For several years I have been working with biofeedback now (see my intro post here: https://steemit.com/introduceyourself/@beervangeer/hi-steemit-i-am-biofeedback-artist-and-want-to-introduce-the-idea-of-blockchain-as-biofeedback-for-society).
I translate physiological patterns into visual and auditive feedback.
My main focus lays on the heart.

A lot of people are not aware of how much you can influence your heart rate by breathing. And how much the heart rate influence all of the other functions in your body.
Did you know that the heart is electrically much more powerful than the brain?

A few years ago I created this installation the BioDome (together with Jarno Burger) where I tought people by breathing exercises to create shapes, colors and sounds by giving feedback on the heart.
Please see a demonstration video over here: https://vimeo.com/57979514

https://s32.postimg.org/ycwprj9l1/Capture.jpg


Different breathing patterns give you a direct physiological effect.
Did you know that when you breath in your heartrate goes faster, and when you breath out your heart rate goes slower?
This variation that you create every second is called Heart Rate Variability.
A lot of people think that your heart rate is constant, like you see in the sportsschool or at the doctor, but thats a average you see. You heart-rate is changing every second, and you can effect it by focusing on your breath.

Someone who is really good in explaining the effect of breathing on the human heart and the effect on the rest of your physiology is Allan Watkins.
I advice, learn about HRV!

https://www.youtube.com/watch?v=q06YIWCR2Js

https://www.youtube.com/watch?v=7c3AVj66ahg