A new heart rate sensor!

The wireless Polar heart rate sensor setup is a pain- the strap has to be on just right with enough moisture on the skin to pick up the signal. Also, any electroluminescent system (EL wire, panel, etc) interfered with the Polar frequency. So I was psyched to find a new wired sensor: http://pulsesensor.com/ I haven't messed around with it yet, but it looks promising.

Parts List and vague instructional for version 1.0

With my sights set on a simpler, more fashionable design, I figure I would recap what I did for the first version of this project starting with a partial parts list from Sparkfun. Additional items not on the list are: wire, resistors, connectors, a parts case, heart rate monitor strap, and a switch.

The basic idea is this: The hrmi board gets a wireless signal from the strap sensor. The board is connected to the arduino and is communicating using i2c. The arduino then changes the text display and LED brightness and color settings and voila the heart on the front pulses with the wearer's heart rate and changes from blue to red as the heart rate goes up. Also, the white LEDs on the back of the shirt pulse with the heart rate.

This is not a one to one pulse display, but the hrmi takes an error-corrected average of the user's heart rate over time. If you'd like to see the source code let me know, but eventually I will be sharing it on GitHub.

A long lost update.

This summer and fall I worked on the heart rate monitor shirt and took a newer version to Burning Man. What's new? I got rid of the single LEDs on the front of the shirt and am now using a light pipe from SparkFun with an RGB LED at the end. Unfortunately this didn't look much better than before, but was a smoother and more obvious heart. Also, I crammed all the control boards and battery into a smaller box.

I have been trying to get one of these wired pulse sensors for detecting the heart rate instead of the wireless Polar heart rate monitor strap that talks to the SparkFun HRMI. Once I get one I will embark on a complete rebuild from the ground up.

Fail

Versions one and two of this project failed. With both I was trying to use a stretchy athletic vest with the heart rate monitor built in. The problem is that the shirt stretches a lot, but the Lilypad conductive thread does not. There were also issues of crossed wires and just too many connections too close to each other. My new plan is as follows: find a vest made of non-stretchy material and with a liner that I will remove for sewing in wiring. Also, I will not use the conductive thread as it is pretty fragile and doesn't seem to have a long lifespan.

I'll probably do a design as follows: Red/Green/Blue LEDs on the back arranged in the shape of a heart. Numeric display on the front and more LEDs and possibly the SparkFun Open Heart Display on the front as well.

it works... mostly

I went to an awesome Valentine's day party recently where I knew there would be some creative outfits, so I decided to crank out some working version of the heart rate monitor vest. I think there are some better images out there, but this is all I have for now:
This is the system working without the shirt on, the number displayed is my current heart rate:

I sewed the leds, lilypad board, and the lilypad power supply into the vest. The battery and heart rate monitor interface are in a pocket inside the front of the shirt. The shirt did not always pick up the heart rate. I think this was because I was not sweating enough. Maybe next time I will put some salt water on the sensors. Also there were some software bugs and I think some of the conductive threads got crossed.

Mostly, people did not realize this was pulsing with my heart rate. I set up a range from 60-160 bpm where the shirt would always pulse atleast 60 bpm(all blue) and pulse up to 160 bpm, slowly becoming all red.

Up next: fix software bugs, maybe range the colors from 70-160 bpm. Also, more lights!

This worked pretty well considering that I finished the thing a few hours before heading off to the party.

Welcome

I'm starting this blog to document the progress of a project that I thought of a few months ago: the heart rate monitor vest. The basic idea is that there is an arrangement of LEDs sewn in to the vest that change based on the user's heart rate. Maybe a slow pulse and cool colors for a slow heart rate and faster, warmer colors for a higher rate. I have all sorts of ideas for accessories, but for now I just want to get a prototype running.


I think that the electronics for this project are not going to be too difficult. Sparkfun Electronics here in Boulder has all kinds of cool stuff that should make this project easier including the LilyPad system of easily sewable circuitry. Also, I'll be using an Arduino controller as the brain and a 7-segment display  to output the user's heart rate in beats per minute. I just ordered a shirt with a built-in heart rate sensor/transmitter from NuMetrex. Sparkfun sells a heart rate monitor interface that can pick up the signal from the shirt.