Method of Measuring Blood Circulation Velocity by Controlling Breath

A method of measuring blood circulation velocity by controlling a person's breath includes the steps of keeping the person in a first breathing status with a blood oxygen saturation analytical instrument; setting an initial time point and starting to record a blood oxygen saturation value per predict time interval; requesting the person to change into a second breathing status at a first time point; requesting the person to change into a third breathing status at a second time point; stopping recording the blood oxygen saturation value at a terminal time point; setting a reference time point according to the blood oxygen saturation value which has a variation according to the records; obtaining the person's blood circulation velocity, which is proportional to the reciprocal of the difference of the reference time point and the first time point.