4 ms·

I'm one of the co-founders of Cardiogram and involved in this study -- happy to answer questions if folks have them! (EDIT: heading to bed, but will answer que

I'm one of the co-founders of Cardiogram and involved in this study -- happy to answer questions if folks have them! (EDIT: heading to bed, but will answer questions in the morning!)

ISL 9y ago
I didn't see a reference in the TechCrunch article -- is there a technical paper out? Edit: A presentation is linked, as "study": Link to presentation: http://www.abstractsonline.com/pp8/#!/4412/presentation/45220 http://www.abstractsonline.com/pp8/#!/4412/presentation/4522... A followup: Does the neural network provide some extra insight into what part of the waveform/time-series of pulses is able to provide predictive information?
- deleted 9y ago
  [deleted]
- brandonb 9y ago
  Correct -- the abstract will be included in a special issue of Circulation: http://circ.ahajournals.org/content/136/Suppl_1/A21042 http://circ.ahajournals.org/content/136/Suppl_1/A21042 The study was presented at the American Heart Association's Scientific Sessions earlier today. We included some details beyond what appears in the TechCrunch article in a blog post here: https://blog.cardiogr.am/screening-for-hypertension-and-sleep-apnea-with-deepheart-416c9bc03efc https://blog.cardiogr.am/screening-for-hypertension-and-slee... I'd expect a more mature version of this work to appear in a medical journal, but that often takes 6-12 extra months.
  - ktta 9y ago
    Couldn't find the measurement process. What is the common root cause of error? Inaccuracies in measurement or the model classifying data incorrectly?
- bertil 9y ago
  Sorry for the habitual rant, but I feel the need to point out those are not open articles. Your case is typically something of interest to people who have no reason to have access to medical journal stores and… :( This thread is not the right place to grab pitchforks, just a reminder open source science was still an on-going effort.
nopinsight 9y ago
What are the false positive and false negative rates for sleep apnea detection? Would it be able to detect sub-clinical symptoms? Second the other comment on technical paper. Is it available?
- brandonb 9y ago
  The accuracies quoted here are c-statistics, or area under the ROC curve. An example operating point for sleep apnea is 97% specificity with a sensitivity of 52% (compared to a 20% diagnosis rate in today's healthcare system). If a specificity of 82% is acceptable, then we can detect about 75% of sleep apnea. No technical paper yet (this was a cardiology conference), but we have some follow-up work in submission to an academic artificial intelligence conference, so hopefully we'll have a technical paper with more details out soon.
canttestthis 9y ago
Do you have plans to commercialize this?
- JumpCrisscross 9y ago
  > Do you have plans to commercialize this? Cardiogram is a venture-backed company.
  - brandonb 9y ago
    That's correct. More from our investors: https://a16z.com/2016/10/20/cardiogram/ https://homebrewvc.tumblr.com/post/152080260668/your-heart-beats-102000-times-a-day-cardiogram
ForFreedom 9y ago
What do you do with the data collected via your app? Whats the end result of your research? Did the 70% people you collected data are aware?
- brandonb 9y ago
  The 70% of people were aware—they enrolled in an IRB-approved study with UCSF Health eHeart Study, and went through an explicit informed consent process (as medical research generally requires). We wrote a bit more about the end goal in the last section of the blog post here: https://blog.cardiogr.am/screening-for-hypertension-and-sleep-apnea-with-deepheart-416c9bc03efc https://blog.cardiogr.am/screening-for-hypertension-and-slee...
fleetingmoments 9y ago
What input signals do you have access to through the Apple Watch? Is it only Heart Rate output or do you get the actual interbeat intervals? Any chance of getting to the raw ADC output of the photodiode?
- rvanmil 9y ago
  I've written a blog about this a while ago [0]. You're limited to what HealthKit allows you to query and the RR intervals are not available. With the release of WatchOS 4 however the SDNN heart rate variability can be queried. [0] https://www.vanmil.org/heart-rate-variability-and-brain-waves/ https://www.vanmil.org/heart-rate-variability-and-brain-wave...
  - fleetingmoments 9y ago
    Interesting, thanks!
  - brandonb 9y ago
    Yes. Apple Watch takes measurements every five minutes (no RR intervals yet). There are a few popular watches, like Garmin, that do support RR intervals.
xrayarx 9y ago
Is it this https://itunes.apple.com/de/app/cardiogram-for-apple-watch/id1000017994?mt=8 https://itunes.apple.com/de/app/cardiogram-for-apple-watch/i... ? Could you please state, if the app can currently do that?

I'm one of the co-founders of Cardiogram and involved in this study -- happy to answer questions if folks have them! (EDIT: heading to bed, but will answer questions in the morning!)

ISL 9y ago

I didn't see a reference in the TechCrunch article -- is there a technical paper out? Edit: A presentation is linked, as "study": Link to presentation: http://www.abstractsonline.com/pp8/#!/4412/presentation/45220 http://www.abstractsonline.com/pp8/#!/4412/presentation/4522... A followup: Does the neural network provide some extra insight into what part of the waveform/time-series of pulses is able to provide predictive information?

deleted 9y ago
[deleted]
brandonb 9y ago
Correct -- the abstract will be included in a special issue of Circulation: http://circ.ahajournals.org/content/136/Suppl_1/A21042 http://circ.ahajournals.org/content/136/Suppl_1/A21042 The study was presented at the American Heart Association's Scientific Sessions earlier today. We included some details beyond what appears in the TechCrunch article in a blog post here: https://blog.cardiogr.am/screening-for-hypertension-and-sleep-apnea-with-deepheart-416c9bc03efc https://blog.cardiogr.am/screening-for-hypertension-and-slee... I'd expect a more mature version of this work to appear in a medical journal, but that often takes 6-12 extra months.
- ktta 9y ago
  Couldn't find the measurement process. What is the common root cause of error? Inaccuracies in measurement or the model classifying data incorrectly?
bertil 9y ago
Sorry for the habitual rant, but I feel the need to point out those are not open articles. Your case is typically something of interest to people who have no reason to have access to medical journal stores and… :( This thread is not the right place to grab pitchforks, just a reminder open source science was still an on-going effort.

nopinsight 9y ago

What are the false positive and false negative rates for sleep apnea detection? Would it be able to detect sub-clinical symptoms? Second the other comment on technical paper. Is it available?

brandonb 9y ago
The accuracies quoted here are c-statistics, or area under the ROC curve. An example operating point for sleep apnea is 97% specificity with a sensitivity of 52% (compared to a 20% diagnosis rate in today's healthcare system). If a specificity of 82% is acceptable, then we can detect about 75% of sleep apnea. No technical paper yet (this was a cardiology conference), but we have some follow-up work in submission to an academic artificial intelligence conference, so hopefully we'll have a technical paper with more details out soon.

canttestthis 9y ago

Do you have plans to commercialize this?

JumpCrisscross 9y ago
> Do you have plans to commercialize this? Cardiogram is a venture-backed company.
- brandonb 9y ago
  That's correct. More from our investors: https://a16z.com/2016/10/20/cardiogram/ https://homebrewvc.tumblr.com/post/152080260668/your-heart-beats-102000-times-a-day-cardiogram

ForFreedom 9y ago

What do you do with the data collected via your app? Whats the end result of your research? Did the 70% people you collected data are aware?

brandonb 9y ago
The 70% of people were aware—they enrolled in an IRB-approved study with UCSF Health eHeart Study, and went through an explicit informed consent process (as medical research generally requires). We wrote a bit more about the end goal in the last section of the blog post here: https://blog.cardiogr.am/screening-for-hypertension-and-sleep-apnea-with-deepheart-416c9bc03efc https://blog.cardiogr.am/screening-for-hypertension-and-slee...

fleetingmoments 9y ago

What input signals do you have access to through the Apple Watch? Is it only Heart Rate output or do you get the actual interbeat intervals? Any chance of getting to the raw ADC output of the photodiode?

rvanmil 9y ago
I've written a blog about this a while ago [0]. You're limited to what HealthKit allows you to query and the RR intervals are not available. With the release of WatchOS 4 however the SDNN heart rate variability can be queried. [0] https://www.vanmil.org/heart-rate-variability-and-brain-waves/ https://www.vanmil.org/heart-rate-variability-and-brain-wave...
- fleetingmoments 9y ago
  Interesting, thanks!
- brandonb 9y ago
  Yes. Apple Watch takes measurements every five minutes (no RR intervals yet). There are a few popular watches, like Garmin, that do support RR intervals.

xrayarx 9y ago

Is it this https://itunes.apple.com/de/app/cardiogram-for-apple-watch/id1000017994?mt=8 https://itunes.apple.com/de/app/cardiogram-for-apple-watch/i... ? Could you please state, if the app can currently do that?