Medical infusion device with a source of controlled compliance

• US 6,537,268 B1
• Filed: 06/18/1999
• Issued: 03/25/2003
• Est. Priority Date: 06/18/1998
• Status: Expired due to Term

• Current Assignee: Medical Research Group, Inc. (Medtronic Plc), Minimed, Inc. (Medtronic Plc)
• Original Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Inventors: Lorenzen, Eric M., Lord, Peter C., Gibson, Scott R., McConnell, Susan M., Bosley, Robert W., Gray, John F.
• Primary Examiner(s): Mendez, Manuel
• Application Number:
  US09/335,936
• Time in Patent Office: 1,376 Days
• Field of Search: 604/30, 604/31, 604/65-67, 604/891.1, 604/93.01, 604/19, 604/131, 604/153, 604/154, 604/155, 604/152, 604/151, 128/DIG.12, 128/DIG.13
• US Class Current: 604/891.1
• CPC Class Codes: A61M 2209/045 for filling, e.g. for filling reservoirs
• CPC Class Codes: A61M 5/14276 specially adapted for implantation

Abstract

Embodiments of medical infusion pumps are provided that include structural elements for providing sources of compliance within a fluid path within the pump. Some preferred embodiments provide implantable infusion pumps with compliance positioned between an exit port of a pumping mechanism and an outlet (e.g. an opening in a catheter) of the infusion pump. Other embodiments provide compliance in fluid path in proximity to entrance port of the pumping mechanism. Insertion of compliance in a flow path that is down stream of the pumping mechanism may aid in minimizing negative effects associated with attempting to force fluid through a restricted flow path that is further down-stream, such as that offered by a catheter or other outlet component. Insertion of compliance before the pumping mechanism may aid in reducing negative effects associated with an up stream restricted flow path, such as that which might be offered by a rigid filter located between the reservoir and the pumping mechanism. Several structural components, assemblies, or configurations may be used as sources of compliance. For example, compressible structures (e.g. pillows, drums) are used within a side port of the infusion pump. The compressible structures may quickly distort to accommodate for a large impulse of fluid into the flow path that can not otherwise be readily dealt with. The compression, in turn, results in a restoring force being exerted that returns the structure substantially to its original volume so as to slowly force fluid from the flow path.

Claims

1. An infusion pump for delivering a fluid from a reservoir to a body of a patient, the infusion pump comprising:

a pumping mechanism located along a fluid path for supplying fluid to the body of a patient; and

a source of compliance located outside of the reservoir and in communication with fluid along said fluid path for providing a source of compliance for fluid in proximity to the pumping mechanism or for fluid exiting the pumping mechanism, wherein the source of compliance comprises a structure selected from the group of (a) a compressible structure, (b) an expandable structure, (c) a non-permeable structure, and (d) a structure located within a flow path defined by a substantially non-compliant material, wherein the structure is a hollow structure having an inside surface and an outside surface, and wherein, in use, the outside surface of the structure is in communication with the fluid in the fluid path and the inside surface is not in communication with the fluid in the fluid path.

2. The infusion pump of claim 1 additionally comprising an inlet for supplying fluid to a reservoir and wherein the infusion pump is implantable.

3. The infusion pump of claim 2 wherein an outlet of the fluid path is formed by an opening in a catheter that is implanted subcutaneously in the body of the patient.

4. The infusion pump of claim 3 wherein the catheter is implanted within the peritoneal cavity of the patient.

5. The infusion pump of claim 2 wherein the reservoir supplies fluid through a filter to an entrance port of the pumping mechanism.

6. The infusion pump of claim 1 wherein the source of compliance comprises a pillow structure that comprises a pair of diaphragms that are hermetically sealed to enclose a volume of a gas.

7. The infusion pump of claim 6, wherein the pillow can accommodate external pressures in the range of about −

8 psi to about 300 psi.

8. The infusion pump of claim 6 wherein the diaphragms are formed from a material selected from the group consisting of metallic materials, metallic composites, and Halar films.

9. The infusion pump of claim 7 wherein the diaphragm comprises titanium.

10. The infusion pump of claim 8 wherein a surface of the diaphragm that is exposed to the fluid is substantially coated with a protein stable surface that comprises a hydrophilic substance.

11. The infusion pump of claim 2 wherein the amount of compliance provided is within a range of 10% to 200% of the intended volume of fluid to be delivered by a single operation of the pump mechanism within a range of 5 to 200 psig.

12. The infusion pump of claim 2 wherein the source of compliance comprises:

a pair of diaphragms; and

a standoff member having two open ends;

wherein the each diaphragm of the pair are hermetically sealed to respective open ends of the standoff member to enclose a volume of a gas and to form a drum structure.

13. The infusion pump of claim 12 wherein the drum structure additionally comprises a spacer member located within the standoff member between the pair of diaphragms.

14. The infusion pump of claim 2 wherein the source of compliance comprises:

a body having a cavity with at least one opening;

a diaphragm that is hermetically sealed to close off the at least one opening in the cavity; and

wherein the diaphragm is in fluid communication with a desired portion of a fluid flow path.

15. An infusion pump according to claim 1, wherein the infusion pump further comprises:

a reservoir for containing the fluid; and

a control device for controllably operating the pumping mechanism;

wherein the pumping mechanism has a fluid entrance port and a fluid exit port for transferring fluid from the entrance port to the exit port;

wherein the reservoir is connected to the entrance port of the pumping mechanism by a first part of the fluid path; and

wherein an outlet of the fluid path is connected to the exit port of the pumping mechanism by a second part of the fluid path for supplying fluid from the reservoir to the body of a patient.

16. An infusion pump according to claim 15, wherein the infusion pump further comprises an inlet for supplying fluid to the reservoir and wherein the infusion pump is implantable.

17. An infusion pump according to claim 16, wherein the reservoir supplies fluid through a filter to the entrance port of the pumping mechanism.

18. An infusion pump according to claim 1,

wherein the pumping mechanism has a fluid entrance port and a fluid exit port for transferring fluid from the entrance port to the exit port;

and

wherein the source of compliance is located along the part of the fluid path that is between the exit port of the pumping mechanism and an outlet of the fluid path into the body.

19. A method for infusing a fluid from a reservoir into a body of a patient, comprising:

directing fluid along a fluid path containing a pumping mechanism for supplying fluid to the body of a patient; and

supplying a source of compliance located outside of the reservoir and in communication with fluid along said fluid path for providing a source of compliance for fluid in proximity to the pumping mechanism or for fluid exiting the pumping mechanism, wherein the source of compliance comprises a structure selected from the group of (a) a compressible structure, (b) an expandable structure, (c) a non-penneable structure, and (d) a structure located within a flow path defined by a substantially non-compliant material, wherein the structure is a hollow structure having an inside surface and an outside surface, and wherein, in use, the outside surface of the structure is in communication with the fluid in the fluid path and the inside surface is not in communication with the fluid in the fluid path.

20. A method for infusing a fluid into the body of a patient according to claim 19, wherein the method further comprises:

providing a fluid to a reservoir within an infusion device;

controlling the pumping mechanism having a fluid entrance port and a fluid exit port for transferring fluid from the entrance port to the exit port;

directing the fluid from the reservoir to the fluid entrance port along a first part of the fluid path; and

operating the pumping mechanism in a controlled manner.

21. An infusion pump for delivering a fluid from a reservoir to a body of a patient, comprising:

a pumping means located along a fluid path for supplying fluid to the body of a patient; and

a compliance means located outside the reservoir and in communication with fluid along said fluid path for providing a source of compliance for fluid in proximity to the pumping means or for fluid exiting the pumping means, wherein the compliance means comprises a structure selected from the group of (a) a compressible structure, (b) an expandable structure, (c) a non-permeable structure, and (d) a structure located within a flow path defined by a substantially non-compliant material, wherein the structure is a hollow structure having an inside surface and an outside surface, and wherein, in use, the outside surface of the structure is in communication with the fluid in the fluid path and the inside surface is not in communication with the fluid in the fluid path.

22. An infusion pump for delivering a fluid into the body of a patient according to claim 21, wherein the infusion pump further comprises:

a means for containing a fluid to be dispensed; and

a means for controllably operating the pumping means;

wherein the pumping means has a fluid entrance port and a fluid exit port for transferring fluid from the entrance port to the exit port; and

wherein the means for containing a fluid to be dispensed is connected to the fluid entrance port of the pumping means by a first part of the fluid path.