Centrifugal blood pump

• US 6,183,220 B1
• Filed: 02/26/1999
• Issued: 02/06/2001
• Est. Priority Date: 02/27/1998
• Status: Expired due to Term

• Current Assignee: Baylor College of Medicine (Baylor College), Kyocera Corporation
• Original Assignee: Baylor College of Medicine (Baylor College), Kyocera Corporation
• Inventors: Yokokawa, Michihiro, Otsuka, Goro, Ohara, Yasuhisa, Makinouchi, Kenzo, Takami, Yoshiyuki, Nose, Yukihiko
• Primary Examiner(s): Leung, Philip H.
• Assistant Examiner(s): Fastovsky, Leonid
• Application Number:
  US09/258,644
• Time in Patent Office: 711 Days
• Field of Search: 417/420, 417/423.7, 417/423.12, 604/131, 415/206, 415/900
• US Class Current: 417/420
• 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 60/804 Impellers
• CPC Class Codes: A61M 60/825 Contact bearings, e.g. ball-and-cup or pivot bearings
• CPC Class Codes: F04D 29/2261 with special measures

Abstract

The present invention provides a blood pump capable of substantially completely preventing thrombus from attaching to the inner bottom portion of the casing without lowering the anti-hemolytic characteristic of blood. A centrifugal blood pump in accordance with the present invention comprises a pump casing, a suction inlet disposed at the central portion on the upper side of the casing, a delivery outlet disposed at the bottom peripheral portion of the casing, a main impeller (D in diameter) for forming a centrifugal flow of blood supplied from the suction inlet in the range from the central portion to the peripheral portion to feed the blood to the delivery outlet, wherein the main impeller is provided with an stirring impeller, the surface of which is provided with one or more stirring elements (L in entire length) having the shape of a fin or a groove, and the dimensions of the stirring elements are determined to satisfy inequality (1): 0.43<LD<1.30 and inequality (2) 0.03<S/A<0.21, where S is the surface area of the blood contact surfaces of the stirring elements.

Claims

1. A centrifugal blood pump comprising a pump casing, a suction inlet disposed at the central portion on the upper side of the casing, a delivery outlet disposed at the bottom peripheral portion of the casing, a main impeller rotated inside the casing to form a centrifugal flow of blood supplied from the suction inlet to the peripheral portion of the casing and to feed the blood to the delivery outlet,

wherein the main impeller is provided with an stirring impeller coaxially facing the inner bottom side to the casing, and the surface of the stirring impeller is provided with one or more stirring elements having the shape of a fin or a groove extending in the approximately radial direction from the center side thereof, and,

the stirring elements satisfy the following inequalities (1) and (2);

2. The centrifugal blood pump according to claim 1, wherein the stirring elements are fins and satisfy the following inequality (3);

3. The centrifugal blood pump according to claim 1, wherein the stirring elements are grooves and satisfy the following inequality (4);

4. The centrifugal blood pump according to claim 1, wherein the number of the stirring elements is 1 to 3.

5. The centrifugal blood pump according to claim 1, wherein both ends of the main impeller are pivotally supported inside the casing and rotated by an external rotating magnetic field.