Nonpulsating TV pump and disposable pump chamber

• US 4,410,322 A
• Filed: 09/10/1980
• Issued: 10/18/1983
• Est. Priority Date: 03/09/1979
• Status: Expired due to Term

• Current Assignee: Graseby Medical Limited (ICU Medical Incorporated)
• Original Assignee: AVI Inc.
• Inventors: Archibald, G. Kent
• Primary Examiner(s): Gluck, Richard E.
• Application Number:
  US06/186,148
• Time in Patent Office: 1,133 Days
• Field of Search: 417/63, 417/474, 417/478, 417/479, 417/480, 417/510, 417/244, 92/98 D, 92/92, 128/214 F, 138/30, 138/26, 604/153, 604/118
• US Class Current: 604/153
• CPC Class Codes: A61M 2205/3355 Controlling downstream pump pressure
• CPC Class Codes: A61M 2206/22 eliminating pulsatile flows, e.g. by the provision of a dampening chamber
• CPC Class Codes: A61M 5/14224 Diaphragm type
• CPC Class Codes: A61M 5/168 Means for controlling media flow to the body or for metering media to the body, e.g. drip meters, counters ; Monitoring media flow to the body flow control in general G05D7/00
• CPC Class Codes: A61M 5/16854 by monitoring line pressure
• CPC Class Codes: A61M 5/365 Air detectors A61M5/1684 takes precedence; in extracorporeal blood circuits A61M1/3626
• CPC Class Codes: F04B 43/021 the plate-like flexible member is pressed against a wall by a number of elements, each having an alternating movement in a direction perpendicular to the plane of the plate-like flexible member and each having its own driving mechanism
• CPC Class Codes: F04B 43/082 the tubular flexible member being pressed against a wall by a number of elements, each having an alternating movement in a direction perpendicular to the axes of the tubular member and each having its own driving mechanism
• CPC Class Codes: F04B 7/00 Piston machines or pumps characterised by having positively-driven valving
• CPC Class Codes: F04B 9/042 the means being cams

Abstract

A small, accurate, reliable and economical pump which is particularly useful in intravenous (IV) feeding includes a disposable pump chamber and a pump housing. The disposable pump chamber has an inlet, an outlet, and first and second flexible rolling diaphragm pumping chambers. First and second cylinders in the pump housing are positioned to eceive the first and second flexible rolling diaphragms of the disposable pump chamber. First and second pistons are movable in the first and second cylinders, respectively. In addition, first and second valves are provided in the pump housing. The first valve controls fluid flow between the inlet and the first flexible rolling diaphragm pump chamber, while the second valve controls fluid flow between the first flexible rolling diaphragm pumping chamber and the second flexible rolling diaphragm pumping chamber. A motor and cam shaft drive the first and second pistons and the first and second valves. The fist and second valves are controlled so that one valve is closed at all times, thereby providing fail safe operation of the pump.

Claims

1. A volumetric infusion pump for pumping fluid from a source to a patient comprising:

a pump inlet for receiving fluid from the source;

a pump outlet for supplying fluid under pressure to the patient;

a first pumping chamber having a first cylinder, a first piston, first flexible diaphragm means between the first cylinder and the first piston, a first inlet, and a first outlet, the first pumping chamber having a variable volume depending upon the relative positions of the first cylinder and first piston;

a second pumping chamber having a second cylinder, a second piston, second flexible diaphragm means between the second cylinder and the second piston, the second inlet connected to the first outlet, and a second outlet, the second pumping chamber having a variable volume depending upon the relative position of the second cylinder and second piston;

a third chamber having a third inlet and a third outlet, the third inlet being connected to the second outlet and the third outlet being connected to the pump outlet, the third chamber comprising a third cylinder, a third piston, and a third flexible diaphragm means between the third cylinder and the third piston so that the third piston moves in the third cylinder as a function of fluid pressure within the third chamber;

means for sensing fluid pressure within the third chamber by sensing position of the third piston;

first valve means for controlling fluid flow between the pump inlet and the first inlet;

second valve means for controlling fluid flow between the first outlet and the second inlet;

drive means for causing relative motion of the first cylinder and first piston and relative motion of the second cylinder and second piston;

valve control means for controlling the first and second valve means such that one of the first and second valve means is closed at all times; and

wherein the first, second and third flexible diaphragm means, the pump inlet and the pump outlet form an integral disposable unit having a sealed main fluid flow passage between the pump inlet and the pump outlet, so that fluid is pumped from the pump inlet to the pump outlet without physically contacting the housing, the cylinders, the pistons, the valve means, the drive means, or the valve control means.

2. The volumetric infusion pump of claim 1 wherein the means for sensing fluid pressure within the third chamber comprises:

a movable electric contact connected to and movable with the third piston;

a first fixed contact located at a fixed position with respect to the third chamber; and

spring means for applying a spring force to the third piston in a direction opposite to force supplied by fluid pressure within the third chamber.

3. The volumetric infusion pump of claim 2 wherein the movable electric contact breaks contact with the first fixed contact when a first pressure within the third chamber is attained.

4. The volumetric infusion pump of claim 3 and further comprising:

a second fixed contact located at a fixed position with respect to the third chamber, wherein the movable electric contact engages the second fixed contact when a second pressure within the third chamber is attained.

5. The volumetric infusion pump of claim 4 and further comprising:

adjusting means for adjusting the fixed positions of the first and second fixed contacts.

6. A volumetric infusion pump for pumping fluid from a source to a patient, the pump comprising:

pump housing means;

a sealed integral disposable unit, which is supported by the pump housing means during operation of the pump, comprising;

an inlet for receiving fluid from the the source;

an outlet for supplying fluid under pressure to the patient;

a sealed main flow passage between the inlet and the outlet;

flexible rolling diaphragm pumping chamber means connected to the main flow passage for pumping fluid from the inlet to the outlet;

a flexible pressure sensing chamber connected to the main flow passage between the flexible rolling diaphragm pumping chamber means and the outlet, the flexible pressure sensing chamber having a flexible rolling diaphragm which is movable as a function of fluid pressure within the flexible rolling diaphragm pumping chamber means;

piston means supported by the pump housing means for engaging the flexible rolling diaphragm means when the sealed integral disposable unit is supported by the pump housing means during operation of the pump;

pump drive means supported by the pump housing means for moving the piston means to cause the rolling diaphragm pumping chamber means to pump fluid from the inlet to the outlet;

valve means for controlling fluid flow through the main flow passage between the flexible rolling diaphragm pumping chamber means and the flexible pressure sensing chamber; and

means supported by the pump housing means external to the flexible pressure sensing chamber and responsive to movement of the flexible diaphragm for providing an output which is a function of fluid pressure within the pressure sensing chamber, so that fluid is pumped from the inlet to the outlet without physically contacting the pump housing means, the pump drive means, or the means external to the pressure sensing chamber.

7. The invention of claim 6 wherein the means external to the pressure sensing chamber comprises:

a cylinder for receiving the flexible rolling diaphragm pressure sensing chamber; and

a piston movable within the cylinder in response to fluid pressure within the flexible rolling diaphragm pressure sensing chamber.

8. The invention of claim 7 wherein the means external to the pressure sensing chamber further comprises:

a movable electric contact connected to and movable with the piston;

a first fixed contact located at a fixed position with respect to the cylinder; and

spring means for applying a spring force to the piston in a direction opposite the force supplied by fluid pressure within the flexible rolling diaphragm pressure sensing chamber.

9. The invention of claim 8 wherein the movable electric contact breaks contact with the first fixed contact when a first pressure within the flexible rolling diaphragm pressure sensing chamber is attained.

10. The invention of claim 9 and further comprising:

a second fixed contact located at a fixed position with respect to the cylinder, wherein the movable electric contact engages the second fixed contact when a second pressure within the flexible rolling diaphragm pressure sensing chamber is attained.

11. The invention of claim 9 and further comprising:

adjusting means for adjusting the fixed positions of the first and second fixed contacts.