This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
Synchrony large. en COHERENCE LLC acknowledges that you are free to share distribute and transmit the graphic of Valsalva Wave Pro presenting coherent Valsalva Wave and heart rate you are free to adapt the work for purposes of the Coherent Breathing article you are free to use with the conditions that you attribute the graphic