Tick-Tock Ton CoeurDecember 26th, 2009 by tekromancr received 2 Comments »
My next project:
A gear powered mechanical heart!
. . . sort of.
Actually, it will be a wearable mechanical heart shaped heart rate display. The project is comprised of three parts.
1) The Heart rate monitoring unit.
I plan on accomplishing this with a home made pulse-oximetry unit. This works by shining high intensity IR-light through the skin and measuring the amount of returned light. Conveniently, the amount of light returned coincides with the rising and falling of ones heart rate.
2)The filtering/processing/amplification circuitry
This part I am a little bit less clear on. Obviously, I need to process the signal in such a way that the motor in step three spins ever so slightly every time a pulse-beat is detected.
3)The motor/heart/gear assembly
This is the part that is visible to the world. A motor, passed through the back of the heart shaped case, spins a gear inside, hopefully in time to the wearer’s heartbeat.
The heart shaped case (according to the seller) is 27mm, so I need to find a slightly smaller gear (preferably brass) to fit inside of it. I am guessing 18mm just to be in the safe side. Any one know where I can make/purchase such a gizmo?
I have a pretty good idea how I am going to pull steps 1 & 3 off, but my lack of electrical engineering knowledge leaves me at a loss as far as number two is concerned. If all else fails, I could just dump the input onto a lillypad arduino, do signal processing that way, and then control the motor from the arduino.projects