[Cyborg] medical mirror

Eric Boyd mrericboyd at yahoo.com
Mon Oct 11 20:03:16 UTC 2010

My guess would be that they can't really get HRV.  It looks to me like 
their analysis system requires multiple beats just to get the heart-rate 
accurately (they do the equivalent of an FFT to get it). But given that 
they can get HR at all, I'm sure getting HRV is just a matter of time. 
Might be hard with only 15Hz webcam though - if my calculations are 
right that limits intra-beat timings to +/-4BPM, yes?  Or could you 
calculate HRV over a big data set?!?

I am looking forward to having my new pulse-choker stuff (using polar 
heart rate receiver and a heart-shaped circuit I have designed), I'm 
totally gonna hack a logger into one of them and when I do so I'll share 
the data here :-).


On 10/9/10 6:03 PM, Tomm wrote:
> A tray app that monitors your heart rate is a great idea.  I wonder if
> the time resolution is good enough to measure heart rate variation
> (HRV)?  Variations in heartrate is also pretty interesting:
> "[...] asked 52 adults to report how often they experienced positive
> emotions like happiness, awe, and gratitude and how socially connected
> they felt in their social interactions every day for a period of nine
> weeks. The researchers also measured the HRV of each individual at the
> beginning and end of the study by measuring heart rate during a
> two-minute session of normal breathing. HRV at the beginning of the
> study predicted how quickly people developed positive feelings and
> experiences of social connectedness throughout the nine-week period. In
> addition, experiences of social connectedness predicted increases in HRV
> at the end of the study, demonstrating a reciprocal relationship between
> heart rate and having satisfying social experiences."
> http://www.scientificamerican.com/article.cfm?id=the-neuroscience-of-heart
>       Tom
> On Sat, Oct 9, 2010 at 8:21 AM, Eric Boyd <mrericboyd at yahoo.com
> <mailto:mrericboyd at yahoo.com>> wrote:
>     http://www.youtube.com/watch?v=LyWnvAWEbWE&feature=player_embedded
>     <http://www.youtube.com/watch?v=LyWnvAWEbWE&feature=player_embedded>
>     Basically, using nothing other than a webcam (1.3MP, 15 Hz!), they can
>     read your heart rate.  Then they built that into a "medical mirror", so
>     you can see your heart beat in the morning when you brush your teeth :-)
>     I found one of his papers about it online, full text:
>     Non-contact, automated cardiac pulse measurements using video imaging
>     and blind source separation
>     http://www.opticsinfobase.org/abstract.cfm?URI=oe-18-10-10762
>     Looks to me like the big breakthrough here is the motion independence,
>     which they got through a combination of face recognition and cropping
>     and separating the video into it's three component colors.  They claim
>     an average error from the reference pulseox reading of less than 1 BPM
>     even with movement, that's pretty impressive.
>     Anyone want to write a laptop app which would just keep the webcam on
>     all the time and log your heartbeat?
>     Eric
>     _______________________________________________
>     Cyborg mailing list
>     Cyborg at lists.noisebridge.net <mailto:Cyborg at lists.noisebridge.net>
>     https://www.noisebridge.net/mailman/listinfo/cyborg

More information about the Cyborg mailing list