Hypersaturation index

• US 9,775,546 B2
• Filed: 09/11/2015
• Issued: 10/03/2017
• Est. Priority Date: 04/17/2012
• Status: Active Grant

• Current Assignee: Masimo Corporation
• Sponsoring Entity: Masimo Corporation
• Inventors: Diab, Mohamed K., Iyengar, Prashanth, Sampath, Anand, Al-Ali, Ammar
• Primary Examiner(s): WINAKUR, ERIC FRANK
• APPLICATION: US 20160000362A1
• Time in USPTO: 753 Days
• CPC Class Codes: A61B 2562/0238 : Optical sensor arrangements for performing transmission measurements on body tissue
• CPC Class Codes: A61B 5/0205 : Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/14551 : for measuring blood gases
• CPC Class Codes: A61B 5/14552 : Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/6826 : Finger
• CPC Class Codes: A61B 5/7282 : Event detection, e.g. detecting unique waveforms indicative of a medical condition A61B5/4094, A61B5/4818, A61B5/0452, A61B5/0823 take precedence
• CPC Class Codes: A61B 5/7405 : using sound
• CPC Class Codes: A61B 5/743 : Displaying an image simultaneously with additional graphical information, e.g. symbols, charts, function plots
• CPC Class Codes: A61B 5/746 : Alarms related to a physiological condition, e.g. details of setting alarm thresholds or avoiding false alarms alarms per se G08B
• CPC Class Codes: A61M 2230/205 : partial oxygen pressure (P-O2)

Abstract

Embodiments of the present disclosure provide a hypersaturation index for measuring a patient'"'"'s absorption of oxygen in the blood stream after a patient has reached 100% oxygen saturation. This hypersaturation index provides an indication of the partial pressure of oxygen of a patient. In an embodiment of the present invention, a hypersaturation index is calculated based on the absorption ratio of two different wavelengths of energy at a measuring site. In an embodiment of the invention, a maximum hypersaturation index threshold is determined such that an alarm is triggered when the hypersaturation index reaches or exceeds the threshold. In another embodiment, an alarm is triggered when the hypersaturation index reaches or falls below its starting point when it was first calculated.

Claims

1. A method of providing an indication of an oxygenation of blood of a non-invasively monitored patient different from oxygen saturation, wherein said oxygen saturation is a measure of a percentage of available carriers in the blood that are bound to oxygen molecules at a time of measurement acquisition, the method comprising:

using an electronic light source including one or more light emitters, emitting at least a plurality of wavelengths of light into a portion of a body of the patient;

using an electronic light detector, detecting the light after attenuation of the body, said attenuation responsive to said oxygenation of said blood, and outputting one or more signals from said light detector, said one or more signals responsive to said attenuation;

processing said one or more signals using one or more signal processors to electronically;

calculate a first index responsive to said percentage of said carriers bound to oxygen, said first index being said measure of said oxygen saturation, and

calculate a second index responsive to a quantity of oxygen dissolved in the blood of a patient and not bound to any of said carriers while the patient is in a hyperoxic state, said second index providing different information to a caregiver than said first index, wherein said second index is calculated based on a ratio of information from at least a first of the plurality of wavelengths and information from at least a second of the plurality of wavelengths during the hyperoxic state of the patient; and

electronically displaying at least a value responsive to said second index.

2. The method of claim 1, wherein the displaying comprises displaying an oxygen hypersaturation index.

3. The method of claim 2, wherein the hypersaturation index is indicative of the partial pressure of oxygen.

4. The method of claim 2, wherein the displaying comprises displaying a graph of the oxygen hypersaturation index.

5. The method of claim 1, wherein the displaying comprises generating an alarm in response to the value responsive to said second index crossing a threshold.

6. The method of claim 5, wherein the displaying comprises displaying an amount of time after oxygen administration is stopped until the value responsive to said second index reaches the threshold.

7. The method of claim 6, wherein the amount of time becomes more certain as time expires.

8. The method of claim 1, wherein the displayed value comprises one or more of a number, a fillable bar where a fill is responsive to said dissolved oxygen, or a color responsive to said dissolved oxygen.

9. The method of claim 1, further comprising displaying a second value responsive to said first index.

10. The method of claim 9, wherein the displayed second value comprises one or more of a numeric percentage, a fillable bar where a fill is responsive to said percentage, or a color responsive to said percentage.

11. The method of claim 1, wherein the calculating of the first and/or second indices comprises using an oxygen saturation curve, wherein the oxygen saturation stays the same within a predetermined range of an R/IR ratio.

12. A system for determining an estimate of an oxygen saturation of a patient and an additional estimate of a non-invasively measured oxygen reserve of said patient, said oxygen saturation being a measure of a percentage of available carriers in blood that are bound to oxygen molecules at a time of measurement acquisition and said oxygen reserve being oxygen dissolved in the blood of a patient during a hyperoxic state of the patient and different from an amount of dissolved oxygen corresponding to said estimate of said oxygen saturation, the system comprising:

an input of an electronic physiological monitor, said input configured to receive one or more signals responsive to light of at least a plurality of wavelengths attenuated by body tissue of the patient, said one or more signals output from a light detector configured to detect said attenuated light;

one or more physiological hardware processors of said electronic physiological monitor, the one or more processors configured to electronically;

calculate a first index responsive to said percentage of said carriers bound to oxygen, said first index being said measure of said oxygen saturation, and

calculate a second index responsive to said dissolved oxygen, wherein said second index is responsive to a ratiometric calculation, said ratiometric calculation including a denominator responsive to portions of said one or more signals that were responsive to at least one of said plurality of wavelengths during the hyperoxic state of the patient and a numerator responsive to portions of said one or more signals that were responsive to at least another of said plurality of wavelengths during the hyperoxic state of the patient; and

a display electronically providing at least a visual indicia of said second index.

13. The system of claim 12, wherein the displayed visual indicia of said second index is an oxygen hypersaturation index.

14. The system of claim 13, wherein the hypersaturation index is indicative of the partial pressure of oxygen.

15. The system of claim 12, wherein the displayed visual indicia of said second index comprises a graph of an oxygen hypersaturation index.

16. The system of claim 12, further comprising an alarm configured to generate an alarm indication in response to the displayed visual indicia of said second index crossing a threshold.

17. The system of claim 12, wherein said visual indicia comprises one or more of a number, a fillable bar where a fill is responsive to said dissolved oxygen, or a color responsive to said dissolved oxygen.

18. The system of claim 12, wherein the display is configured to electronically provide a second visual indicia of said first index.

19. The system of claim 18, wherein said second visual indicia comprises one or more of a numeric percentage, a fillable bar where a fill is responsive to said percentage, or a color responsive to said percentage.