Linear peristaltic pumping apparatus and disposable casette therefor

• US 4,493,706 A
• Filed: 08/12/1982
• Issued: 01/15/1985
• Est. Priority Date: 08/12/1982
• Status: Expired due to Term

• Current Assignee: Baxter International Inc.
• Original Assignee: American Hospital Supply Corp. (Baxter International Inc.)
• Inventors: Bobo, Donald E., Borsanyi, Alexander S.
• Primary Examiner(s): NOT, DEFINED
• Application Number:
  US06/407,440
• Time in Patent Office: 887 Days
• Field of Search: 128/DIG. 12, 604/151-153, 604/34, 604/250, 417/474, 417/475, 417/477
• US Class Current: 604/153
• CPC Class Codes: A61M 2205/12 with interchangeable cassettes forming partially or totally the fluid circuit
• CPC Class Codes: A61M 5/142 Pressure infusion, e.g. using pumps
• CPC Class Codes: A61M 5/14228 with linear peristaltic action, i.e. comprising at least three pressurising members or a helical member
• CPC Class Codes: Y10S 128/12 Pressure infusion

Abstract

A linear peristaltic pump, and a disposable casette therefor, particularly suitable for the infusion of parenteral fluids. The pump includes a housing having a power-driven shaft and a series of small bearing assemblies having their inner members eccentrically mounted upon that shaft. A thin elastomeric membrane extends along the series of bearing assemblies for engagement with the outer members thereof along a first band or linear zone of contact lying in the same plane as the axis of the shaft. The disposable casette is removably supported by the housing and takes the form of a rigid, planar, perimetric frame having an opening across which is stretched a section of elastomeric tubing. Locators provided by the housing and frame orient the casette with the axis of the tubing in the same plane as the first band of contact and the axis of the shaft, and a platen provided by the housing engages the section of elastomeric tubing that bridges the opening of the frame to urge that section into engagement with the opposite side of the membrane along a second band or linear zone of contact parallel with the first band of contact. The casette may include tubular extensions and connectors for connecting opposite ends of the section of elastomeric tubing to a source of fluid and to a patient.

Claims

1. A linear peristaltic pump apparatus comprising a housing having an opening therein;

a shaft rotatably supported within said housing adjacent said opening;

means for rotating said shaft;

a series of bearing assemblies within said housing each having concentric inner and outer bearing members;

said inner member being eccentrically mounted upon said shaft with the centers of said inner members being arranged to describe a helix about the axis of said shaft;

an elastomeric membrane secured to said housing about said opening and covering said opening;

said membrane extending along and tangentially engaging the outer members of said bearing assemblies along a first linear zone of contact;

a casette removably and externally supported by said housing adjacent to said membrane and comprising a rigid frame and a generally straight section of elastomeric tubing supported thereby;

means provided by said housing for orienting said frame with said section of tubing lying in the same plane as said first zone of contact; and

platen means provided by said housing and engagable with said section of elastomeric tubing to urge the same into engagement with the opposite side of said membrane along a second linear zone of contact parallel with said first zone of contact.

2. The apparatus of claim 1 in which said rigid frame is perimetric and is provided with an opening;

said generally straight section of tubing extending across said opening; and

said platen means extending into said opening to urge said tubing section into engagement with said membrane when said apparatus is in operation.

3. The apparatus of claims 1 or 2 in which said generally straight section of elastomeric tubing is supported by said frame in predetermined axially stretched and tensioned condition.

4. The apparatus of claim 3 in which said casette is coded to indicate the average inside diameter of said stretched and tensioned section of tubing.

5. The apparatus of claim 2 in which said opening is generally rectangular and is elongated in a direction parallel with said section of tubing.

6. The apparatus of claims 1 or 2 in which said casette includes a pair of end sections of tubing extending axially from opposite ends of said generally straight section of tubing;

and connecting means at the free end of one of said end sections for connection with a patient.

7. The apparatus of claim 6 in which said casette includes coupling means at the free end of the other of said end sections for fluid-transmitting coupling with a medical container.

8. The apparatus of claims 1 or 2 in which said section of elastomeric tubing is transparent.

9. The apparatus of claims 1 or 2 in which said means for orienting said casette comprises at least one locating pin provided by said housing and at least one aperture provided by said casette frame for receiving said pin.

10. A linear peristaltic pump apparatus comprising a housing having an opening therein;

a shaft rotatably supported within said housing adjacent said opening;

means for rotating said shaft;

a series of bearing assemblies within said housing each having concentric inner and outer bearing members freely rotatable with respect to each other;

said inner members being eccentrically mounted upon said shaft with the centers of said inner members being arranged to describe a helix about the axis of said shaft;

an elastomeric membrane secured to said housing about said opening and covering said opening;

said membrane extending along said series of bearing assemblies for tangential engagement with the outer members thereof along a first band of contact extending in the same plane as the axis of said shaft;

a casette removably and externally supported by said housing adjacent to said membrane and comprising a rigid perimetric frame having an opening and a generally straight section of elastomeric tubing extending across said opening;

said frame including rigid sleeve elements secured to said frame on opposite sides of said opening with said section of said elastomeric tubing having opposite ends thereof secured to said sleeve elements;

means for orienting said casette with said section of tubing extending along the side of said membrane opposite from said bearing assemblies and in the same plane as said first band of contact and said axis of said shaft; and

platen means provided by said housing and engagable with said section of elastomeric tubing for urging the same into engagement with said membrane along a second band of contact parallel with said first band of contact.

11. The apparatus of claim 10 in which said frame includes a tab portion that projects from said housing when said casette is in operative position.

12. The apparatus of claim 10 in which said means for orienting said casette comprises male and female locating means provided by said frame and said housing, said locating means being mated together when said casette is in operative position.

13. The apparatus of claim 10 in which said section of elastomeric tubing is transparent.

14. The apparatus of claims 10 or 13 in which said section of elastomeric tubing is axially stretched and tensioned to a predetermined extent.

15. The apparatus of claim 14 in which said casette is coded to indicate the average inside diameter of said stretched and tensioned section of tubing.

16. A disposable casette for use with a linear peristaltic pump having a housing equipped with at least one casette-locating pin disposed in close proximity to a pump mechanism covered by an elastomeric membrane and also having a door equipped with a platen aligned with said membrane when the door is closed,

said casette comprising a rigid planar frame having a locating aperture for receiving the casette-locating pin of a pump housing for orienting said casette in relation to such housing, said frame also having an enlarged generally-rectangular opening for registration with the membrane and platen of a pump housing, a pair of rigid attachment sleeves provided by said frame on opposite edges of said opening, and a straight section of transparent elastomeric tubing extending across said opening and having end portions immovably secured to said attachment sleeves, said attachment sleeves each being provided with a pair of outwardly-projecting wing portions permanently secured to said frame adjacent opposite edges of said opening.