SIMULTANEOUS MEASUREMENT OF PULSE AND REGIONAL BLOOD OXYGEN SATURATION

• US 20140073886A1
• Filed: 11/15/2013
• Published: 03/13/2014
• Est. Priority Date: 11/12/2009
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Covidien LP (Medtronic Plc)
• Inventors: Li, Youzhi, Chen, Bo, McKenna, Edward M., Addison, Paul Stanley
• Granted Patent: US 9,357,954 B2
• Time in Patent Office: Days
• US Class Current: 600/323
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/7203 for noise prevention, reduction or removal
• CPC Class Codes: A61B 5/726 using Wavelet transforms

Abstract

Methods and systems are provided that allow for the simultaneous calculation of pulse and regional blood oxygen saturation. An oximeter system that includes a sensor with a plurality of emitters and detectors may be used to calculate a pulse and/or regional blood oxygen saturation. A plurality of light signals may be emitted from light emitters. A first light signal may be received at a first light detector and a second light signal may be received at a second light detector. A pulse and/or regional blood oxygen saturation value may be calculated based on the received first and/or second light signals. The pulse and regional blood oxygen saturation values may be calculated substantially simultaneously. The calculated pulse and regional blood oxygen saturation values as well as other blood oxygen saturation values may be displayed simultaneously in a preconfigured portion of a display.

Claims

1. A method for calculating blood oxygen saturations, the method comprising:

receiving a first light signal corresponding to a first mean path length through tissue of a subject;

receiving a second light signal corresponding to a second mean path length through tissue of the subject;

calculating, using a processor, a pulse blood oxygen saturation based on at least one of the first and second light signals;

calculating, using a processor, a regional blood oxygen saturation based on the first and second light signals; and

calculating, using a processor, a venous blood oxygen saturation based on the pulse blood oxygen saturation and the regional blood oxygen saturation.

2. The method of claim 1, wherein calculating the venous blood oxygen saturation is further based on a weighting.

3. The method of claim 1, wherein calculating the venous blood oxygen saturation comprises subtracting a weighted pulse blood oxygen saturation from the regional blood oxygen saturation.

4. The method of claim 1, further comprising simultaneously displaying the venous blood oxygen saturation, the regional blood oxygen saturation, and the pulse blood oxygen saturation.

5. The method of claim 4, wherein the displayed size of one of the venous blood oxygen saturation, the regional blood oxygen saturation, and the pulse blood oxygen saturation is larger than the displayed size of a different one of the venous blood oxygen saturation, the regional blood oxygen saturation, and the pulse blood oxygen saturation.

6. The method of claim 4, wherein the displayed color of one of the venous blood oxygen saturation, the regional blood oxygen saturation, and the pulse blood oxygen saturation is different than the displayed color of a different one of the venous blood oxygen saturation, the regional blood oxygen saturation, and the pulse blood oxygen saturation.

7. The method of claim 1, wherein the first light signal comprises a first light component corresponding to a first wavelength of light and a second light component corresponding to a second wavelength of light and wherein the second light signal comprises a first light component corresponding to the first wavelength of light and a second light component corresponding to the second wavelength of light.

8. The method of claim 7, further comprising emitting the first wavelength of light and the second wavelength of light at a first location on the subject, wherein the first mean path length extends from the first location on the subject to a second location on the subject, wherein the second mean path length extends from the first location on the subject to a third location on the subject, and wherein the distance between the first location and the second location is greater than the distance between the first location and the third location.

9. The method of claim 1, wherein calculating the pulse blood oxygen saturation comprises a ratio-of-ratios technique and wherein calculating the regional blood oxygen saturation involves a differencing technique.

10. The method of claim 1, wherein calculating the pulse blood oxygen saturation comprises pre-processing the first light signal using a first technique and the calculating the regional blood oxygen saturation comprises pre-processing the first light signal using a second technique.

11. A system for calculating blood oxygen saturations, the system comprising:

one or more processors configured for;

receiving a first light signal corresponding to a first mean path length through tissue of a subject;

receiving a second light signal corresponding to a second mean path length through tissue of the subject;

calculating a pulse blood oxygen saturation based on at least one of the first and second light signals;

calculating a regional blood oxygen saturation based on the first and second light signals; and

calculating a venous blood oxygen saturation based on the pulse blood oxygen saturation and the regional blood oxygen saturation.

12. The system of claim 11, wherein calculating the venous blood oxygen saturation is further based on a weighting.

13. The system of claim 11, wherein calculating the venous blood oxygen saturation comprises subtracting a weighted pulse blood oxygen saturation from the regional blood oxygen saturation.

14. The system of claim 11, further comprising a display, wherein the one or more processors are further configured for simultaneously displaying the venous blood oxygen saturation, the regional blood oxygen saturation, and the pulse blood oxygen saturation on the display.

15. The system of claim 14, wherein the displayed size of one of the venous blood oxygen saturation, the regional blood oxygen saturation, and the pulse blood oxygen saturation is larger than the displayed size of a different one of the venous blood oxygen saturation, the regional blood oxygen saturation, and the pulse blood oxygen saturation.

16. The system of claim 14, wherein the displayed color of one of the venous blood oxygen saturation, the regional blood oxygen saturation, and the pulse blood oxygen saturation is different than the displayed color of a different one of the venous blood oxygen saturation, the regional blood oxygen saturation, and the pulse blood oxygen saturation.

17. The system of claim 11, wherein the first light signal comprises a first light component corresponding to a first wavelength of light and a second light component corresponding to a second wavelength of light and wherein the second light signal comprises a first light component corresponding to the first wavelength of light and a second light component corresponding to the second wavelength of light.

18. The system of claim 17, further comprising light emitter configured for emitting the first wavelength of light and the second wavelength of light at a first location on the subject, wherein the first mean path length extends from the first location on the subject to a second location on the subject, wherein the second mean path length extends from the first location on the subject to a third location on the subject, and wherein the distance between the first location and the second location is greater than the distance between the first location and the third location.

19. The system of claim 11, wherein calculating the pulse blood oxygen saturation comprises a ratio-of-ratios technique and wherein calculating the regional blood oxygen saturation involves a differencing technique.

20. The system of claim 11, wherein calculating the pulse blood oxygen saturation comprises pre-processing the first light signal using a first technique and the calculating the regional blood oxygen saturation comprises pre-processing the first light signal using a second technique.