Non-Invasive Oxygen Delivery Measurement System and Method

• US 20150080669A1
• Filed: 03/15/2012
• Published: 03/19/2015
• Est. Priority Date: 03/22/2011
• Status: Abandoned Application

• Current Assignee: Bmeye B.V. (Edwards Lifesciences Corporation), Edwards Lifesciences Corporation
• Original Assignee: Bmeye B.V. (Edwards Lifesciences Corporation)
• Inventors: Settels, Jos, Kuijkens, Hans
• Application Number:
  US14/006,652
• Publication Number:
  US 20150080669A1
• Time in Patent Office: Days
• US Class Current: 600/301
• CPC Class Codes: A61B 5/02028 Determining haemodynamic parameters not otherwise provided for, e.g. cardiac contractility or left ventricular ejection fraction
• CPC Class Codes: A61B 5/02108 from analysis of pulse wave characteristics
• CPC Class Codes: A61B 5/02241 of small dimensions, e.g. adapted to fingers
• CPC Class Codes: A61B 5/02255 the pressure being controlled by plethysmographic signals, e.g. derived from optical sensors
• CPC Class Codes: A61B 5/02422 within occluders
• CPC Class Codes: A61B 5/026 Measuring blood flow A61B3/1233, A61B3/1241 take precedence
• CPC Class Codes: A61B 5/029 Measuring or recording blood output from the heart, e.g. minute volume A61B8/065 takes precedence
• CPC Class Codes: A61B 5/0833 Measuring rate of oxygen consumption
• CPC Class Codes: A61B 5/14546 for measuring analytes not otherwise provided for, e.g. ions, cytochromes
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/6826 Finger
• CPC Class Codes: A61B 5/6838 Clamps or clips
• CPC Class Codes: A61B 5/7278 Artificial waveform generation or derivation, e.g. synthesising signals from measured signals A61B5/327 takes precedence

Abstract

A method of determining the oxygen delivery, comprising the steps of non-invasive measurement of the arterial blood pressure waveform, determination of cardiac output from a pulse wave analysis of said blood pressure waveform, non-invasive measurement of oxygen saturation and hemoglobin concentration and real time calculation of oxygen delivery based on the measured quantities.

Claims

1. Method of determining the oxygen delivery (10) to a patient'"'"'s tissues, comprising the steps of:

non-invasive measurement of the arterial blood pressure waveform, wherein the measured finger arterial blood pressure waveform is reconstructed into the brachial arterial pressure waveform;

determination of cardiac output (15) from a pulse wave analysis of said blood pressure waveform;

non-invasive measurement of oxygen saturation (20) and hemoglobin concentration (25); and

real time calculation of oxygen delivery (10).

2. Method according to claim 1, wherein the oxygen delivery (10) is calculated by multiplying the Cardiac Output (15), Oxygen Saturation (20), hemoglobin concentration (25) and a version of Hufner'"'"'s constant.

3. Method according to any of the preceding claims, wherein the arterial blood pressure waveform is measured by a finger arterial volume clamp method, in which the arterial volume is kept at a constant level by varying the pressure outside the artery in concordance with intra arterial blood pressure.

4. Method according to any of the preceding claims, wherein the oxygen delivery (10) parameter is combined with an analysis of respiratory variations in beat-to-beat data, so that information about the oxygen delivery (10) as well as about the fluid responsiveness state of a patient is available.

5. Method according to any of the preceding claims, wherein the oxygen delivery (10) parameter is combined with a determination of oxygen consumption (VO₂) to determine an oxygen extraction ratio which can be used as an indicator whether oxygen delivery (10) is adequate in relation to metabolic demands of a patient.

6. Method according to any of the preceding claims, wherein pulse pressure variation and stroke volume variation are monitored using the arterial blood pressure waveform.

7. Method according to any of the preceding claims, wherein the arterial blood pressure is measured non-invasively with at least one sensor on a finger and wherein the oxygen saturation (20) and the hemoglobin (25) is non-invasively measured with at least one multi-wavelength sensor on another finger.

8. Apparatus for determining the oxygen delivery (10), comprising:

means for non-invasive measurement (3) of the arterial blood pressure waveform, wherein the measured finger arterial blood pressure waveform is reconstructed into the brachial arterial pressure waveform;

means for determination of cardiac output (15) from a pulse wave analysis of said blood pressure waveform;

means for non-invasive measurement (6) of oxygen saturation (20) and hemoglobin (25) comprising at least one multi-wavelength sensor; and

means for real time calculation (7) of oxygen delivery (10).

9. Apparatus according to claim 8, wherein the oxygen delivery (10) is calculated by multiplying the Cardiac Output (15), Oxygen Saturation (20), hemoglobin concentration (25) and a conversion constant.

10. Apparatus according to any of the claims 8 or 9, further comprising:

means for measuring the arterial blood pressure waveform by a finger arterial volume clamp method, in which the arterial volume is kept at a constant level by varying the pressure outside the artery in concordance with intra arterial blood pressure.

11. Apparatus according to any of the claims 8 to 10, further comprising means for combining the oxygen delivery (10) parameter with an analysis of respiratory variations in beat-to-beat data, so that information about the oxygen delivery (10) as well as about the fluid state of a patient is available.

12. Apparatus according to any of the claims 8 to 11, wherein the oxygen delivery (10) parameter is combined with a determination of oxygen consumption (VO₂) to determine an oxygen extraction ratio which can be used as an indicator whether oxygen delivery (10) is adequate in relation to metabolic demands of a patient.

13. Apparatus according to any of the claims 8 to 12, wherein pulse pressure variation and stroke volume variation are monitored using the arterial blood pressure waveform.