CASSETTE FOR DIFFERENTIAL PRESSURE BASED MEDICATION DELIVERY FLOW SENSOR ASSEMBLY FOR MEDICATION DELIVERY MONITORING AND METHOD OF MAKING THE SAME

• US 20100198155A1
• Filed: 05/20/2009
• Published: 08/05/2010
• Est. Priority Date: 01/30/2009
• Status: Active Grant

• Current Assignee: ICU Medical Incorporated
• Original Assignee: Hospira Incorporated (Pfizer Inc.)
• Inventors: Ziegler, John S., Fathallah, Marwan A., Hahn, John J., Jacobson, James D., Johnson, Thomas D., Lowery, Michael G., Moy, Yei Feng
• Granted Patent: US 8,048,022 B2
• Time in Patent Office: Days
• US Class Current: 604/118
• CPC Class Codes: A61M 2205/12 with interchangeable cassettes forming partially or totally the fluid circuit
• CPC Class Codes: A61M 2205/128 with incorporated valves
• CPC Class Codes: A61M 2205/3334 Measuring or controlling the flow rate
• CPC Class Codes: A61M 5/16886 for measuring fluid flow rate, i.e. flowmeters
• CPC Class Codes: G01F 1/363 with electrical or electro-mechanical indication G01F1/37 and G01F1/38 take precedence
• CPC Class Codes: G01F 1/42 Orifices or nozzles
• CPC Class Codes: G01F 15/14 Casings, e.g. of special material
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

A disposable assembly for use with a sensor assembly, the disposable comprising a body, a flow restricting element, and a fluid pressure membrane. The body has a lid portion and a base portion. The body defines a fluid flow passage that forms an inlet and an outlet. The flow restricting element is positioned in the fluid flow passage between the inlet and the outlet. The fluid pressure membrane is disposed along the fluid flow passage between the inlet and the outlet. The fluid pressure membrane is located between the lid portion and the base portion of the body.

Claims

1. A disposable assembly for use with a flow sensor assembly, the disposable assembly comprising:

a body having a lid portion and a base portion, the body defining a fluid flow passage forming an inlet and an outlet, the lid portion having a first opening and a second opening;

a flow restricting element positioned in the fluid flow passage between the inlet and the outlet, the flow restricting element being formed into the base portion;

a fluid pressure membrane disposed along the fluid flow passage between the inlet and the outlet, the fluid pressure membrane being located between the lid portion and the base portion of the body.

2. The disposable assembly for use with a flow sensor assembly of claim 1, wherein the fluid pressure membrane has a first and a second area adapted to be aligned with the first opening and the second opening of the lid portion.

3. The disposable assembly for use with a flow sensor assembly of claim 1, wherein the flow restricting element is molded into the base portion.

4. The disposable assembly for use with a flow sensor assembly of claim 3, wherein the flow restricting element comprises a strip of material having an orifice molded into the base portion.

5. The disposable assembly for use with a flow sensor assembly of claim 1, wherein the fluid pressure membrane has a first and a second area adapted to be aligned with the first opening and the second opening of the lid portion and are recessed from the first and second openings when the disposable assembly is used with a flow sensor assembly.

6. The disposable assembly for use with a flow sensor assembly of claim 5, the fluid pressure membrane first area is a first membrane portion and the fluid pressure membrane second area is a second membrane portion, the first membrane portion and the second membrane portion being separate membranes.

7. The disposable assembly for use with a flow sensor assembly of claim 6, wherein first membrane portion has a first protruding lip and the second membrane portion has a second protruding lip, the first protruding lip and the second protruding lip being adapted to interact with a trough in the base portion to form a fluid tight seal between the lid portion and the base portion.

8. The disposable assembly for use with a flow sensor assembly of claim 7, wherein the base portion and the lid portion of the body are ultrasonically welded together.

9. A disposable assembly for use with a sensor assembly, the disposable assembly comprising:

a body having a lid portion and a base portion, the body defining a fluid flow passage forming an inlet and an outlet;

a flow restricting element positioned in the fluid flow passage between the inlet and the outlet, the flow restricting element being formed within the base portion;

a fluid pressure membrane disposed along the fluid flow passage between the inlet and the outlet, the fluid pressure membrane being located between the lid portion and the base portion of the body;

a first rigid disk positioned between the fluid pressure membrane and the lid, the first rigid disk being positioned near a first opening formed in the lid; and

a second rigid disk positioned between the fluid pressure membrane and the lid, the second rigid disk being positioned near a second opening formed in the lid.

10. The disposable assembly of claim 9, wherein the fluid pressure membrane has a first and a second area adapted to be aligned with the first rigid disk and the second rigid disk.

11. The disposable assembly of claim 10, wherein the first area of the membrane forms a recess to position the first rigid disk between the fluid pressure membrane and the lid, and wherein the second area of the membrane forms a recess to position the second rigid disk between the fluid pressure membrane and the lid.

12. The disposable assembly of claim 9, wherein the first rigid disk comprises a ledge portion and a protruding portion, the ledge portion adapted to contact the lid to limit the displacement of the first rigid disk, the protruding portion adapted to at least partially pass through the first opening of the lid, and wherein the second rigid disk comprises a ledge portion and a protruding portion, the ledge portion adapted to contact the lid to limit the displacement of the second rigid disk, the protruding portion adapted to at least partially pass through the second opening of the lid.

13. The disposable assembly of claim 12, wherein the protruding portion of the first rigid disk is a adapted to interact with a first sensor of the differential pressure based fluid flow sensor assembly, and wherein the protruding portion of the second rigid disk is adapted to interact with a second sensor of the differential pressure based fluid flow sensor assembly.

14. The disposable assembly of claim 9, wherein the flow restricting element comprises a micromolded orifice chip molded into the base portion.

15. The disposable assembly of claim 14, wherein the flow restricting element and the base portion comprise the same material.

16. The disposable assembly of claim 9, wherein the lid portion is ultrasonically welded to the base portion.

17. A method of forming a disposable portion for a fluid flow sensor assembly comprising:

providing a preformed flow restricting element;

forming a base portion around the flow restricting element, the base portion forming at least a portion of a fluid flow passage having an inlet and an outlet, the inlet being in fluid communication with an upstream side of the flow restricting element and the outlet being in fluid communication with a downstream side of the flow restricting element;

positioning a fluid pressure membrane along the fluid flow passage between the inlet and the outlet, the fluid pressure membrane contacting the base portion; and

securing a lid portion to the base portion, the fluid pressure membrane being positioned between the lid portion and the base portion following the securing.

18. The method of claim 17, wherein the act of providing the flow restricting element includes supplying a strip of material having a plurality of orifices located at predetermined intervals, such that a single orifice is positioned within a mold used in the forming of the base portion.

19. The method of claim 17, wherein the act of providing the flow restricting element includes supplying a single molded flow restricting element having an orifice within a mold used in forming the base portion.

20. The method of claim 17, wherein the securing the lid portion to the base portion includes ultrasonic welding.

21. The method of claim 17 further comprising providing a first rigid disk between the fluid pressure membrane and the lid at the upstream side of the flow restricting element, and providing a second rigid disk between the fluid pressure membrane and the lid at the downstream side of the flow restricting element.