Auxiliary artificial heart of an embedded type

• US 6,346,120 B1
• Filed: 12/22/1999
• Issued: 02/12/2002
• Est. Priority Date: 06/23/1992
• Status: Expired due to Fees

• Current Assignee: Sun Medical Technology Research Corporation (Misuzu & Sun Medical Holdings Co., Ltd.), NOK Corporation, Seiko Epson Corporation (Seiko Group)
• Original Assignee: Sun Medical Technology Research Corporation (Misuzu & Sun Medical Holdings Co., Ltd.), NOK Corporation, Seiko Epson Corporation (Seiko Group)
• Inventors: Yamazaki, Kenji, Adachi, Hitoshi, Hori, Masanori, Yamazaki, Shunichi, Iwasaki, Yukio, Ito, Nobutaka, Higuchi, Kouji, Mori, Toshio, Miyao, Osami, Iiyama, Haruo
• Primary Examiner(s): Snow, Bruce
• Application Number:
  US09/469,294
• Time in Patent Office: 783 Days
• Field of Search: 623/3.13, 623/3.15, 623/3.24, 623/3.26, 623/3.1, 415/109, 415/110, 415/112, 415/900, 600/16
• US Class Current: 623/3.13
• CPC Class Codes: A61M 2205/8243 by induction
• CPC Class Codes: A61M 60/148 in line with a blood vessel using resection or like techniques, e.g. permanent endovascular heart assist devices
• CPC Class Codes: A61M 60/174 discharging the blood to the ventricle or arterial system via a cannula internal to the ventricle or arterial system
• CPC Class Codes: A61M 60/196 replacing the entire heart, e.g. total artificial hearts [TAH]
• CPC Class Codes: A61M 60/216 including a rotating member acting on the blood, e.g. impeller
• 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 60/824 Hydrodynamic or fluid film bearings
• CPC Class Codes: A61M 60/829 having a purge fluid supply
• CPC Class Codes: A61M 60/857 Implantable blood tubes
• CPC Class Codes: A61M 60/863 Apex rings
• CPC Class Codes: A61M 60/878 Electrical connections within the patient's body
• CPC Class Codes: Y10S 415/90 Rotary blood pump

Abstract

An artificial heart has a driving section, a nozzle section, a pump section for insertion into a ventricle of a human heart, and a sealing section forming a seal for a driving shaft extending from the driving section for driving the pump section. A sealing liquid chamber filled with a sealing liquid is formed around the driving shaft between the sealing mechanism and the driving section. The sealing liquid in the sealing liquid chamber maintains the sealing mechanism in a liquid-tight state and lubricates the sealing mechanism, whereby blood is prevented from entering the driving section. Even if blood happens to enter the driving section, the blood is mixed with the sealing liquid and does not coagulate. Thus, the operation of the artificial heart is not suppressed.

Claims

1. An artificial heart for embedment in a heart of a human body comprising:

a casing having a longitudinal axis, first and second rooms positioned along the longitudinal axis, and a partition wall having a through hole extending along the longitudinal axis and between said first and second rooms to separate the rooms, the casing including inlet and outlet ports in communication with the first room;

a motor in the second room, and having a rotary mechanism including a rotor and a drive shaft connected to the rotor, the drive shaft extending along the longitudinal axis from the second room to the first room through the through hole of the partition wall;

a pump having an impeller received in the first room and driven by the drive shaft;

a stationary seal member attached to the partition wall and positioned apart from the drive shaft to define a chamber therebetween in which a seal liquid is received, the stationary seal member having a first seal surface;

a movable seal member carried by the drive shaft and positioned in the first room, the movable seal member having a second seal surface; and

a magnet assembly for axially urging the drive shaft in one direction by a magnetic force enabling the second seal surface to contact the first seal surface to seal the chamber from the first room.

2. The artificial heart according to claim 1 wherein said stationary seal member includes a mating ring surrounding the drive shaft, said chamber including an annular space between the mating ring and the drive shaft, and said movable seal member includes a seal ring coaxially attached to the drive shaft.

3. The artificial heart according to claim 2 wherein said magnet assembly includes a movable permanent magnet carried by the rotating mechanism, and a stationary permanent magnet cooperable with the movable permanent magnet to urge the drive shaft in an axial direction.

4. The artificial heart according to claim 3 wherein said movable permanent magnet is carried by the rotor.

5. The artificial heart according to claim 3 wherein said stationary permanent magnet is carried by the casing in registration with the movable permanent magnet.

6. The artificial heart according to claim 5 wherein said movable and stationary permanent magnets have opposite surfaces of the same polarity.

7. The artificial heart according to claim 5 wherein said movable and stationary permanent magnets have opposite surfaces of different polarities.

8. The artificial heart according to claim 5 wherein at least one of said movable and stationary permanent magnets has a ring shape and is coaxially positioned against the drive shaft.

9. The artificial heart according to claim 1 wherein said pump includes a centrifugal pump.

10. The artificial heart according to claim 1 wherein said pump includes an axial pump.