DIALYSIS SYSTEM HAVING OPTICAL FLOWRATE DETECTION

• US 20080200865A1
• Filed: 02/15/2007
• Published: 08/21/2008
• Est. Priority Date: 02/15/2007
• Status: Active Grant

• Current Assignee: Baxter Healthcare SA (Baxter International Inc.), Baxter International Inc.
• Original Assignee: Baxter International Inc.
• Inventors: Bedingfield, John
• Granted Patent: US 7,998,115 B2
• Time in Patent Office: Days
• US Class Current: 604/29
• CPC Class Codes: A61M 1/152 Details related to the interface between cassette and machine
• CPC Class Codes: A61M 1/153 the cassette being adapted for heating or cooling the treating fluid, e.g. the dialysate or the treating gas
• CPC Class Codes: A61M 1/155 with treatment-fluid pumping means or components thereof
• CPC Class Codes: A61M 1/1561 at least one cassette surface or portion thereof being flexible, e.g. the cassette having a rigid base portion with preformed channels and being covered with a foil
• CPC Class Codes: A61M 1/166 Heating for sterilisation A61M1/1686
• CPC Class Codes: A61M 1/28 Peritoneal dialysis ; Other peritoneal treatment, e.g. oxygenation
• CPC Class Codes: A61M 1/284 Continuous flow peritoneal dialysis [CFPD]
• CPC Class Codes: A61M 1/288 Priming priming in extracorporeal blood circuits A61M1/3643
• CPC Class Codes: A61M 1/3626 Gas bubble detectors
• CPC Class Codes: A61M 2205/12 with interchangeable cassettes forming partially or totally the fluid circuit
• CPC Class Codes: A61M 2205/3306 Optical measuring means
• CPC Class Codes: A61M 2205/3331 Pressure; Flow
• CPC Class Codes: G01F 1/661 using light
• CPC Class Codes: G01P 5/20 using particles entrained by a fluid stream G01P5/22 takes precedence
• CPC Class Codes: Y10T 137/0324 With control of flow by a condition or characteristic of a fluid

Abstract

A medical fluid machine includes an enclosure; a disposable unit accepted by the enclosure, the disposable unit including a conduit through which a medical fluid can flow, the conduit including a viewing portion; a light source configured and arranged to emit light onto the viewing portion of the conduit; a camera focused on the viewing portion of the conduit; and a processor configured to determine a speed of a particle entrained in the medical fluid based on at least two images of the particle in the viewing area taken by the camera.

Claims

1. A medical fluid machine comprising:

an enclosure;

a disposable unit accepted by the enclosure, the disposable unit including a conduit through which a medical fluid can flow, the conduit including a viewing portion;

a light source configured and arranged to emit light onto the viewing portion of the conduit;

a camera focused on the viewing portion of the conduit; and

a processor operable with the camera configured to determine a speed of a particle entrained in the medical fluid based on at least two images of the particle in the viewing area taken by the camera.

2. The medical fluid machine of claim 1, wherein the disposable unit includes at least one characteristic selected from the group consisting of:

(i) having an at least semi-rigid valve portion;

(ii) having a flexible pumping portion;

(iii) having a tube configured to operate with a peristaltic pump;

(iv) having a flow path portion for the medical fluid to be heated;

(v) having an air trap portion;

(vi) the conduit being a rigid pathway formed in the disposable unit; and

(vii) the conduit being a tube connected fluidly to the disposable unit.

3. The medical fluid machine of claim 1, wherein the light source includes at least one characteristic selected from the group consisting of:

(i) employing a light emitting diode (“

LED”

) or laser diode;

(ii) including multiple lights configured to illuminate the viewing portion from multiple angles;

(iii) being positioned on a side of the viewing position that is at least substantially opposite from a side of the viewing portion that the camera is positioned;

(iv) being positioned on a side of the viewing portion that is at least substantially the same as the side of the viewing portion that the camera is positioned;

(v) being positioned on a side of the viewing portion that is at an angle with respect to a side of the viewing portion that the camera is positioned;

(vi) being illuminated intermittently and in sync with when the camera is taking images of the viewing portion; and

(vii) being a high intensity light source.

4. The medical fluid machine of claim 1, wherein the light source is configured to be at least one of:

(i) lighted sequentially when the light source includes multiple light emitting elements and (ii) positioned so that light reflecting off the viewing portion does not impinge the camera.

5. The medical fluid machine of claim 1, wherein the camera includes at least one characteristic selected from the group consisting of:

(i) having a frame rate of at least five hundred frames per second;

(ii) being monochrome; and

(iii) being capable of color imaging.

6. The medical fluid machine of claim 1, wherein the viewing portion includes at least one characteristic selected from the group consisting of:

(i) being formed in the conduit;

(ii) being spliced into the conduit;

(iii) being connected to the conduit;

(iv) having a relatively high aspect ratio;

(v) being at least substantially rectangular;

(vi) being relatively thin;

(vii) being configured so that the particle tends not to be masked by another particle; and

(viii) having a known cross-sectional area.

7. The medical fluid machine of claim 1, wherein the processor includes at least one characteristic selected from the group consisting of:

(i) being configured to determine at least one of a quantity, size, type and velocity of the particle in the medical fluid;

(ii) being configured to determine at least one of the speed, velocity and the volumetric fluid flowrate of the medical fluid;

(iii) being a digital signal processor; and

(iv) being operable with an assumption that the particles are distributed across the entire cross-section of the viewing portion.

8. The medical fluid machine of claim 1, which includes an apparatus configured and arranged to induce vibrations into the medical fluid flowing through the viewing portion.

9. A medical fluid flowrate detector comprising:

a light source configured and arranged to emit light onto a viewing portion of a conduit carrying a medical fluid;

a camera focused on the viewing portion of the conduit; and

a processor operable with the camera and configured to;

(i) determine a speed of a particle entrained in the medical fluid based on at least two images of the particle in the viewing area taken by the camera; and

(ii) determine a flowrate of the medical fluid based on the speed of the particle and a geometry of the viewing portion.

10. The medical fluid flowrate detector of claim 9, wherein the processor includes at least one characteristic selected from the group consisting of:

(i) being configured to determine at least one of a quantity, size, type and velocity of the particle in the medical fluid;

(ii) being configured to determine at least one of the speed, velocity and the volumetric fluid flowrate of the medical fluid;

(iii) being a digital signal processor; and

(iv) being operable with an assumption that the particles are distributed across the entire cross-section of the viewing portion.

11. The medical fluid machine of claim 9, wherein the light source includes at least one characteristic selected from the group consisting of:

wherein the light source includes at least one characteristic selected from the group consisting of;

(i) employing a light emitting diode (“

LED”

) or laser diode;

(ii) including multiple lights configured to illuminate the viewing portion from multiple angles;

(iii) being positioned on a side of the viewing position that is at least substantially opposite from a side of the viewing portion that the camera is positioned;

(iv) being positioned on a side of the viewing portion that is at least substantially the same as the side of the viewing portion that the camera is positioned;

(v) being positioned on a side of the viewing portion that is at an angle with respect to a side of the viewing portion that the camera is positioned;

(vi) being illuminated intermittently and in sync with when the camera is taking images of the viewing portion; and

(vii) being a high intensity light source.

12. The medical fluid machine of claim 9, wherein the light source is configured to be at least one of:

(i) lighted sequentially when the light source includes multiple lights and (ii) positioned so that light reflecting off the viewing portion does not impinge the camera.

13. The medical fluid machine of claim 9, wherein the camera includes at least one characteristic selected from the group consisting of:

(i) having a frame rate of at least five hundred frames per second;

(ii) being monochrome; and

(iii) being capable of color imaging.

14. The medical fluid machine of claim 9, wherein the viewing portion includes at least one characteristic selected from the group consisting of:

(i) being formed in the conduit;

(ii) being spliced into the conduit;

(iii) being connected to the conduit;

(iv) having a relatively high aspect ratio;

(v) being at least substantially rectangular;

(vi) being relatively thin;

(vii) being configured so that the particle tends not to be masked by another particle; and

(viii) having a known cross-sectional area.

15. The medical fluid rate detector of claim 9, which is configured to operate with at least one medical fluid device selected from the group consisting of:

a dialysis machine and a drug infusion machine.

16. A medical fluid machine comprising:

a fluid carrying unit including a conduit through which a medical fluid can flow, the conduit including a viewing portion;

a light source configured and arranged to emit light onto the viewing portion of the conduit;

a camera focused on the viewing portion of the conduit; and

a processor operable with the camera and configured to determine that a particle entrained in the medical fluid is an air bubble based on a determined shape of the bubble.

17. The medical fluid machine of claim 16, wherein the fluid carrying unit is disposable.

18. The medical fluid machine of claim 16, wherein the determined shape for an air bubble is an at least substantially circular or rectangular shape.

19. The medical fluid machine of claim 16, wherein the process is configured to determine that the particle is an air bubble when a reflected highlight indicative of a spherical shape is detected by the camera.

20. The medical fluid machine of claim 16, wherein the processor is configured to determine that a particle entrained in the medical fluid is an acceptable therapy particle when a determined shape of the particle is irregular.