JP2001061957A - Blood pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize two pumps different in pumping amount corresponding to a difference of the pumping amount of right and left ventricles of the heart. SOLUTION: Impellers 12, 14, are rotatably supported to a supporting shaft 30. Permanent magnets 23, 24, are provided buried within pedestals 20, 22, of the impellers 12, 14. Staters 50, 52, are provided at a position opposing to the permanent magnets 23, 24, outside a shaft direction of the impellers 12, 14. Since electric power supplied to the staters 50, 52, can be individually controlled and the impellers 12, 14, are independently rotatable to the supporting shaft 30, speed of rotation of the impellers 12, 14, can be individually set and controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blood pump for pumping blood in place of or in support of a living heart, and more particularly to a pump for pumping blood to two locations.

[0002]

2. Description of the Related Art A blood pump for pumping blood has been used for the purpose of compensating for a decrease in the function of the heart of a living body. The heart sends blood from the left heart to the lungs and blood returned from the lungs to the whole body through the right heart. Therefore, when the functions of both the left heart and the right heart are degraded, two pumps are used to assist both functions.

[0003]

As described above, if the left heart and the right heart have reduced functions, and the degree of the deterioration is different between the left heart and the right heart, the blood flow to be assisted by the pump for each of the left heart and the right heart Are different. In addition, since the degree of functional deterioration differs for each patient, the blood flow to be assisted also differs for each patient. Therefore, it is required that the flow rates of the two pumps can be adjusted individually for the left and right for each patient. The discharge pressure is also 1
The difference is about 20 mmHg because the right heart is the pulmonary circulatory system.

As described above, when two pumps are used for the left and right hearts, it is necessary to use separate pumps because the flow rates and pressures of the left atrium and the right atrium are greatly different. Therefore, there has been a problem that the outer shape becomes large as a whole and it is difficult to embed it in a living body.

An object of the present invention is to provide two small pumps that can be operated under different conditions corresponding to the left heart and the right heart.

[0006]

In order to solve the above-mentioned problems, a blood pump according to the present invention supports first and second impellers, and supports the first and second impellers, at least. A common support shaft for rotatably supporting one of the impellers, and first and second shafts provided for each of the first and second impellers and capable of independently driving the respective impellers And the first and second impeller driving means.
The blood is separately pumped out by the impeller.

Further, the support shaft itself can be rotatably supported by the casing.

Further, the first and second impellers include:
The first and second pumps are arranged so that suction sides face each other.
The impeller driving means may include a permanent magnet provided on a pedestal on which the blades of each impeller are erected, a stator facing the permanent magnet, and a stator facing the axial direction of the impeller. .

[0009]

Embodiments of the present invention (hereinafter referred to as embodiments) will be described below with reference to the drawings. FIG. 1 shows a schematic configuration of a blood pump 10 according to the present embodiment. Blood pump 10 has impellers 12 and 14 arranged with the suction sides facing each other. Impeller 12, 1
Reference numeral 4 denotes a semi-open impeller type in which the blades 16, 18 do not have a shroud in front of the blades 16, 18 as shown in FIG.
Permanent magnets 23 and 24 are embedded in 22.
The impellers 12 and 14 are housed in two impeller chambers 26 and 28 provided in a casing 25, respectively. A support shaft 30 that supports the impellers 12 and 14 is disposed at the center of the casing 25. Spherical ends 32, 33 are provided at both ends of the support shaft 30, and the spherical ends 32, 33 are provided.
Are accommodated in the holding concave portions 34 and 35 provided in the casing 25, and the positioning of the support shaft 30 is performed. Support shaft 3
The length of 0 is slightly shorter than the distance between the two holding recesses 34, 35, so that a slight gap can be formed between the spherical ends 32, 33 and the holding recesses 34, 35. The support shaft 30 is also loosely held near its center by a shaft holding portion 38 provided on a partition wall 36 separating the two impeller chambers. Shaft holding part 38 and support shaft 3
In the gap 0, blood flow is generated due to the pressure difference between the suction sides of the two impellers 12 and 14, thereby preventing blood from staying. As described above, the blood mixes between the two impeller chambers 26 and 28, but the amount is small. Therefore, in the present embodiment, a seal is provided at this portion to prevent stagnation of blood. Absent. The casing 25 has two impellers 1
Suction pipes 40 and 42 and discharge pipes 44 and 46 are provided in correspondence with the pipes 2 and 14, respectively. These suction pipes 40,
42, each of the discharge pipes 44, 46 is an impeller 12, 1
4 are arranged in a plane substantially perpendicular to the rotation axis. Therefore,
The pipes connected to these pipes can be easily handled.

The impellers 12 and 14 are rotatably supported on a support shaft 30. Further, in the portions of the pedestals 20 and 22 adjacent to the support shaft 30, there are provided through holes 48 penetrating therethrough, as shown in FIG. FIG. 2 shows the impeller 12, but the impeller 14 has exactly the same configuration, and a through hole 49 is provided. Through holes 48, 49
Are provided so as to communicate with holes through which the support shafts 30 of the impellers 12 and 14 pass, and the impellers 12 and 14 between the through holes 48 and 49 are provided.
Positioning with respect to the support shaft 30 is performed by the remaining portion. Due to the pressure difference between the front and rear of the impellers 12 and 14, the through holes 4 are formed from the rear of the impellers 12 and 14 toward the front suction side.
A blood flow through 8,49 is formed. Accordingly, it is possible to prevent blood from staying between the pedestals 20 and 22 on the rear side of the impellers 12 and 14 and the casing 25, particularly around the support shaft 30.

On the outer side in the axial direction of the casing 25, stators 50 and 52 are arranged corresponding to the impellers 12 and 14, respectively. The stators 50, 52 are
4,56. Stator cores 58, 6
0 are the permanent magnets 23 and 24 arranged in the impeller.
It is arranged at the position facing to. In addition, cores 58 and 6
The coils 62 and 64 are formed by winding a conductive wire around 0.

When electric power is supplied to the stators 50 and 52, a rotating magnetic field is generated. The interaction between the rotating magnetic field and the permanent magnets 23 and 24 causes the impellers 12 and 14 to rotate. That is, the stators 50 and 52 and the permanent magnets 23,
24 functions as impeller driving means for rotatingly driving the impellers 12 and 14. Blood is sent out by the rotation of the impellers 12 and 14. By adjusting the power supplied to the two stators 50, 52, in particular by adjusting their frequency, the two impellers 12, 14 can be rotated at different speeds. As described above, since the impellers 12 and 14 are rotatably supported by the support shafts 30, rotation at different speeds is allowed. In order for the two impellers to rotate at different speeds, it is sufficient that at least one of the impellers is rotatable with respect to the support shaft.

FIG. 3 shows another embodiment of the present invention. The same components as those in the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted. A feature of the present embodiment is that gap sensors 166 and 168 are provided in portions of the stator cases 154 and 156 facing the spherical ends 32 and 33 of the support shaft. The gap sensors 166, 168 detect the distance to the spherical ends 32, 33. Based on the detected values, the stators 50, 52
Is adjusted, and the force for attracting the impellers 12 and 14 is adjusted. Thereby, the spherical ends 32, 3
3 and the contact pressure between the holding recesses 34 and 35 are reduced. Preferably, the contact pressure is zero.

As described above, in the present embodiment, since the rotation speeds of the two impellers can be made different,
The discharge amounts of both impellers can be adjusted independently. In addition, a permanent magnet can be embedded in the impeller, and the impeller can function as a rotor of the motor, thereby reducing the size. Furthermore, since the hole penetrating the impeller is provided, it is possible to prevent the blood flow from remaining on the back surface of the impeller and suppress the formation of a thrombus.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a schematic configuration of the present embodiment.

FIG. 2 is a view showing a shape of an impeller.

FIG. 3 is a cross-sectional view illustrating a schematic configuration of another embodiment.

[Explanation of symbols]

10 blood pump, 12,14 impeller, 20,22
Pedestal, 23, 24 permanent magnet, 25 casing, 30
Support shaft, 32, 33 spherical end, 34, 35 holding recess, 48, 49 through hole, 50, 52 stator, 5
4,56 Stator case.

Claims (3)

[Claims] 1. A first and second impeller, a common support shaft that supports the first and second impellers and rotatably supports at least one of the impellers, Provided for each of the second impeller,
A first and a second which can independently drive the respective impellers;
And a pump for pumping blood separately by the first and second impellers. 2. The blood pump according to claim 1, wherein
The blood pump, wherein the support shaft itself is rotatably supported by the casing. 3. The blood pump according to claim 1, wherein the first and second impellers are arranged so as to face each other on a suction side, and the first and second impeller driving means are provided. Is a blood pump, comprising: a permanent magnet provided on a pedestal of each impeller on which the blade is erected; the permanent magnet; and a stator facing the axial direction of the impeller.