Linear peristaltic pump with reshaping fingers interdigitated with pumping elements

• US 6,234,773 B1
• Filed: 10/12/1998
• Issued: 05/22/2001
• Est. Priority Date: 12/06/1994
• Status: Expired due to Term

• Current Assignee: B Braun Medical Incorporated (B. Braun Holding GmbH & Co. KG)
• Original Assignee: B Braun Medical Incorporated (B. Braun Holding GmbH & Co. KG)
• Inventors: Lindemann, Gary, Copp, Harry C., Oliver, Joseph A., Hill, Roger J., Monti, James H. Jr.
• Primary Examiner(s): Thorpe, Timothy S.
• Assistant Examiner(s): Solak, Timothy P
• Application Number:
  US09/169,892
• Time in Patent Office: 953 Days
• Field of Search: 417/53, 417/474, 417/476, 417/477.1, 417/477.9, 417/478, 604/153
• US Class Current: 417/474
• 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: 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

Abstract

A linear peristaltic pump of the type for removable engagement of a portion of a flexible tubing and having a plurality of sequentially actuated pumping elements which act along the engaged portion of the flexible tubing, with the pumping elements reciprocated in a first direction to collapse adjacent segments of the tubing and then in a second direction to release the adjacent segments of the tubing, each pumping element having a flat pumping surface reciprocated in a sequence so that fluid in the flexible tubing is moved along the engaged portion of the tubing. The linear peristaltic pump is provided with a plurality of opposed pairs of pivotable reshaping fingers, with each pair of the reshaping fingers interposed adjacent to one of the pumping elements in sequence along the engaged portion of the flexible tubing. A finger drive and follower mechanism is formed by and engaged between each of the plurality of pairs of reshaping fingers and the adjacent ones of the pumping elements for actuating the reshaping fingers into reshaping engagement with the flexible tubing upon release thereof by the adjacent one of the pumping elements.

Claims

1. A linear peristaltic pump for use in pumping fluid through a flexible tubing and for reshaping said flexible tubing, comprising:

(a) a pump body, including a face having a channel formed therein for releasably receiving said flexible tubing into said channel and a door having a backing surface closable parallel to and against said face and against said flexible tubing received into said channel;

(b) a plurality of pumping elements operatively associated in said pump body for reciprocation therein, each of said pumping elements comprising plates having a tubing contact surface and a cam engaging surface, each said tubing contact surface of said plurality of pumping elements positioned for contact against said flexible tubing;

(c) a cam shaft having a plurality of cams for reciprocating each of said plurality of pumping elements sequentially between compression and release of said flexible tubing so that fluid is pumped through said flexible tubing;

(d) a plurality of reshaping fingers, each reshaping finger having first and second angled edge portions, each of said plurality of reshaping fingers pivotably mounted and positioned in said pump body so that said plurality of reshaping fingers are interdigitated with said plurality of pumping elements and positioned for non-collapsing reshaping contact with said flexible tubing adjacent to each of said plurality of pumping elements; and

(e) first and second angled finger driving projections formed on each of said pumping elements defining actuator channels in which said reshaping fingers are movably engaged, said first angled finger driving projection for actuating each of said plurality of reshaping fingers sequentially into reshaping, non-collapsing contact against said flexible tubing, upon retraction of an adjacent one of said plurality of pumping elements corresponding to release of said tubing and said second finger driving projection for actuating each of said plurality of reshaping fingers sequentially out of reshaping contact upon advancement of said adjacent one of said plurality of pumping elements corresponding to compression of said tubing by adjacent ones of said plurality of pumping elements.

2. The linear peristaltic pump for use in pumping fluid through a flexible tubing and for reshaping said flexible tubing as in claim 1, wherein said tubing contact surface on each pumping plate defines a flat plane parallel to said face of said housing and extending coextensive with said pumping elements for pumping contact with said flexible tubing.

3. A linear peristaltic pump for pumping fluid through a flexible tubing, comprising:

(a) a pump body having a face with a channel elongated in a direction for receiving said flexible tubing thereinto;

(b) a plurality of pumping elements operatively associated in said pump body positioned along said channel for sequential reciprocation of each one of said pumping elements between compression and release of said flexible tubing;

(c) a drive mechanism operatively connected to said plurality of pumping elements through said pump body for driving said plurality of pumping elements with said sequential reciprocation;

(d) a plurality of separate reshaping fingers pivotably mounted and arranged in opposed a alternatingly interdigitated with said plurality of pumping elements and each reshaping finger positioned for pivoting into and out of non-collapsing reshaping contact with said flexible tubing and positioned adjacent to each of said plurality of pumping elements for sequentially reshaping said flexible tubing when sequentially released by each of said pumping elements;

(e) a plurality of finger driving cam mechanisms between said pumping elements and said reshaping fingers for sequentially actuating said reshaping fingers to pivot against said tubing upon release of said tubing by said each of said pumping elements; and

(f) a retractable spring loaded platen mounted for spring loaded contact against said face of said pump to provide a substantially flat backing surface at a consistent position against which said pumping elements compress said flexible tubing.

4. A linear peristaltic pump as in claim 3 where:

(a) said drive mechanism comprises a variable speed electrical motor driving a rotary camshaft by which said pumping elements are reciprocated; and

(b) said controls operatively connected to said drive mechanism comprise a control panel having selectable input buttons for providing electrical signals to said variable speed motor to selectably change and thereby control the speed of said rotary camshaft.

5. An apparatus for pumping fluid through a flexible tubing as in claim 3 wherein a spring-loaded backing surface further comprises:

(a) a door pivotable into and out of a locked parallel position with and spaced apart from said tubing contact surfaces of said plurality of pumping plates;

(b) a platen held in said door for movement into and out of abutment against a face of said apparatus for pumping fluid and covering an area of pumping engagement with said flexible tubing;

(c) springs between said door and said platen to bias said platen into abutment with said face; and

(d) a retracting mechanism and controls for said retracted mechanism for selectably retracting said spring loaded platen out of abutment with said face for initializing said pump and for selectably releasing said spring loaded into abutment against said face for supporting said flexible tubing when it is sequentially compressed by said pumping plates during operation.

6. An apparatus for pumping fluid through a flexible tubing, comprising:

(a) a pump body having a face with a channel formed therein sized for removably receiving a fluid-filled flexible tubing and said pump body having a pump engagement portion along said channel;

(b) a door closable against said face of said pump body;

(c) a retractable spring-loaded backing surface formed in said door for contact with said face over said pump engagement portion;

(d) a plurality of pumping plates, each having a tubing contact surface and each mounted along said pump engagement portion in said pump body adjacent each other one of said plurality of pumping plates for reciprocating motion compressing against and retracting from said flexible tubing when said door is closed and when said flexible tubing is engaged between said contact surfaces of said plurality of pumping plates and said retractable spring loaded backing surface;

(e) a plurality of rotary cams for reciprocating said plurality of pumping plates sequentially so that fluid is movable through said flexible tubing by action of said reciprocating pumping plates;

(f) a plurality of reshaping fingers, each separately and pivotably mounted in said pump body interdigitated with said plurality of pumping plates, said reshaping fingers constructed and positioned for non-collapsing transverse reshaping contact with said flexible tubing, each reshaping finger positioned for contacting said flexible tubing adjacent to at least one of said pumping plates;

(g) angled finger driving projections formed on each of said pumping plates for moving each of said reshaping fingers out of contact with said tubing when said adjacent one of said plurality of pumping plates is compressed against said tubing and for advancing each of said reshaping fingers into non-collapsing reshaping contact with said flexible tubing when said adjacent one of said plurality of pumping plates is retracted from said flexible tubing;

(h) an upstream pressure sensor in said face of said pump body along said channel upstream from said pump engagement portion;

(i) a downstream pressure sensor in said face of said pump along said channel downstream from said pump engagement portion;

(j) a valve positioned along said channel downstream from said downstream sensor said valve actuatable to close said flexible tubing when received in said channel and retractable to open said flexible tubing during operation of said apparatus for pumping; and

(k) a retraction mechanism for retracting said spring loaded backing surface from said face of said pump body when said valve downstream from said downstream sensor is actuated to close said flexible tubing so that said downstream and upstream sensors can be calibrated at the same internal fluid pressure.

8. The apparatus for pumping fluid of claim 6 further comprising a third and fourth spring loaded backing plates on said door adjacent to said upstream and said downstream pressure sensors for contacting said face of said housing when said door is closed so that said face is maintained as a reference surface for said pressure sensors.

7. An apparatus for pumping fluid through a flexible tubing comprising:

(a) a pump body having a face with a channel formed therein sized for removably receiving a fluid-filled flexible tubing and said pump body having a pump engagement portion along said channel;

(b) a door closable against said face of said pump body;

(c) a retractable spring loaded backing surface formed in said door for contact with said face over said pump engagement portion;

(d) a plurality of pumping plates, each having a tubing contact surface and each mounted along said pump engagement portion in said pump body adjacent each other one of said plurality of pumping plates for reciprocating motion compressing against and retracting from said flexible tubing when said door is closed and when said flexible tubing is engaged between said contact surfaces of said plurality of pumping plates and said retractable spring loaded backing surface;

(e) a plurality of rotary cams for reciprocating said plurality of pumping plates sequentially so that fluid is movable through said flexible tubing by action of said reciprocating pumping plates;

(f) a plurality of reshaping fingers, each separately and pivotably mounted in said pump body interdigitated with said plurality of pumping plates, said reshaping fingers constructed and positioned for non-collapsing transverse reshaping contact with said flexible tubing, each reshaping finger positioned for contacting said flexible tubing adjacent to at least one of said pumping plates;

(g) angled finger driving projections formed on each of said pumping plates for moving each of said reshaping fingers out of contact with said tubing when said adjacent one of said plurality of pumping plates is compressed against said tubing and for advancing each of said reshaping fingers into non-collapsing reshaping contact with said flexible tubing when said adjacent one of said plurality of pumping plates is retracted from said flexible tubing;

(h) an upstream pressure sensor in said face of said pump body along said channel upstream from said pump engagement portion;

(i) a downstream pressure sensor in said face of said pump along said channel downstream from said pump engagement portion;

(j) a valve positioned along said channel downstream from said downstream sensor said valve actuatable to close said flexible tubing when received in said channel and retractable to open said flexible tubing during operation of said apparatus for pumping;

(k) a retraction mechanism for retracting said spring loaded backing surface from said face of said pump body when said valve downstream from said downstream sensor is actuated to close said flexible tubing so that said downstream and upstream sensors can be calibrated at the same internal fluid pressure; and

(l) a second spring loaded backing plate on said door adjacent to said downstream valve so that said second backing surface contacts said face of said pump when said door is closed thereby maintaining the face of said pump as a reference surface for said valve actuation.

9. A method of pumping fluid through a flexible tubing and of reshaping said tubing during said pumping, comprising the steps of:

(a) releasably engaging said flexible tubing into a channel of predetermined depth formed in a face of a linear peristaltic pump along a plurality of pumping element for pumping fluid through said tubing;

(b) applying a spring loaded backing plate against said face and said flexible tubing engaged into said channel in said face;

(c) reciprocating each of said plurality of pumping elements sequentially between compression and release of said flexible tubing against said backing plate along a length of said tubing thereof so that fluid is pumped there through;

(d) actuating each of a plurality of reshaping fingers sequentially with non-collapsing reshaping contact against said tubing, corresponding to release thereof by adjacent ones of said plurality of pumping elements; and

(e) initializing said apparatus for pumping fluid by retracting said spring loaded backing plate from said engaged flexible tubing, sensing pressure in said flexible tubing, with separate upstream and downstream sensors, when said backing plate is retracted and said tubing is released, normalizing the upstream and downstream pressure sensed by said separate sensors and placing said backing plate into spring loaded contact with said pump face into which said flexible tubing is engaged so that said pumping elements actuate against said tubing at a precise position determined by said depth of said channel.