Centrifugal blood pump apparatus

• US 20040143151A1
• Filed: 12/17/2003
• Published: 07/22/2004
• Est. Priority Date: 12/17/2002
• Status: Active Grant

• Current Assignee: TC1 LLC (Abbott Laboratories Incorporated)
• Original Assignee: NTN Corporation, Terumo Kabushiki Kaisha (Terumo Corporation)
• Inventors: Ozaki, Takayoshi, Mori, Takehisa, Yaegashi, Mitsutoshi
• Granted Patent: US 7,470,246 B2
• Time in Patent Office: Days
• US Class Current: 600/16
• CPC Class Codes: A61M 60/109 incorporated within extracorporeal blood circuits or systems
• CPC Class Codes: A61M 60/205 Non-positive displacement blood pumps
• 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

Abstract

A centrifugal blood pump apparatus has a centrifugal pump section including an impeller having a first magnetic material therein and rotating inside the housing to feed a fluid by a centrifugal force generated during a rotation thereof; an impeller rotational torque generation section having a rotor having a magnet for attracting the first magnetic material of the impeller thereto, and a motor for rotating the rotor; and a dynamic pressure groove formed at a portion, of an inner surface of the housing, located at a rotor-disposed side thereof. The centrifugal blood pump apparatus further includes an electromagnet for attracting the impeller in a direction opposite to a direction in which the magnet of the rotor attracts the impeller and helping the impeller levitate.

Claims

1. A centrifugal blood pump apparatus comprising:

a housing having a fluid inlet port and a fluid outlet port;

a centrifugal pump section including an impeller having a first magnetic material therein and rotating inside said housing to feed a fluid by a centrifugal force generated during a rotation thereof;

an impeller rotational torque generation section for attracting and rotating said impeller; and

a hydrodynamic pressure groove formed at a portion of an inner surface of said housing at a rotor-disposed side or at a portion of a surface of said impeller at said rotor-disposed side,

said impeller rotating without contacting said housing owing to an action of said hydrodynamic groove,

said centrifugal blood pump apparatus further comprising;

an electromagnet for attracting said first magnetic material of said impeller or a second magnetic material provided on said impeller separately from said first magnetic material in a direction opposite to a direction in which said impeller rotational torque generation section attracts said first magnetic material and helping said impeller levitate.

2. A centrifugal blood pump apparatus according to claim 1, wherein said impeller rotational torque generation section has a rotor having a magnet for attracting said first magnetic material of said impeller and a motor for rotating said rotor;

and said hydrodynamic pressure groove formed at the portion of an inner surface of said housing at a rotor-disposed side or the portion of a surface of said impeller at said rotor-disposed side, and said electromagnet for attracting said first magnetic material or a second magnetic material in a direction opposite to the direction in which said magnet of said rotor attracts said first magnetic material and helping said impeller levitate.

3. A centrifugal blood pump apparatus according to claim 2, wherein said first magnetic material of said impeller and said magnet of said rotor for attracting said first magnetic material consist of a plurality of permanent magnets respectively;

and said permanent magnets of said impeller and said permanent magnets of said rotor are arranged on a circumference respectively in such a way that said permanent magnets of said impeller and said permanent magnets of said rotor have the same polarity respectively; and

said permanent magnets of said impeller and said permanent magnets of said rotor are arranged on two different circumferences facing each other in such a way that a polarity of said permanent magnets of said impeller arranged on one of said two circumferences and a polarity of said permanent magnets of said rotor arranged on the other of said two circumferences are opposite to each other.

4. A centrifugal blood pump apparatus according to claim 1, wherein said impeller rotational torque generation section has a plurality of stator coils, disposed circumferentially to rotate said impeller, for attracting said first magnetic material of said impeller of said centrifugal blood pump section;

and said hydrodynamic pressure groove formed at the portion of an inner surface of said housing at a stator coil-disposed side or at the portion of a surface of said impeller at said stator coil-disposed side thereof, and said electromagnet for attracting said first magnetic material or a second magnetic material in a direction opposite to the direction in which said stator coils attract said first magnetic material and helping said impeller levitate.

5. A centrifugal blood pump apparatus according to claim 1, further comprising a control mechanism, for controlling said impeller rotational torque generation section and said electromagnet, having a function of changing a degree of an impeller-attracting force of said electromagnet according to a rotation speed generated by said impeller rotational torque generation section.

6. A centrifugal blood pump apparatus according to claim 5, wherein said control mechanism has a function of keeping a distance between said impeller and said housing constant by changing a degree of an impeller-attracting force of said electromagnet according to a rotation speed generated by said impeller rotational torque generation section.

7. A centrifugal blood pump apparatus according to claim 1, further comprising a control mechanism, for controlling said motor and said electromagnet, having a rotation start state control function of starting a rotation of said impeller rotational torque generation section with said electromagnet attracting said impeller thereto at a force not less than a predetermined value.

8. A centrifugal blood pump apparatus according to claim 1, further comprising a control mechanism, for controlling said motor and said electromagnet, having a rotation start state control function of starting a rotation of said impeller rotational torque generation section with said electromagnet attracting said impeller thereto at a force not less than a predetermined value;

and a control function of reducing an attractive force of said electromagnet to a value less than said predetermined value after said impeller rotational torque generation section starts to rotate.

9. A centrifugal blood pump apparatus according to claim 5, wherein said control mechanism has a function of monitoring electric current of said impeller rotational torque generation section and controls said electromagnet by using an electric current value detected by said function of monitoring said electric current of said impeller rotational torque generation section.

10. A centrifugal blood pump apparatus according to claim 1, wherein a corner of said hydrodynamic pressure groove is chamfered to allow said corner to have a radius of rounding at not less than 0.05 mm.

11. A centrifugal blood pump apparatus according to claim 1, wherein said centrifugal blood pump apparatus has a second hydrodynamic pressure groove formed at a portion of an inner surface of said housing at a electromagnet-disposed side or at a portion of a surface of said impeller at said electromagnet-disposed side.

12. A centrifugal blood pump apparatus according to claim 11, wherein a corner of said second hydrodynamic pressure groove is chamfered to allow said corner to have a radius of rounding at not less than 0.05 mm.