MAGNETICALLY BALANCED FINGER-TYPE PERISTALTIC PUMP

• US 20150275886A1
• Filed: 06/10/2015
• Published: 10/01/2015
• Est. Priority Date: 11/13/2006
• Status: Active Grant

• Current Assignee: Eitan Medical Limited
• Original Assignee: Q Core Medical Ltd.
• Inventors: Rotem, Shachar, Goldor, Ori
• Granted Patent: US 9,581,152 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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: F04B 43/0072 of tubular flexible members
• 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: 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 43/1223 the actuating elements, e.g. rollers, moving in a straight line during squeezing

Abstract

A peristaltic pump includes a plurality of effecters, actuated in a periodic manner upon by obstructive forces of a flexible infusion tube so as flow of infusion fluid is provided along said infusion tube, the magnitude of the obstructive forces being dependent upon the displacement of said moving effecters; and a plurality of balancing magnets providing balancing forces upon one or all the moving effecters, the balancing forces at each point along the path of motion of the moving effecters being of approximately equal magnitude to that of the obstructive forces at the point; such that the parasitic output due to work performed against the obstructive forces is approximately zero and yield is maximized.

Claims

1. A peristaltic pump (DDS) comprising a plurality of effecters, actuated in a periodic manner upon by obstructive forces of a flexible infusion tube so as flow of infusion fluid is provided along said infusion tube, the magnitude of said obstructive forces being dependent upon the displacement of said moving effecters;

and a plurality of balancing magnets providing balancing forces upon one or all said moving effecters, said balancing forces at each point along the path of motion of the moving effecters being of approximately equal magnitude to that of said obstructive forces at said point;

such that the parasitic output due to work performed against said obstructive forces is approximately zero and yield is maximized.

2. A finger-type peristaltic pump (DDS) according to claim 1, comprising a plurality of pressing-fingers, actuated in a periodic manner upon by obstructive forces of a flexible infusion tube so as flow of infusion fluid is provided along said infusion tube, the magnitude of said obstructive forces being dependent upon the displacement of said moving fingers;

and a plurality of balancing magnets providing balancing forces upon one or all said moving fingers, said balancing forces at each point along the path of motion of the moving finger being of approximately equal magnitude to that of said obstructive forces at said point;

such that the parasitic output due to work performed against said obstructive forces is approximately zero and yield is maximized.

3. The magnetically balanced peristaltic pump according to claim 1, especially adapted to be utilized as ambulatory and hospital infusion pumps.

4. The peristaltic pump according to claim 1, wherein at least a portion of said plurality of pressing-fingers or members are magnetically balanced and wherein each of said magnetic balanced pressing-fingers comprises one or more magnets located on the moving finger and one or more metal members are located on the stationery conduit of the fingers, with is part of the static enclosure of the pumping mechanism, and with said metal members are optionally selected from ferromagnetic materials, and wherein the position of the said magnets and the said metal members is designed to produce the said balancing forces.

5. The peristaltic pump according to claim 1, wherein at least a portion of said balancing magnets is located in a location selected from a group consisting of the elongated body portion of the finger-type pressing members (fingers), the fingers block or any combination thereof.

6. The peristaltic pump according to claim 1, wherein at least a portion of said balancing magnets comprises metal and other paramagnetic materials which location is one or more of a group consisting of in one or more portions of the finger-type pressing members (fingers), on one or more portions of the fingers, in the fingers block, on the fingers block or any combination thereof.

7. The magnetically balanced finger-type peristaltic pump according to claim 1, wherein some or all of said pressing-fingers who are magnetically balanced are combined with said metal members instead of said magnets, and were this said fingers conduct, the metal members are replaced with said magnets;

and wherein some or all of the magnetically balanced fingers the metal members, either located on the fingers or on the fingers conducts, are replaced with said magnets.

8. The peristaltic pump according to claim 1, wherein each of said magnetically balanced pressing-fingers of linear movement is actuated periodically by a rotating cam towards a flexible infusion tube, i.e., until a complete yet temporary shut off of said tube is obtained, and backwards, i.e., until said fingers are not pressing said tube;

wherein said magnetic balance avoids significant pressing forces between said cam, its shaft and said fingers.

9. The peristaltic pump according to claim 8, wherein at least a portion of said magnetically balanced pressing-fingers actuated in at least partially non-linear movement.

10. The peristaltic pump as defined in claim 8, wherein said magnetic balance prevent significant pressing forces build-up between said cam and said fingers along their entire forth and backwards linear movement.

11. The peristaltic pump as defined in claim 8 wherein the magnetic force is applied in one or more specific points along the circumference of the rotating cam.

12. The peristaltic pump according to claim 1, wherein said fingers remain at maximum extension for a large angular sweep .DELTA.theta. of the shaft, such as 87.5.degree., causing complete tube shutoff during said large and predetermined range.

13. The peristaltic pump according to claim 1, comprising a plurality of N pressing fingers, N is any integer number higher 2, especially 4, wherein per any given pumping cycle, each of said fingers are in one of two alternating states of being either static or moving (or approaching to movement);

in said static state said at least one finger is pressing said flexible infusion tube and at least one finger is withdrawn and not pressing said tube;

in said moving state at least one finger is withdrawing from said tube and at least one finger is pressing the same.

14. The peristaltic pump according to claim 13, wherein the static and moving states of said fingers per any given pumping cycle are as defined in FIGS. 2 and 3.

15. The peristaltic pump according to claim 1, wherein at least a portion of said cams are characterized by one or more crescent forms, each of which of said crescent forms is adapted to provide pressing of said finger by magnetic forces of said balancing magnets in the manner that said magnetic forces are at least slightly stronger, at the angular position per FIG. 4, than the oppositely directed elastic forces, provided by the squeezing of said flexible tube by said finger while shutting off said tube;

by applying said magnetic force, complete tube'"'"'s shut off is assured, especially in cases of worn out tubes and pumping mechanisms with noticeable tolerances.

16. The peristaltic pump according to claim 15, wherein at least a portion of said cams are characterized by a first and a second crescent forms located in opposite directions, said first crescent form is adapted to provide pressing of said finger by magnetic forces of said balancing magnets in the manner that said magnetic forces are at least slightly stronger than the oppositely directed elastic forces, provided by the squeezing of said flexible tube by said finger while shutting off said tube;

by applying said magnetic force, complete tube'"'"'s shut off is assured;

said second crescent form is adapted to provide additional finger movement in the direction of withdrawing said tube, so as to facilitate a more relaxed form of mechanical pressure on the tube walls, especially in wider tubes, tubes of wider walls, and pumping mechanisms with noticeable tolerances;

the said more relaxed form of mechanical pressure on the said tube enable a prolonged life of the tube and as a consequence a more accurate flow rate throughout the pumping.

17. The peristaltic pump according to claim 1, wherein the pressing-finger are of rounded cross sections, additionally comprising sealing means that hermetically barriers between proximal portion of the fingers, i.e., the portion constantly located inside said pump'"'"'s housing, including the pumping mechanism, and distal portion of said fingers, i.e., the pressing tip located outside said housing;

said sealing means is especially selected from O-rings, U-rings or the like.

18. A mechanism of reducing the parasitic output of periodic systems comprising:

at least one moving member acted upon by obstructive forces, the magnitude of said obstructive forces being dependent upon the displacement of said moving member; and

a plurality of balancing elements providing balancing forces upon said moving member, said balancing forces at each point along the path of motion of the moving member being of approximately equal magnitude to that of said obstructive forces at said point;

such that the parasitic output is reduced to about zero.

19. A method of reducing the parasitic output of periodic systems comprising;

obtaining a force-displacement profile that is the forces of at least one moving member acted upon by obstructive forces; and

, providing magnetic balancing forces at each point along the path of the moving member, said balancing forces being of approximately equal magnitude to the obstructive forces but acting in the opposite direction;

of said obstructive forces at said point;

thereby reducing the parasitic output to about zero.