JP2874060B2 - Blood pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blood pump, and more particularly, to a small and lightweight blood pump, which causes little hemolysis,
The present invention relates to a blood pump that can be used safely for a long time and can be suitably used for an extracorporeal circulation circuit such as a heart-lung machine and a cardiac assist circulator after open heart surgery.

[0002]

2. Description of the Related Art Conventionally, as a blood pump for an extracorporeal circuit such as an artificial heart-lung machine or a cardio-assistive circulator after open heart surgery, a pulsating pump type for supplying a pulsating flow and a smoothing pump have been known. A centrifugal pump type blood pump is known in addition to a roller pump type for supplying a flow.

This centrifugal pump type blood pump rotates the impeller in a pump chamber (corresponding to a first housing chamber, which will be described later) having an inlet and an outlet port. This is a blood pump that supplies a smooth flow according to the pressure difference between the front and rear.

The rotating shaft of the impeller extends from the pump chamber to the outside, and the end of the extending portion is connected to a motor via a shaft or the like.

The centrifugal pump type blood pump does not require an expensive artificial valve and a control device unlike the pulsating pump type blood pump, so that the blood pump can be reduced in size and weight. There is no tube breakage like a roller pump type blood pump, and the durability as a blood pump is high.

[0006] Therefore, in recent years, this centrifugal pump type blood pump has been frequently used as a blood pump for an extracorporeal circulation circuit of a heart-lung machine or a heart assisting device after open heart surgery.

However, in this type of blood pump, since the rotating shaft of the impeller contacts the blood near the bottom of the pump chamber, hemolysis (a phenomenon in which blood cells are destroyed) easily occurs around the rotating shaft. There is a point.

In addition, blood stagnation is formed between the pedestal of the impeller and the bottom of the pump chamber, and the heat generated from the seal portion is accumulated in the stagnation, so that hemolysis is also easily generated from this portion.

The present invention has been made to improve the above situation. That is, an object of the present invention is to provide a small extracorporeal circuit such as a heart-lung machine or a cardio-assistive circulatory device after open heart surgery, which is small in size and light in weight, can be used safely for a long time, and produces little hemolysis. An object of the present invention is to provide a centrifugal pump type blood pump that can be suitably used.

[0010]

First means for Means for solving the problems] To solve the above problems is provided with a blood introduction hole at the top, and from this blood introduction hole to the side provided with a perpendicular direction of the blood discharge port
In the first housing chamber, a plurality of blades are provided on a pedestal on which a first magnet is mounted ,
A projection provided on the central bottom portion stands upright on the bottom surface of the first housing chamber, and a rear end is connected to a driving source and the front end is connected to a second housing chamber adjacent to the first housing chamber via a partition. A rotating shaft equipped with a second magnet is attached, and the impeller is rotatable by a suction force acting between the first magnet and the second magnet, and a blood circulation hole penetrating from the upper surface to the lower surface of the pedestal. a blood pump which is characterized by comprising a second hand for solving the problems
In the step, the pedestal substantially covers the entire bottom surface of the first housing chamber.
First means blood pump having a truncated conical shape with a bottom surface
, And the third means for solving the above problem, the
The first or second blood flow hole is perpendicular to the bottom surface of the base;
Means of blood pump .

Hereinafter, the present invention will be described in detail.

[0012]

In the blood pump of the present invention, the rotation of the impeller of the centrifugal pump is controlled by a second magnet attached to a rotating shaft connected to a drive source outside the second housing chamber and a first magnet attached to a base of the impeller. The impeller does not have a rotating shaft connected to an external drive source unlike the conventional one.

Therefore, it is possible to reduce the haemolysis in the vicinity of the rotating shaft of the impeller, which has occurred so far.

Since the pedestal has a blood flow hole penetrating from the upper surface to the lower surface, the stagnation of blood between the pedestal and the bottom of the first housing chamber (the side where the wing of the pedestal is not provided) is reduced, The accumulation of heat in blood due to the rotation of the impeller is also reduced, and as a result, the hemolysis phenomenon can be reduced. In order to enhance such an effect, it is desirable that the blood circulation hole is perpendicular to the bottom surface of the pedestal.

Further, if the pedestal has a truncated cone shape and the bottom surface is formed so as to cover substantially the entire bottom surface of the first housing chamber, the flow of blood is smooth, and no eddy current of blood is generated. For example, stress due to, for example, shear force or vortex applied to blood flowing in the pump can be reduced.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A blood pump according to the present invention comprises a first housing chamber 1 and a second housing chamber 4 which is adjacent to the first housing chamber 1 through a partition 3 as shown in an embodiment of FIG. .

The first housing chamber 1 is provided with a blood inlet port 5 at the top and an outlet port 6 at right angles to the side. In the first housing chamber 1, an impeller 10 having a plurality of blades 9 provided on the upper surface of a truncated cone-shaped pedestal 8 from the vicinity of the apex A of the cone to the outer peripheral end of the pedestal 8 is rotatably set. I have.

The size of the bottom surface of the pedestal 8 is large enough to cover almost the entire bottom surface of the first housing chamber 1.

A slight gap h is formed between the bottom of the pedestal 8 and the bottom of the first housing chamber 1, and a projection 10 supported on the bottom of the first housing chamber 1 is formed at the center bottom of the pedestal 8.
a is formed. The tip of the projection 10a may be rounded.

The pedestal 8 integrally incorporates a ring-shaped first magnet 11 and a first back yoke (magnetic line leakage preventing device) 12 which share a central axis and are parallel to the bottom surface of the pedestal 8.

The smaller the gap h, the better. However, if it is too small, a shearing force may be applied to the blood, causing hemolysis. Conversely, when the gap h increases, the magnetic force of the first magnet 11 needs to be increased, and the size of the device is increased.

The pedestal 8 having a truncated cone shape is provided with a plurality of blood circulation holes 13 penetrating from the upper surface to the lower surface.
The blood circulation hole 13 is preferably perpendicular to the lower surface of the pedestal. Regarding the shape of the blood circulation hole 13,
There is no particular limitation, for example, a circular blood circulation hole may be used,
It may be a square blood flow hole or another shape of blood flow hole. If the opening area of the blood circulation hole 13 is too small, the effect of preventing blood from staying in the gap h may not be sufficiently exhibited. Further, if the opening area of the blood circulation hole 13 is too large, the effect of preventing the vortex of blood near the impeller may not be sufficiently exhibited.

On the other hand, the rotating shaft 1 is
A ring-shaped second magnet 15 and a second back yoke 16 are integrally mounted on the front end of the fourth member 4 via a funnel-shaped support member 14 a so as to face the first magnet 11. The rotating shaft 14 is supported on the side of the second housing chamber 4 via a bearing 17, and its rear end extends outside from the second housing chamber 4, and is driven by a motor or the like via a flexible shaft (not shown). Source (not shown)
It is connected to the.

In the above configuration, when the driving source is turned on, the rotating shaft 14 rotates, and the second magnet 15 mounted on the rotating shaft also rotates. Since an attractive force acts between the second magnet 15 and the first magnet 11, the first magnet 11 also rotates as the second magnet 15 rotates. That is, the impeller 10 rotates, and blood is introduced from the inlet port 5 and discharged to the outlet port 6.

As is clear from the above, according to the present invention, unlike the related art, it is not necessary to attach a rotating shaft to the impeller, and therefore, the hemolysis phenomenon conventionally caused by the rotation is significantly reduced. Further, since the blood flow hole is provided in the pedestal of the impeller, blood is unlikely to stay between the lower surface of the pedestal and the bottom surface of the first housing chamber.

The present invention is not limited to the above embodiment,
Various modifications can be made without departing from the scope of the invention.

For example, when the first magnet is mounted on the impeller, it is most preferable that the first magnet be incorporated in the pedestal of the impeller, but it is also possible to fix the first magnet to the lower surface of the pedestal.

The method of supporting the impeller at the bottom of the first housing chamber may be any method as long as the impeller is rotatably supported at the bottom of the first housing chamber.

It is also preferable to attach a back yoke, but this can be omitted in some cases.

As the structure of the impeller of the centrifugal pump, a conventionally known one can be applied to the present invention. For example, a cone other than a truncated cone can be adopted as the shape of the pedestal.

[0031]

The blood pump of the present invention is a centrifugal pump type blood pump in which the rotating shaft of the impeller is omitted, and furthermore, the blood flow hole is provided in the pedestal of the impeller, so that hemolysis is significantly reduced. Can be. Furthermore, since it is small, lightweight, and hard to break down, it can be used safely for a long period of time.

Therefore, the present invention can be suitably used for an extracorporeal circulation circuit such as a heart-lung machine or a heart assisting circuit after open heart surgery.

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view showing an example of a blood pump of the present invention.

[Description of sign]

 DESCRIPTION OF SYMBOLS 1 First housing chamber 4 Second housing chamber 8 Pedestal 9 Blade 11 First magnet 13 Blood circulation hole 14 Rotation axis 15 Second magnet

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-198556 (JP, A) JP-A-2-121035 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) A61M 1/10 530

Claims (3)

(57) [Claims] [Claim 1, further comprising a blood inlet hole at the top, and the first housing chamber formed by comprising a perpendicular direction of the blood discharge port and the blood inlet holes on the side, a plurality of the pedestal and the first magnet is mounted Place the impeller provided with the blades at the center bottom of the pedestal.
The projection is provided on the bottom of the first housing chamber with a projection provided in the second housing chamber adjacent to the first housing chamber via a partition wall, the rear end is connected to a driving source, and the second magnet is mounted at the front end. The attached rotating shaft is attached, the impeller is made rotatable by a suction force acting between the first magnet and the second magnet, and a blood circulation hole is provided that penetrates from the upper surface to the lower surface of the pedestal. And blood pump. 2. The blood pump according to claim 1, wherein the pedestal has a truncated cone shape having a bottom surface substantially covering the entire bottom surface of the first housing chamber. 3. The blood pump according to claim 1, wherein the blood circulation hole is perpendicular to a bottom surface of the pedestal.