Infusion pump actuators, system and method for controlling medical fluid flowrate

• US 8,137,083 B2
• Filed: 03/11/2009
• Issued: 03/20/2012
• Est. Priority Date: 03/11/2009
• Status: Expired due to Fees

• Current Assignee: Baxter Healthcare SA (Baxter International Inc.), Baxter International Inc.
• Original Assignee: Baxter Healthcare SA (Baxter International Inc.), Baxter International Inc.
• Inventors: Zhou, Yu
• Primary Examiner(s): Kramer, Devon C
• Assistant Examiner(s): LETTMAN, BRYAN MATTHEW
• Application Number:
  US12/402,255
• Publication Number:
  US 20100229978A1
• Time in Patent Office: 1,105 Days
• Field of Search: 417/474, 417/476, 417/477.1, 417/477.3, 417/477.5, 417/477.7, 417/477.8, 417/477.6, 417/478, 417/481, 417/479, 92/90, 92/91, 92/92, 741/10, 745/20, 604/131, 604/151, 604/153
• US Class Current: 417/478
• CPC Class Codes: A61M 5/14228 with linear peristaltic action, i.e. comprising at least three pressurising members or a helical member
• CPC Class Codes: F04B 43/084 the tubular member being deformed by stretching or distortion
• CPC Class Codes: F04B 43/09 Pumps having electric drive
• CPC Class Codes: Y10T 137/85986 Pumped fluid control

Abstract

An infusion pump includes an actuator having an output shaft; a pump actuator having a length (l_actuator) moved by the output shaft and in contact with tubing, such that the pump actuator at an output shaft actuated distance (x) creates flat contact areas with the tubing, and wherein remaining non-contact areas of the tubing are at least substantially circular in shape; and a logic implementer configured to use at least two relationships to solve for a same number of variables to calculate a cross-sectional area of the tubing at an output shaft actuated distance (x).

Claims

1. An infusion pump comprising:

an actuator having an output shaft;

a plurality of members, at least two of the members in a first hinged communication with the output shaft, and at least two of the members in a second hinged communication with each other, at least one of the first and second hinged communications formed via at least one hinge pin, such that the members at an output shaft actuated distance (x) create flat contact areas with tubing inserted within the members, and wherein remaining non-contact areas of the a tubing are at least substantially circular in shape; and

a logic implementer configured to use a calculated cross-sectional area of the tubing at the output shaft actuated distance (x) to control the actuator to obtain a desired flowrate.

2. The infusion pump of claim 1, wherein being configured to use the calculated cross-sectional area of the tubing at the output shaft actuated distance (x) includes using a motion profile that varies a change in the output shaft actuated distance (x) based on an expected change in the calculated cross-sectional area of the tubing to obtain the desired flowrate.

3. The infusion pump of claim 1, wherein the calculated cross-sectional area of the tubing is calculated knowing an angle (θ

) of one of the members at the output shaft actuated distance (x) relative to a theoretical horizontal centerline of the tubing.

4. The infusion pump of claim 3, wherein the angle (θ

) at the output shaft actuated distance (x) is common to each of the members.

5. The infusion pump of claim 1, wherein the calculated cross-sectional area of the tubing is calculated knowing a length of at least one of the members.

6. The infusion pump of claim 1, wherein the calculated cross-sectional area of the tubing is calculated knowing a nominal uncompressed radius or diameter of the tubing.

7. The infusion pump of claim 1, wherein the calculated cross-sectional area of the tubing has removed from it a cross-sectional thickness area of the tubing.

8. The infusion pump of claim 1, wherein the desired flowrate is a constant flowrate.

9. The infusion pump of claim 1, wherein the desired flowrate is based on a desired volume change, which is based on a desired change in the calculated cross-sectional area of the tubing multiplied by a constant length (l_actuator) of the members.

10. An infusion pump comprising:

an actuator having an output shaft;

a pump actuator having a plurality of members, at least two of the members in a first hinged communication with the output shaft, and at least two of the members in a second hinged communication with each other, at least one of the first and second hinged communications formed via at least one hinge pin

the pump actuator having a length (l_actuator) moved by the output shaft and in contact with a tubing, such that the plurality of members of the pump actuator at an output shaft actuated distance (x) create flat contact areas with the tubing, and wherein remaining non-contact areas of the tubing are at least substantially circular in shape; and

a logic implementer configured to use at least two relationships to solve for a same number of variables to calculate a cross-sectional area of the tubing at the output shaft actuated distance (x).

11. The infusion pump of claim 10, the logic implementer further configured to use the calculated cross-sectional area of the tubing at the output shaft actuated distance (x) to control the actuator to obtain a desired flowrate.

12. The infusion pump of claim 10, wherein one of the relationships is based on a constant length (L) of at least one member of the pump actuator.

13. The infusion pump of claim 10, wherein one of the relationships is based on a known uncompressed radius of the tubing.

14. An infusion pump comprising:

an actuator having an output shaft;

first and second members in a first hinged communication with the output shaft;

a third member in a second hinged communication with the first member;

a fourth member in a third hinged communication with the second member, at least one of the first, second, and third hinged communications provided via at least one hinge pin; and

the third and fourth members held mechanically such that when the actuator is actuated in a first direction, a tube section extending through the members is compressed to expel a fluid from the tube section and when the actuator is actuated in a second direction, the tube section is decompressed to draw fluid into the tube section.

15. The infusion pump of claim 14, wherein the actuator is extended in the first direction and retracted in the second direction.

16. The infusion pump of claim 14, wherein the first member is in the second hinged communication with the third member via a slide member, the slide member held slideably within a restraint.

17. The infusion pump claim 14, wherein the second member is in the third hinged communication with the fourth member via a slide member, the slide member held slideably within a restraint.

18. The infusion pump of claim 14, wherein the third member is in a fourth hinged communication with the fourth member.

19. The infusion pump of claim 18, wherein the third member is in the fourth hinged communication with the fourth member via a slide member, the slide member held slideably within a restraint.

20. The infusion pump of claim 14, wherein the members have a depth, the depth at least substantially defining a length of the tube section.

21. The infusion pump of claim 14, wherein at least one of:

(i) the third member is hinged directly to the first member, (ii) the fourth member is hinged directly to the second member, and (iii) the third member is hinged directly to the fourth member.

22. The infusion pump of claim 14, wherein the third member is hinged directly to the fourth member at a location fixed to a restraint.