Abstract: A method for measuring blood flow velocity comprises: placing a first and second blood vessel signal detectors on a body of a person to be measured in such a manner that the first and second blood vessel signal detectors are located a predetermined distance from each other; amplifying blood signal detected by the first and second blood vessel signal detectors; using the first and second blood vessel signal analyzers to record the blood signal at a predetermined time interval; setting an interval of time from the moment a specific blood vessel signal appears in a record of the first blood vessel signal analyzer to the moment the specific blood vessel signal appears in a record of the second blood vessel signal analyzer to be a predetermined time period; and dividing a value of the predetermined distance by a value of the predetermined time period can get a blood flow velocity.

Abstract: A system and method of measuring blood circulation velocity includes the steps of keeping a person measured by a blood oxygen saturation analytical instrument and served by a ventilator; setting an initial time point, providing a first gas to the person via the ventilator, and starting to record a blood oxygen saturation value per predict time interval; providing a second gas to the person at a first time point; providing a third gas to the person 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.

Abstract: 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.