SYSTEM, METHOD AND COMPUTER PROGRAM PRODUCT FOR OPTICAL MEASUREMENT OF BLOOD PARAMETERS

• US 20130310668A1
• Filed: 10/03/2011
• Published: 11/21/2013
• Est. Priority Date: 10/08/2010
• Status: Abandoned Application

• Current Assignee: Edwards Lifesciences Corporation
• Original Assignee: Edwards Lifesciences Corporation
• Inventors: YOUNG, CLAYTON M.
• Application Number:
  US13/878,408
• Publication Number:
  US 20130310668A1
• Time in Patent Office: Days
• US Class Current: 600/328
• 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 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/1459 invasive, e.g. introduced into the body by a catheter A61B5/1464 takes precedence

Abstract

A system for optically measuring blood parameters including a light source and light transmitter for transmitting light to the blood, a light remitter for capturing remitted light, a spectrometer breaking the remitted light into its spectral components and a processor for comparing a morphologically distinct portion of the remitted light to a database of known morphologies. Each of the known morphologies corresponds to a measurement value at least one parameter, such as an analyte. Advantageously, the determined morphologies can uniquely correspond to two or more blood parameters, such as O₂Hb and tHb, allowing simultaneous determination of the two parameters.

Claims

1. A system for optically measuring parameters in blood, the system comprising:

a light source configured to generate light having a range of spectra;

a light transmitter configured to direct the generated light from the light source into the blood;

a light remitter configured to receive and direct light remitted from the blood;

a detector configured to receive the remitted light from the light remitter and determine a spectral composition of the remitted light; and

a processor configured to determine a morphology of at least one distinct portion of the spectral composition,

wherein the morphology corresponds to a known value for at least one blood parameter.

2. The system of claim 1, wherein the processor is further configured to compare the morphology to a database of known morphologies to determine the value for the at least one blood parameter.

3. The system of claim 2, wherein the database of known morphologies is defined by a reference matrix of at least three dimensions and wherein each of the known morphologies corresponds to the known value for at least two parameters.

4. The system of claim 3, wherein the three-dimensional matrix has dimensions of at least 61×

467×

101.

5. The system of claim 4, wherein the 467 slices of the matrix represent points between 440 nm and 540 nm.

6. The system of claim 5, wherein the 61 slices of the matrix represent one of O₂Hb or tHb.

7. The system of claim 3, wherein the matrix includes at least 6161 unique curves.

8. The system of claim 3, wherein the at least two parameters are tHb and O₂Hb.

9. The system of claim 1, wherein the light source is a broad spectrum light source and the range of spectra is the visible light range.

10. The system of claim 9, wherein the light source is a white LED light source.

11. The system of claim 1, wherein the light transmitter is a first optical waveguide.

12. The system of claim 11, wherein the light remitter is a second optical waveguide.

13. The system of claim 12, wherein the first and second optical waveguides are optical fibers extending through a catheter and wherein the catheter includes a tip configured to reside in the blood.

14. The system of claim 2, wherein the known morphologies are derived from remitted spectra of 600 nm or less.

15. The system of claim 14, wherein the known morphologies are derived from remitted spectra of 440 nm to 540 nm.

16. The system of claim 2, wherein the known morphologies are derived from remitted spectra of 730 nm to 796 nm.

17. The system of claim 2, wherein the known morphologies correspond to unique measurements of O₂Hb and tHb.

18. The system of claim 17, wherein the known morphologies are in incremental slices of 1% or less for O₂Hb and 0.1 g/dL or less for tHb.

19. The system of claim 2, wherein the processor is configured to apply a least-squares fit to compare the morphology to the database of known morphologies.

20. The system of claim 2, wherein the processor is further configured to report a plurality of the known values for display.

21. The system of claim 20, wherein the processor is further configured to smooth the plurality of known values.

22. The system of claim 21, wherein the processor is configured to smooth the known values using a weighted average.

23. A method of optically measuring parameters in blood, the method comprising:

generating light having a range of spectra;

directing the light into blood;

receiving remitted light from the blood;

determining a spectral composition of the remitted light;

determining a morphology of at least one distinct portion of the remitted light; and

determining a parameter measurement based on the morphology.

24. The method of claim 23, wherein determining the parameter measurement includes comparing the morphology to a database of known morphologies.

25. The method of claim 24, wherein comparing includes comparing to a three-dimensional matrix and determining includes simultaneously determining at least two parameter measurements.

26. The method of claim 25, wherein comparing includes comparing to the three dimensional matrix with dimensions of at least 61×

467×

101.

27. The method of claim 26, wherein comparing includes comparing 467 slices of the matrix between 440 nm and 540 nm.

28. The method of claim 27, wherein comparing includes comparing 61 slices of the matrix representing one of O₂Hb or tHb.

29. The method of claim 25, wherein comparing includes comparing to known morphologies from remitted spectra of 600 nm or less.

30. The method of claim 25, wherein comparing includes comparing to known morphologies from remitted spectra of 440 nm to 540 nm.

31. The method of claim 25, wherein comparing includes comparing to known morphologies from remitted spectra of 730 nm to 796 nm.

32. The method of claim 31, wherein comparing includes comparing to known morphologies in incremental slices of 1% or less for O₂Hb and 0.1 g/dL or less for tHb.

33. The method of claim 25, wherein comparing includes applying a least-squares fit to compare the morphologically distinct portion of the spectral composition to the database of known morphologies.

34. A system for optically measuring parameters in blood using a light signal remitted from blood, the system comprising:

a detector configured to receive the remitted light from the blood; and

a processor configured to determine a spectral composition of the remitted light and a morphology of at least one distinct portion of the spectral composition to a database of known morphologies,

wherein each of the morphology corresponds to a known value for at least one blood parameter.

35. The system of claim 34, wherein the processor is further configured to compare the morphology to a database of known morphologies to determine the value for the at least one blood parameter.

36. The system of claim 35, wherein the database of known morphologies is defined by a reference matrix of at least three dimensions and wherein each of the known morphologies corresponds to the known value for at least two parameters.

37. The system of claim 36, wherein the three-dimensional matrix has dimensions of at least 61×

467×

101.

38. The system of claim 37, wherein the 467 slices of the matrix represent points between 440 nm and 540 nm.

39. The system of claim 38, wherein the 61 slices of the matrix represent one of O₂Hb or tHb.

40. The system of claim 36, wherein the matrix includes at least 6161 unique curves.

41. The system of claim 36, wherein the at least two parameters are tHb and O₂Hb.

42. The system of claim 35, wherein the known morphologies are derived from remitted spectra of 600 nm or less.

43. The system of claim 42, wherein the known morphologies are derived from remitted spectra of 440 nm to 540 nm.

44. The system of claim 35, wherein the known morphologies are derived from remitted spectra of 730 nm to 796 nm.

45. The system of claim 35, wherein the known morphologies correspond to unique measurements of O₂Hb and tHb.

46. The system of claim 45, wherein the known morphologies are in incremental slices of 1% or less for O₂Hb and 0.1 g/dL or less for tHb.

47. The system of claim 35, wherein the processor is configured to apply a least-squares fit to compare the morphologically distinct portion of the spectral composition to the database of known morphologies.

48. The system of claim 35, wherein the processor is further configured to report a plurality of the known values for display.

49. The system of claim 48, wherein the processor is further configured to smooth the plurality of known values.

50. The system of claim 49, wherein the processor is configured to smooth using a weighted average.