Intravenous feeding pump failure alarm system

• US 4,056,333 A
• Filed: 11/26/1975
• Issued: 11/01/1977
• Est. Priority Date: 07/15/1974
• Status: Expired due to Term

• Current Assignee: Valleylab Inc. (Medtronic Plc)
• Original Assignee: Valleylab Inc. (Medtronic Plc)
• Inventors: Lundquist, Ingemar H.
• Primary Examiner(s): Freeh, Willliam L.
• Application Number:
  US05/635,656
• Time in Patent Office: 706 Days
• Field of Search: 417/40, 417/43, 417/44, 417/9, 417/63, 417/38, 417/211.5, 200/83, 128/214 E, 128/214 C, 128/214 F, 128/218 A, 128/DIG. 12, 128/DIG. 13, 128/DIG. 1, 128/1 D
• US Class Current: 417/44.2
• CPC Class Codes: A61M 5/14216 Reciprocating piston type
• CPC Class Codes: A61M 5/16854 by monitoring line pressure
• CPC Class Codes: F04B 43/0081 systems, control, safety measures
• CPC Class Codes: F04B 43/08 having tubular flexible members F04B43/12 takes precedence
• CPC Class Codes: Y10S 128/13 Infusion monitoring

Abstract

The present invention relates to a failure alarm system for an intravenous feeding pump in which the pumping force is secured by the projection of a plunger into a chamber filled with the liquid to be pumped, which plunger is encased in a tightly fitting sheath of elastic material. In such a pump, actuation is secured by the application of a force from an actuator to the end of the plunger extending without the wall of a pumping chamber and the return force is secured by the elasticity of the sheath. The actuator of such a pump provides an actuator which can be selectively set to provide an extended range of operations per unit of time and can be modified to control the amount of projection into the pumping chamber by the plunger. In such a combination means is provided by the present invention for sensing the fact that there is a negative pressure, or suction, in the system that is not balanced by the in-flow of liquid, i.e., the amount of fluid delivered to the pump for each operation is less than that required by the setting (thus sensing when a supply is shut off, or less than the preset amount of liquid is reaching the pump).

Claims

1. In combination with an intravenous feeding pump having:

a. pumping chamber having an inlet and an outlet,

b. inlet valve means disposed in the inlet and outlet valve means disposed in the outlet,

c. a plunger serving as a pumping member projecting through the wall of said chamber and having an outer end portion always extending out of said chamber whereby the plunger can be reciprocated between first and second positions in said chamber,

d. resilient biasing means for returning said plunger to the first position,

e. a pump actuator having means adapted to urge the outer end of said plunger to the second position against the force of the resilient biasing means and;

an alarm system comprising;

3. The apparatus of claim 1 wherein the signal means comprises:

(a) a sensing arm movable to one position by said actuator as the actuator moves the plunger to said second position and movable to another position by the force of said resilient biasing means;

(b) a switch held in one position by conjoint movement of the sensing arm and the actuator means and movable to another position when said sensing arm and said actuator means move independently of each other and wherein the signal means operated by movement of said switch to said another position.

6. The apparatus of claim 3 wherein the inlet to said pumping chamber is provided with a very soft and resilient tubular section and a float in said section adapted to seal said inlet in the event the supply of fluid to be pumped is exhausted.

7. The apparatus of claim 3 wherein the switch is mounted upon one of said arms, and the other of said arms carries a member adapted to bear upon said switch.

8. The apparatus of claim 3 wherein the sensing arm is rotatably mounted on said rocking arm.

10. A system as in claim 7 together with lever arm means for moving said plunger in at least one direction.

11. Apparatus as in claim 8 together with resilient means for moving said plunger in a direction opposite said one direction.

2. means for sensing failure of said plunger to return to its inoperative position, andsignal means operated by said sensing means.

4. In combination with an intravenous feeding pump having:

a. a pumping chamber,

b. an inlet into and an outlet from said pumping chamber and an inlet valve disposed in the inlet and an outlet disposed in the outlet,

c. a plunger serving as a pumping member projecting through the wall of said chamber whereby the plunger can be pushed inwardly into said chamber, and

d. an elastic sheath tightly enclosing the interior section of said plunger, which sheath is sealed to the wall of said chamber to provide an air-tight seal therewith, and

e. a pump actuator having a rocking arm effective to depress the outer end of said plunger;

an alarm system comprising;

5. means for sealing the inlet to said pumping chamber upon termination of fluid flow into said inlet,a sensing arm rocked to one position by said actuator arm as the latter moves to project the plunger into said pumping chamber but returned to the other position only by the force of the elastic sheath,a switch held in one position by the conjoint movement of the auxiliary arm and the rocking arm but set to the other position by the separation of the rocking arm and the sensing arm, andsignal means operated by the change in the condition of said switch.

9. In an intravenous fluid delivery system for use with a container of I.V. fluid, means forming a drip chamber, said drip chamber having a wall with at least a portion of the same which is transparent, said means forming a drip chamber including a resilient lower member having an outlet formed therein, means carried by the drip chamber adapted to form a connection to said container whereby I.V. fluid can pass from the container into the drip chamber, a ball-like member disposed within said drip chamber and being capable of floating in said I.V. fluid, said ball-like member being of a size so it is capable of closing said outlet when drip chamber is empty of I.V. fluid and is disposed in a vertical direction with the outlet extending downwardly, means forming a pump chamber having an inlet and an outlet, inlet valve means disposed in the inlet, outlet valve means disposed in the outlet, means for connecting the outlet of the drip chamber to the inlet of the pump chamber, means connecting the outlet to a patient, a plunger serving as a pumping member, means for causing reciprocatory movement of said plunger for causing movement of I.V. fluid through said pump chamber from said inlet to said outlet of said pump chamber and means for sensing when the reciprocatory movement of said plunger ceases and for giving an alarm.

12. A system as in claim 9 wherein said means for moving said plunger in the opposite direction is of insufficient strength to move said plunger in said opposite direction when greater than a predetermined vacuum occurs in said pumping chamber.

15. Apparatus as in claim 12 wherein said resilient lower member is of sufficient length so that it can be manually manipulated.

13. In an alarm apparatus for use with an intravenous fluid delivery system including a pump having a pumping chamber and an inlet and an oulet in communication with the pumping chamber, inlet valve means disposed in the inlet, outlet valve means disposed in the outlet, a plunger serving as a pumping member, means for causing reciprocatory movement of said plunger to cause movement of intravenous fluid through said pumping chamber from the inlet through said outlet and means for sensing when the reciprocatory movement of said plunger ceases and for giving an alarm when such a condition is sensed, said means for causing reciprocatory movement including lever arm means for moving said plunger in at least one direction, said means for sensing the reciprocatory movement of said plunger including means for sensing the movement of said lever arm, resilient means for moving said plunger in the opposite direction, said resilient means being of insufficient strength to return said plunger in the opposite direction when a vacuum condition is created in said pumping chamber in excess of a predetermined value.

14. In an alarm apparatus for use with an intravenous fluid delivery system including a pump having a pumping chamber and an inlet and an outlet in communication with the pumping chamber, inlet valve means disposed in the inlet, outlet valve means disposed in the outlet, a drip chamber in communication with the inlet of the pumping chamber, said drip chamber having a wall with at least a portion of the same being transparent, said means forming a drip chamber including a resilient lower member having an outler formed therein, a ball-like member disposed in the chamber and being capable of floating in the intravenous fluid, said ball-like member being capable of closing said oulet in said drip chamber when said drip chamber is empty of intravenous fluid and is vertically disposed with the outlet extending downwardly, a plunger serving as a pumping member, means for causing reciprocatory movement of said plunger to cause movement of intravenous fluid through said pumping chamber from the inlet through said outlet and means for sensing when the reciprocating movement of said plunger ceases and for giving an alarm when such a condition is sensed.

16. In a method for initiating an alarm for use with an intravenous liquid delivery system including a pump and a drip chamber having an inlet and an oulet in which the lower portion of the drip chamber is defined by a deformable member having an oulet therein and in which a ball capable of floating in the liquid is provided in the drip chamber, connecting the drip chamber to a source of intravenous liquid, repeatedly squeezing the deformable member defining the drip chamber to cause intravenous liquid to enter into the drip chamber and to at least partially fill the drip chamber so that the ball floats in the liquid in the drip chamber and permits the liquid to flow through the outlet to the pump, supplying intravenous liquid to the patient by the use of the pump, creating a vacuum condition in the pump when all of the liquid has been dispensed from the drip chamber by permitting the ball to close off the oulet in the drip chamber and initiating an alarm in response to creating of the vacuum condition.