Webcam Pulse Detector • Hacker News Board

Re: Webcam Pulse Detector

#11

Post by dr_ » Tue, Apr 16, 2013, 4:43 AM UTC

Interesting. There was a Rock Health company that created an app using this technology. The app is called Cardiio. I know the founders were from MIT/Harvard but can't recall if they were the same people who conducted this research.

Re: Webcam Pulse Detector

#12

Post by acgourley » Tue, Apr 16, 2013, 4:45 AM UTC

toomuchtodo wrote: post #8

dyno12345 wrote: post #4

I want to point it at crowds and get an aggregate crowd-pulse rate! Measure the excitement!

I expect to see this used by DJs, where the momentum of the music is controlled by the crowd.

Need way more light than that for a standard camera... now, maybe with an IR camera...

Re: Webcam Pulse Detector

#13

Post by pstuart » Tue, Apr 16, 2013, 5:00 AM UTC

Add some software to do expression analysis a la Paul Ekman [1] and one has a remote non-invasive "lie detector".

[1] https://www.paulekman.com/

Re: Webcam Pulse Detector

#14

Post by timothybone » Tue, Apr 16, 2013, 5:29 AM UTC

This looks great for a music performance stunt -- the audience doesn't know but the DJ rigged up a webcam as a trigger!

Re: Webcam Pulse Detector

#15

Post by jacobjbernstein » Tue, Apr 16, 2013, 5:33 AM UTC

Awesome. Could open up a whole field of applications.

Re: Webcam Pulse Detector

#16

Post by tamersalama » Tue, Apr 16, 2013, 5:35 AM UTC

I haven't been amazed for a while. Thank you.

Re: Webcam Pulse Detector

#17

Post by leed25d » Tue, Apr 16, 2013, 5:41 AM UTC

Great App for poker players

Re: Webcam Pulse Detector

#18

Post by dlgeek » Tue, Apr 16, 2013, 5:43 AM UTC

Has anyone been able to get it to work? Whenever I try to open the stats display, I get:

OpenCV Error: Assertion failed (p.checkVector(2, CV_32S) >= 0) in polylines, file /tmp/buildd/opencv-2.3.1/modules/core/src/drawing.cpp, line 2064

Re: Webcam Pulse Detector

#19

Post by vacri » Tue, Apr 16, 2013, 6:05 AM UTC

nl wrote: post #10

hcarvalhoalves wrote: post #6

How precise is this, do we have data? I'm guessing it depends on the refresh rate of your webcam.

It's precise enough for the application. Webcams typically have a 15-30 fps framerate. Heartrates are typically 30-200 bpm (~= 0.5 to 3.3 bps).

The duration of the pulse is much shorter than the beat, though. Should still be visible at that framerate, just noting that pulses aren't sinewaves :)

Re: Webcam Pulse Detector

#20

Post by afhof » Tue, Apr 16, 2013, 6:10 AM UTC

nl wrote: post #10

hcarvalhoalves wrote: post #6

How precise is this, do we have data? I'm guessing it depends on the refresh rate of your webcam.

It's precise enough for the application. Webcams typically have a 15-30 fps framerate. Heartrates are typically 30-200 bpm (~= 0.5 to 3.3 bps).

It seems that the Nyquist-Shannon sampling rate would be too low for the results to be accurate.