Citrate detector for blood processing system

• US 9,176,047 B2
• Filed: 06/17/2014
• Issued: 11/03/2015
• Est. Priority Date: 11/09/2012
• Status: Active Grant

• Current Assignee: Fenwal Incorporated (Fresenius SE & Co. KGaA)
• Original Assignee: Fenwal Incorporated (Fresenius SE & Co. KGaA)
• Inventors: Sandford, Craig
• Primary Examiner(s): Kim, Kiho
• Application Number:
  US14/306,526
• Publication Number:
  US 20140291535A1
• Time in Patent Office: 504 Days
• US Class Current: 1/1
• CPC Class Codes: A61M 1/0209 Multiple bag systems for separating or storing blood components
• CPC Class Codes: A61M 1/16 with membranes
• CPC Class Codes: A61M 1/342 Adding solutions to the blood, e.g. substitution solutions for preventing coagulation A61M1/3672
• CPC Class Codes: A61M 1/3437 downstream of the filter, e.g. post-dilution with filtrate
• CPC Class Codes: A61M 1/3455 Substitution fluids
• CPC Class Codes: A61M 1/3621 Extra-corporeal blood circuits single-needle circuits A61M1/30
• CPC Class Codes: A61M 1/362227 the interface providing means for actuating on functional elements of the cassette, e.g. plungers
• CPC Class Codes: A61M 1/36225 with blood pumping means or components thereof
• CPC Class Codes: A61M 1/362265 Details of valves
• CPC Class Codes: A61M 1/367 Circuit parts not covered by the preceding subgroups of group A61M1/3621
• CPC Class Codes: A61M 1/3672 Means preventing coagulation
• CPC Class Codes: A61M 1/3693 using separation based on different densities of components, e.g. centrifuging
• CPC Class Codes: A61M 1/3696 with means for adding or withdrawing liquid substances during the centrifugation, e.g. continuous centrifugation
• CPC Class Codes: A61M 2205/18 with alarm
• CPC Class Codes: A61M 2205/3306 Optical measuring means
• CPC Class Codes: A61M 2205/3313 used specific wavelengths
• CPC Class Codes: A61M 5/00 Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests vaccination appliances for veterinary use A61D1/025 ; tube connectors, tube couplings, valves or branch units specially adapted for medical use A61M39/00; containers specially adapted for medical or pharmaceutical purposes A61J1/00; combinations of vial and syringe for mixing or transferring their contents A61J1/20; holders for containers for collecting, storing or administering blood or medical fluids A61J1/16
• CPC Class Codes: G01N 21/17 Systems in which incident light is modified in accordance with the properties of the material investigated where the material investigated is optically excited causing a change in wavelength of the incident light G01N21/63
• CPC Class Codes: G01N 33/49 Blood chemical methods for determining blood cell populations G01N33/5094; chemical analysis of blood groups or blood types G01N33/80

Abstract

A citrate detector is provided for use in combination with a blood processing system and replacement fluid tubing or conduit of a disposable set. The citrate detector comprises a light source and a light detector. The light source is configured to emit a light having a wavelength absorbed by citrate, but at least partially transmitted by the replacement fluid conduit of the disposable set. The light detector is configured to receive at least a portion of the light from the light source and generate a signal indicative of the presence or absence of citrate in the replacement fluid conduit based, at least in part, on the amount of light received from the light source. A blood processing system incorporating such a citrate detector may include a flow detector for determining whether fluid is present in the conduit prior to checking for the presence of citrate.

Claims

1. A citrate detector for use in combination with a blood processing system and a replacement fluid flow conduit of a disposable set, the citrate detector comprising:

a light source positioned and configured to emit a light onto the replacement fluid flow conduit of the disposable set and a fluid flowing through the replacement fluid flow conduit, the light having a wavelength absorbed by citrate, but at least partially transmitted by the replacement fluid flow conduit;

a light detector positioned so as to receive at least a portion of the light from the light source that is exiting or reflected by the fluid in the replacement fluid flow conduit and generate a signal indicative of the presence or absence of citrate in the fluid in the replacement fluid flow conduit based, at least in part, on the amount of light received from the light source; and

a flow detector configured to determine the presence of fluid in the replacement fluid flow conduit prior to the light source emitting light onto the replacement fluid flow conduit and the fluid flowing through the replacement fluid flow conduit.

2. The citrate detector of claim 1, wherein the light source is configured to emit an ultraviolet light.

3. The citrate detector of claim 2, wherein the light source is configured to emit ultraviolet light having a wavelength in the range of approximately 200 nm and approximately 250 nm.

4. The citrate detector of claim 1, further comprising a reflector configured to focus reflected light from the light source on the light detector.

5. The citrate detector of claim 1, wherein the light source comprises a light-emitting diode.

6. A blood processing system for use in combination with a replacement fluid flow conduit of a disposable set and comprising:

a citrate detector including

a light source positioned and configured to emit a light onto the replacement fluid flow conduit of the disposable set and a fluid flowing through the replacement fluid flow conduit, the light having a wavelength absorbed by citrate, but at least partially transmitted by the replacement fluid flow conduit,

a light detector positioned so as to receive at least a portion of the light from the light source that is exiting or reflected by the fluid in the replacement fluid flow conduit and generate a signal indicative of the presence or absence of citrate in the replacement fluid flow conduit based, at least in part, on the amount of light received from the light source;

a controller configured to receive the signal from the light detector and determine whether citrate is present in the fluid in the replacement fluid flow conduit based, at least in part, on the signal; and

a light-absorbing member adjacent to the light source and configured to absorb ultraviolet light.

7. The blood processing system of claim 6, wherein the light source is configured to emit an ultraviolet light.

8. The blood processing system of claim 7, wherein the light source is configured to emit ultraviolet light having a wavelength in the range of approximately 200 nm and approximately 250 nm.

9. The blood processing system of claim 6, further comprising a reflector configured to focus reflected light from the light source on the light detector.

10. The blood processing system of claim 6, wherein the light source comprises a light-emitting diode.

11. The blood processing system of claim 6, wherein the controller is configured to compare the signal to a baseline value to determine whether citrate is present in the replacement fluid flow conduit.

12. The blood processing system of claim 6, further comprising a flow detector configured to determine the presence of fluid in the replacement fluid flow conduit prior to the light source emitting light onto the replacement fluid flow conduit and the fluid flowing through the replacement fluid flow conduit.

13. A method of monitoring fluid within a blood processing system having a replacement fluid flow conduit, the method comprising:

flowing a fluid through the replacement fluid flow conduit;

determining whether fluid is present in the replacement fluid flow conduit;

after determining that fluid is present in the replacement fluid flow conduit, directing light into the replacement fluid flow conduit, the light having a wavelength absorbed by citrate, but at least partially transmitted by the replacement fluid flow conduit;

detecting light exiting or reflected by the fluid in the replacement fluid flow conduit; and

determining whether citrate is present in the fluid in the replacement fluid flow conduit based, at least in part, on the light exiting or reflected by the fluid in the replacement fluid flow conduit.

14. The method of claim 13, wherein said emitting light into the replacement fluid flow conduit includes emitting ultraviolet light into the replacement fluid flow conduit.

15. The method of claim 13, wherein said emitting light into the replacement fluid flow conduit includes emitting ultraviolet light having a wavelength in the range of approximately 200 nm and approximately 250 nm into the replacement fluid flow conduit.

16. The method of claim 13, wherein said determining includes comparing the amount of light exiting or reflected by the fluid in the replacement fluid flow conduit to a baseline value.

17. The method of claim 13, wherein said directing light into the replacement fluid flow conduit includes directing light through a generally flat surface of the replacement fluid flow conduit.

18. The method of claim 13, wherein said directing light into the replacement fluid flow conduit and said detecting light exiting or reflected by the fluid in the replacement fluid flow conduit occurs on the same side of the replacement fluid flow conduit.

19. The method of claim 13, wherein said directing light into the replacement fluid flow conduit and said detecting light exiting or reflected by the fluid in the replacement fluid flow conduit occurs on opposite sides of the replacement fluid flow conduit.

20. A citrate detector for use in combination with a blood processing system and a replacement fluid flow conduit of a disposable set, the citrate detector comprising:

a light source positioned and configured to emit a light onto the replacement fluid flow conduit of the disposable set and a fluid flowing through the replacement fluid flow conduit, the light having a wavelength absorbed by citrate, but at least partially transmitted by the replacement fluid flow conduit;

a light detector positioned so as to receive at least a portion of the light from the light source that is exiting or reflected by the fluid in the replacement fluid flow conduit and generate a signal indicative of the presence or absence of citrate in the fluid in the replacement fluid flow conduit based, at least in part, on the amount of light received from the light source; and

a light-absorbing member adjacent to the light source and configured to absorb ultraviolet light.

21. A method of monitoring fluid within a blood processing system having a replacement fluid flow conduit, the method comprising:

flowing a fluid through the replacement fluid flow conduit;

directing light into the replacement fluid flow conduit, the light having a wavelength absorbed by citrate, but at least partially transmitted by the replacement fluid flow conduit;

detecting light exiting or reflected by the fluid in the replacement fluid flow conduit; and

determining whether citrate is present in the fluid in the replacement fluid flow conduit based, at least in part, on the light exiting or reflected by the fluid in the replacement fluid flow conduit, wherein said detecting light exiting or reflected by the fluid in the replacement fluid flow conduit includes absorbing environmental light prior to said environmental ultraviolet light being detected.