FLOW PULSATILITY DAMPENING DEVICES FOR CLOSED-LOOP CONTROLLED INFUSION SYSTEMS

• US 20090131859A1
• Filed: 11/16/2007
• Published: 05/21/2009
• Est. Priority Date: 11/16/2007
• 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: Akonur, Alp, DelCastillo, Jorge
• Granted Patent: US 8,449,500 B2
• Time in Patent Office: Days
• US Class Current: 604/65
• CPC Class Codes: A61M 2206/10 Flow characteristics
• CPC Class Codes: A61M 2206/22 eliminating pulsatile flows, e.g. by the provision of a dampening chamber
• CPC Class Codes: A61M 5/14212 Pumping with an aspiration and an expulsion action
• CPC Class Codes: A61M 5/14216 Reciprocating piston type
• CPC Class Codes: A61M 5/14224 Diaphragm type
• 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: A61M 5/14232 Roller pumps
• CPC Class Codes: A61M 5/16831 Monitoring, detecting, signalling or eliminating infusion flow anomalies low-level float-valves causing cut-off A61M5/40; indicating or recording presence, absence or direction of flow in general G01P13/0066
• CPC Class Codes: A61M 5/172 electrical or electronic A61M5/16804, A61M5/16831 take precedence
• CPC Class Codes: F04B 39/005 with direct action on the fluid flow using absorptive materials

Abstract

A flow monitoring infusion system that includes an infusion circuit having a fluid with a pulsatile fluid flow flowing therethrough. The infusion circuit includes a dampening element having a dampening chamber that absorbs the pressure fluctuations of the pulsatile fluid flow to transform the pulsatile fluid flow to a more smooth fluid flow. A fluid flow sensor that measures the flowrate of the more smooth fluid flow is disposed along the infusion circuit downstream of the dampening element.

Claims

1. A flow monitoring infusing system, comprising:

a fluid pathway for containing a fluid pumped at a non-continuous fluid flow;

a dampening chamber in communication with the fluid pathway, the dampening chamber configured to hold a gas that absorbs pressure fluctuations of the non-continuous fluid flow to smoothen the non-continuous fluid flow; and

a fluid flow sensor disposed along the fluid pathway downstream of the dampening chamber to measure the flowrate of the smoothened fluid flow.

2. The infusion system of claim 1, which includes a pulsatile infusion pump in communication with the fluid pathway for providing a non-continuous fluid flow.

3. The infusion system of claim 2, wherein the pulsatile infusion pump is selected from the group consisting of a membrane pump and a peristaltic pump.

4. The infusion system of claim 1, wherein the dampening chamber includes a generally cylindrical or rectangular body shape.

5. The infusion system of claim 1, wherein the dampening chamber is a length of tubing extending from the fluid pathway.

6. The infusion system of claim 1, wherein the dampening chamber has a volume between about 8 ml and about 30 ml.

7. The infusion system of claim 1, wherein the gas includes air.

8. The infusion system of claim 1, further including a closed-looped control system configured to optimize the flowrate.

9. The infusion system of claim 6, wherein the closed-looped control system includes a PID controller.

10. An infusion system comprising:

a fluid pathway;

an infusion pump for pumping a non-continuous flow of fluid through the fluid pathway;

a generally tubular shaped member defining a chamber that is in communication with the fluid pathway, the chamber containing a compressible gas that absorbs pressure fluctuations of the non-continuous fluid to smoothen the non-continuous flow;

a fluid flow sensor disposed along the fluid pathway downstream of the tubular shaped member, the flow sensor configured to measure a flowrate of the smoothened fluid flow; and

a control member operable with the flow sensor and the infusion pump, the control member configured to receive flowrate information from the flow sensor and to adjust the infusion pump based on the flowrate information.

11. The infusion system of claim 10, wherein the generally tubular shaped member is operably connected to the fluid pathway by a T-shaped connector.

12. The infusion system of claim 10, wherein the generally tubular shaped element comprises a length of flexible tubing.

13. The infusion system of claim 10, wherein the tubular shaped member extends in a generally perpendicular direction from the fluid pathway.

14. The infusion system of claim 10, wherein the chamber has a volume between about 8 ml and about 30 ml.

15. The infusion system of claim 10, wherein the control member includes a PID controller.

16. The infusion system of claim 10, wherein the infusion pump is selected from the group consisting of a membrane pump and a peristaltic pump.

17. A method of controlling fluid flowrate within an infusion system comprising:

flowing a non-continuous fluid flow through a fluid pathway of infusion system at an initial flowrate;

smoothing the non-continuous fluid flow;

monitoring a flowrate of the smoothened fluid flow; and

adjusting the initial flowrate based on the flowrate of the smoothened fluid flow.

18. The method of claim 17, including monitoring the smoothed fluid flow with a fluid flow sensor.

19. The method of claim 17, including smoothing the non-continuous fluid flow with a dampening chamber.

20. The method of claim 17, including smoothing the non-continuous fluid flow with a compressible gas.