Cassette for use in a medication delivery flow sensor assembly and method of making the same

• US 7,819,838 B2
• Filed: 05/20/2009
• Issued: 10/26/2010
• Est. Priority Date: 09/02/2008
• Status: Active Grant

• Current Assignee: ICU Medical Incorporated
• Original Assignee: Hospira Incorporated (Pfizer Inc.)
• Inventors: Currat, Olivier F., Bransky, Jeff D., Morrow, James D., Ziegler, John S., Fathallah, Marwan A., Jacobson, James D., Barclay, Brian
• Primary Examiner(s): BUMGARNER, MELBA N
• Application Number:
  US12/469,459
• Publication Number:
  US 20100057058A1
• Time in Patent Office: 524 Days
• Field of Search: 604/65, 604/66, 604/67, 604/250, 417/413.1, 417/63
• US Class Current: 604/65
• CPC Class Codes: A61M 2205/12 with interchangeable cassettes forming partially or totally the fluid circuit
• CPC Class Codes: A61M 2205/3351 Controlling upstream pump pressure
• CPC Class Codes: A61M 2205/3355 Controlling downstream pump pressure
• CPC Class Codes: A61M 5/16854 by monitoring line pressure
• CPC Class Codes: A61M 5/16886 for measuring fluid flow rate, i.e. flowmeters
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

A disposable assembly for use with a sensor assembly comprises 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 membrane is located between the lid and base portions along the fluid flow passage. A reinforcing structure, such as a ring or a rigid disk, is positioned between the fluid pressure membrane and the lid portion to provide increased resistance to pressure in the fluid flow passage. The ring or disk can be a separate component or formed on the membrane. The membrane thickness adjacent to sensor access openings in the lid portion can be increased for pressure resistance, too.

Claims

1. A fluid-tight disposable assembly for removably coupling to a reusable flow sensor assembly, the disposable assembly comprising:

a sealed body having a lid portion connected to 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 and between the first opening and the second opening;

an impermeable fluid pressure membrane disposed along the fluid flow passage between the inlet and the outlet and located between the lid portion and the base portion of the body so as to be accessible at the first opening and the second opening of the lid portion, the fluid pressure membrane being secured to the base portion and the lid portion so as to provide a first movable pressure responsive wall portion that sealingly covers a first chamber of the fluid flow passage at a location upstream of the flow restricting element and moves with respect to the first opening in response to fluid pressure in the first chamber of the fluid flow passage and a second movable pressure responsive wall portion that sealingly covers a second chamber of the fluid flow passage at a location downstream of the flow restricting element and moves with respect to the second opening in response to fluid pressure in the second chamber of the fluid flow passage;

a first reinforcing ring disposed on the first movable pressure responsive wall portion of the fluid pressure membrane in surrounding relation to and outwardly adjacent to the first opening of the lid portion, the first reinforcing ring being positioned between the lid portion and the fluid pressure membrane and being movable into contact with the lid portion by fluid pressure in the first chamber of the fluid flow passage; and

a second reinforcing ring disposed on the second movable pressure responsive wall portion of the fluid pressure membrane and in surrounding relation to and outwardly adjacent to the second opening of the lid portion, the second reinforcing ring being positioned between the lid portion and the fluid pressure membrane and being movable into contact with the lid portion by fluid pressure in the second chamber of the fluid flow passage.

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

3. The disposable assembly of claim 2, wherein the first reinforcing ring surrounds the first area of the fluid pressure membrane, and the second reinforcing ring surrounds the second area of the fluid pressure membrane.

4. The disposable assembly of claim 3, wherein at least a portion of the first area of the fluid pressure membrane and at least a portion of the second area of the fluid pressure membrane have an increased thickness relative to a third area of the fluid pressure membrane that resides outside of the first area and the second area.

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

6. The disposable assembly of claim 1, wherein the first reinforcing ring and the second reinforcing ring are each defined by a rib on the fluid pressure membrane.

7. The disposable assembly of claim 1, wherein the flow restricting element is a separate component from the lid portion and the base portion and is secured within the fluid pressure membrane.

8. The disposable assembly of claim 1, wherein the base portion and the lid portion of the body are ultrasonically welded together to secure the fluid pressure membrane between the base portion and the lid portion and seal the body.

9. A fluid-tight disposable assembly for removably coupling to a reusable sensor assembly, the disposable assembly comprising:

a sealed body having a lid portion connected to 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;

an impermeable fluid pressure membrane disposed along the fluid flow passage between the inlet and the outlet and located between the lid portion and the base portion of the body, the fluid pressure membrane being secured to the base portion and the lid portion so as to provide a first movable pressure responsive wall portion that sealingly covers a first chamber of the fluid flow passage at a location upstream of the flow restricting element and moves with respect to the first opening in response to fluid pressure in the first chamber of the fluid flow passage and a second movable pressure responsive wall portion that sealingly covers a second chamber of the fluid flow passage at a location downstream of the flow restricting element and moves with respect to the second opening in response to fluid pressure in the second chamber of the fluid flow passage;

a first rigid disk positioned on an upper surface of the first movable pressure responsive wall portion between the fluid pressure membrane and the lid portion, the first rigid disk being positioned adjacent to the first opening formed in the lid portion and being movable into contact with the lid portion by fluid pressure in the first chamber of the fluid flow passage; and

a second rigid disk positioned on an upper surface of the second movable pressure responsive wall portion between the fluid pressure membrane and the lid portion, the second rigid disk being positioned adjacent to the second opening formed in the lid portion and being movable into contact with the lid portion by fluid pressure in the second chamber of the fluid flow passage.

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

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

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 portion 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 portion.

13. The disposable assembly of claim 12, wherein the second rigid disk comprises a ledge portion and a protruding portion, the ledge portion adapted to contact the lid portion 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 portion.

14. The disposable assembly of claim 13, wherein the sensor assembly is a differential pressure based fluid flow sensor assembly.

15. The disposable assembly of claim 14, wherein the protruding portion of the first rigid disk is 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.

16. The disposable assembly of claim 9, wherein the lid portion is ultrasonically welded to the base portion to secure the fluid pressure membrane between the lid portion and the base portion and seal the body.

17. The disposable assembly of claim 9, wherein the flow restricting element is a separate component from the lid portion and the base portion and is secured within the fluid pressure membrane.