Method and apparatus for controlling the dispensing of fluid

• US 4,261,356 A
• Filed: 10/23/1978
• Issued: 04/14/1981
• Est. Priority Date: 10/23/1978
• Status: Expired due to Term

• Current Assignee: Baxter Travenol Laboratories Incorporated (Baxter International Inc.)
• Original Assignee: Baxter Travenol Laboratories Incorporated (Baxter International Inc.)
• Inventors: Turner, Charles R., Turner, Roger S.
• Primary Examiner(s): Truluck, Dalton L.
• Application Number:
  US05/953,861
• Time in Patent Office: 904 Days
• Field of Search: 128/214 R, 128/214 E, 128/214 F, 128/214 C, 128/214 Z, 128/227, 128/DIG. 12, 128/DIG. 13, 222/445, 222/450-452, 222/207
• US Class Current: 604/246
• CPC Class Codes: A61M 5/16809 by repeated filling and emptying of an intermediate volume pressure infusion using positive displacement pumps A61M5/142

Abstract

A method is disclosed for controlling the dispensing of fluid from a source at a hydrostatic pressure involving the sequential measuring and dispensing of predetermined volumetric increments of fluid from the source of fluid during different ones of a series of time intervals. Apparatus is also provided for controlling the dispensing of fluid, including metering means for receiving a predetermined increment of fluid and for emptying the predetermined increment of fluid, conduit means for delivering fluid from a source of fluid to the metering means, and control means for actuating the metering means between a condition for receiving one predetermined increment of fluid and a condition for emptying the predetermined increment of fluid.

Claims

1. A disposable metering unit for use in controlling the intravenous administration of a fluid to a patient, comprising:

inlet conduit means for delivering fluid at a hydrostatic pressure from a source of fluid;

metering means for receiving a predetermined increment of fluid from the conduit means and for emptying the predetermined increment of fluid by the suction of gravity flow without adding substantial pressure to the hydrostatic pressure, said metering means defining a metering chamber having opposed inner walls, and movable diaphragm means positioned in the metering chamber, said diaphragm means being capable of being moved at the hydrostatic pressure between a first position in which said diaphragm means is positioned against one of the opposed inner walls of the metering chamber with substantially all of the volume of the chamber being on one side of the diaphragm means, and a second position in which the diaphragm is in contact with the other of said opposed inner walls of the metering chamber with substantially all of the volume of said metering chamber being on the other side of said diaphragm means, whereby said metering means may be repeatedly filled with fluid to impel the diaphragm means into its second position and then to drain said fluid from the metering means with the diaphragm means moving to the first position, whereby said predetermined increments of fluid may be of constant volume and may be passed through said metering means; and

outlet conduit means communicating with the metering means for receiving said increments wherein gravity suction flow takes place to empty the metering means when the outlet means is opened, both said inlet and outlet conduit means communicating with the metering chamber at the same side of said diaphragm means, said metering means defining exterior vent means communicating into said metering chamber adjacent the opposed inner wall of said metering chamber with which the diaphragm is in contact in its second position, to facilitate free flow of air into and out of said metering chamber as said diaphragm means moves between its first and second positions;

and means for permitting the alternative and sequential valving of fluid through said inlet conduit means and outlet conduit means.

2. The disposable metering unit of claim 1 in which a projection is positioned on the inner wall of each inlet and outlet conduit means in opposed relation to apertures in said walls to serve as part of said valve means.

3. The metering unit of claim 1 in which the unit includes a rigid body portion and a cover portion with a cavity formed in the unit to provide the metering chamber, the size of the cavity determining the capacity for the predetermined increments of fluid.

4. The metering unit of claim 1 in which the movable diaphragm means is resilient to conform to the shape of the cavity.

5. The metering unit of claim 1 in which the unit includes a rigid body portion and a cover portion with an arcuate-shaped cavity formed in the body portion and a communicating arcuate-shaped cavity formed in the cover portion to provide the metering chamber.

6. The metering unit of claim 5 in which said diaphragm has an arcuate-shaped portion which conforms to the arcuate-shaped cavity of one of the body and cover portions.

7. The metering unit of claim 1 in which the metering chamber has a volumetric capacity of less than one cubic centimeter.

8. The metering unit of claim 7 in which the valve means is actuated to provide the predetermined rate of administration of fluid in the range of two tenths milliliter per minute to ten milliliters per minute.

9. The metering unit of claim 1 further including hydraulic means with a fluid chamber receiving fluid from the metering chamber for having fluid in the fluid chamber moved into the metering chamber to cause air in the metering chamber to be expelled through the inlet conduit means when the metering unit is in operative relationship.

10. The metering unit of claim 1 further including a reservoir chamber adapted to receive a portion of the increments of fluid from the source at a first hydrostatic pressure and to hold the fluid at a second hydrostatic pressure, the metering chamber receiving the predetermined increment of fluid from the reservoir chamber and emptying the predetermined increment of fluid without adding substantial pressure to the second hydrostatic pressure.

11. The metering unit of claim 10 in which means is provided for supporting the reservoir chamber with respect to the metering chamber so that when the source of fluid has been drained below a predetermined level, the second hydrostatic pressure of the fluid in the reservoir chamber is only sufficient to have the metering chamber receive a portion of a predetermined increment of fluid from the reservoir chamber to be emptied from the metering chamber.

12. A disposable metering unit for use in controlling the intravenous administration of a fluid to a patient, comprising:

inlet conduit means for delivering fluid at a hydrostatic pressure from a source of fluid;

metering means for receiving a predetermined increment of fluid from the conduit means and for emptying the predetermined increment of fluid by the suction of gravity flow without adding substantial pressure to the hydrostatic pressure, said metering means defining a metering chamber having opposed inner walls, and movable diaphragm means positioned in the metering chamber, said diaphragm means being capable of being moved at said hydrostatic pressure between a first position in which said diaphragm means is positioned against one of the opposed inner walls of the metering chamber with substantially all of the volume of the chamber being on one side of the diaphragm means, and a second position in which the diaphragm is in contact with the other of said opposed inner walls of the metering chamber with substantially all of the volume of said metering chamber being on the other side of said diaphragm means, whereby said metering means may be repeatedly filled with fluid to impel the diaphragm means into its second position and then to drain said fluid from the metering means with the diaphragm means moving to the first position, whereby said predetermined increments of fluid may be of constant volume and may be passed through said metering means;

outlet conduit means communicating with the metering means for receiving said increments wherein gravity suction flow takes place to empty the metering means when the outlet means is opened, the transverse dimensions of said inlet and outlet conduit means being substantially less than the transverse dimension of said metering means, said diaphragm means defining extensions residing in said inlet and outlet conduit means;

both said inlet and outlet conduit means communicating with the metering chamber at the same side of said diaphragm means, said metering means defining exterior vent means communicating into said metering chamber adjacent the opposed inner wall of said metering chamber with which the diaphragm is in contact in its second position, to facilitate free flow of air into and out of said metering chamber as said diaphragm means moves between its first and second positions; and

apertures positioned in said inlet conduit means and outlet conduit means adapted to permit passage of plunger means respectively into said inlet and outlet conduit means to respectively press said diaphgram extensions into sealing relationship with walls of the inlet and outlet conduit means, to selectively block liquid flow through said inlet and outlet conduit means.

13. The disposable metering unit of claim 12 in which a projection is positioned on the inner wall of each inlet and outlet conduit means in opposed relation to said apertures, to define a valve face against which said diaphragm extensions are pressed by said plunger means.

14. A disposable metering unit for use in controlling the intravenous administration of fluid to a patient, comprising:

(a) a reservoir chamber adapted to receive a portion of the increments of fluid from a source of fluid at a first hydrostatic pressure, and to hold the fluid at a second hydrostatic pressure;

(b) a metering chamber for receiving a predetermined increment of fluid from said reservoir chamber and for emptying the predetermined increment of fluid without adding substantial pressure to the second hydrostatic pressure, said metering chamber having a movable diaphragm means therein to meter a predetermined quantity of fluid therethrough;

(c) conduit means for delivering fluid at the source of fluid having a supply of predetermined increments of fluid to the metering chamber; and

(d) valve means actuatable for regulating the receiving and emptying of each of the predetermined increments of fluid by the metering chamber to be administered to the patient at a predetermined rate of administration.

15. The metering unit of claim 14 in which means is provided for supporting the reservoir chamber with respect to the metering chamber so that when the source of fluid has been drained below a predetermined level, the second hydrostatic pressure of the fluid in the reservoir chamber is only sufficient to have the metering chamber receive a portion of a predetermined increment of fluid from the reservoir chamber to be emptied from the metering chamber.

16. Apparatus for controlling the intravenous administration of fluid to a patient which comprises:

inlet conduit means for delivering fluid at a hydrostatic pressure from a source of fluid;

metering means for receiving a predetermined increment of fluid from the conduit means and for emptying the predetermined increment of fluid by the suction of gravity flow without adding substantial pressure to the hydrostatic pressure, said metering means defining a metering chamber having opposed inner walls, and movable diaphragm means positioned in the metering chamber, said diaphragm means capable of being moved at the hydrostatic pressure between a first position in which said diaphragm means is positioned against one of the opposed inner walls of the metering chamber with substantially all of the volume of the chamber being on one side of the diaphragm and a second position in which the diaphragm is in contact with the other of said opposed inner walls of the metering chamber with substantially all of the volume of said metering chamber being on the other side of said diaphragm means, whereby said metering chamber may be repeatedly filled with fluid to impel the diaphragm means into its second position and then to drain said fluid from the metering means with the diaphragm means moving to the first position, whereby said predetermined increments of fluid may be of constant volume and may be passed through said metering means, both said inlet and outlet conduit means communicating with the metering chamber at the same side of said diaphragm means, said metering means defining exterior vent means communicating into said metering chamber adjacent the opposed inner wall of said metering chamber with which the diaphragm is in contact in its second position, to facilitate free flow of air into and out of said metering chamber as said diaphragm means moves between its first and second positions; and

outlet conduit means communicating with the metering means for receiving said increments and conveying them to a patient wherein gravity suction flow takes place to empty the metering means when the outlet means is opened, and valve means in said inlet and outlet conduit means for the alternative and sequential valving of fluid through said inlet conduit means and outlet conduit means.

17. The apparatus of claim 16 in which the transverse dimensions of said inlet and outlet conduit means are substantially less than the transverse dimension of said metering means, said diaphragm means defining extensions residing in said inlet and outlet conduit means, apertures positioned in said inlet conduit means and outlet conduit means, and plunger means adapted to pass respectively into said inlet and outlet conduit means through said apertures to respectively press said diaphragm extensions into sealing relationship with walls of the inlet and outlet conduit means, to selectively block liquid flow through said inlet and outlet conduit means.

18. The apparatus of claim 17 in which a projection is positioned on the inner wall of each inlet and outlet conduit means in opposed relationship to said apertures, to define a valve face against which said diaphragm extensions are pressed by said plunger means.