleep and see patterns over time.
|
| It also shows when I woke up in the middle of the night,
| which isn't always obvious to me when I fall back asleep
| soon after, but definitely impacts my sleep quality.
| chrisbroadfoot wrote:
| Yep. It's useless for activity tracking.
|
| It thought I was sedentary while I was doing a spin workout.
|
| They still don't have a way to manually start activity
| tracking via an app.
| sadfasdfsad wrote:
| It's not useless for activity tracking. It _may_ be useless
| for spin workouts though.
|
| I've worn it with a gear fit and phone based trackers at
| the same time and the deltas are negligible in my
| experience.
| dillonmckay wrote:
| You can tag a 'workout', right? Start time, duration, and
| level of intensity.
| trollied wrote:
| Would you recommend it? I've looked at them a few times & have
| been close to buying one a few times.
| fanttazio wrote:
| I'd totally recommend if you want to form a healthy sleeping
| habit. It helped me understand my body a lot and put me in
| the right direction in terms of having quality sleep. The
| activity tracker in my opinion is good and a bonus but not as
| important as sleep tracking
| theshrike79 wrote:
| I've had mine for about 6 months now and would recommend it
| to anyone who is interested in sleep tracking.
|
| As others have said, watches and other devices are better for
| generic activity tracking, but the Oura ring is just so easy
| to wear to bed. No worrying about battery life or sweaty
| wrists.
|
| The readiness and sleep scores the ring gives me are pretty
| much on point every time and make it easy to quantify your
| sleep to actual numbers you can compare with other data.
| Hamuko wrote:
| So it basically consumes 3-4 mAh a day? That's crazy little.
| voisin wrote:
| I have an Apple Watch that I wear overnight and have a sleep
| tracking app. Have you compared your ring to your watch to see
| if they report similar results? I have been considering the
| ring for HRV tracking (the Apple Watch only tracks HRV at
| random times when you are still, whereas the ring apparently
| tracks continuously) but also wondered if the sleep tracking is
| superior. Thoughts?
| bradleyankrom wrote:
| I started wearing an Oura ring about 10 days ago, and I've
| continued wearing my Apple Watch at night to compare the data
| collected by the ring and a couple of apps I use (AutoSleep
| and Pillow). Feel free to send along any specific questions
| (email is on my profile) about how they compare.
| onlydnaq wrote:
| It's worth to know that the watch also tracks HRV whenever
| you use the Breathe app, so if you want to get consistent HRV
| readings the easiest way is to use Breathe once a day (for
| example right when you wake up).
| BiteCode_dev wrote:
| Just did the Tour du Mont Blanc (8 days of mountain hiking) with
| the oura 2 in plane mode. It recorded everything.
|
| I misplaced it in the washing machine twice and it still works as
| brand new.
|
| Besides the proprietary aspect of the platform and false positive
| reporting sleeping while not, I have only good things to say
| about mine.
|
| Nifty little device.
| cinntaile wrote:
| What's the reason that you can't use this ring for exercise? It
| feels like such an obvious feature to include so there must be
| some technical reason?
| gregwebs wrote:
| It achieves low power consumption by being off most of the
| time. That works out just fine for sleep because sleep phases
| take a long time to change and to verify that you need to take
| multiple samples over long time periods. But to accurately
| track movement characteristics you need to be always on.
| swebs wrote:
| The instructions it came with tell you not to wear it while
| using dumbbells or barbells. As for cardio, I guess it's ok.
| Mine tends to say I took 20% more steps per day than reported
| by the pedometer app on my phone. I have no clue which one is
| more accurate though.
| hobofan wrote:
| I would assume that to achieve a 7 day battery life they only
| take rare measurements of your heart rate, which makes it unfit
| for the kind of high resolution heart rate tracking people are
| used to from fitness watches. They also mention that any sport
| which has a significant level of hand involvement might disturb
| the reading.
|
| They do still track general intensity of activity though, which
| for general health is probably a more relevant metric than
| exact heart rate.
| underyx wrote:
| Indeed, the automatic HR measurement powers the heart rate
| sensor array only when the accelerometer reports that the
| ring is stationary, i.e. the user is likely sleeping. This
| also makes sense because hand movements tank the accuracy of
| the sensors anyway. With manual measurements, you can still
| only get useful data if you're using it to measure during
| meditation or rest.
| dirtyaura wrote:
| Night-time PPG measurement of Oura ring IS high-resolution.
| PPG is measured only when you are still enough.
|
| Activity tracking is based on accelerometer data.
| jerlam wrote:
| The Oura only measures heart rate in five-minute intervals
| [1] while sleeping. A workout set/running interval could
| easily be completed within five minutes, making the
| measurement useless.
|
| I've had many instances where my Oura failed to track heart
| rate while I was asleep, if the ring rotates, slides to a
| thinner part of my finger, or I am moving a little too much.
|
| [1]https://ouraring.com/heart-rate-while-sleeping
| Hamuko wrote:
| Guessing the extremely tiny battery has something to do with
| it. It's a bit like how Apple Watch's battery life tanks when
| you use it for exercising and I don't think the Apple Watch
| gives the most accurate/highest resolution readings.
| dirtyaura wrote:
| A long-time HN user here and I'm stoked to see our product on the
| HN front page
|
| Note: If you are interested in working at Oura, we are hiring SW
| Engineers both in Helsinki, Finland and San Francisco.
|
| Current open positions can be found on
| https://ouraring.com/careers and new positions are opening in a
| few weeks.
| robterrell wrote:
| Congrats on getting your product ripped apart on video ;)
| Jhsto wrote:
| Also worth noting that the ring itself is not designed by Oura
| but by another company: https://haltian.com/reference/oura-ring/
|
| Further, even though Oura is a private company, its financial
| information is public (as is any Finnish company's):
| https://www.finder.fi/Tuotekehitys+tutkimus-+ja+suunnittelup...
| dirtyaura wrote:
| This is incorrect, the Oura ring 2 has been mostly designed by
| in-house team, not Haltian. They have been involved in the
| process though.
| Jhsto wrote:
| Thanks for the correction! I don't know the details on the
| second iteration (assumed same applies as with the first
| gen), so I assume you have better information.
| wazHFsRy wrote:
| From my experience the last thing you need for good sleep is a
| tracker. I'd try to fix sleep hygiene first and adapt a strict
| sleep schedule you do every day.
| crmrc114 wrote:
| Yeah this seems like a solution in search of a problem. I don't
| see how it's worth the price. Reading the comments in this
| thread gives me an interesting view into why people choose
| them.
| scrollaway wrote:
| Some people (myself included) fix (sleep) hygiene problems by
| first closely watching and diagnosing them.
|
| Your comment would sound silly if it said "last thing you need
| for good code is a debugger, I'd try to add a linter first". Or
| "last thing you need to maintain a good weight is a scale, I'd
| try to eat better first".
|
| Neither are exclusive, and the former helps the latter if you
| use it well.
| theshrike79 wrote:
| There are multiple things under the "sleep hygiene" umbrella,
| Oura lets me quantify my experiments.
|
| Do I sleep better when it's colder, how about different
| pillows, blankets? What does alcohol do to my sleep? etc.
|
| With the ring I've got actual data to back up a general feeling
| of did I sleep well/badly.
| krustyburger wrote:
| I am impressed with my ring after having had it for about a year.
| The battery life seems to be as good as ever. The only concern I
| have is that I often have to wear it on a different finger. My
| hands are less bloated, which I credit partly to having been more
| active since I've had it.
| gregwebs wrote:
| If you have an oaura ring you can participate in a USCF study
| that is trying to determine if it can help predict COVID:
| https://ouraring.com/ucsf-tempredict-study
|
| I think the idea is similar to what the NBA is doing: monitor
| doctors and nurses with the ring to try to detect COVID. But they
| are trying to properly study the idea.
| underyx wrote:
| > The Oura Ring came out in May 2019
|
| Wait, what? I got mine in Feb 2019. Did they re-release it or
| something?
| dirtyaura wrote:
| Oura ring 2 launched in Dec 2017 and shipments started in April
| 2018.
| voisin wrote:
| That's a long time since new launch. Have they refined it
| since 2018?
| social_quotient wrote:
| Gen 2
| underyx wrote:
| I'm pretty sure mine is gen 2 as well.
| unicornporn wrote:
| Didn't know what this ring was. Is it better than binary
| sleep/wake tracking? Here's the closest thing to a study on this
| thing I found:
| https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6095823/ :-/
| dirtyaura wrote:
| There are a few others, some of them by in-house science team
|
| https://iopscience.iop.org/article/10.1088/1361-6579/ab840a
|
| https://www.researchgate.net/publication/335764849_Following...
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(page generated 2020-07-11 23:01 UTC)