Method and apparatus for pumping blood

• US 4,375,941 A
• Filed: 09/08/1980
• Issued: 03/08/1983
• Est. Priority Date: 03/20/1978
• Status: Expired due to Term

• Current Assignee: Child Laboratories Incorporated
• Original Assignee: Child Laboratories Incorporated
• Inventors: Child, Frank W.
• Primary Examiner(s): Look, Edward K.
• Application Number:
  US06/185,018
• Time in Patent Office: 911 Days
• Field of Search: 417/416-418, 417/570, 417/571, 92/162, 251/129, 310/14, 310/15, 310/23, 310/30, 310/34, 3/1.7, 128/1 D
• US Class Current: 417/53
• CPC Class Codes: A61M 60/462 Electromagnetic force
• CPC Class Codes: A61M 60/508 Electronic control means, e.g. for feedback regulation
• CPC Class Codes: A61M 60/894 Passive valves, i.e. valves actuated by the blood
• CPC Class Codes: F04B 17/044 using solenoids directly actuating the piston
• CPC Class Codes: H02K 33/16 with polarised armatures moving in alternate directions by reversal or energisation of a single coil system

Abstract

A pump and method for moving a fluid, as blood, having a body and end members forming a cylindrical chamber. A free floating piston located in the chamber is moved along the length of the chamber with a solenoid to pump blood into and out of opposite ends of the chamber. The end members containing inlet and outlet valves and sleeves are adapted to attach to veins or tubes to carry the blood to and from the pump. When electrical power is applied to the solenoid, a magnetic force operates to move the piston in the chamber, thereby pumping blood into and out of the chamber through the valves in the opposite end members.

Claims

1. A method of pumping blood with the use of a body having a chamber and piston means located in said chamber comprising:

separating the chamber into a first section and a second section with the piston means movably disposed in said chamber, reciprocating the piston means in said chamber with sequential reverse magnetic force to move blood into and out of said first and second sections of said chamber, allowing a limited amount of blood of flow around the piston means during movement thereof in said chamber, controlling the flow of blood into and out of the first section of the chamber in response to movement of the piston means in said chamber, and controlling the flow of blood into and out of the second section of the chamber in response to movement of the piston means in said chamber.

2. The method of claim 1 wherein:

the chamber has a longitudinal axis, and said piston means is reciprocated along said longitudinal axis, said flow of a limited amount of blood being a generally annular flow of blood around said piston means between said first and second sections of said chamber.

3. The method of claim 2 including:

allowing the piston means to rotate about said longitudinal axis simultaneously with the reciprocation of the piston means along said longitudinal axis.

4. The method of claim 1 wherein:

the piston means is moved in said chamber in one direction in response to a first magnetic force and moved in said chamber in the direction opposite the one direction in response to a second magnetic force.

5. The method of claim 1 wherein:

the piston means is reciprocated in said chamber with separate magnetic forces acting in opposite directions.

6. The method of claim 1 wherein:

said limited amount of blood flow moves through spaces provided by ribs separating a cylindrical wall of the body surrounding the chamber and the piston means.

7. The method of claim 6 wherein:

said piston means has a surface having a substantially constant radius of curvature engageable with said ribs to provide spaces between said surface and cylindrical wall for accommodating said limited flow of blood around the piston means.

8. The method of claim 1 wherein:

said body has a generally cylindrical wall surrounding said chamber, and said piston means has an outer peripheral surface located adjacent said cylindrical wall, said limited flow of blood past the piston means occurring around the piston means between the surface and the cylindrical wall whereby the blood moving past said piston means washes said surface and cylindrical wall.

9. The method of claim 8 wherein:

said cylindrical wall is separated from said outer peripheral surface with a plurality of ribs which provide arcuate spaces between said cylindrical wall and said outer peripheral surface, said limited flow of blood moving through said arcuate spaces.

10. The method of claim 9 including:

allowing the piston means to rotate about the longitudinal axis of the chamber as the piston means reciprocates in said chamber.

11. The method of claim 1 wherein:

the flow of blood into and out of the first chamber is controlled with first one-way inlet and outlet valves, and the flow of blood into and out of the second chamber is controlled with second one-way inlet and outlet valves.

12. An apparatus for pumping blood comprising:

rigid means having a cylindrical wall surrounding a chamber, said means having an inlet port and an outlet port at each end thereof, check valve means associated with said inlet and outlet ports for controlling the flow of blood through said ports, and electric coils associated with said rigid means for creating a magnetic field when current flows through said coils, piston means located within said chamber, said piston means being movable therein, said piston means having characteristics such that the piston means is attracted by the magnetic field resulting from the current flowing through the electric coils whereby the magnetic field moves the piston means in the chamber, said piston means having an outside diameter being significantly less than the inside diameter of the cylindrical chamber so as to foster at least some reverse flow of blood around said piston means during movement of the piston means in said chamber to promote the washing of the cylindrical wall and the piston means, and electrical means for passing current alternately through said electric coils so as to cause the piston means to reciprocate between the ends of the chamber.

13. The apparatus of claim 12 wherein:

the electric coils are positioned circumferentially around the cylindrical wall.

14. The apparatus of claim 12 including:

rib means on said cylindrical wall engageable with said piston means to space said piston means from said wall.

15. The apparatus of claim 14 wherein:

said rib means comprise a plurality of ribs, each rib having a length extended longitudinally of said chamber.

16. The apparatus of claim 12 wherein:

said electric coils comprise a pair of coils positioned around separate portions of said cylindrical wall.

17. The apparatus claim 12 including:

means located within said chamber and being adapted to engage said piston means to hold said piston means away from the wall of the chamber as the piston means reciprocates in said chamber.

18. The apparatus of claim 17 wherein:

said means mounted within said chamber comprise a plurality of longitudinal ribs fixed to the cylindrical wall.

19. The apparatus of claim 18 wherein:

said piston means has an outer surface having a substantially constant radius of curvature engageable with said rib to provide spaces between said surface and said cylindrical wall for accommodating said limited flow of blood around the piston means.

20. An apparatus for pumping blood comprising:

a body having an inside wall surrounding a chamber for accommodating blood, means having inlet and outlet passages in communication with opposite ends of the chamber, a plurality of longitudinally extended ribs on said wall, said ribs extended into the chamber, one-way inlet valve means operable to allow blood to flow through the inlet passages into the opposite ends of the chamber and restrict the flow of blood out of the opposite ends of the chamber, one-way outlet valve means operable to allow blood to flow through the outlet passages out of the opposite ends of the chamber and restrict the flow of blood into the opposite ends of the chamber, movable piston means located in the chamber, said piston means being engageable with the ribs to space the piston means from the wall whereby a limited amount of blood flows around the piston means when the piston means moves in the chamber, solenoid means associated with said body for establishing sequential reverse magnetic force, and control means connected to the solenoid means operable to provide electric energy to energize the solenoid means whereby the sequential reverse magnetic force acting on the piston means moves the piston means in a manner to move blood into and out of the opposite ends of said chamber.

21. The apparatus of claim 20 including:

stop members on opposite ends of the ribs to limit the reciprocating movement of the piston means in the chamber.

22. The apparatus of claim 20 wherein:

the solenoid means includes a pair of solenoids surrounding the body.

23. The apparatus of claim 22 wherein:

said pair of solenoids includes a first solenoid surrounding one end section of the body and a second solenoid surrounding the opposite end section of the body.

24. The apparatus of claim 20 wherein:

said means having said inlet and outlet passages comprise first end means mounted on one end of the body and second end means mounted on the opposite end of the body, each of said end means having an inlet passage and an outlet passage in communication with an associated end of the chamber.

25. The apparatus of claim 20 wherein:

each one-way inlet valve means and each one-way outlet valve means has a movable valving member.

26. The apparatus of claim 20 wherein:

said piston means has an outer surface having a substantially constant radius of curvature engageable with said rib to provide spaces between said surface and said cylindrical wall for accommodating said limited flow of blood around the piston means.