Early stage peritonitis detection apparatus and methods

• US 20080045884A1
• Filed: 07/23/2007
• Published: 02/21/2008
• Est. Priority Date: 07/27/2006
• Status: Active Grant

• Current Assignee: Fresenius Medical Care Holdings Incorporated (Fresenius SE & Co. KGaA)
• Original Assignee: Fresenius Medical Care Holdings Incorporated (Fresenius SE & Co. KGaA)
• Inventors: Lan, Jay, Landherr, Frank, Jensen, Lynn
• Granted Patent: US 8,801,652 B2
• Time in Patent Office: Days
• US Class Current: 604/29
• CPC Class Codes: A61M 1/28 Peritoneal dialysis ; Other peritoneal treatment, e.g. oxygenation
• CPC Class Codes: A61M 2205/331 used as turbidity change detectors, e.g. for priming-blood or plasma-hemoglubine-interface detection

Abstract

The invention provides, inter alia, automated medical methods and apparatus that test PD effluent in a flow path (e.g., with an APD system or CAPD setup) to detect, for example, the onset of peritonitis, based on optical characteristics of the effluent resolved at cellular scales of distance. For example, according to one aspect of the invention, an APD machine includes, in an effluent flow path, apparatus for early stage peritonitis detection comprising an illumination source and a detector. The source is arranged to illuminate peritoneal effluent in a chamber that forms part of the flow path, and the detector is arranged to detect illuminant scattered by the effluent. The detector detects that reflected or scattered illuminant at a cellular scale of resolution, e.g., on a scale such that separate cellular-sized biological (or other) components in the effluent can be distinguished from one another based on scattering events detected by the detector.

Claims

1. Apparatus for testing peritoneal dialysis (PD) effluent in a flow path, comprising

A. an illumination source that illuminates peritoneal effluent in the flow path,

B. a detector that detects illuminant any of reflected and scattered (collectively, “

scattered”

) by the effluent, and

C. the detector detects that scattered illuminant at a cellular scale of resolution such that at least selected separate cellular-sized components in the effluent can be distinguished from one another based on illuminant that is scattered therefrom and that is detected by the detector.

2. Apparatus according to claim 1, in which the detector is arranged to detect illuminant scattered from separate white blood cells (WBCs) in the effluent such that those WBCs can be distinguished from one another.

3. Apparatus according to claim 2, wherein the detector counts WBCs in the effluent based on illuminant scattered therefrom.

4. Apparatus according to claim 3, wherein the detector signals an onset of peritonitis if said counts change over time and/or vary from a baseline.

5. Apparatus according to claim 4, wherein said baseline is a baseline previously established for a patient from which the PD effluent is drained.

6. Apparatus according to claim 1, in which the detector is arranged to detect illuminant scattered from cellular-sized components of different types in the effluent such that those components can be distinguished from one another.

7. Apparatus according to claim 6, in which the detector is arranged to detect illuminant scattered from white blood cells (WBCs) in the effluent such that they can be distinguished from red blood cells (RBCs), fibrin and/or other components from which illuminant is scattered in the effluent.

53. Device for automated peritoneal dialysis comprising the apparatus of any of claims 1, 8, 14 and 32 in a flow path of peritoneal dialysis (PD) effluent produced by such device.

8. Apparatus for testing peritoneal dialysis (PD) effluent in a flow path, comprising

A. an illumination source that illuminates peritoneal effluent in the flow path,

B. a detector that detects illuminant any of reflected and scattered (collectively, “

scattered”

) by the effluent, the detector detecting that scattered illuminant at a cellular scale of resolution such that at least selected separate cellular-sized components in the effluent can be distinguished from one another based on illuminant that is scattered therefrom and that is detected by the detector, and

C. the detector signals an onset of peritonitis based on variance, over time and/or from a baseline, in counts of at least selected reflections and/or scatterings (collectively, “

scatterings”

) detected thereby from components in the effluent.

9. Apparatus according to claim 8, wherein the detector determines a trend over time of variance of said counts.

10. Apparatus according to claim 9, wherein the detector determines the trend with respect to counts of white blood cells (WBCs) from which scatterings are detected.

11. Apparatus according to claim 9, wherein the detector determines a slope of a curve of those counts with respect to time.

12. Apparatus according to claim 11, wherein the detector signals an onset of peritonitis when said slope exceeds a selected amount.

13. Apparatus according to claim 8, wherein the detector counts illuminant scattering events occurring with respect to the effluent based on intensity and/or location of those scattering events.

14. Apparatus for testing peritoneal dialysis (PD) effluent in a flow path, comprising

A. a laser that illuminates peritoneal effluent in the flow path, and

B. a detector including a pin-diode configured to signal detection of illuminant any of reflected and scattered (collectively, “

scattered”

) by the effluent a resolution resolvable at a scale such that at least selected separate cellular-sized components in the effluent can be distinguished from one another based on illuminant that is scattered therefrom.

15. Apparatus according to claim 14, in which the pin-diode is arranged to detect scattering events detectable within a field of view perpendicular to a ray of illuminant sourced by the laser.

16. Apparatus according to claim 14, in which the laser generates a beam of illuminant that is positioned within a portion of the flow path from which scattering events detected by the pin-diode.

17. Apparatus according to claim 16, in which the beam is substantially centered within the portion of the flow path from which scattering events detected by the pin-diode.

18. Apparatus according to claim 16, in which the beam has a width selected in accord with size characteristics of the components from which scattering events are to be detected by the pin-diode.

19. Apparatus according to claim 16, in which the beam has any of a circular and gaussian cross-section.

20. Apparatus according to claim 14, where the detector counts at least selected reflections and/or scatterings (collectively, “

scatterings”

) signaled by the pin-diode from components in the effluent.

21. Apparatus according to claim 14, wherein the detector signals an onset of peritonitis based on variance, over time and/or from a baseline, in counts of at least selected scatterings signaled by the pin-diode.

22. Apparatus according to claim 21, wherein the detector determines a trend over time of variance of those counts.

23. Apparatus according to claim 22, wherein the detector determines the trend with respect to counts of white blood cells (WBCs) from which scatterings are detected.

24. Apparatus according to claim 22, wherein the detector determines a slope of a curve of those counts with respect to time.

25. Apparatus according to claim 24, wherein the detector signals an onset of peritonitis when that slope exceeds a selected amount.

26. Apparatus according to claim 14, wherein the pin-diode is arranged to signal illuminant scattered from separate white blood cells (WBCs) in the effluent such that those WBCs can be distinguished from one another.

27. Apparatus according to claim 26, wherein the detector counts WBCs in the effluent based on illuminant scattered therefrom.

28. Apparatus according to claim 27, wherein the detector signals the onset of peritonitis if said counts change over time and/or vary from a baseline.

29. Apparatus according to claim 28, wherein said baseline is a baseline previously established for a patient from which the PD effluent is drained.

30. Apparatus according to claim 14, in which the pin-diode is arranged to signal illuminant scattered from cellular-sized components of different types in the effluent such that those components can be distinguished from one another.

31. Apparatus according to claim 30, in which the pin-diode is arranged to signal illuminant scattered from WBCs in the effluent such that they can be distinguished from red blood cells (RBCs), fibrin and/or other components from which illuminant is scattered in the effluent.

32. Apparatus for testing peritoneal dialysis (PD) effluent in a flow path, comprising

A. an illumination source that illuminates peritoneal effluent in the flow path, and

B. a detector including a charge-coupled device (CCD) configured to image illuminant any of reflected and scattered (collectively, “

scattered”

) by the effluent a resolution resolvable at a scale such that at least selected separate cellular-sized components in the effluent can be distinguished from one another based on illuminant that is scattered therefrom.

33. Apparatus according to claim 32, wherein the detector generates a histogram of one or more such images.

34. Apparatus according to claim 33, wherein the detector counts scattering events based on intensities imaged by the CCD.

35. Apparatus according to claim 34, wherein the detector generates the histogram from multiple images taken during a drain of spent PD solution from a patient.

36. Apparatus according to claim 32, wherein the illumination source is a laser diode.

37. Apparatus according to claim 36, in which the CCD is arranged to detect scattering events detectable within a field of view perpendicular to a ray of illuminant sourced by the laser diode.

38. Apparatus according to claim 36, in which the laser diode generates a beam of illuminant disposed within a portion of the flow path from which scattering events are detected by the CCD.

39. Apparatus according to claim 38, in which the beam is substantially centered within the a portion of the flow path from which scattering events are detected by the CCD.

40. Apparatus according to claim 38, in which the beam has a width selected in accord with size characteristics of the components from which scattering events are to be detected by the CCD.

41. Apparatus according to claim 38, in which the beam has any of a circular and gaussian cross-section.

42. Apparatus according to claim 32, in which the CCD is arranged to image illuminant scattered from separate white blood cells (WBCs) in the effluent such that those WBCs can be distinguished from one another.

43. Apparatus according to claim 42, wherein the detector counts WBCs in the effluent based on illuminant scattered therefrom.

44. Apparatus according to claim 43, wherein the detector signals an onset of peritonitis if said counts change over time and/or vary from a baseline.

45. Apparatus according to claim 44, wherein said baseline is a baseline previously established for a patient from which the PD effluent is drained.

46. Apparatus according to claim 32, in which the CCD is arranged to image illuminant scattered from cellular-sized components of different types in the effluent such that those components can be distinguished from one another.

47. Apparatus according to claim 46, in which the detector is arranged to image illuminant scattered from white blood cells (WBCs) in the effluent such that they can be distinguished from red blood cells (RBCs), fibrin and/or other components from which illuminant is scattered in the effluent.

48. Apparatus according to claim 32, wherein the detector signals an onset of peritonitis based on variance, over time and/or from a baseline, in counts of at least selected reflections and/or scatterings (collectively, “

scatterings”

) imaged by the CCD from components in the effluent.

49. Apparatus according to claim 48, wherein the detector determines a trend over time of variance of those counts.

50. Apparatus according to claim 49, wherein the detector determines the trend with respect to counts of white blood cells (WBCs) from which scatterings are imaged.

51. Apparatus according to claim 48, wherein the detector determines a slope of a curve of those counts with respect to time.

52. Apparatus according to claim 51, wherein the detector signals the onset of peritonitis when that slope exceeds a selected amount.

54. Method for testing peritoneal dialysis (PD) effluent in a flow path, comprising

A. illuminating peritoneal effluent in the flow path,

B. detecting illuminant any of reflected and scattered (collectively, “

scattered”

) by the effluent at a cellular scale of resolution such that at least selected separate cellular-sized components in the effluent can be distinguished from one another based on illuminant that is scattered therefrom.

55. Method according to claim 54, comprising detecting illuminant scattered from separate white blood cells (WBCs) in the effluent such that those WBCs can be distinguished from one another.

56. Method according to claim 55, comprising counting WBCs in the effluent based on illuminant scattered therefrom.

57. Method according to claim 56, comprising signaling an onset of peritonitis if said counts change over time and/or vary from a baseline.

58. Method according to claim 54, comprising detecting illuminant scattered from cellular-sized components of different types in the effluent such that those components can be distinguished from one another.

60. Method according to claim 59, comprising detecting illuminant scattered from white blood cells (WBCs) in the effluent such that they can be distinguished from red blood cells (RBCs), fibrin and/or other components from which illuminant is scattered in the effluent.

61. Apparatus for testing dialysis effluent in a flow path, comprising

A. an illumination source that illuminates effluent in the flow path,

B. a detector that detects illuminant scattered by the effluent, and

C. the detector detects that scattered illuminant at a cellular scale of resolution such that at least selected separate cellular-sized components in the effluent can be distinguished from one another based on illuminant that is scattered therefrom and that is detected by the detector.

62. Method for testing effluent in a flow path, comprising

A. illuminating effluent in the flow path,

B. detecting illuminant any of reflected and scattered (collectively, “

scattered”

) by the effluent at a cellular scale of resolution such that at least selected separate cellular-sized components in the effluent can be distinguished from one another based on illuminant that is scattered therefrom.