Surgery – Cardiac augmentation
Patent
1999-03-09
2000-12-05
Kamm, William E.
Surgery
Cardiac augmentation
A61M 110
Patent
active
061559695
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a centrifugal pump comprising a pump head and a drive for delivering blood and other shear-sensitive fluids, such as cell-containing cleaning suspensions, for example, in blood-cleaning units.
Increasing use is being made of centrifugal pumps for delivering sensitive fluids which can change in their composition owing to excessive friction and shear stress. Particularly in medical and biological applications, such pumps are used, For example, for heart-lung machines, for supporting the failing heart, as well as for purpose of blood preparation for suspensions of cells or biologically active particles. In this case, the rotor of the pump is mostly driven via a conventional motor, it being the case either that the energy is injected into the magnets of the pump rotor via an additional magnet disk of the drive, or that the magnets of the pump rotor are lengthened in the axial direction and are therefore arranged as rotor of electric motor in the rotary field of the stator. Combinations of disk-rotor motors with magnetic couplings have also been described (for example EP-401 761-A2, Ebara Corp.), but they also provide for structural separation of the magnetic circuits of the rotor and the pump. These arrangements entail a substantial overall height of the pump, and this is disadvantageous.
Particularly in the case of blood pumps for cardiac support, which can be implanted or are fitted near the body, but also in the case of bedside mounted units for blood purification and in other applications, the aim is a pump/drive combination of low overall height and of low volume and weight. A pump of low design is proposed in the PCT application WO-92/03 181-A1, Baylor College. In this pump, the magnetic disk driven by the disk-rotor stator is used simultaneously for the magnetic coupling of the rotor. In the case of a motor of this design, a considerable volume of iron is required for the magnetic return path and, at the same time, a relatively low magnetic saturation is achieved.
A pump has become known (via Schima et al., Artificial Organrs 19:7 (1995), Pages 639-643) in which coupling of the magnetic circuits of the motor and pump rotor is performed. However, with this arrangement the rotor is stabilized by three supporting points on the pump base, and this can lead to increased blood traumatization during the conveyance of blood. Furthermore, a pump has become known (Yamane et al: Artificial Organs 19:7 (1995), Pages 625-630) in which there is a magnetic suspension of the rotor on the tip facing the intake, fit being the case there, however, that because of the unfavorable distribution of the magnetic forces the overall height must be relatively large and the intake is disturbed. Finally, mention may be made of a centrifugal pump (Akamatsu et al: Artificial Organs 19:7 (1995), Pages 631-634), in which in addition to the magnetic injection of the rotational energy via additional magnet disks, electromagnetic stabilization of the rotor is provided by complete floating in the housing. However, this stabilization requires a relatively large coil apparatus on the circumference of the pump.
It is the object of the present invention to create and improve the pump of the type described at the beginning and the drive therefore, in which the existing disadvantages are avoided. In particular, the pump is intended to have a low overall height and low volume and weight, as well as a high operational reliability. The unfavorable mechanical effects on the delivered medium, such as high shear forces, are to be avoided.
The present invention is defined by virtue of the fact that the drive has a drive rotor with a rotor disk which is provided with permanent magnets which are assigned permanent magnets, fitted on the pump rotor, for the purpose of magnetic coupling, and are assigned in the drive to the magnetic coils of a stator for the purpose of generating the rotary movement, and in that the pump rotor axis extends into the pump intake and is magnetically centered in the pump intake.
According to a
REFERENCES:
patent: 5470208 (1995-11-01), Kletschka
patent: 5503615 (1996-04-01), Goldstein et al.
Schima Heinrich
Schmallegger Helmut
Dubno Herbert
Kamm William E.
Kyocera Corporation
Schima Heinrich
LandOfFree
Centrifugal pump for pumping blood and other shear-sensitive liq does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Centrifugal pump for pumping blood and other shear-sensitive liq, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Centrifugal pump for pumping blood and other shear-sensitive liq will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-956522