INTEGRATED WATER TESTING SYSTEM AND METHOD FOR ULTRA-LOW TOTAL CHLORINE DETECTION

• US 20140110341A1
• Filed: 03/12/2013
• Published: 04/24/2014
• Est. Priority Date: 10/22/2012
• Status: Active Grant

• Current Assignee: Baxter Healthcare SA (Baxter International Inc.), Baxter International Inc.
• Original Assignee: Baxter Healthcare SA (Baxter International Inc.), Baxter International Inc.
• Inventors: White, Jeff, Chen, Ye, Ding, Samuel, Titus, Joel, Rohde, Justin, Maliekkal, Shincy, Cooper, Kevin
• Granted Patent: US 9,162,021 B2
• Time in Patent Office: Days
• US Class Current: 210/647
• CPC Class Codes: A61M 1/1603 Regulation parameters
• CPC Class Codes: A61M 1/1656 Apparatus for preparing dialysates
• CPC Class Codes: A61M 1/1664 with temperature control
• CPC Class Codes: A61M 1/1668 Details of containers
• CPC Class Codes: A61M 2205/3327 Measuring
• CPC Class Codes: A61M 2205/502 User interfaces, e.g. screens or keyboards
• CPC Class Codes: A61M 2205/75 with filters
• CPC Class Codes: C02F 1/50 by addition or application of a germicide or by oligodynamic treatment C02F1/4606, C02F1/467, C02F1/76 take precedence
• CPC Class Codes: C02F 2103/026 Treating water for medical or cosmetic purposes
• CPC Class Codes: G01N 27/30 Electrodes, e.g. test electrodes; Half-cells G01N27/414 takes precedence
• CPC Class Codes: G01N 27/413 Concentration cells using liquid electrolytes measuring currents or voltages in voltaic cells
• CPC Class Codes: G01N 27/4168 Oxidation-reduction potential, e.g. for chlorination of water water analysis G01N33/18
• CPC Class Codes: G01N 33/0036 Specially adapted to detect a particular component all the other sub-groups of G01N33/0004 take precedence
• CPC Class Codes: Y02W 10/33 using wind energy

Abstract

A system and method for determining a concentration of total chlorine in dialysis water are provided. The system comprises a main unit housing an iodide/water sample chamber and a reducing agent chamber. An electrode pair bridges the two chambers and generates tri-iodide proportional to the amount of total chlorine in the dialysis water. The electrode pair detects the amount of tri-iodide generated in proportion to the amount of active chloride in the dialysis water. The system is suitable for use in connection with, or for incorporation into, a water purification system for generating dialysis fluid, and may include a display that alerts the user to stop or prevent a hemodialysis treatment if the total chlorine level exceeds a predetermined level.

Claims

1. A system for determining a level of total chlorine in a dialysis water sample, the system comprising:

a water purification machine;

a dialysis machine in fluid communication with the water purification machine; and

a total chlorine detector in fluid communication with the water purification machine, said total chlorine detector including;

an iodide reservoir,

a reducing agent reservoir,

a first chamber in fluid communication with the iodide reservoir and a water sample produced by the water purification machine,

a second chamber in fluid communication with the reducing agent reservoir, wherein the first and second chambers are separated by a membrane that allows charge but not fluid to pass between the chambers,

an electrode pair associated with a voltage source, wherein one electrode of the electrode pair is in contact with iodide fluid and the water sample mixed in the first chamber and the other electrode of the electrode pair is in contact with a reducing agent solution in the second chamber, and

a control unit connected operably to the electrode pair, the control unit configured to (i) at one time cause the voltage source to apply a source voltage to the electrode pair and (ii) at a second time stop applying the source voltage to the electrode pair and instead monitor a sensed electrical parameter through or across the electrode pair.

2. The system of claim 1, wherein at least one of the electrodes includes platinum, gold, stainless steel, copper, combinations or alloys thereof.

3. The system of claim 1, wherein at least one of the first and second chambers includes a tube.

4. The system of claim 1, wherein the first and second chambers both include tubes, and wherein the first chamber is disposed within a lumen of the second tube.

5. The system of claim 2, wherein the membrane is selected from the group consisting of:

a semipermeable membrane, and a membrane including a plurality of perforations.

6. The system of claim 1, wherein at least one electrode of the electrode pair includes or is provided with a resistor.

7. The system of claim 1, wherein one electrode of the electrode pair is placed in electrical communication with a ground.

8. The system of claim 1, which includes an agitator in contact with at least one of the first and second chambers.

9. The system of claim 1, wherein during (i), tri-iodide is generated.

10. The system of claim 1, wherein from (ii), the control unit can determine an amount of total chlorine in the water sample.

11. The system of claim 1, wherein the control unit is configured to sequentially perform (i) and (ii) multiple times.

12. The system of claim 11, wherein the control unit is further configured to merge results obtained from performing (i) and (ii) multiple times.

13. The system of claim 1, which is embedded into the water purification machine enabling at least one filter of the water purification machine to be evaluated.

14. The system of claim 1, wherein the total chlorine detector is downstream of a water filter including carbon.

15. The system of claim 1, which includes a user interface configured and arranged to indicate at least one of (i) an alarm to a user if a level of total chlorine in the water sample exceeds a predetermined value or (ii) indicate a safe status to a user if the level of total chlorine in the water sample falls below a predetermined value.

16. The system of claim 15, wherein the predetermined value is between and including 0.1 ppm to 0.5 ppm.

17. The system of claim 1, wherein at least one of the first chamber, the iodide reservoir, or the reducing agent reservoir is provided in a replaceable cartridge or cassette form.

18. The system of claim 1, which includes a plurality of pumps and valves positioned and arranged to meter preset amounts of sample water and iodide reagent into the first chamber and reducing agent into the second chamber.

19. The system of claim 1, which includes at least one pump and valve positioned and arranged to pump deionized water into at least one of the first and second chambers.

20. The system of claim 1, which includes at least one pump and valve positioned and arranged to pull fluid from at least one of the first and second chambers to drain.

21. The system of claim 1, which is provided as part of the water purification machine feeding water to the dialysis machine that prepares dialysate using the water from the water purification machine, and wherein information concerning the level total chlorine is displayed on a user interface of the dialysis machine.

22. A method of providing a hemodialysis treatment to a subject in need thereof, the method comprising:

providing the system of claim 1, wherein the water sample is from water for preparing dialysate; and

determining a level of total chlorine in the water sample;

alerting the user to perform a corrective action if the level of total chlorine exceeds a predetermined level; and

allowing the user to perform the hemodialysis treatment if the level of total chlorine is below the predetermined level.

23. The method of claim 22, wherein the alerting step further includes preventing the user from performing the hemodialysis treatment until a subsequent level of total chlorine in a subsequent water sample is below the predetermined level.

24. The method of claim 22, wherein the water sample is from water for preparing dialysate that has been passed through a filter including carbon.

25. A method of for determining an amount of total chlorine in water for dialysis, the method comprising:

(a) providing a water purification machine in fluid communication with a dialysis machine;

(b) providing a total chlorine detection system, in fluid communication with the water purification machine, the total chlorine detection system including

a first chamber in fluid communication with an iodide reservoir and a water sample source,

a second chamber in fluid communication with a reducing agent reservoir, and

an electrode pair associated with a voltage source, wherein one electrode of the electrode pair is in contact with an iodide fluid in the first chamber and the other electrode of the electrode pair is in contact with a reducing agent solution in the second chamber, and wherein the first and second chambers are separated by a membrane that allows charge but not fluid to pass between the chambers;

(c) measuring a background voltage V_B in the electrode pair, the background voltage V_B associated with any tri-iodide in the system before introduction of a water sample;

(d) providing a water sample from the water purification machine, the water sample including an amount of total chlorine;

(e) metering an amount of the water sample into the system;

(f) monitoring a baseline voltage V₀ via the electrode pair, the baseline voltage V₀ associated with tri-iodide present in the water sample before application of a tri-iodide generating voltage to the electrode pair;

(g) generating a first amount of tri-iodide from the water sample by applying a voltage V₁ to the electrode pair for a time t₁;

(h) thereafter monitoring a first voltage V₂ in the electrode pair, optionally for a time t₂, the first monitored voltage V₂ associated with a sum of the amount of total chlorine and the first amount of tri-iodide;

(i) thereafter generating a second amount of tri-iodide from the water sample by applying a voltage V₃ to the electrode pair for a time t₃;

(j) thereafter monitoring a second voltage V₄ in the electrode pair, optionally for a time t₄, the second monitored voltage V₄ associated with a sum of the amount of total chlorine and the first and second amounts of tri-iodide;

(k) optionally thereafter generating a third amount of tri-iodide from the water sample by applying a voltage V₅ to the electrode pair for a time t₅, the third amount of tri-iodide corresponding to the third amount of tri-iodide;

(l) optionally monitoring a third voltage V₆ in the electrode pair, optionally for a time t₆, the third monitored voltage V₆ associated with a sum of the amount of total chlorine and the first, second and third amounts of tri-iodide; and

(m) calculating the unknown total chlorine concentration in the water sample from the baseline voltage V₀, the background voltage V_B, and at least one of the first, second and optional third monitored voltages V₂, V₄ and V₆.