JP5412090B2 - Centrifugal blood pump - Google Patents

Description

The present invention relates to a centrifugal blood pump, and more particularly to a centrifugal blood pump suitable for use in an extracorporeal circuit for blood during heart-lung or open heart surgery.

Conventionally, an artificial heart-lung machine or an extracorporeal circuit for blood at the time of open-heart surgery has advantages that a prosthetic valve is not required, a small size, and a light weight, and thus a centrifugal pump is sometimes used.
In general, a centrifugal pump is formed of a casing provided with a fluid suction port and a discharge port, and an impeller rotatably accommodated in the casing, and the fluid flowing into the centrifugal pump from the suction port is The direction is changed in the rotational radial direction of the impeller, and the angular momentum is given by the impeller at this time, whereby the fluid is pressurized and the pressurized fluid flows out from the discharge port.

A technique of using such a centrifugal pump as a blood pump used in an extracorporeal circuit for blood is disclosed in Patent Document 1.
FIG. 6 is a cross-sectional view of a conventional centrifugal pump used for extracorporeal circulation of blood.
The conventional centrifugal pump shown in FIG. 6 includes a first housing chamber 101 and a second housing chamber 104 which is adjacent to the first housing chamber 101 via a partition wall 103. The first housing chamber 101 includes blood. The inlet port 105 is provided at the top and the outlet port 106 is provided in a direction perpendicular to the inlet port 105. In the first housing chamber 101, an impeller 110 provided with a plurality of blades 109 on the upper surface of the base 108 is rotatably attached. In addition, a protrusion 110 a that is supported by the bottom of the first housing chamber 101 is formed at the center bottom of the pedestal 108.
Further, the pedestal 108 incorporates a ring-shaped first magnet 111 and a first back yoke (magnetic field leakage prevention tool) 112, which share the central axis, in one piece in parallel with the bottom surface of the pedestal 108, In the second housing chamber 104, a ring-shaped second magnet 115 and a second back yoke 116 are integrally attached to the tip of the rotating shaft 114 via a support member 114 a so as to face the first magnet 111. Has been.
Further, in such a centrifugal pump, a volute channel 101a shown in an upper plan view in FIG. 7 and a perspective view in FIG. 8 is formed in the first housing chamber 101 on the outer peripheral side of the impeller 110. The outlet port 106 is located at the end of the volute channel 101a.

  In the centrifugal pump shown in FIG. 6 configured as described above, when a drive source (not shown) is driven, the rotating shaft 114 rotates, and the second magnet 115 attached thereto via the support member 114a also rotates. As the second magnet 115 rotates, the first magnet 111 also rotates, and the impeller 110 rotates. Thereby, blood is introduced from the inlet port 105, pressurized by the impeller 110, and discharged from the outlet port 106 through the volute channel 101a.

Japanese Patent No. 2874060

A centrifugal pump (centrifugal blood pump) used for extracorporeal circulation of blood as disclosed in Patent Document 1 usually has one end of a resin tube attached to each of the inlet port 105 and the outlet port 106, and the resin Connect the other end of the tube to the patient or other necessary equipment such as an oxygenator.
However, in the centrifugal pump disclosed in Patent Document 1, the blood suction port (inlet port) and the discharge port (outlet port) are in a plane orthogonal to each other, and the resinous type attached to each of the suction port and the discharge port. Since the tube cannot be bent at a steep angle, there is a problem that the occupied area of the extracorporeal circuit for blood becomes large.
In addition, since the resin tube cannot be bent suddenly, the total flow length of the extracorporeal circulation circuit for blood is increased, which increases the amount of blood to be circulated by exsanguination outside the body. The burden of.

  Therefore, in view of the problems of the prior art, the present invention is a centrifugal pump for extracorporeal circulation of blood, in which an impeller is rotatably accommodated in a casing in which an inlet and an outlet are formed, and blood inhalation Occupancy of the extracorporeal circuit of blood by extending the flow path on the mouth side and the flow path on the discharge port side in the same direction and in such a way that the flow of fluid on the discharge port side and the suction port side is reversed. An object of the present invention is to provide a centrifugal pump for extracorporeal blood circulation, which reduces the area and reduces the amount of blood circulating outside the body and reduces the burden on the patient.

In order to solve the above problems, in the present invention,
An impeller is rotatably accommodated inside a casing in which an inlet and an outlet are formed,
In the centrifugal blood pump that applies a pressure in the rotational radial direction to the fluid sucked from the suction port by the centrifugal force of the rotation of the impeller, and discharges the fluid from the discharge port.
Forming a volute channel provided with the discharge port at the outer peripheral end of the impeller;
The outer periphery of the impeller the volute passage from the starting end to the terminating side after being one turn or more, the terminal end by deflecting direction different from the tangent direction of the volute passage, the discharge port side Extending the flow path in the same direction as the flow path on the suction port side and the flow of fluid on the discharge port side and the suction port side in opposite directions ,
A first tube and a second tube constituting an extracorporeal blood circulation path are respectively connected to the start end portion of the suction port and the end portion of the discharge port .
Since the volume of the volute channel is changed after the impeller has made one or more turns, the entire amount of blood pressurized by the impeller can be smoothly guided to the discharge port.

In this way, the flow path on the suction port side and the flow path on the discharge port side are in the same direction and the fluid flow on the discharge port side and the suction port side is reversed, thereby occupying the extracorporeal circuit. The space volume and the occupied area can be reduced. Therefore, the space around the centrifugal pump can be saved, and the operating room where the centrifugal pump is usually placed, the bedside space of the patient, and the like can be effectively utilized due to the space saving.
In addition, since it is possible to reduce the total flow path length of the extracorporeal circulation circuit of blood, it is possible to reduce the amount of blood to be circulated by exsanguination outside the body, reducing the burden on the physical condition of the patient and reducing blood Can be circulated outside the body.

  In addition, the suction port is provided at the center of the shaft of the impeller, and the volute channel is turned 90 ° in the axial direction of the impeller after turning the impeller more than once, The flow path is extended in the same direction as the flow path on the suction port side so that the fluid flows on the discharge port side and the suction port side are in opposite directions.

  As a result, both the suction-side flow path and the discharge-side flow path are directed upward of the centrifugal pump, and the circulation flow path is compared with the case where the suction-side flow path and the discharge-side flow path are directed in directions other than the upward direction. Although the occupied space volume is the same, the dead space formed by the circulation channel (for example, the lower side of the tube) can be reduced, and the space such as the operating room where the centrifugal pump is placed can be used more effectively. It becomes.

Further, the discharge port and the suction port are provided in the upper part of the impeller, and the impeller has no bearing in the upper part of the shaft center part.
Thereby, it becomes possible to flow in blood from above the rotational axis center of the impeller of the centrifugal pump.

The suction port start end portion and the discharge port end portion may be different in height.
As described above, it is necessary to attach resin tubes to the inlet end portion and the outlet end portion, respectively. Usually, the tube is attached to the suction port start end and the discharge port end using a band. In the present invention, since the suction port start end and the discharge port end are in the same direction, the bands may interfere if the suction port start end and the discharge port end have the same height. However, it is possible to prevent the bands from interfering with each other by making the heights of the suction port start end portion and the discharge port end portion different.

  As described above, according to the present invention, there is provided a centrifugal pump for extracorporeal circulation of blood in which an impeller is rotatably accommodated in a casing in which a suction port and a discharge port are formed. By extending the flow path and the flow path on the outlet side in the same direction, the area occupied by the extracorporeal circuit for blood is reduced, and the extracorporeal blood circulation that reduces the amount of blood circulating outside the body and reduces the burden on the patient. A centrifugal pump can be provided.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, but are merely illustrative examples. Not too much.

First, the configuration of the centrifugal pump in the first embodiment will be described.
FIG. 1 is a configuration diagram illustrating a configuration of a centrifugal pump according to the first embodiment.
As shown in FIG. 1, the centrifugal pump according to the first embodiment includes a pump casing 1 and a motor casing 4 adjacent to the pump casing 1 via a partition wall 3. Further, the partition wall 3 has a substantially cylindrical recess at the center thereof.

  The pump casing 1 has an inlet port 5 which is a blood suction port at the top, and blood discharge so that fluid flows in the same direction as the inlet port 5 and in the flow direction of the discharge port and the suction port. An exit port 6 that is an exit is provided. In the pump casing 1, a pedestal 8 having a T-shaped cross section whose lower part is accommodated in the recess of the partition wall 3, and a blade 10 is provided on the upper surface of the pedestal 8. No bearing is provided on the upper part of the impeller 9 including the blades 10, thereby allowing blood to flow from the inlet port 5 provided above the impeller 9.

  A slight gap is formed between the bottom surface of the pedestal 8 and the bottom of the pump casing 1, and the pedestal 8 is rotatably supported by the bottom of the recess of the pump casing 1 at the center bottom surface. The pedestal 8 may be supported as long as the pedestal 8 can be rotatably supported. For example, a recess is provided in the center of the recess in the pump casing 1, and a protrusion that fits into the recess is provided on the bottom surface of the pedestal 8. Means such as providing in the central part can be mentioned.

  The pedestal 8 includes a ring-shaped driven magnet 11 that shares the center of rotation with the pedestal 8. A ring-shaped back yoke (magnetic field leakage prevention tool) that shares the rotation center with the driven magnet 11 may be integrated in the inner periphery of the driven magnet 11.

  Further, a ring-shaped drive magnet 15 is mounted on the motor casing 4 so as to face the driven magnet 11 through a bowl-shaped support member 14 at the tip of a rotating shaft 17 of the motor 16. Has been.

A volute channel 1 a is formed inside the pump casing 1 and on the outer peripheral side of the impeller 9. The shape of the volute channel 1a will be described with reference to FIGS.
FIG. 2 is a top plan view of the volute channel according to the first embodiment, and FIG. 3 is a perspective view of the volute channel according to the first embodiment.
Inside the pump casing, on the outer peripheral side of the impeller 9, there is a volute channel 1 a that widens the distance from the impeller 9 with a gentle curved surface toward the discharge side on the same plane as the rotation direction of the impeller 9. The volute channel 1a is formed such that after the outer circumference of the impeller 9 has been turned one or more times, the end side is turned upward 90 ° and the outlet port 6 is located at the tip. Thereby, the inlet port 5 and the outlet port 6 can be provided in the same direction.

4A is a schematic configuration diagram around the inlet port 5 and the outlet port 6, and FIG. 4B is a schematic configuration diagram of another example around the inlet port 5 and the outlet port 6.
As shown in FIG. 4A, the heights of the upper end (starting end) of the inlet port 5 and the upper end (terminal end) of the outlet port 6 are made different so that the upper end of the outlet port 6 is higher than the upper end of the inlet port 5. I have to. In addition, resin tubes are attached to the inlet port 5 and the outlet port 6 using bands 25 and 26, respectively. However, since the height of the upper end of the inlet port 5 and the upper end of the outlet port 6 are different, the band 25 And 26 do not interfere with each other.
Further, as shown in FIG. 4B, the upper end of the inlet port 5 may be higher than the upper end of the outlet port 6, and the height of the upper end of the inlet port 5 and the upper end of the outlet port 6 may be It only has to be different.

Next, the operation of the centrifugal pump configured as described above will be described.
In the above centrifugal pump, when the motor 16 is driven, the rotating shaft 17 rotates, and the driving magnet 15 attached to the rotating shaft 17 also rotates. An attractive force acts between the drive magnet 15 and the driven magnet 11 facing the drive magnet 15, and the driven magnet 11 rotates as the drive magnet 15 rotates. The impeller 9 is rotated by the rotation of the driven magnet 11. As a result, blood is introduced from the inlet port 5, and the direction is changed in the rotational radial direction of the rotating impeller 9 and the pressure is increased. It flows in the same direction as the rotation direction of the gas and is discharged from the outlet port 6.

According to the first embodiment described above, the area occupied by the circuit circulating outside the body can be reduced by setting the inlet port and the outlet port in the same direction. Therefore, the space around the centrifugal pump can be saved, and the operating room where the centrifugal pump is usually placed, the bedside space of the patient, and the like can be effectively utilized due to the space saving.
In addition, since it is possible to reduce the total flow path length of the extracorporeal circulation circuit of blood, it is possible to reduce the amount of blood to be circulated by exsanguination outside the body, reducing the burden on the physical condition of the patient and reducing blood Can be circulated outside the body.

The space saving will be described with reference to FIG.
FIG. 5A is a schematic diagram of the centrifugal pump according to the first embodiment and its surroundings, and FIG. 5B is a schematic diagram of the centrifugal pump according to the conventional example and its surroundings.
As shown in FIG. 5B, in a conventional centrifugal pump, blood collected from a patient's vena cava or the like is put into a casing 101 that forms a centrifugal pump from a resin tube 125 attached to an inlet port 105. Inflow, pressure is increased by an impeller (not shown) in the casing 101, an artificial lung or the like through an outlet port 106 provided in a direction perpendicular to the inlet port 105 and a resin tube 126 attached to the outlet port 106 After being processed by another device (not shown), it returns to the patient's body from the aorta or the like.

  Similarly, as shown in FIG. 5A, in the centrifugal pump according to the first embodiment, blood collected from a patient's vena cava forms a centrifugal pump from a resin tube 25 attached to the inlet port 5. It flows into the casing 1, is pressurized by an impeller (not shown) in the casing 1, is turned by the volute flow path shown in FIGS. 2 and 3, and is provided in the same direction as the inlet port 5. After being processed by another device (not shown) such as an artificial lung through the outlet port 6 and the resin tube 26 attached to the outlet port 6, it returns to the patient's body from the aorta or the like.

  As is clear from FIG. 5 (A), in the centrifugal pump of the first embodiment, the route 126 ′ previously occupied by the resin tube is no longer necessary, and the upper part of the centrifugal pump, which has conventionally been a dead space, is eliminated. The resin tube 26 can be occupied. As a result, the occupied area becomes smaller than the conventional area by an area corresponding to S shown in FIG.

  A centrifugal pump for extracorporeal circulation of blood in which an impeller is rotatably accommodated in a casing in which an inlet and an outlet are formed, the blood inlet side channel and the outlet side channel Can be provided in the same direction, thereby reducing the area occupied by the extracorporeal circuit for blood and providing a centrifugal pump for extracorporeal blood circulation that reduces the amount of blood circulating outside the body and reduces the burden on the patient. .

1 is a configuration diagram illustrating a configuration of a centrifugal pump according to Embodiment 1. FIG. FIG. 3 is an upper plan view of a volute flow path related to Example 1. FIG. 3 is a perspective view of a volute flow path related to Example 1. 4A is a schematic configuration diagram around the inlet port 5 and the outlet port 6, and FIG. 4B is a schematic configuration diagram of another example around the inlet port 5 and the outlet port 6. FIG. 5A is a schematic diagram of the centrifugal pump according to the first embodiment and its surroundings, and FIG. 5B is a schematic diagram of the centrifugal pump according to the conventional example and its surroundings. It is sectional drawing of the centrifugal pump used for the extracorporeal circulation of the conventional blood. It is a top plan view of a volute channel relating to a conventional example. It is a perspective view of the volute flow path regarding a conventional example.

1 Pump casing 1a Volute flow path 5 Inlet port (suction port)
6 Outlet port (discharge port)
9 impeller

Claims (5)

An impeller is rotatably accommodated inside a casing in which an inlet and an outlet are formed,
In the centrifugal blood pump that applies a pressure in the rotational radial direction to the fluid sucked from the suction port by the centrifugal force of the rotation of the impeller, and discharges the fluid from the discharge port.
Forming a volute channel provided with the discharge port at the outer peripheral end of the impeller;
After along the outer circumference is at least 1 round of said impeller the volute passage from the starting side to the end side and the terminating side is deflected to a direction different from the tangent direction of the volute passage, the discharge port The flow path on the side extends in the same direction as the flow path on the suction port side, and the flow of fluid on the discharge port side and the suction port side is reversed ,
A centrifugal blood pump, wherein a first tube and a second tube constituting an extracorporeal blood circulation path are connected to a start end portion of the suction port and a termination portion of the discharge port, respectively . The suction port is provided at the center of the shaft of the impeller,
The volute channel is turned 90 ° in the axial direction of the impeller after the impeller has made one or more rounds, and the discharge side channel is in the same direction as the suction side channel and the discharge port. 2. The centrifugal blood pump according to claim 1, wherein the flow of the fluid on the outlet side and the inlet side is extended so as to be opposite to each other. The discharge port and the suction port are provided in the upper part of the impeller,
The centrifugal blood pump according to claim 2, wherein the impeller does not have a bearing at an upper portion of a shaft center portion. Said leading end of said suction port, centrifugal blood pump according to any one of claims 1 to 3, characterized in that with different height between the end portion of the discharge port. The first tube is attached to the starting end of the suction port by a first band;
The centrifugal blood pump according to claim 4, wherein the second tube is attached to the terminal end of the discharge port by a second band.

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