A method for measuring blood oxygen content under low perfusion, which is
used in a device for measuring blood oxygen content, includes the steps
of: initializing the device that is applied with power, collecting and
processing data with a driving circuit of light emitting device, a bias
circuit, a gain circuit and an A/D sampling circuit, which are controlled
under a core control module; calculating blood oxygen saturation based on
the collected data with a data processing module which integrates the
collected data in a period of time with an area integration method; and
outputting from a communication functional module results of the blood
oxygen saturation or pulse rate calculated with the data processing
module. The method further includes a decision step of deciding the two
results acquired from the data processing module with the waveform method
and the integration method respectively based on the intensity of the
measured signal and generating the final measured result, performed by a
decision unit included in the device. By adopting the above method, the
disturbance to effective signal by noise can be eliminated. As a result,
the measuring accuracy of blood oxygen content under low perfusion can be
improved without increasing the production cost for the measuring device.