Active-pulse blood analysis system

• US 10,610,139 B2
• Filed: 08/07/2017
• Issued: 04/07/2020
• Est. Priority Date: 01/16/2013
• Status: Active Grant

• Current Assignee: Masimo Corporation
• Original Assignee: Masimo Corporation
• Inventors: Kiani, Massi Joe E., Paul, Mathew, Chen, Jesse, Lamego, Marcelo M.
• Primary Examiner(s): Winakur, Eric F
• Application Number:
  US15/670,405
• Publication Number:
  US 20180146902A1
• Time in Patent Office: 974 Days
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/6826 Finger
• CPC Class Codes: A61B 5/7207 of noise induced by motion artifacts
• CPC Class Codes: A61B 5/721 using a separate sensor to detect motion or using motion information derived from signals other than the physiological signal to be measured

Abstract

An active-pulse blood analysis system has an optical sensor that illuminates a tissue site with multiple wavelengths of optical radiation and outputs sensor signals responsive to the optical radiation after attenuation by pulsatile blood flow within the tissue site. A monitor communicates with the sensor signals and is responsive to arterial pulses within a first bandwidth and active pulses within a second bandwidth so as to generate arterial pulse ratios and active pulse ratios according to the wavelengths. An arterial calibration curve relates the arterial pulse ratios to a first arterial oxygen saturation value and an active pulse calibration curve relates the active pulse ratios to a second arterial oxygen saturation value. Decision logic outputs one of the first and second arterial oxygen saturation values based upon perfusion and signal quality.

Claims

1. An active-pulse blood analysis system comprising:

an optical sensor that illuminates a tissue site with multiple wavelengths of optical radiation and that outputs sensor data responsive to the optical radiation after attenuation by pulsatile blood flow within the tissue site;

one or more filters configured to receive the sensor data and separate the sensor data into arterial pulse data and active-pulse data, wherein the one or more filters comprise a first bandpass filter having a first passband configured to generate the arterial pulse data and a second bandpass filter having a second passband configured to generate the active-pulse data;

one or more memory devices storing an arterial calibration curve that relates arterial pulse ratios to oxygen saturation values;

one or more processor configured to;

receive the arterial pulse data and active-pulse data,

generate an arterial ratio from the arterial pulse data,

generate an active-pulse ratio from the active-pulse data,

output an arterial saturation value (SpO₂) by comparing the generated arterial ratio to the arterial calibration curve, and

output a venous oxygen saturation value (SpvO₂^A) by comparing the generated active-pulse ratio to the arterial calibration curve.

2. The active-pulse blood analysis system of claim 1, wherein the arterial calibration curve is numerically-derived by correlating arterial blood draws with corresponding sensor data responsive to pulsatile arterial blood flow.

3. The active-pulse blood analysis system of claim 2, wherein the arterial calibration curve comprises a lookup table.

4. The active-pulse blood analysis system of claim 1, wherein the first pass band is at a lower range of frequencies and the second pass band is at a higher range of frequencies.

5. An active-pulse blood analysis method comprising:

receiving sensor data responsive to optical radiation after attenuation by pulsatile blood flow within the tissue site from an optical sensor that illuminates a tissue site with multiple wavelengths of optical radiation;

filtering the sensor data to separate the sensor data into arterial pulse data and active-pulse data using a first bandpass filter that has a first passband configured to generate the arterial pulse data and a second bandpass filter that has a second passband so as to generate the active-pulse data;

calculating an arterial ratio from the arterial pulse data;

calculating an active-pulse ratio from the active-pulse data;

outputting an arterial saturation value (SpO₂) by comparing the calculated arterial ratio to an arterial calibration curve that relates arterial pulse ratios to oxygen saturation values;

outputting a venous oxygen saturation value (SpvO₂^A) by comparing the generated active-pulse ratio to the arterial calibration curve.

6. The active-pulse blood analysis method of claim 5, wherein the arterial calibration curve is numerically-derived by correlating arterial blood draws with corresponding sensor data responsive to pulsatile arterial blood flow.

7. The active-pulse blood analysis method of claim 6, wherein the arterial calibration curve comprises a lookup table.

8. The active-pulse blood analysis system of claim 5, wherein the first pass band is at a lower range of frequencies and the second pass band is at a higher range of frequencies.

9. An active-pulse blood analysis method comprising:

inputting optical sensor data;

filtering the optical sensor data into arterial pulse data at a lower range of frequencies and active pulse data at a higher range of frequencies using a first bandpass filter that has a first passband configured to generate the arterial pulse data and a second bandpass filter that has a second passband so as to generate the active-pulse data;

calculating arterial pulse ratios from the arterial pulse data;

calculating active pulse ratios from the active pulse data;

applying an arterial calibration curve stored in one or more memory devices to the arterial pulse ratios so as to generate an SpO₂ parameter indicative of arterial oxygen saturation; and

applying the arterial calibration curve stored in the one or more memory devices to the active pulse ratios so as to generate an SpvO₂^A parameter indicative of venous oxygen saturation.

10. The active-pulse blood analysis method of claim 9, wherein the arterial calibration curve is numerically-derived by correlating arterial blood draws with corresponding sensor data responsive to pulsatile arterial blood flow.

11. The active-pulse blood analysis method of claim 10, wherein the arterial calibration curve comprises a lookup table.