EKG with the SpikerBox?

I taped wet cotton gauze around two fingertips, and inserted the SpikerBox electrodes into the gauze.  Viewed the output on xoscope: sure looks like an EKG.  Time units seem wrong – it looks like about 8 ms between heartbeats, and I know that my heart rate is not that fast (this would be about 125 bpm).  Maybe recording from two finger gives redundant signals?  If I recorded each heartbeat twice then a rate of about 63 bpm would be about right for me.  Certainly the wave form looks right.  I provide a photo of my preparation, a screenshot from xoscope, and a graph constructed from the saved data (with arbitrary units).

Edit (4 hrs later): A close examination of the traces shows that each beat is being recorded twice – each of a pair of similar sized traces is an inverted version of its mate.  So: a beat is recorded with Finger-1 positive relative to Finger-2, then 2 positive relative to 1.  I love science!

Please follow and like:
  • By Tim Marzullo, January 17, 2011 @ 12:13 pm

    Thanks for the doing the experiment we always wondered. Looking at your traces though, the XO output is 2 ms/div, not 2 s/div. Thus, it looks like the signal is ~120 beats per second, which may be a harmonic of the dreaded 60 Hz line noise. If your labtop is plugged into the line voltage, the 60 Hz will dominate, so I do all labtop recordings on battery power.
    Since the SpikerBox can record EMG, perhaps better placement of electrodes, like Ian says, may enable the EKG. I am thinking of making a low pass filtered SpikerBox prototype. Thanks!

  • By WJWilson, January 17, 2011 @ 12:34 pm

    Laptop was unplugged. Shape of the pulse is the typical Q-R-S of an EKG, possibly with the P and T components as well. I’ll keep playing with it.

Other Links to this Post

WordPress Themes