System and method for delivering a target volume of fluid

1. A system for delivering a target volume of fluid to a destination, the target volume being approximately the sum of a first volume of fluid and a second volume of fluid, comprising:

a fluid control module for delivering the first volume of fluid to the destination in increments each having approximately a first incremental volume, and for delivering the second volume of fluid to the destination in increments each having approximately a second incremental volume, the second incremental volume being less than the first incremental volume;

a valve arrangement for controlling fluid communication to the destination; and

a controller for determining the volume of fluid delivered to the destination and for controlling the valve arrangement and the fluid control module, the controller having computer readable program code comprising:

program code for calculating the first volume of fluid delivered and the second volume of fluid delivered to the destination,

program code for suspending delivery of the first volume of fluid to the destination when the first volume of fluid delivered exceeds the second volume of fluid delivered by a predetermined fraction of the first incremental volume, and

program code for resuming delivery of the first volume of fluid to the destination after further delivery of the second volume of fluid.

2. A system according to claim 1 , wherein the fluid control module is configured to deliver the first and second volumes of fluid to a human subject.

3. A system according to claim 2 , wherein the fluid control module is configured to deliver the first and second volumes of fluid parenterally.

4. A system according to claim 1 , wherein the fluid control module delivers the first and second volumes of fluid to a fluid reservoir.

5. A system according to claim 1 , wherein the fluid control module delivers the first and second volumes of fluid to a container.

6. A system according to claim 5 , wherein the container is a heating bag.

7. A system according to claim 5 , wherein the container is a pump chamber.

8. A system according to claim 1 , wherein the first volume is approximately equal to the target volume minus a finish volume.

9. A system according to claim 8 , wherein the second incremental volume is less than the finish volume.

10. A system according to claim 8 , wherein the second incremental volume is less than one third the finish volume.

11. A system for simultaneously delivering a target volume of fluid from two sources in a desired ratio to a common destination, the system comprising:

a first fluid source;

a second fluid source;

a fluid control module for delivering a first volume of fluid from the first fluid source and a second volume of fluid from the second fluid source to the destination in increments each having approximately a first incremental volume, the first incremental volume being substantially less than the target volume, and for measuring the volume of fluid delivered to the destination from the first source and the volume of fluid delivered to the destination from the second source;

a valve arrangement for controlling fluid communication between the destination and the first and second fluid sources; and

a controller for determining the first and second volumes of fluid, the first incremental volume of fluid, and for controlling the valve arrangement and the fluid control module, the controller having computer readable program code comprising;

program code for calculating the first and second volumes of fluid delivered to the destination,

program code for suspending delivery of the first volume of fluid to the destination when the first volume delivered exceeds the second volume delivered by a predetermined fraction of the first incremental volume, and

program code for resuming delivery of the first volume of fluid to the destination after further delivery of fluid from the second fluid source.

12. A system according to claim 11 , wherein the first incremental volume is less than one quarter of the target volume.

13. A system according to claim 11 , wherein the desired ratio is 1:1.

14. A system according to claim 13 , wherein the predetermined fraction is approximately one half.

15. A system according to claim 11 , wherein the fluid control module is configured to deliver the first and second volumes of fluid to a human subject.

16. A system according to claim 15 , wherein the fluid control module is configured to deliver the first and second volumes of fluid parenterally.

17. A system according to claim 11 , wherein the fluid control module delivers the first and second volumes of fluid to a fluid reservoir.

18. A system according to claim 11 , wherein the fluid control module delivers the first and second volumes of fluid to a container.

19. A system according to claim 18 , wherein the container is a heating bag.

20. A system according to claim 18 , wherein the container is a pump chamber.

21. A system for delivering a target volume of fluid from two sources in a desired ratio to a common destination, the system comprising:

a first fluid source;

a second fluid source;

a fluid control module for delivering a first volume of fluid from the first fluid source and a second volume of fluid from the second fluid source to the destination in increments each having approximately a first incremental volume, the first incremental volume being substantially less than the target volume, and for measuring the volume of fluid delivered to the destination from the first source and the volume of fluid delivered to the destination from the second source;

a valve arrangement for controlling fluid communication between the destination and the first and second fluid sources; and

a controller for determining the first and second volumes of fluid, the first incremental volume of fluid, and for controlling the valve arrangement and the fluid control module, the controller having computer readable program comprising;

program code for calculating the first and second volumes of fluid delivered to the destination,

program code for calculating that approximately the target volume minus a finish volume of fluid has been delivered to the destination;

program code for calculating the volume of fluid delivered to the destination from the first source and the volume of fluid delivered to the destination from the second source; and

program code for delivering a third volume of fluid from the source that has delivered a smaller volume of fluid to the destination, said delivery of a third volume occurring in increments each having approximately a second incremental volume, wherein the second incremental volume is less than the first incremental volume, such that the volume of fluid delivered to the destination from the first source and the volume of fluid delivered from the second source are in approximately the desired ratio.

22. A system according to claim 21 , wherein the sum of the first volume delivered and the second volume delivered is approximately equal to the target volume minus the finish volume.

23. A system according to claim 22 , wherein the second incremental volume is less than the finish volume.

24. A system according to claim 22 , wherein the second incremental volume is less than one third the finish volume.

25. A system for delivering a target volume of fluid to a destination comprising:

fluid delivery means for delivering a first volume of fluid to the destination in one or more first incremental volumes, the first volume of fluid being less than the target volume, and for delivering a second volume of fluid to the destination in one or more second incremental volumes, the second incremental volume being less than the first incremental volume;

measuring means for measuring the first volume of fluid and the second volume of fluid delivered to the destination;

control means for controlling the fluid delivery means; and

control means for suspending delivery of the first volume of fluid to the destination when the measured first volume exceeds by a fraction of the first incremental volume an amount required to maintain a desired ratio with respect to the second volume, and for resuming delivery of the first volume of fluid to the destination after further delivery of the second volume of fluid.

26. A system for simultaneously delivering a target volume of fluid from two sources in a desired ratio to a common destination, the system comprising:

a first fluid source;

a second fluid source;

fluid delivery means for delivering a first volume of fluid from the first fluid source and a second volume of fluid from the second fluid source to the destination in one or more first incremental volumes, the first incremental volume being substantially less than the target volume;

measuring means for measuring the volume of fluid delivered to the destination from the first source and the volume of fluid delivered to the destination from the second source; and

control means for suspending delivery of the first volume of fluid to the destination when the measured first volume exceeds an amount needed to maintain the desired ratio with respect to the second volume by a fraction of the first incremental volume, and for resuming delivery of the first volume of fluid to the destination after further delivery of the second volume of fluid.

27. A system for simultaneously delivering a target volume of fluid from two sources in a desired ratio to a common destination, the system comprising:

a first fluid source;

a second fluid source;

fluid delivery means for delivering a first volume of fluid from the first fluid source and a second volume of fluid from the second fluid source to the destination in one or more first incremental volumes, the first incremental volume being substantially less than the target volume;

measuring means for measuring the volume of fluid delivered to the destination from the first source and the volume of fluid delivered to the destination from the second source; and

control means for suspending delivery of the first volume of fluid to the destination when the measured first volume exceeds the measured second volume by a predetermined fraction of the first incremental volume, and for resuming delivery of the first volume of fluid to the destination after further delivery of the second volume of fluid.

28. A system according to claim 27 , wherein the desired ratio is 1:1.

29. A system according to claim 28 , wherein the predetermined fraction is approximately one half.