Motor driven sealless blood pump

• US 5,399,074 A
• Filed: 09/04/1992
• Issued: 03/21/1995
• Est. Priority Date: 09/04/1992
• Status: Expired due to Term

• Current Assignee: Kyocera Corporation
• Original Assignee: Kyocera Corporation
• Inventors: Sakuma, Ichiro, Nose, Yukihiko, Takatani, Setsuo
• Primary Examiner(s): Bertsch, Richard A.
• Assistant Examiner(s): McAndrews, Roland G.
• Application Number:
  US07/940,520
• Time in Patent Office: 928 Days
• Field of Search: 417/410 R, 417/423.1, 417/423.7, 417/423.11, 417/423.12, 417/423.14, 417/423.15, 417/424.1, 415/900, 415/122.1, 604/151, 416/3
• US Class Current: 417/423.1
• CPC Class Codes: A61M 60/113 in other functional devices, e.g. dialysers or heart-lung machines
• CPC Class Codes: A61M 60/232 Centrifugal pumps
• CPC Class Codes: A61M 60/419 the force acting on the blood contacting member being permanent magnetic, e.g. from a rotating magnetic coupling between driving and driven magnets
• CPC Class Codes: A61M 60/422 the force acting on the blood contacting member being electromagnetic, e.g. using canned motor pumps
• CPC Class Codes: A61M 60/804 Impellers
• CPC Class Codes: A61M 60/81 Pump housings
• CPC Class Codes: A61M 60/825 Contact bearings, e.g. ball-and-cup or pivot bearings
• CPC Class Codes: A61M 60/849 Disposable parts
• CPC Class Codes: F04D 29/0465 Ceramic bearing designs
• CPC Class Codes: F04D 29/0467 Spherical bearings
• CPC Class Codes: F04D 29/242 Geometry, shape
• CPC Class Codes: F05C 2203/0817 of silicon
• CPC Class Codes: Y10S 415/90 Rotary blood pump

Abstract

A centrifugal blood pump, used for heart-lung machines or the like, comprises an impeller, a casing having a suction inlet and a delivery outlet and being equipped with a space for rotatably accommodating the impeller, and a magnetic drive means disposed outside the casing. The impeller is of a rotationally symmetric shape and has a rotary vane section and a cylindrical section equipped with a magnet means. The magnet drive means for generating a rotating magnetic field coaxially encloses the magnet means of the above-mentioned cylindrical section and rotates the impeller in cooperation with the magnet means. At least the end section of the impeller'"'"'s rotation center on the rotary vane section side is supported preferably by a pivot bearing. The pivot and the bearing thereof are preferably made of ceramics.

Claims

1. A blood pump comprising a casing having a suction side provided with a suction inlet and an outlet side provided with a delivery outlet, an impeller of a rotationally symmetric shape which is encased in the casing, and a magnet drive means disposed outside the casing coaxially to said impeller, said impeller having a rotary vane section on the outlet side and a cylindrical section equipped with a magnet means on the suction side away from the rotary vane section, and said magnet drive means being positioned so as to enclose the magnet means with the casing interposed therebetween in order to rotate the impeller around the rotation center thereof in cooperation with the magnet means, wherein the impeller is supported at the outlet side by a pivot and a pivot bearing.

2. A blood pump according to claim 1, wherein the impeller is supported at the suction side by a contact-type bearing.

3. A blood pump according to claim 1, wherein the impeller is supported at the suction side by a non-contact-type bearing.

4. A blood pump according to claim 1, wherein said pivot is made of ceramics.

5. A blood pump according to claim 4, wherein said rotary vane section of said impeller has a surface which faces said pivot and pivot bearing, and said impeller further comprises vanes on said surface of said impeller.

6. A blood pump according to claim 1 or 4, wherein the ratio of the radius of curvature r of the leading end of said pivot to the radius of curvature R of the recessed curved surface of said bearing is in the range of 1 to 4.

7. A blood pump according to claim 1, or 4, wherein said magnetic means is composed of permanent magnets, said magnetic drive means is composed of an electric coil for generating a rotating magnetic field, and the gap between said cylindrical section equipped with said magnetic means and said casing opposite thereto is in the range of 0.5 to 3.0 mm.

8. A blood pump according to claim 1 or 5, wherein said magnet means and said magnet drive means are composed of permanent magnets, and the gap between said cylindrical section equipped with said magnet means and said casing opposite thereto is in the range of 0.5 to 10.0 mm.

9. A blood pump according to claim 1 or 4, wherein the casing forms a chamber containing the impeller and communicating with the delivery outlet, and through holes passing between said chamber and the outside of said casing are provided at positions around said bearing for supporting the end section of the impeller'"'"'s rotation center on the rotary vane section side.

10. A blood pump according to claim 1 wherein said pivot bearing is made of ceramics.

11. A blood pump according to claim 10, wherein the ratio of the radius of curvature R of the leading end of said pivot to the radius of curvature R of the recessed curved surface of said bearing is in the range of 1 to 4.

12. A blood pump according to claim 10, wherein said magnetic means is composed of permanent magnets, said magnetic drive means is composed of an electric coil for generating a rotating magnetic field, and the gap between said cylindrical section equipped with said magnetic means and said casing opposite thereto is in the range of 0.5 to 3.0 mm.

13. A blood pump according to claim 10, wherein said magnet means and said magnet drive means are composed of permanent magnets, and the gap between said cylindrical section equipped with said magnet means and said casing opposite thereto is in the range of 0.5 to 10.0 mm.

14. A blood pump according to claim 10 wherein the casing forms a chamber containing the impeller and communicating with the delivery outlet, and through holes passing between said chamber and the outside of said casing are provided at positions around said bearing for supporting the end section of the impeller'"'"'s rotation center on the rotary vane section side.

15. A blood pump according to claim 10, wherein said rotary vane section of said impeller has a surface which faces said pivot and pivot bearing, and said impeller further comprises vanes on said surface of said impeller.

16. A blood pump comprising a casing having a suction side provided with a suction inlet and an outlet side provided with a delivery outlet, an impeller of a rotationally symmetric shape which is encased in the casing, and a magnet drive means disposed outside the casing coaxially to said impeller, said impeller having a rotary vane section on the outlet side and a cylindrical section equipped with a magnet means on the suction side away from the rotary vane section, and said magnet drive means being positioned so as to enclose the magnet means with the casing interposed therebetween in order to rotate the impeller around the rotation center thereof in cooperation with the magnet means, wherein the impeller is supported at the outlet side by a bearing, the casing forms a chamber containing the impeller and communicating with the delivery outlet, and through holes passing between said chamber and the outside of said casing are provided at positions around said bearing for supporting the end section of the impeller'"'"'s rotation center on the rotary vane section side.