The goal of my project was to explore how heart rate can implicitly express emotion. A faster heart rate can mean many different things, from adrenaline, to fear, to excitement. In this specific case, I wanted to see how an increased heart rate can be linked to negative emotions associated with being off-balance.
As you knock the person off-balance, the heart rate increases rapidly. Once the person is back on his feet, the heart rate returns to a steadier, more relaxed rhythm. The heart rate is represented by a string of LEDs in the shape of a heart mounted on a protoboard. The protoboard is mounted to a servo, which moves in rhythm with the heart beat. The person is hand carved from a bar of soap, with an accelerometer embedded in its back.
All details (Arduino sketch, demo video, etc.) can be found here: