Portable Centrifugal Blood Pump

The present invention relates to a small-scale centrifugal blood pump. In particular, the present invention relate to a hand-carried portable centrifugal blood pump for emergency use, which may be powered by batteries.

Technical Background

The European patent 0425257 Bl discloses a disposable pumping unit releasably mounted on magnetic drive means for pumping blood, wherein an impeller has a plurality of openings to direct blood flow along a bearing.

The US patent 5658136 discloses a centrifugal blood pump, wherein permanent magnets have a height in an axial direction of a pump rotor, at least approximately equal to a height of ferromagnetic regions of the pump rotor in the axial direction of the pump rotor.

Summary of the invention

A number of demands may be placed on a portable blood pump: It should preferably be of small scale, small volume and small weight, in order to be easy to transport. The energy use should preferably be limited, allowing it to be driven by a limited amount of batteries, or alternatively by such means as solar cells, a small generator and/or a crank handle. Related to the limited use of energy, is that it should preferably exhibit limited heat dissipation, which would also provide the advantage of avoiding non-intended heating of blood. In addition, and related, it should preferably not need a cooling system, which would require added energy consumption, and added weight and volume of the system.

Further, additional requirements may be placed, because a portable blood pump should preferably be able to work during transport of a patient. Thus, the pump should preferably exhibit improved stability, as the surroundings of the pump may be moving and shaking, i.e. the pump should preferably be able to function even in the absence of a stable surface, on which the pump could be placed. Further, during transport, the pump may be inclined, i.e. the angle of the rotating pump may be varying; e.g. in a plane or helicopter due to acceleration, such as turning, or to changing angle of attack of the flying machine. Additionally, the pump may be subjected to bumps, such as experienced in an ambulance car, or due to convection or thermal columns for flying machines. The smallness of a portable pump may accentuate problems with non-stable environment, as the low weight makes it easier to disturb or shake the pump.

In order to address these challenges, demands and requirements, the present invention relates to a number of aspects and embodiments.

According to an aspect the invention concerns a portable centrifugal blood pump for which no cooling system is necessary, hence reducing the energy consumption and the weight of the pump. According to an aspect, the invention relates to a centrifugal blood pump according to claim 1.

According to a further aspect, the invention relates to a partition element according to claim 6. According to an aspect, the invention relates to a portable centrifugal blood pump according to claim 14.

According to an aspect, the invention relates to the use of a centrifugal blood pump according to claim 25.

According to an aspect, the invention relates to a centrifugal blood pump according to claim 26.

According to further aspects, the invention relates to a centrifugal blood pump according to any of the claims 27 - 34.

According to an aspect, the present invention relates to a rotary coupling part according to claim 36.

According to another aspect, the invention relates to a centrifugal blood pump according to claim 42.

According to an aspect, the invention relates to a centrifugal blood pump according to claim 43.

According to an additional aspect, the invention relates to a coupling part according to claim 61.

According to an aspect, the invention relates to a rotary pump according to claim 65.

According to another aspect, the invention relates to a rotary pump according to claim 71.

A number of aspects of the present invention are described in the appended independent claims and further elucidated in the present text.

Detailed Disclosure

Certain aspects and embodiments of the present invention are described in the points below and the claims.

A magnet has magnetic poles. The "longitudinal line" of a magnet is here defined by a line intersecting the poles of the magnet. The "front end" of a magnet is here defined as the end of a magnet closest to the circumference of an associated rotary pump. If both ends are equally close, the front end is defined to be the north pole of the magnet.

The "radial angle", a, of a magnet is here defined as the smallest angle between the longitudinal line of the magnet and a radial plane, the radial plane intersecting the front end of the magnet as well as the axis of rotation of the associated rotary pump. For a radially arranged magnet, the radial angle will be 0°. For a tangentially arranged magnet, the radial angle will be 90°.

The "axis angle", β, of a magnet is here defined as the smallest angle between the longitudinal line of the magnet and the axis of rotation of an associated rotary pump. For a magnet aligned parallel to the axis of rotation of an associated rotary pump, the axis angle will be 0°. For a magnet placed in the plane of rotation of an associated rotary pump, the axis angle will be 90°. The angle between the longitudinal line of a magnet and a plane perpendicular to the axis of rotation of an associated rotary pump is 90°-β.

When a magnet is placed in "radial direction", the radial angle is 0°, and the axis angle is 90°. When a magnet is placed in "non-radial direction", the radial angle is different from 0° and/or the axis angle is different from 90°.

According to an embodiment, the invention concerns a rotary coupling part (103) for a centrifugal blood pump (101) having a rotary pump (102) with at least one ferromagnetic region, said rotary coupling part being driven by driving means (104); said rotary coupling part comprising at least one permanent magnet, said at least one permanent magnet being adapted to engage in a magnetic coupling with the at least one ferromagnetic region of the rotary pump, said permanent magnet having magnetic poles defining a longitudinal line of said magnet, wherein the longitudinal line of said at least one permanent magnet is arranged at an angle between 3° and 42° from a plane perpendicular to the axis of rotation of the rotary pump. Surprisingly, it has been found that an angle, such as between 3° and 42° below the horizontal plane, provides improved stability of the rotary pump, e.g. when the rotary pump is above the rotary coupling part. Stability towards external disturbances, such as shaking and/or changing the tilt or inclination of the centrifugal blood pump, is important for a movable centrifugal blood pump.

According to an embodiment, the invention concerns a rotary coupling part, wherein said at least one permanent magnet is arranged between a plane perpendicular to the axis of rotation and intersecting the center of mass of the rotary pump and a plane perpendicular to the axis of rotation and intersecting the center of mass of said rotary coupling part.

According to an embodiment, the invention concerns a rotary coupling part, wherein the angle between the longitudinal line of said at least one permanent magnet and the plane perpendicular to the axis of rotation of the rotary pump is 4°-24°, preferably 5°-20°, more preferred 6°-18°; preferably 7°-16°; more preferred 8°-14°; preferably 9°-12°; more preferred 10°-11°. The angle may suitably be 5°-40°, preferably 2°-35°, more preferred 4°-19°; preferably 5°-18°; more preferred 6°-17°; preferably 7°-16°; more preferred 8°-15°; preferably 9°-14°; more preferred 10°- 13°; preferably 11°-12°; more preferred 12°-20°; preferably 13°-21°; more preferred 14°-22°; preferably 15°-23°; more preferred 18°-24°; 15°-30°; preferably 20°-25°.

According to an embodiment, the invention concerns a rotary coupling part, wherein the rotary coupling part has a number of permanent magnets selected among 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12, preferably evenly distributed around axis of rotation of the rotary pump. Preferably, the rotary pump has the same number of ferromagnetic regions.

According to an embodiment, the invention concerns a rotary coupling part, wherein said rotary coupling part additionally comprises at least one stabilizing permanent magnet, said at least one stabilizing permanent magnet being placed opposing a corresponding ferromagnetic region in the rotary pump, allowing magnetic coupling along a direction parallel to the axis of rotation of the rotary pump, between said at least one stabilizing permanent magnet and the corresponding ferromagnetic region in the rotary pump. This provides increased stability in the direction along the axis of rotation of the rotary pump.

According to an embodiment, the invention concerns a rotary coupling part, wherein the rotary coupling part has a number of stabilizing permanent magnets selected among 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12, preferably evenly distributed around the axis of rotation of the rotary pump.

Preferably, the rotary pump has one or more ferromagnetic regions for coupling with the stabilizing magnets. These one or more ferromagnetic regions may be combined with the at least one ferromagnetic region, or they may be separate.

According to an embodiment, the invention concerns a centrifugal blood pump comprising a rotary coupling part according to the invention.

According to an embodiment, the invention concerns a centrifugal blood pump (101) comprising: A separately replaceable rotary pump (102) with at least one ferromagnetic region; a rotary coupling part (103) comprising at least one permanent magnet; said at least one permanent magnet being adapted to engage in a magnetic coupling with the at least one ferromagnetic region of the rotary pump, driving means (104) connected to said rotary coupling part for rotating said rotary coupling part, thereby driving the rotary pump magnetically engaged with the rotary pump; power supply connected to said driving means; and means for controlling the speed of said rotary pump, by affecting at least one of the power supply, the driving means or the rotary coupling part. The may be achieved by placing a gear between the driving means and the rotary coupling part. While batteries are preferred, the power supply could be an external AC or, preferably, DC current source.

According to an embodiment, the invention concerns a centrifugal blood pump, further comprising: A base (106) for supporting said driving means and said power supply.

According to an embodiment, the invention concerns a centrifugal blood pump, further comprising: First damping means for damping vibrations of said driving means, said first damping means connecting said base with said driving means.

According to an embodiment, the invention concerns a centrifugal blood pump, further comprising: A frame (105) for supporting said driving means and said power supply, said frame being connected to said base.

According to an embodiment, the invention concerns a centrifugal blood pump, further comprising: Second damping means (108) for damping vibrations of said driving means, said second damping means connecting said frame with said driving means.

According to an embodiment, the invention concerns a centrifugal blood pump, wherein said frame comprises said power supply.

According to an embodiment, the invention concerns a centrifugal blood pump, wherein said driving means comprise an electrical motor having an axle connected to and driving said rotary coupling part. According to an embodiment, the invention concerns a centrifugal blood pump, wherein said driving means comprises a DC motor, which is controlled by pulse-width modulation (PWM) for adjusting the speed of the DC motor. This allows for limited power consumption and limited loss of power, as compared to e.g. a variable resistance controlling the power input to the motor. According to an embodiment, the invention concerns a centrifugal blood pump, further comprising a microcontroller, configured to compare pulses generated by the DC motor with the desired PM, and adjusting the speed by pulse-width modulation (PWM) to achieve the desired RPM.

According to an embodiment, the invention concerns a centrifugal blood pump, wherein said driving means comprise an electrical motor, and said power supply comprise a plurality of batteries, arranged around said electrical motor.

According to a preferred embodiment, a centrifugal pump of the invention may be split in two parts, and still be functioning.

According to an embodiment, the invention concerns a centrifugal blood pump, wherein said driving means comprise an electrical motor, and said power supply comprise at least one primary battery and at least one secondary battery, said at least one secondary battery providing power when said at least one primary battery does not provide power; and said primary battery being separable from said secondary battery, said driving means and said rotary coupling part.

According to an embodiment, the invention concerns a centrifugal blood pump, further comprising: means for maintaining the speed of said rotary pump connected to said means for controlling the speed of said rotary pump; said means for controlling the speed of said rotary pump communicating the selected speed to said means for maintaining the speed of said rotary pump; wherein said primary battery and said means for controlling the speed of said rotary pump are separable from said means for maintaining the speed of said rotary pump, said secondary battery, said driving means and said rotary coupling part.

This may be achieved by incorporating two microcontrollers in the centrifugal blood pump.

This allows for the complicated means for controlling the speed of the rotary pump to be replaced separately, e.g. if a dysfunction is registered or for replacement of the main/primary batteries, without stopping the pump.

According to an embodiment, the invention concerns a method for ensuring the operation of a rotating pump magnetically coupled to driving means, said method comprising:

a) Checking whether the rotating pump is being rotated by the magnetically coupled driving means,

b) In case the rotating pump is not being rotated by the magnetically coupled driving means, decreasing the speed of the driving means. c) Repeating step a) and b), usually until the rotating pump is being rotated by the magnetically coupled driving means. The rotating pump may lose the magnetic coupling to the driving means, e.g. if the device is subjected to physical disturbance, or if the driving means are being driven at a speed, which the rotary pump is not able to follow. This method ensures that the rotary pump is quickly accelerated to a speed for proper function. E.g. a suitable starting speed may be 2100 rpm, but the device may set to run at 3000 rpm. If a too high speed is applied, the rotary pump may stop. Then, the method decreases the speed of the driving means by e.g. 100 rpm stepwise, until the rotary pump is accelerated. Subsequently, the rotary pump may be accelerated to the desired speed, e.g. by increasing the speed of the driving means by 100 rpm stepwise.

According to an embodiment, the invention concerns the method, wherein step a) is being conducted by measuring the speed of the driving means. When the rotating pump is not pumping, the driving means may rotate at a very high speed, indicating the rotating pump is not being rotated by the magnetically coupled driving means.

According to an embodiment, the invention concerns the method, wherein the speed of said rotating pump is continuously adjusted according to a predetermined program, selected according to the patient status, such as cooling, heating or maintaining the body temperature of the patient. Allowing rotating pump to change speed according to a program while maintaining magnetic coupling gives alleviates the work load of an attending physician.

According to an embodiment, the invention concerns the method, wherein measured and applied parameters are read into a memory unit for subsequent data analysis.

According to an embodiment, the invention concerns a centrifugal blood pump, wherein said rotary pump is further stabilized by repulsive magnetic forces. Additional magnetic stabilization improves the stability of the pump, in particular in challenging environments, such as ambulances and flying machines.

According to an embodiment, the invention concerns a centrifugal blood pump, wherein said rotary pump is further stabilized by attractive magnetic forces counteracting gravity.

According to an embodiment, the invention concerns a coupling part for a centrifugal blood pump having a rotary pump with at least one ferromagnetic region, said coupling part comprising at least one magnetic means, said at least one magnetic means being adapted to provide engagement by a magnetic coupling with the at least one ferromagnetic region of the rotary pump, said at least one magnetic means providing magnetic poles defining a longitudinal line of said at least one magnetic means, wherein the longitudinal line of said at least one magnetic means is arranged in a non-radial direction with respect to the axis of rotation of the rotary pump. The at least one magnetic means may be e.g. a permanent magnet, or a coil, which acts as a magnet when an electrical current runs through the coil. For a coil, the longitudinal line will be defined when current runs through the coil.

According to an embodiment, the invention concerns a coupling part, wherein the radial angle of said at least one magnetic means is between 3° and 90°. The angle may be selected among the group consisting of 0°-90°, l°-89°, 3°-87°, 5°-85°, 10°-80°, 15°-75°, 20°-70°, 25°-65°, 30°-60°, 35°- 55°, 40°-50°, 43°-48° and 45°. In principle, best acceleration of the rotary pump may be achieved by having the magnetic means in the plane of rotation of the rotary pump, and tangent to the circle described by the rotating at least one ferromagnetic region of the rotary pump, i.e. 90° from radial orientation. However, depending on the geometry of the at least one magnetic means, this also tends to increase the distance between the at least one magnetic means and the at least one ferromagnetic region. Further, an angle closer to radial orientation may provide better stabilization of the rotary pump.

According to an embodiment, the invention concerns a coupling part, having at least one portion of ferromagnetic material, situated to be in close proximity of the rotary pump, and abutting said at least one magnetic means. The at least one portion of ferromagnetic material allows for close proximity to the at least one ferromagnetic region of the rotary pump, while allowing the longitudinal line of the magnetic means to be in a non-radial direction.

According to an embodiment, the invention concerns a coupling part, wherein the axis angle of said at least one magnetic means is between 48° and 87°. The angle may be selected among the group consisting of 0°-90°, l°-89°, 3°-87°, 5°-85°, 10°-80°, 15°-75°, 20°-70°, 25°-65°, 30°-60°, 35°- 55°, 40°-50°, 43°-48° and 45°. Having the magnetic means acting at a slanted angle as indicated appears to improve the stability of the rotary pump.

According to an embodiment, the invention concerns a rotary pump for a centrifugal blood pump with magnetic driving means, said rotary pump comprising: at least one inner permanent magnet, said inner permanent magnet allowing magnetic coupling with the at least one magnetic driving means; wherein the longitudinal line of said at least one inner permanent magnet is arranged in a non-radial direction with respect to the axis of rotation of the rotary pump.

According to an embodiment, the invention concerns a rotary pump, wherein the axis angle of said at least one inner permanent magnet is between 0° and 87°. The angle may be selected among the group consisting of 0°-90°, l°-89°, 3°-87°, 5°-85°, 10°-80°, 15°-75°, 20°-70°, 25°-65°, 30°-60°, 35°-55°, 40°-50°, 43°-48° and 45°.

According to an embodiment, the invention concerns a rotary pump, wherein the radial angle of said at least one inner permanent magnet is between 3° and 90°. The angle may be selected among the group consisting of 0°-90°, l°-89°, 3°-87°, 5°-85°, 10°-80°, 15°-75°, 20°-70°, 25°-65°, 30°-60°, 35°-55°, 40°-50°, 43°-48° and 45°. In principle, best acceleration of the rotary pump may be achieved by having the magnetic means in the plane of rotation of the rotary pump, and tangent to the circle described by the rotating at least one ferromagnetic region of the rotary pump, i.e. 90° from radial direction. However, depending on the geometry of the at least one magnetic means, this also tends to increase the distance between the at least one magnetic means and the at least one ferromagnetic region. Further, an angle closer to radial direction may provide better stabilization of the rotary pump.

According to an embodiment, the invention concerns a rotary pump, wherein said rotary pump comprises a top, a bottom opposite of said top, and sides located between and connecting said bottom to said top. Here, the axis of rotation protrudes the bottom and top. The side or sides of the rotary pump may have one or more faces.

According to an embodiment, the invention concerns a rotary pump, wherein said at least one inner permanent magnet is situated to allow magnetic coupling through the bottom of the rotary pump.

According to an embodiment, the invention concerns a rotary pump, wherein said at least one inner permanent magnet is situated to allow magnetic coupling through the sides of the rotary pump.

According to an embodiment, the invention concerns a device for rotating a rotary pump having ferromagnetic regions, said device comprising electromagnetic coils adapted to generate varying magnetic fields for driving the rotary pump by providing magnetic coupling between the varying magnetic fields and the ferromagnetic regions of the rotary pump. The use of electromagnetic coils avoids moving parts within the device, thus reducing wear, and further dispenses of a heavy, energy consuming and heat generating motor. Preferably, the varying magnetic fields are generated by supplying electric pulses to the coils with the frequency of the rotary pump.

According to an embodiment, the invention concerns a device, wherein said electromagnetic coils are stationary with respect to the device and the ferromagnetic regions of the rotary pump are inner permanent magnets.

According to an embodiment, the invention concerns a centrifugal blood pump with a separately replaceable rotary pump having at least one ferromagnetic region, comprising: Magnetic driving means outside of the rotary pump for magnetic coupling with said at least one ferromagnetic region, wherein the magnetic driving means and said at least one ferromagnetic region are separated by non-conductive material.

Use of a non-conductive material between the magnetic driving means and the rotary pump provides less heat generation due to locally varying magnetic fields. The non-conductive material may be air or plastic. Avoids cooling system - saves energy to cooling system and limits the energy lost in the centrifugal blood pump; saves space and weight.

In general, such non-conductive material and/or material not dissipating heat upon being subjected to a varying magnetic field may preferably be used according to the invention, in places in a rotary pump or centrifugal blood pump, which are subjected to varying fields.

According to an embodiment, the invention concerns a centrifugal blood pump, wherein the heat generated by the centrifugal blood pump is sufficiently low allowing the pump to function without the need of cooling means.

According to an embodiment, the invention concerns a centrifugal blood pump, wherein the dimension of at least one cross section in of the centrifugal blood pump is substantially the size of the cross diameter of the rotary pump or smaller. According to an embodiment, the invention concerns a centrifugal blood pump, wherein said electrically non-conductive material is stationary with respect to the centrifugal blood pump.

According to an embodiment, a rotating part of a centrifugal blood pump may comprise electrically conductive material. A varying magnetic field with respect to an electrically conductive material may generate heat, but if the magnetic field is constant with respect to a part comprising electrically conductive material, such heat will not be generated. Hence, if a part is moving or rotating along with the movement or rotation of a magnetic field, that part will not experience variation of the magnetic field.

According to an embodiment, the invention concerns a centrifugal blood pump, wherein said electrically non-conductive material is solid.

According to an embodiment, the invention concerns a partition element for a centrifugal blood pump having magnetic driving means and a separately replaceable rotary pump, wherein the magnetic driving means and the rotary pump are magnetically coupled; said partition element separating the magnetic driving means and the rotary pump, allowing the rotary pump to be replaced; wherein said partition element is made of an electrically substantially non-conductive material.

Preferably the partition element is shaped as a plate (or disc) having horizontal or slanted walls. Preferably electrically non-conductive material is used. Less preferred, small conduction may be acceptable.

The partition element is made from a material allowing magnetic coupling between the magnetic driving means and the rotary pump. In principle, the partition element could be replaced with air, but a physical barrier between the magnetic driving means and the rotary pump ensures impurities such as blood or water does not enter the magnetic driving means.

Earlier known solutions used metals to conduct heat away from the pump. Surprisingly, it has now been discovered that it is better not to use metal, in particular in places subjected to a varying magnetic field, as the use of metal will increase heat generation.

The problems with the heating has earlier been attempted solved e.g. by using aluminum for dissipating the heat. However, the inventors have surprisingly discovered that aluminum may advantageously be replaced with other materials, as aluminum (and other metals) generates heat upon being subjected to a varying magnetic field.

According to an embodiment, the invention concerns a partition element, wherein said partition element is made from a polymer, preferably a plastic material. A plastic material has a number of advantages, such as easy cleaning and low friction associated with the rotary pump.

According to an embodiment, the invention concerns a partition element, wherein said partition element is made from POM. POM (polyoxymethylene, also known as polyactal or

polyformaldehyde) is a thermoplastic, used for precision parts requiring high stiffness, low friction and excellent dimensional stability. POM is a homopolymer or copolymer. With the copolymer, the second unit is a normally a cyclic ether which resists chain cleavage. It may be sensitive to oxidation, and an anti-oxidant is normally added to molding grades of the material.

Other synthetic polymers may be used. Preferred are synthetic polymers with similar properties, such as thermoplastics. Preferably the polymer has high stiffness. It is also preferred that the polymer exhibits low friction.

As examples, envisioned is the use of polycarbonate, polyamide, polyester and/or polyurethane.

The use of POM has reduced the heat generation considerably as compared to the use of aluminum. This means that less energy is dissipated and hence lost, and cooling is not necessary. The reduced heat dissipation further means the blood is not harmed during passage of the pump. In general, it appears that electrically non-conductive materials should preferably be used where suitable in the pump, in particular in places which are subjected to a varying magnetic field.

It seems that the use of materials, which does not generate heat upon being subjected to a varying magnetic field, is preferred, in places in the pump, which are subjected to such varying fields.

According to an embodiment, the invention concerns a partition element, wherein said partition element is made from a non-magnetic material. The partition element should still allow some, preferably strong, magnetic coupling across the plate.

By a non-magnetic material is meant a material, which does not generate heat or which substantially does not generate heat, upon being subjected to an external, varying magnetic field. According to an embodiment, the invention concerns a partition element, for a centrifugal blood pump, wherein the magnetic driving means are permanent magnets in a rotary coupling part.

According to an embodiment, the invention concerns a partition element, for a centrifugal blood pump, wherein the magnetic driving means are coils adapted to provide a varying magnetic field.

According to an embodiment, the invention concerns a portable centrifugal blood pump comprising means for detachably attaching the blood pump during transport of the centrifugal blood pump thereby allowing the centrifugal blood pump to be operating during transport. A portable centrifugal blood pump may be fixed to a bed, such as a hospital bed, a stretcher, or a trolley; to a vehicle or machine transporting the patient, such as a car, e.g. an ambulance, a ship, a craft or a rubber boat, a flying machine, e.g. a plane or a helicopter; to a chair; or even to a person, such as the patient herself/himself, a nurse, an attending physician or any emergency staff aiding the patient.

According to an embodiment, the invention concerns a portable centrifugal blood pump, said portable centrifugal being adapted to operate during changing inclination of up to 180°. During transport of a patient, e.g. during hoisting up to a helicopter, the portable centrifugal blood pump may be fixed to a stretcher carrying the patient, which is hanging at an unusual attitude, changing the inclination of the portable centrifugal blood pump. According to an embodiment a portable centrifugal blood pump is adapted to operate during changing inclination of up to 180°, i.e. running up-side down with respect to gravity. Alternatively, the allowable maximum change of inclination may be 45°, preferably 90°, more preferred 135°, with respect to gravity.

According to an embodiment, the invention concerns a portable centrifugal blood pump, comprising a frame supporting the centrifugal blood pump; wherein said means for detachably attaching the centrifugal blood pump comprise openings in said frame supporting the centrifugal blood pump. The openings allow means such as straps or brackets to go through the openings for detachably fixing the frame to the bed of a patient.

According to an embodiment, the invention concerns a portable centrifugal blood pump, wherein said openings are close to the edge of said frame.

According to an embodiment, the invention concerns a portable centrifugal blood pump, wherein the number of said openings is selected among the group consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12.

According to an embodiment, the invention concerns a portable centrifugal blood pump, wherein at least one pair of said openings is symmetrically arranged, such that a plane, perpendicular to and bisecting a line through said at least one pair, intersects or is in close proximity to the center of gravity of said portable centrifugal blood pump.

According to an embodiment, the invention concerns a portable centrifugal blood pump, comprising a frame supporting the centrifugal blood pump; wherein said means for detachably attaching the centrifugal blood pump comprise straps going through the openings for detachably fixing the frame to the bed of a patient or to the patient. When fixed to a patient, the pump may suitably be placed between the legs of the patient.

According to an embodiment, the invention concerns a portable centrifugal blood pump, comprising an outer bag; wherein said means for detachably attaching the centrifugal blood pump comprise straps attached to said outer bag.

According to an embodiment, the invention concerns a portable centrifugal blood pump, wherein said means for detachably attaching the centrifugal blood pump comprises brackets for fixing the centrifugal blood pump to the bed of a patient.

According to an embodiment, the invention concerns a portable centrifugal blood pump, wherein said means for detachably attaching the centrifugal blood pump comprises brackets for fixing the centrifugal blood pump to the sides and/or end of the bed of a patient.

According to an embodiment, the invention concerns a portable centrifugal blood pump, wherein said means for detachably attaching the centrifugal blood pump comprises depressions in said centrifugal blood pump for fixing the centrifugal blood pump to the bed of a patient, said bed having brackets corresponding to said depressions. According to an embodiment, the invention concerns the use of a portable centrifugal blood pump, the portable centrifugal blood pump preferably being according to the invention, before hospitalization of a patient. Use of a portable centrifugal blood pump before hospitalization usually requires the pump to be fixed during transport, e.g. to the patient or to a stretcher or a bed carrying the patient.

According to an embodiment, the invention concerns a portable centrifugal blood pump according to the invention, which is a portable centrifugal blood pump comprising means for detachably attaching the blood pump during transport of the centrifugal blood pump thereby allowing the centrifugal blood pump to be operating during transport.

According to an embodiment, the invention concerns a centrifugal blood pump, wherein the dimension of at least one cross section perpendicular to the axis of rotation of the rotary pump, is about the size of the diameter of the rotary pump or smaller. The cross section may be 80-200%, preferably 100-150%, more preferred 110-130% of the diameter of the rotary pump.

According to an embodiment, the invention concerns a centrifugal blood pump comprising at least one battery, having a weight of less than 15, 12, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 kg, in fully operational state, including batteries for driving said centrifugal blood pump.

According to an embodiment, the invention concerns a centrifugal blood pump, having a weight of less than 15, 12, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 kg, in fully operational state, not including any battery.

According to an embodiment, the invention concerns a centrifugal blood pump, which is able to run continuously on batteries without replacing or recharging said batteries, for a period of at least a period selected among the group consisting of 2, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 16, 18, 20, 24 hours; 1, 2, 4, 7, and 14 days. Preferably the batteries are part of the centrifugal blood pump.

According to an embodiment, the invention concerns a centrifugal blood pump, comprising a rotary coupling part for a centrifugal blood pump; an electrical motor as part of the driving means for said rotary coupling part; and batteries as a power source for said electrical motor; said centrifugal blood pump being able to pump blood without being connected to external sources of energy; wherein two perpendicular cross sections of said centrifugal blood pump, each perpendicular to the axis of rotation of said rotary pump, are both smaller than a dimension of 20 cm, preferably 18 cm, more preferred 16 cm, preferably 15 cm, more preferred 14 cm, preferably 13 cm, more preferred 12 cm, preferably 11 cm, more preferred 10 cm, preferably 9 cm, more preferred 8 cm.

A small cross section allows the centrifugal blood pump to be picked up in one hand, which is a particular advantage for a centrifugal blood pump intended to be easily portable.

According to an embodiment, the invention concerns a centrifugal blood pump, wherein at least one cross section of said centrifugal blood pump, perpendicular to axis of rotation of the associated rotary pump, is smaller than a dimension of 30 cm, preferably 25 cm, more preferred 20 cm, preferably 18 cm, more preferred 16 cm, preferably 15 cm, more preferred 14 cm, preferably 13 cm, more preferred 12 cm, preferably 11 cm, more preferred 10 cm, preferably 9 cm, more preferred 8 cm. According to this embodiment, having such maximum dimensions allows placement of a centrifugal blood pump between the legs of a patient being transported.

According to an embodiment, the invention concerns a centrifugal blood pump, wherein the longest dimension of said centrifugal blood pump is smaller than a dimension of 60 cm, preferably 55 cm, more preferred 50 cm, preferably 45 cm, more preferred 40 cm, preferably 35 cm, more preferred 30 cm, preferably 25 cm, more preferred 20 cm, preferably 15 cm, more preferred 10 cm.

According to an embodiment, the invention concerns a centrifugal blood pump, wherein the largest dimension perpendicular to said longest dimension of said centrifugal blood pump is smaller than a dimension of 20 cm, preferably 18 cm, more preferred 16 cm, preferably 15 cm, more preferred 14 cm, preferably 13 cm, more preferred 12 cm, preferably 11 cm, more preferred 10 cm, preferably 9 cm, more preferred 8 cm.

All cited references are incorporated by reference.

The accompanying Figures and Examples are provided to explain rather than limit the present invention. It will be clear to the person skilled in the art that aspects, embodiments and points of the present invention may be combined.

Figures

Fig. 1 depicts the main parts of an embodiment of a centrifugal blood pump (101) according to the invention.

The centrifugal blood pump (101) comprises a separately replaceable rotary pump (102); a rotary coupling part (103) adapted to engage in a magnetic coupling with the rotary pump (102); driving means (104) for driving the rotary coupling part (103), the driving means comprising a motor having an axle; batteries within a frame (105), the batteries acting as a power supply for the motor; a base (106) supporting damping means, supporting the motor (104), further being stabilized by further damping means (108).

Fig. 2 depicts the main parts of an embodiment of a centrifugal blood pump (201) according to the invention.

The centrifugal blood pump (201) comprises a separately replaceable rotary pump (202); a rotary coupling part (203) adapted to engage in a magnetic coupling with the rotary pump (202); driving means (204) for driving the rotary coupling part (203), the driving means comprising a motor having an axle; batteries within a frame (205), the batteries acting as a power supply for the motor; a base (206) supporting damping means, supporting the motor (204), further being stabilized by further damping means (208). Fig. 3 depicts the main parts of an embodiment of a centrifugal blood pump (301) according to the invention.

The centrifugal blood pump (301) comprises a separately replaceable rotary pump (302); a rotary coupling part (303) adapted to engage in a magnetic coupling with the rotary pump (302); driving means (304) for driving the rotary coupling part (303), the driving means comprising a motor having an axle; batteries within a frame (305), the batteries acting as a power supply for the motor; a base (306) supporting damping means, supporting the motor (304), further being stabilized by further damping means (308).

Fig. 4 depicts the main parts of an embodiment of a centrifugal blood pump (401) according to the invention.

The centrifugal blood pump (401) comprises a separately replaceable rotary pump (402); a rotary coupling part (403) adapted to engage in a magnetic coupling with the rotary pump (402); driving means (404) for driving the rotary coupling part (403), the driving means comprising a motor having an axle; batteries within a frame (405), the batteries acting as a power supply for the motor; a base (406) supporting damping means, supporting the motor (404), further being stabilized by further damping means (408).

Fig. 5 is a schematic diagram showing a cross section parallel to the axis of rotation of an embodiment of a centrifugal blood pump (501). The centrifugal blood pump (501) comprises a separately replaceable rotary pump (502) having an inlet (530) and an outlet (531).

The centrifugal blood pump (501) further comprises a rotary coupling part (503) providing magnetic coupling with the separately replaceable rotary pump (502), across a partition element (513), made of the plastic POM.

In addition, the centrifugal blood pump (501) comprises a base (506), supporting a DC motor (509) the power source, which is a battery (511), and side walls (512). The motor (509) has an axle (510), driving the rotary coupling part (503).

The rotary coupling part (503) comprises permanent magnets, (514; 515). These permanent magnets engage in a magnetic coupling with corresponding permanent magnets and

ferromagnetic regions in the separately replaceable rotary pump (502). The separately

replaceable rotary pump (502) comprises such permanent magnets (516) and a ferromagnetic region (517). Note that for explanatory purposes the distance between the coupling magnets is exaggerated on the figure.

A controller (540) is connected by a connection (542) to and controlling the motor (509) by pulse- width modulation (PWM). Pulses generated by the motor (509) are communicated by the connection (543) to the controller (540). Power is fed from the battery (511) to the controller (540) by a power cable (541). Fig. 6 is a schematic diagram showing a cross section perpendicular to the axis of rotation of a rotary pump. The radial angle, a, is the angle between the longitudinal line of a magnet and a radial through the front end of the magnet.

Fig. 7 is a schematic diagram showing a cross section comprising the axis of rotation of a rotary pump. The axis angle, β, is the angle between the longitudinal line of a magnet and a line parallel to the axis of rotation of the rotary pump. The depicted disc is perpendicular to the cross section.

Fig. 8 is a schematic diagram showing a cross section comprising the axis of rotation of a rotary pump. A magnet outside the rotary pump for driving the rotary pump is shown. The longitudinal line of the magnet is not perpendicular to the axis of rotation of the rotary pump, but is at an angle smaller than 90° for improving the stability of the rotary pump.

Fig. 9 is a schematic diagram showing a cross section perpendicular to the axis of rotation of a rotary pump. A proposed arrangement of round permanent magnets in the top of a magnetic coupling part is shown, for magnetic coupling with a ferromagnetic part of the rotary pump. The radial lines indicate proposed alignment of permanent magnets outside the rotary pump.

Fig. 10 is a schematic diagram showing a cross section perpendicular to the axis of rotation of a rotary pump. As indicated, a permanent magnet outside of the rotary pump should in principle act along the tangent of the rotary pump for maximizing the acceleration of the rotary pump.

Fig. 11 is a schematic diagram showing a cross section perpendicular to the axis of rotation of a rotary pump. As indicated, a permanent magnet outside of the rotary pump may suitably be aligned between the tangential and radial positions. Moving the magnet to a position closer to a radial position may increase the magnitude of the field acting on a ferromagnetic, e.g. permanent magnetic, region of the rotary pump.

Fig. 12 is a schematic diagram showing a cross section perpendicular to the axis of rotation of a rotary pump. As indicated, providing the permanent magnet outside of the rotary pump with a portion of ferromagnetic material, may direct the field lines of the magnet towards a

ferromagnetic, e.g. permanent magnetic, region of the rotary pump.

Fig. 13 is a schematic diagram showing a cross section perpendicular to the axis of rotation of a rotary pump. As indicated, non-radial and non-tangential positioning of magnets inside and outside of the rotary pump may provide the best compromise between acceleration and stabilization of the rotary pump.

Fig. 14 is a photograph of an embodiment of a centrifugal blood pump according to the invention. The bottom part with circular cross section the photograph shows the part of the centrifugal blood pump comprising a separately replaceable rotary pump, a partition element, a rotary coupling part, driving means, secondary batteries and a microcontroller, while the top part with rectangle shape shows an input device comprising a display; buttons for setting the speed of the pump; and internally another microcontroller and primary batteries. The buttons allow turning the power on and off, stopping and starting the pump, setting the speed, and silencing an alarm tone. The alarm tone will sound if batteries are low or the pump detects a malfunction. The display indicates the selected speed, the current speed and the status of the primary batteries.

The two separable parts, shown in the bottom and top, are connected via an electronic link. Both parts are further connected to a large aluminum base plate. The base plate has two elongated openings adapted to accept means for detachably attaching the centrifugal blood pump to other equipment or e.g. the bed of a patient.

Fig. 15 is a photograph of an embodiment of a centrifugal blood pump for a rotary pump according to the invention. The separately replaceable rotary pump is not shown. The white part in top of the black cylinder is a plastic partition element made of POM, separating a rotary pump from the rotary coupling part inside the black cylinder. The base plate has, in addition to the two elongated openings adapted to accept means for detachably attaching the centrifugal blood pump to other equipment, four openings for fixing the input device, which is here removed and not shown. The button on the side of the cylinder makes it possible to turn off the pump in the absence of the input device. The pump may continue to run without the input device, but has limited internal battery capacity and does not in this embodiment comprise means for changing the speed (except to standstill by shutting it off).

Example

An embodiment of a centrifugal blood pump was constructed, and shown to be able to function properly on human and animal subjects for more than 100 hours. No cooling was necessary to make the centrifugal blood pump run properly.

The device had a weight of about 6.2 kg. The total weight of the batteries was about 3 kg.

The batteries are able to run the rotary pump with 3000 rpm for 6 hours. Other tests have shown the capability of the batteries to run the rotary pump with 2400 rpm for 24 hours. Hence, the device is able to work sufficiently long time for e.g. long distance flights.

It is contemplated the weight may be reduced to about 5.6 kg by replacing the large aluminum base plate with plastic or a composite material, or by removing part of the material, e.g. by drilling additional holes.

Aspects and embodiments of the present invention are also provided in the following points. Points:

A rotary coupling part (103) for a centrifugal blood pump (101) having a rotary pu (102) with at least one ferromagnetic region,

said rotary coupling part being driven by driving means (104); said rotary coupling part comprising at least one permanent magnet,

said at least one permanent magnet being adapted to engage in a magnetic coupling with the at least one ferromagnetic region of the rotary pump,

said permanent magnet having magnetic poles defining a longitudinal line of said magnet, wherein the longitudinal line of said at least one permanent magnet is arranged at an angle between 3° and 42° from a plane perpendicular to the axis of rotation of the rotary pump.

The rotary pump according to point 1, wherein said at least one permanent magnet is arranged between a plane perpendicular to the axis of rotation and intersecting the center of mass of the rotary pump and a plane perpendicular to the axis of rotation and intersecting the center of mass of said rotary coupling part.

The rotary coupling part according to point 1 or 2, wherein the angle between the longitudinal line of said at least one permanent magnet and the plane perpendicular to the axis of rotation of the rotary pump is 4°-24°, preferably 5°-20°, more preferred 6°-18°; preferably 7°-16°; more preferred 8°-14°; preferably 9°-12°; more preferred 10°-11°.

The rotary coupling part according to any of the preceding points, wherein the rotary coupling part has a number of permanent magnets selected among 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12, preferably evenly distributed around axis of rotation of the rotary pump.

The rotary coupling part according to any of the preceding points, wherein

said rotary coupling part additionally comprises at least one stabilizing permanent magnet, said at least one stabilizing permanent magnet being placed opposing a corresponding ferromagnetic region in the rotary pump, allowing magnetic coupling along a direction parallel to the axis of rotation of the rotary pump, between said at least one stabilizing permanent magnet and the corresponding ferromagnetic region in the rotary pump.

The rotary coupling part according to point 5, wherein the rotary coupling part has a number of stabilizing permanent magnets selected among 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12, preferably evenly distributed around the axis of rotation of the rotary pump. A centrifugal blood pump comprising a rotary coupling part according to any of preceding points.

A centrifugal blood pump (101) comprising:

A separately replaceable rotary pump (102) with at least one ferromagnetic region;

A rotary coupling part (103) comprising at least one permanent magnet;

said at least one permanent magnet being adapted to engage in a magnetic coupling with the at least one ferromagnetic region of the rotary pump,

Driving means (104) connected to said rotary coupling part for rotating said rotary coupling part, thereby driving the rotary pump magnetically engaged with the rotary pump;

Power supply connected to said driving means; and

Means for controlling the speed of said rotary pump, by affecting at least one of the power supply, the driving means or the rotary coupling part.

A centrifugal blood pump according to point 8, further comprising:

A base (106) for supporting said driving means and said power supply.

A centrifugal blood pump according to point 9, further comprising:

First damping means for damping vibrations of said driving means, said first damping means connecting said base with said driving means.

A centrifugal blood pump according to point 9 or 10, further comprising:

A frame (105) for supporting said driving means and said power supply, said frame being connected to said base.

A centrifugal blood pump according to point 11, further comprising:

Second damping means (108) for damping vibrations of said driving means, said second damping means connecting said frame with said driving means. A centrifugal blood pump according to point 10, wherein said frame comprises said power supply.

A centrifugal blood pump according to any of the points 8 - 13, wherein

said driving means comprise an electrical motor having an axle connected to and driving said rotary coupling part.

A centrifugal blood pump according to any of the points 8 or 14, wherein

said driving means comprises a DC motor, which is controlled by pulse-width modulation (PWM) for adjusting the speed of the DC motor.

A centrifugal blood pump according to point 15, further comprising a microcontroller, configured to compare pulses generated by the DC motor with the desired PM, and adjusting the speed by pulse-width modulation (PWM) to achieve the desired RPM.

A centrifugal blood pump according to any of the points 8 - 16, wherein

said driving means comprise an electrical motor, and

said power supply comprise a plurality of batteries, arranged around said electrical motor.

A centrifugal blood pump according to point 8, wherein

said driving means comprise an electrical motor, and

said power supply comprise at least one primary battery and at least one secondary battery,

said at least one secondary battery providing power when said at least one primary battery does not provide power;

and said primary battery being separable from said secondary battery, said driving means and said rotary coupling part. 19. A centrifugal blood pump according to point 18, further comprising:

means for maintaining the speed of said rotary pump connected to said means for controlling the speed of said rotary pump;

said means for controlling the speed of said rotary pump communicating the selected speed to said means for maintaining the speed of said rotary pump;

wherein said primary battery and said means for controlling the speed of said rotary pump are separable from said means for maintaining the speed of said rotary pump, said secondary battery, said driving means and said rotary coupling part.

20. Method for ensuring the operation of a rotating pump magnetically coupled to driving means, said method comprising:

a) Checking whether the rotating pump is being rotated by the magnetically coupled driving means,

b) In case the rotating pump is not being rotated by the magnetically coupled driving means, decreasing the speed of the driving means.

c) Repeating step a) and b).

21. Method according to point 20, wherein step a) is being conducted by measuring the

speed of the driving means.

22. Method according to point 20 or 21, wherein the speed of said rotating pump is

continuously adjusted according to a predetermined program, selected according to the patient status, such as cooling, heating or maintaining the body temperature of the patient.

23. Method according to any of the points 20 - 22, wherein measured and applied parameters are read into a memory unit for subsequent data analysis.

24. A centrifugal blood pump according to point 8,

wherein said rotary pump is further stabilized by repulsive magnetic forces A centrifugal blood pump according to point 8,

wherein said rotary pump is further stabilized by attractive magnetic forces counteracting gravity.

A coupling part for a centrifugal blood pump having a rotary pump with at least one ferromagnetic region,

said coupling part comprising at least one magnetic means,

said at least one magnetic means being adapted to provide engagement by a magnetic coupling with the at least one ferromagnetic region of the rotary pump,

said at least one magnetic means providing magnetic poles defining a longitudinal line of said at least one magnetic means,

wherein the longitudinal line of said at least one magnetic means is arranged in a non- radial direction with respect to the axis of rotation of the rotary pump.

The coupling part according to point 26, wherein the radial angle of said at least magnetic means is between 3° and 90°.

The coupling part according to any of the points 26 - 27, having

at least one portion of ferromagnetic material, situated to be in close proximity of the rotary pump, and abutting said at least one magnetic means.

The coupling part according to any of the points 26 - 28, wherein the axis angle of said at least one magnetic means is between 48° and 87°.

Rotary pump for a centrifugal blood pump with magnetic driving means, said rotary pump comprising:

at least one inner permanent magnet, said inner permanent magnet allowing magnetic coupling with the at least one magnetic driving means;

wherein the longitudinal line of said at least one inner permanent magnet is arranged in a non-radial direction with respect to the axis of rotation of the rotary pump. Rotary pump according to point 30,

wherein the axis angle of said at least one inner permanent magnet is between 0° and 87°.

Rotary pump according to point 30 or 31,

wherein the radial angle of said at least one inner permanent magnet is between 3° and 90°.

Rotary pump according to any of the points 30 - 32,

wherein said rotary pump comprises a top, a bottom opposite of said top, and sides located between and connecting said bottom to said top.

Rotary pump according to any of the points 33,

wherein said at least one inner permanent magnet is situated to allow magnetic coupling through the bottom of the rotary pump.

Rotary pump according to any of the points 33 or 34,

wherein said at least one inner permanent magnet is situated to allow magnetic coupling through the sides of the rotary pump.

Device for rotating a rotary pump having ferromagnetic regions,

said device comprising electromagnetic coils adapted to generate varying magnetic fields for driving the rotary pump by providing magnetic coupling between the varying magnetic fields and the ferromagnetic regions of the rotary pump.

Device according to point 36, wherein said electromagnetic coils are stationary with respect to the device and the ferromagnetic regions of the rotary pump are inner permanent magnets. Centrifugal blood pump with a separately replaceable rotary pump having at least one ferromagnetic region, comprising:

Magnetic driving means outside of the rotary pump for magnetic coupling with said at least one ferromagnetic region,

Wherein the magnetic driving means and said at least one ferromagnetic region are separated by non-conductive material.

Centrifugal blood pump according to point 38, wherein the heat generated by the centrifugal blood pump is sufficiently low allowing the pump to function without the need of cooling means.

Centrifugal blood pump according to point 38 or 39, wherein the dimension of at least one cross section of the centrifugal blood pump is substantially the size of the cross diameter of the rotary pump or smaller.

Partition element for a centrifugal blood pump having magnetic driving means and a separately replaceable rotary pump, wherein the magnetic driving means and the rotary pump are magnetically coupled;

said partition element separating the magnetic driving means and the rotary pump, allowing the rotary pump to be replaced;

wherein said partition element is made from an electrically substantially non-conductive material.

Partition element according to point 41, wherein said partition element is made from a polymer, preferably a plastic material.

Partition element according to point 42, wherein said partition element is made from POM.

Partition element according to point 41, wherein said partition element is made from a non-magnetic material. Partition element, according to any of the points 41 - 44, for a centrifugal blood pump, wherein the magnetic driving means are permanent magnets in a rotary coupling part.

Partition element, according to any of the points 41 - 44, for a centrifugal blood pump, wherein the magnetic driving means are coils adapted to provided a varying magnetic field.

A portable centrifugal blood pump comprising means for detachably attaching the blood pump during transport of the centrifugal blood pump thereby allowing the centrifugal blood pump to be operating during transport.

The portable centrifugal blood pump according to point 47, said portable centrifugal being adapted to operate during changing inclination of up to 180°.

The portable centrifugal blood pump according to point 47, comprising a frame supporting the centrifugal blood pump;

wherein said means for detachably attaching the centrifugal blood pump comprise openings in said frame supporting the centrifugal blood pump.

The portable centrifugal blood pump according to point 49,

wherein said openings are close to the edge of said frame.

The portable centrifugal blood pump according to point 49 or 50,

wherein the number of said openings is selected among the group consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12.

The portable centrifugal blood pump according to any of the points 49 - 51,

wherein at least one pair of said openings is symmetrically arranged, such that a plane, perpendicular to and bisecting a line through said at least one pair, intersects or is in close proximity to the center of gravity of said portable centrifugal blood pump. The portable centrifugal blood pump according to point 47, comprising a frame supporting the centrifugal blood pump;

wherein said means for detachably attaching the centrifugal blood pump comprise straps going through the openings for detachably fixing the frame to the bed of a patient or to the patient.

The portable centrifugal blood pump according to point 47, comprising an outer bag; wherein said means for detachably attaching the centrifugal blood pump comprise straps attached to said outer bag.

The portable centrifugal blood pump according to point 47,

wherein said means for detachably attaching the centrifugal blood pump comprises brackets for fixing the centrifugal blood pump to the bed of a patient.

The portable centrifugal blood pump according to point 55,

wherein said means for detachably attaching the centrifugal blood pump comprises brackets for fixing the centrifugal blood pump to the sides and/or end of the bed of a patient.

The portable centrifugal blood pump according to point 47,

wherein said means for detachably attaching the centrifugal blood pump comprises depressions in said centrifugal blood pump for fixing the centrifugal blood pump to the bed of a patient, said bed having brackets corresponding to said depressions.

Use of a portable centrifugal blood pump, the portable centrifugal blood pump prefi being according to any of the points 47 - 57, before hospitalization of a patient.

Centrifugal blood pump according to any of the points 7, 8-19, 24-25, 37-38, and 39-41, which is a portable centrifugal blood pump comprising means for detachably attaching the blood pump during transport of the centrifugal blood pump thereby allowing the centrifugal blood pump to be operating during transport. Centrifugal blood pump, wherein the dimension of at least one cross section

perpendicular to the axis of rotation of the rotary pump, is about the size of the diameter of the rotary pump or smaller.

Centrifugal blood pump, wherein the dimension of at least one cross section

perpendicular to the axis of rotation of the rotary pump, is 80-200%, preferably 100-150%, more preferred 110-130% of the diameter of the rotary pump.

Centrifugal blood pump comprising at least one battery, having a weight of less than 15, 12, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 kg, in fully operational state, including batteries for driving said centrifugal blood pump.

Centrifugal blood pump, having a weight of less than 15, 12, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 kg, in fully operational state, not including any battery.

Centrifugal blood pump, preferably according to any of the points 60 - 62, which is able to run continuously on batteries without replacing or recharging said batteries, for a period of at least a period selected among the group consisting of 2, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 16, 18, 20, 24 hours; 1, 2, 4, 7, and 14 days.

Centrifugal blood pump, preferably according to any of the points 60 - 64, comprising a rotary coupling part for a centrifugal blood pump; an electrical motor as part of the driving means for said rotary coupling part; and batteries as a power source for said electrical motor;

said centrifugal blood pump being able to pump blood without being connected to external sources of energy;

wherein two perpendicular cross sections of said centrifugal blood pump, each perpendicular to the axis of rotation of said rotary pump, are both smaller than a dimension of 20 cm, preferably 18 cm, more preferred 16 cm, preferably 15 cm, more preferred 14 cm, preferably 13 cm, more preferred 12 cm, preferably 11 cm, more preferred 10 cm, preferably 9 cm, more preferred 8 cm. Centrifugal blood pump, preferably according to any of the points 60-65, wherein at least one cross section of said centrifugal blood pump, perpendicular to axis of rotation of the associated rotary pump, is smaller than a dimension of 20 cm, preferably 18 cm, more preferred 16 cm, preferably 15 cm, more preferred 14 cm, preferably 13 cm, more preferred 12 cm, preferably 11 cm, more preferred 10 cm, preferably 9 cm, more preferred 8 cm.

Centrifugal blood pump, preferably according to any of the points 60-66, wherein the longest dimension of said centrifugal blood pump is smaller than a dimension of 60 cm, preferably 55 cm, more preferred 50 cm, preferably 45 cm, more preferred 40 cm, preferably 35 cm, more preferred 30 cm, preferably 25 cm, more preferred 20 cm, preferably 15 cm, more preferred 10 cm.

Centrifugal blood pump according to point 67, wherein the largest dimension perpendicular to said longest dimension of said centrifugal blood pump is smaller than dimension of 20 cm, preferably 18 cm, more preferred 16 cm, preferably 15 cm, more preferred 14 cm, preferably 13 cm, more preferred 12 cm, preferably 11 cm, more preferred 10 cm, preferably 9 cm, more preferred 8 cm.