Is my heart still beating? Build yourself a DIY heart pulsing pendant that shows you exactly when your heart beats via its LED lights.
I think they can make this even more advanced if it can display the actual heart beats per minute. That might be a helluva heart attack-sensing device.
While reading through Charles Platt’s excellent book Make: Electronics, I came across this nice little circuit for making a gentle pulsing LED. I built it for fun, and was struck by the “humanness” of the pulse, but couldn’t figure out what to do with it. Later I found a heart-shaped tag on some pants I had bought, and well, this is the result. I opted to use mainly scrap parts salvaged from various sources. I liked the hacky recycled feel that gave it.