CASSETTE FOR USE IN A MEDICATION DELIVERY FLOW SENSOR ASSEMBLY AND METHOD OF MAKING THE SAME

• US 20100057058A1
• Filed: 05/20/2009
• Published: 03/04/2010
• Est. Priority Date: 09/02/2008
• Status: Active Grant

• Current Assignee: ICU Medical Incorporated
• Original Assignee: Hospira Incorporated (Pfizer Inc.)
• Inventors: Ziegler, John S., Fathallah, Marwan A., Jacobson, James D., Barclay, Brian, Currat, Olivier F., Bransky, Jeff D., Morrow, James D.
• Granted Patent: US 7,819,838 B2
• Time in Patent Office: Days
• US Class Current: 604/890.100
• 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 disposable assembly for use with a flow sensor assembly, the disposable assembly comprising:

a 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;

a 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;

a first reinforcing ring surrounding a portion of the fluid pressure membrane 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

a second reinforcing ring surrounding a portion of the fluid pressure membrane adjacent to the second opening of the lid portion, the second reinforcing ring being positioned between the lid portion and the fluid pressure membrane.

2. The disposable assembly for use with a flow sensor 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 for use with a flow sensor 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 for use with a flow sensor 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 for use with a flow sensor 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 for use with a flow sensor 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 for use with a flow sensor 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 for use with a flow sensor 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.

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

a body having a lid portion connected to 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;

a 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;

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

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

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 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 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.

17. A method of forming a differential pressure based fluid flow sensor assembly comprising the steps of:

providing a reusable assembly having at least a first pressure sensor and a second pressure sensor;

providing a disposable 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;

a fluid pressure membrane disposed along the fluid flow passage and 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 portion, the first rigid disk being positioned adjacent to a first opening formed in the lid portion; and

a second rigid disk positioned between the fluid pressure membrane and the lid portion, the second rigid disk being positioned adjacent to a second opening formed in the lid portion;

securing the disposable assembly to the reusable assembly in a removable manner to form a differential pressure based fluid pressure sensor.

18. The method of claim 17, wherein the step of securing the disposable assembly to the reusable assembly includes sliding a ledge portion of the disposable assembly under a lip portion of the reusable assembly.

19. The method of claim 17, wherein the step of securing the disposable assembly to the reusable assembly includes clipping a ledge portion of the disposable assembly under at least one clip portion of the reusable assembly.

20. The method of claim 17, wherein the step of securing the disposable assembly to the reusable assembly includes covering the disposable assembly under a rotatable lid portion of the reusable assembly.

21. The method of claim 17, wherein the step of securing the disposable assembly to the reusable assembly includes sliding the disposable assembly into the reusable assembly and covering the disposable portion with a pivotable access door to secure the disposable assembly within the reusable assembly.

22. The method of claim 17, wherein the step of securing the disposable assembly to the reusable assembly includes sliding a first slot and a second slot of the disposable assembly over respective first and second securing protrusions of the reusable assembly.

23. The method of claim 17, wherein the step of securing the disposable assembly to the reusable assembly includes positioning the disposable assembly within the reusable assembly and covering the disposable assembly under a sliding access door of the reusable assembly.