Pressurized fluid dispenser

• US 5,120,315 A
• Filed: 04/25/1991
• Issued: 06/09/1992
• Est. Priority Date: 11/26/1986
• Status: Expired due to Term

• Current Assignee: 501 Baxter International Incorporated
• Original Assignee: 501 Baxter International Incorporated
• Inventors: Hessel, Stephen R.
• Primary Examiner(s): Frinks, Ronald
• Assistant Examiner(s): CLARKE, ROBERT A
• Application Number:
  US07/691,675
• Time in Patent Office: 411 Days
• Field of Search: 604/74-76, 604/132, 604/133, 604/135, 604/214, 128/DIG. 12
• US Class Current: 604/132
• CPC Class Codes: A61M 5/152 pressurised by contraction of elastic reservoirs containers for dispensing contents by contraction of an elastic bag provided therein, in general B65D83/0061
• CPC Class Codes: Y10S 128/12 Pressure infusion

Abstract

Disclosed is an elastomeric bladder infusion pump which may be used for delivering a pharmaceutically active material to a patient at a substantially constant flow rate. A unitary internal stress member or mandrel is disposed within the bladder, prestressing the bladder in both the axial and radial dimensions.

Claims

1. An infusion pump for delivering a quantity of fluid material at a substantially constant flow rate, comprising:

an elongate elastomeric bladder having a central lumen and at least one open end, said central lumen having an internal length dimension and an internal diameter dimension in its relaxed state;

an elongate stress member having a substantially uniform cross-sectional area throughout its axial length, said stress member extending throughout the length of and within the central lumen of the bladder;

said stress member having a length dimension which is greater than the relaxed internal length of the central lumen on the elastomeric bladder, and said stress member having a diameter which is greater than the relaxed internal diameter of the central lumen on the elastomeric bladder;

wherein the assembly of the elastomeric bladder onto the stress member prestresses the bladder in both the axial and radial directions prior to introduction of any of the fluid material into the bladder, and the axial length of the bladder is substantially unchanged upon filling with said fluid material.

2. An infusion pump as in claim 1, wherein the length of the stress member is at least about 10% longer than the internal length of the central lumen on the elastomeric bladder, prior to the assembly of said bladder onto said stress member.

3. An infusion pump as in claim 1, wherein the diameter of the stress member is at least about 10% greater than the internal diameter of the central lumen on the elastomeric bladder prior to the mounting of said bladder onto said stress member.

4. An infusion pump as in claim 2, wherein the length of the stress member is no more than about 150% longer than the internal length of the central lumen on the bladder prior to mounting the bladder onto the stress member.

5. An infusion pump as in claim 3, wherein the diameter of the stress member is no more than about 100% greater than the internal diameter of the central lumen on the bladder prior to mounting the bladder onto the stress member.

6. An infusion pump as in claim 4, wherein the length of the stress member is within the range of from about 35% to about 50% longer than the relaxed internal length of the central lumen of the bladder.

7. An infusion pump as in claim 6, wherein the length of the stress member is within the range of from about 35% to about 45% longer than the relaxed internal length of the central lumen of the bladder.

8. An infusion pump as in claim 5, wherein the diameter of the stress member is within the range of from about 15% to about 40% greater than the relaxed internal diameter of the central lumen on the bladder.

9. An infusion pump as in claim 8, wherein the diameter of the stress member is within the range of from about 18% to about 25% greater than the relaxed internal diameter of the central lumen on the bladder.

10. An infusion pump as in claim 1, further comprising at least one flow path in the stress member, in fluid communication with the central lumen of the bladder.

11. An infusion pump as in claim 10, further comprising a bypass duct on the flow path for introduction of the fluid material into the central lumen of the bladder.

12. An infusion pump as in claim 11, further comprising a one-way valve on the bypass duct to substantially prevent the flow of fluid in a reverse direction through the bypass duct.

13. An infusion pump as in claim 12, wherein the one-way valve comprises an elastomeric band which extends around the stress member, and is biased radially inwardly against the bypass duct.

14. An infusion pump as in claim 10, further comprising a flow regulator in the flow path.

15. An infusion pump for delivering a quantity of fluid material at a substantially constant flow rate, comprising:

an elongate elastomeric bladder having a central lumen and at least one open end, said bladder having in its relaxed, unassembled state a relaxed interior diameter and a relaxed internal length;

an elongate, unitary stress member extending throughout the length of and within the lumen of the bladder, said stress member having a diameter which is greater than the relaxed diameter of the bladder and a length which is greater than the relaxed length of the bladder, thereby prestressing the bladder in both the axial and radial directions; and

a flow channel through at least a portion of the stress member and in fluid communication with the interior of the bladder;

said stress member having a substantially cylindrical configuration throughout the portion of its length which is disposed within the bladder, so that the radial prestressing of the bladder when it is assembled onto the stress member is substantially constant throughout the length of the portion of the internal stress member which is disposed within the bladder.