Heart Rate Recorder

[Lorenzo M. Oliver]

http://www.parallax.com/tabid/816/Default.aspx

This began as a project after I had a heart attack on April 27, 2008. I was enrolled in Cardiac Rehab at Fla Hospital and was "encouraged" to get a Heart Rate Monitor. The nurses suggested I look at Polar and after a little searching; I purchased a Polar FS-3 from Amazon. It worked just fine, but after getting back to biking, I became curious what my Heart Rate was doing along the ride.

The FS-3 is an un-encoded model and puts out a 10ms burst of 5 KHz for each heart beat. I figured I could just sample this burst and store the interval data to be retrieved later. It turns out that this was the case and I developed a little recorder that I mount on the handlebars that does the deed. I will describe how it works and how to build it below.