US 8,275,434 B2 · Method for measuring blood oxygen content under low perfusion

Abstract

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 cone 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.

Claims22

Dependent claims

A method for measuring blood oxygen content under low perfusion, the method comprising:

receiving signals from a light-receiving device representing intensities of two different wavelengths of light attenuated by body tissue;
converting the signals, using an analog-to-digital converting circuit, into digital data;
collecting, in a memory of a patient monitoring device, the data representative of the intensities of light over a period of time that includes more than one cycle, wherein the collected data is cyclical to indicate blood pulsing through the body tissue;
integrating, by a microprocessor, the collected data in the memory over the period of time that includes more than one cycle using an area integration method that determines an area between the collected data and a normalized value of the collected data;
and
determining, by the microprocessor, based at least in part on the integration of the collected data, a first value of blood oxygen saturation.

3 more elements

A patient monitoring device for measuring blood oxygen content under low perfusion, the device comprising:

a sensor to receive signals from a light-receiving device representing intensities of two different wavelengths of light attenuated by body tissue;
and
a data processing circuit to:
convert the signals, using an analog-to-digital converting circuit, into digital data;
collect, in a memory of a patient monitoring device, the data representative of the intensities of light over a period of time that includes more than one cycle, wherein the collected data is cyclical to indicate blood pulsing through the body tissue;
integrate, by a microprocessor, the collected data in the memory over the period of time that includes more than one cycle using an area integration method that determines an area between the collected data and a normalized value of the collected data;
and
determine, by the microprocessor, based at least in part on the integration of the collected data, a value of blood oxygen saturation.

5 more elements

A system for measuring blood oxygen content under low perfusion, the system comprising:

means for receiving signals from a light-receiving device representing intensities of two different wavelengths of light attenuated by body tissue;
means for converting the signals, using an analog-to-digital converting circuit, into digital data;
means for collecting the data representative of the intensities of light over a period of time that includes more than one cycle, wherein the collected data is cyclical to indicate blood pulsing through the body tissue;
means for integrating, by a microprocessor, the collected data in the memory over the period of time that includes more than one cycle using an area integration method that determines an area between the collected data and the normalized value of the collected data;
and
means for determining, by the microprocessor, based at least in part on the integration of the collected data, a first value of blood oxygen saturation.

3 more elements

Dependencies are inferred from the claim text.

Method for measuring blood oxygen content under low perfusion

Life of this patent

Method for measuring blood oxygen content under low perfusion

Life of this patent

Abstract

Claims22