Infusion method and means

• US 4,850,971 A
• Filed: 02/23/1988
• Issued: 07/25/1989
• Est. Priority Date: 05/06/1986
• Status: Expired due to Term

• Current Assignee: Pyramid Technologies International Incorporated
• Original Assignee: Gulf Research and Development Company
• Inventors: Colvin, David P.
• Primary Examiner(s): Truluck, Dalton L.
• Application Number:
  US07/159,257
• Time in Patent Office: 518 Days
• Field of Search: 222/99-101, 604/134, 604/135, 604/246
• US Class Current: 604/134
• CPC Class Codes: A61M 5/148 flexible, e.g. independent bagsA61M5/155 takes precedence

Abstract

This invention is an infusion pump utilizing a linear roller driven by a one or more constant force springs in combination with changeable flow regulating needles to provide a constant flow, gravity independent device. The spring constant is chosen so that infusion substantially decreases should the infusion needle become dislodged from the vein and come to rest in the surrounding tissue. Also, there is a means for introduction of an anticoagulant to maintain vein access if a delay is encountered in replacement of the infusion bag.

Claims

1. An improved infusion means comprising:

a frame means having guide means associated therewith;

a take-up drum means operatively associated with said guide means;

at least one coil type constant tension spring means secured at one end to said frame means and unsecuringly wound about said take-up drum at its opposite end;

an infusion bag means containing a fluid disposed in contacting relation with and at least partially between the coils of said spring means adjacent said drum means;

an infusion tube communicatively connected to said infusion bag;

a fixed orifice flow regulating means operatively associated with said infusion tube; and

wherein said spring means has a preselected spring constant such that said spring means applies a force to the infusion bag means to induce a pressure therein which is at least sufficient to overcome the venous back pressure thereby infusing the fluid into the vein, but is less than the force required to infuse a substantial amount of the fluid into the surrounding body tissue should the flow regulating means become dislodged from the vein and come to rest in the surrounding body tissue.

2. The infusion means of claim 1 wherein said flow regulating means is a fixed orifice smooth bore.

3. The infusion means of claim 1 wherein said flow regulating needle is changeable to vary the fluid flow rate.

4. The infusion means of claim 1 wherein said flow regulating means is a changeable flow regulating needle.

5. The infusion means of claim 1 wherein a means for dispensing an anticoagulant into said infusion tube is provided.

6. The infusion means of claim 5 wherein said means for dispensing an anticoagulant is a rupturable pouch contained within said infusion bag.

7. The infusion means of claim 6 wherein said pouch is ruptured by said infusion bag being wound between the coils of said constant tension spring means on said take-up drum.

8. A method of infusing a liquid into a patient comprising:

placing an infusion bag under the coils of a constant tension spring unsecuringly wound on a take-up drum;

placing an infusion tube in one end of said infusion bag;

placing a flow regulating orifice of a predetermined size in said infusion tube;

inserting said flow regulating orifice into the vein of said patient; and

allowing said constant tension spring to wind up on said infusion bag and wherein the spring has a preselected spring constant such that the spring applies a force to the infusion bag to create a constant predetermined interior pressure therein which is at least sufficient to overcome the venous back pressure thereby infusing the liquid into the vein, but is less than the force required to infuse a substantial amount of the liquid into the surrounding body tissue should the flow regulating orifice become dislodged from the vein and come to rest in the surrounding tissue.

9. The method of claim 8 wherein said flow regulating orifice is in the form of a fixed orifice smooth bore flow regulating needle.

10. The method of claim 8 wherein said flow regulating orifice can be changed to vary the flow rate of fluid from said infusion bag into said patient.

11. The method of claim 8 wherein said infusion bag is mounted at a predetermined location relative to the heart of the patient.

12. An infusion means adapted to hold an infusion bag containing a fluid and wherein the infusion bag has connected to it an infusion tube, the other end of the infusion tube being connected to a fixed orifice needle which is inserted into the vein of a patient and comprising:

a frame means having guide means associated therewith;

a take-up drum means operatively associated with said guide means;

at least one coil type constant tension spring means secured at one end to said frame means and unsecuringly wound about said take-up drum at its opposite end; and

wherein said spring means has a preselected spring constant such that said spring means applies a force to the infusion bag to induce a pressure therein when the infusion bag is disposed in said frame means at least partially in contacting relation between the coils of said spring means and wherein the force induced is at least sufficient to overcome the venous back pressure thereby infusing the fluid into the vein, but is less than the force required to infuse a substantial amount of the fluid into the surrounding body tissue should the fixed orifice needle become dislodged from the vein and come to rest in the surrounding body tissue.

13. An infusion means according to claim 12 wherein said frame means further includes an end panel proximate the secured end of said constant tension spring means, whereby the fluid is more fully expelled from the bag as the constant tension spring means contracts.

14. An infusion means according to claim 12 wherein said end panel includes a notch means for facilitating insertion and removal of the infusion bag into and out of said frame.