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  • Author Author: fustini
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Setting the Open Heart a flutter

fustini

Howdy,

 

This year I decided to make my own version of the HeartSpark which I gave my girlfriend last year for Valentine's Day:

 

http://www.element14.com/community/blogs/pdp7/2011/02/14/heart-spark-an-open-source-valentine-3

 

I posted last week about the Open Heart LED display that I assembled:

 

http://www.element14.com/community/message/43638

 

I've now connected it and a Polar chest strap receiver chip to an Arduino:

image

By combining source code from the Heartspark and Open Heart, a heart beat animation is played each time a pulse is received:

 

 

The receiver chip is a Polar RMCM-01:

 

http://www.sparkfun.com/datasheets/Wireless/General/RMCM01.pdf

 

It is the same chip as used in the HeartSpark and works with the Polar WearLink 31 chest strap:

 

http://www.amazon.com/Wearlink-31-Transmitter-by-Polar/dp/B001J8W5N2

 

The receiver chip simply outputs a 3V 1ms pulse for each heart beat detected.  My scope shows a pulse about every 1,000 ms when sitting which translates to about 60 bpm:

image

After doing some push-ups, the time between pulses cuts in half which indicates my heart rate has nearly doubled:

image

The Arduino code prints out the BPM and microseconds since previous pulse, and I found it matches what I observed on the scope.   Although I think the code still needs some tweaking, especially for edge cases.  I've attached the current version to this blog post.

 

My plans now are to assemble the Adafruit data logging shield:

 

http://www.adafruit.com/products/243

 

I will use it to log the BPM data with a timestamp to a SD card.  The data can then be plotted later on a computer.

 

I'll use the prototyping area on the data logging shield to solder on Polar receiver & components along with a header for the Open Heart.  My goal is place the Arduino, shield & Open Heart along with a USB power source (like a Duracell cellphone charger) into an enclosure which my girlfriend can take to yoga and set it near her mat.  I'll probably have to add switch to disable the Open Heart animation when needed so it doesn't annoy others.

 

 

Cheers,

Drew

Attachments:
heartbeat.pde.zip
  • in reply to fustini

    Hi Drew,

     

    I know what you mean about a gym, but having recently gone through physical therapy for my knee surgery, I can see where having something like this available for people who need to rebuild movement and strength after accidents.

     

    On the Yoga end, part of the exercises is to bring you body to a state of calmness without overdoing yourself.  Knowing when you are in the zone would encourage people to continue.

     

    I think you could work in ports for an ear piece microphone to record heart beat and breath rate.  I don't know about you, but if I put my fingers in my ears, I can hear each breath and each pulse of the heart.  A microphone should be able to hear the noise, plus blocking the ears with earphones would also let the person concentrate better.

     

    Just a thought.

    DAB

  • in reply to nlarson

    Interesting idea to aggregate sensor data to do 'gamification'.  I could definitely see that applied to a gym setting.  Leaderboards, badges, etc.  Maybe that already exists?  I've not been in a gym since high school image

  • in reply to DAB

    Interesting point.  I would like to record additional biosignals but I'm not sure how I would do it without being too awkward.  If I was doing pulse via IR with fingertip then I could attempt to do an oximeter to get oxygen saturation by using two leds.  But I think that would probably be too obtrusive.  Repistory rate would be interesting too, but I'm not sure how to do that without something on the mouth or nose.  I could see maybe using a mic to listen to breathing and filtering the signal.

  • Very cool!  I wonder if a yoga studio might let you experiment with hooking everyone up to one of these to give a combined class "relaxation score"?  image

  • If you use the color LED's and tie them to heart and breath rate it would be perfect for someone doing yoga.  They would see how quickly they can reach a calm state and know when they are getting agitated.

     

    There are a lot of interesting potential for this little gadget.

     

    DAB