Claims
- 1. A method of identifying a blood flow rate in a dialysis shunt, comprising:
(a) fluidly connecting a venous line of a dialysis system to deliver blood from the dialysis system to an upstream location in a dialysis shunt, and fluidly connecting an arterial line of the dialysis system to remove blood from a downstream location in the dialysis shunt; (b) identifying an amount of recirculation in the dialysis shunt between the downstream location and the upstream location; and (c) identifying a rate of blood flow in the dialysis shunt corresponding to the amount of recirculation.
- 2. A method of identifying a blood flow rate in a dialysis shunt, comprising:
(a) changing a blood parameter in blood removed from a downstream location in a dialysis shunt; (b) returning the blood having the changed blood parameter to an upstream location in the dialysis shunt; (c) measuring an amount of change in a blood parameter of the blood flowing through the dialysis shunt resulting from the return of blood having the changed blood parameter to the dialysis shunt; and (d) identifying, from the measured amount of change in the blood parameter, a blood flow rate in the dialysis shunt.
- 3. The method of claim 2, wherein the step of measuring the amount of change in the blood parameter includes measuring the amount of change in a dialysis system venous line.
- 4. The method of claim 2, wherein the step of identifying, from the measured amount of change in the blood parameter, a blood flow rate in the dialysis shunt includes employing at least one of the following equations or an equation derived from at least one of the following equations:
- 5. A method of identifying a blood flow rate in a dialysis shunt, comprising:
(a) arranging an arterial line and a venous line of a dialysis system to deliver blood from the dialysis system via the venous line to an upstream location in a dialysis shunt and remove blood from a downstream location in the dialysis shunt via the arterial line; (b) introducing an indicator at the upstream location in the dialysis shunt via the venous line, such that the indicator mixes with blood flowing in the dialysis shunt; (c) withdrawing a mixture of blood and the indicator from the downstream location in the dialysis shunt via the arterial line; (d) measuring a change in a blood parameter caused by the introduction of the indicator; and (e) identifying, from the measured blood parameter, a blood flow rate in the dialysis shunt.
- 6. The method of claim 5, further comprising determining the amount of indicator present in the withdrawn fluid in correspondence to the measured amount of change in the blood parameter.
- 7. The method of claim 5, further comprising measuring the change in the blood parameter in the arterial line.
- 8. The method of claim 5, further comprising employing, as the indicator, blood having a blood characteristic different than the blood flow in the dialysis shunt.
- 9. The method of claim 5, wherein the step of identifying, from the measured blood parameter, a blood flow rate in the dialysis shunt includes employing at least one of the following equations or an equation derived from at least one of the following equations:
- 10. A system for identifying a blood flow rate in a dialysis shunt, comprising:
(a) a sensor configured to measure a change in a blood characteristic resulting from the introduction of an indicator to the blood flowing in the dialysis shunt via a venous line of a dialysis system; and (b) a computer coupled to the sensor, the computer configured to compute, from the measured amount of change, a rate at which blood is flowing through the dialysis shunt.
- 11. The system of claim 10, wherein the introduction of an indicator to the blood flowing in the dialysis shunt via a venous line of a dialysis system occurs at an upstream location with respect to a downstream location for removing blood from the dialysis shunt via an arterial line of the dialysis system.
- 12. The system of claim 10, wherein the indicator comprises blood having a parameter differing from that of blood entering the dialysis shunt via an artery.
- 13. The system of claim 10, wherein the computer employs one of the following equations:
- 14. The system of claim 10, wherein the computer employs an equation derived from at least one of the following equations:
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation of U.S. Ser. No. 09/734,352 filed Dec. 11, 2000, now U.S. Pat. No. 6,514,419 issuing Feb. 4, 2003, which is a continuation of U.S. Ser. No. 09/348,130 filed Jul. 2, 1999, now U.S. Pat. No. 6,210,591 issuing Apr. 3, 2001, which is a continuation of U.S. Ser. No. 09/010,697 filed Jan. 22, 1998, now U.S. Pat. No. 6,153,109 issuing Nov. 28, 2000, which is a continuation-in-part of U.S. Ser. No. 08/965,975 filed Nov. 7, 1997, now abandoned, which is a continuation of U.S. Ser. No. 08/305,953 filed Sep. 16, 1994, now U.S. Pat. No. 5,685,989 issuing Nov. 11, 1997, each of which is expressly incorporated by reference.
Divisions (1)
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Number |
Date |
Country |
Parent |
09734352 |
Dec 2000 |
US |
Child |
10355944 |
Jan 2003 |
US |
Continuations (3)
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Number |
Date |
Country |
Parent |
09348130 |
Jul 1999 |
US |
Child |
09734352 |
Dec 2000 |
US |
Parent |
09010697 |
Jan 1998 |
US |
Child |
09348130 |
Jul 1999 |
US |
Parent |
08305953 |
Sep 1994 |
US |
Child |
08965975 |
Nov 1997 |
US |
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
08965975 |
Nov 1997 |
US |
Child |
09010697 |
Jan 1998 |
US |