JPS646827Y2 - - Google Patents

Description

[Detailed Description of the Invention] Background Technical Field of the Invention The present invention relates to a blood perfusion pump used in an artificial heart-lung extracorporeal circulation circuit, etc., which is small in size and causes little hemolysis even when used for a long time. Prior Art Conventionally, roller type pumps have been used for blood pumps used in artificial heart-lung extracorporeal circulation circuits because of their low hemolysis and excellent ability to prevent microbial contamination. When such a roller type pump is connected to an extracorporeal circulation circuit, a thick pump tube is used to obtain a large flow rate, and the amount of priming increases due to the piping between the patient and various devices. Careful monitoring is required to maintain balance in blood withdrawal. In order to alleviate this, devices such as roller-type pumps are tried to be brought closer to the patient, but blood perfusion roller-type pumps that require a large flow rate are large and have limitations, and if you try to increase the flow rate, Therefore, there has been a desire to develop a small, high-performance blood pump that can provide a large flow rate. BACKGROUND ART Centrifugal and centrifugal pumps are known as small-sized pumps that can obtain a large flow rate. However, these pumps pump fluid using vanes that rotate at high speed within the pump chamber, so when used as a blood pump, blood damage or hemolysis occurs, especially when the pump is operated for a long time to circulate blood. It has the disadvantage that the amount increases cumulatively and is ultimately difficult or impossible to use. Therefore, the inventors of the present invention believed that the cause of hemolysis within the pump was due to the structure of the rotor of the pump, and as a result of extensive research, they arrived at the present invention. Purpose of the invention The purpose of the invention is to eliminate the drawbacks of the conventional centrifugal pumps mentioned above, and to create a blood pump that is small, high-performance, significantly reduces the amount of hemolysis, and can be used for long-term blood circulation. It is about providing. DISCLOSURE OF THE INVENTION These objects are achieved by the present invention as described below. That is, the present invention includes a substantially conical support and an inlet angle of 10 to 10 on the curved surface of the support from a position a predetermined distance away from the apex of the support to the vicinity of the outer peripheral edge of the support.
a rotor having a plurality of curved blades standing radially at an angle of 30 degrees and an exit angle of 40 to 60 degrees; a housing having a space for rotatably housing the rotor; and the rotor shaft of the housing. a blood inlet that is provided in the direction and introduces blood toward the vicinity of the apex of the substantially conical support; and a blood inlet that is provided in the tangential direction of the housing in the tangential direction of the rotational direction of the rotor or adjacent to the tangential direction. The blood pump is characterized in that it has a blood outlet for discharging blood in the space, and a drive means for rotating the rotor. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The preferred embodiments of the blood pump of the present invention shown in the accompanying drawings will be described in detail below. An example of the configuration of the blood pump of the present invention is shown in FIG. 1 is a housing, 2 is a space for storing the rotor,
3 is a blood inflow port, 4 is a blood outflow port, 5 is a support body,
6 is a curved blade, 7 is a rotating shaft, 8 is a bearing, 9
10 is a seal ring, 10 is a motor, 11 is a coupler, and 12 is a terminal of the motor. In the blood pump of the present invention, a rotor composed of a support body 5 and curved blades 6 is rotatably housed in a space 2 for housing the rotor of a housing 1, and the rotor is rotated by a motor 10. When this happens, blood flows into the empty space 2 through the blood inlet 3 and is discharged through the blood outlet 4. The rotor has a structure in which a plurality of curved blades 6 are radially arranged on the upper surface of a conical support 5, and each curved blade 6 is positioned a certain distance d away from the conical apex of the support 5. It is formed up to the vicinity of the outer peripheral edge of the support body 5. The features of the rotary die having such a structure will be explained below. In a centrifugal pump, if the rotor structure is an open type as shown in Figure 3, the blood flow 1
3 generates a high-speed vortex 14 near the outer periphery of the support 5, resulting in hemolysis. In contrast, in the rotor of the present invention, the fourth
As shown in the figure, the blood flow 13 flows along the upper surface of the support 5 and does not generate the vortex flow 14 as described above, so that hemolysis does not occur. The apex angle of such a conical support 5 is preferably 120 to 160 degrees. This is because if the apex angle is less than 120°, the pump efficiency will be poor, and if it exceeds 160°, unnecessary vortices will be generated at the time of inflow. Further, the diameter of the support is preferably about 30 to 50 mm. This is because if the diameter is less than 30 mm, a sufficient flow rate cannot be obtained, and if it exceeds 50 mm, the amount of priming becomes large. Next, the formation position of the curved blade 6 will be explained with reference to FIG. 2. FIG. 2 is a plan view of the rotor, where 61 indicates the blood inflow side of the curved blade 6, and 62 indicates the blood outflow side of the curved blade 6. The blood inflow side 61 of the blade is preferably formed at a position d approximately 2 to 5 mm away from the conical apex of the support 5. This is because if it is less than 2 mm, the inflowing blood will be damaged, and if it exceeds 5 mm, the pump efficiency will decrease. The blood outflow side 62 of the blade is connected to the outer peripheral edge 5 of the support.
It is formed up to around 1. This blood outflow side 62
The ends of the blades may be aligned with the outer peripheral edge 51, or may be formed slightly inside or outside of the outer peripheral edge 51. In any case, the position may be small enough not to generate the vortex 14 at the end of the blade. In the present invention, the forming angle of the curved blade 6 is limited. That is, the entrance angle α of the curved blade 6 is 10°≦α
≦30°, and the exit angle β of the curved blade 6 is 40°≦β≦60°
shall be. In particular, it is preferable that the exit angle β≈50°. As shown in FIG. 2, the entrance angle α here refers to the angle formed by the tangent to the circle connecting the tips of the blood outflow side 62 and the tangent to the curved blade 6 on the blood inflow side 61, and the exit angle β , is the angle formed by the tangent to the outer circumferential circle of the support body 5 and the tangent to the curved blade 61 on the blood outflow side 62. The reason why the entrance angle and exit angle of the curved blade 6 are limited in this way will be explained below. The blood in the blood inlet 3 flows into the space 2 while rotating in advance by the rotation of the blades 6, and the blood flows into the space 2 through the support 5.
The blood flow 13 spreads radially from the apex of the blood flow 13, but since the rotor is rotating at high speed in the direction of the arrow shown in FIG. go. Therefore, blood cells in the blood rub against the curved surface 63, causing hemolysis. Therefore, when α is less than 10°, the pump efficiency decreases, and when it exceeds 30°, the impact with the blade increases. When β is less than 40°, the contact length of blood cells with the blade becomes large, and when β exceeds 60°, the contact angle between the blade and blood cells becomes large. In particular, when β≒50°, the amount of hemolysis decreases the most. FIG. 6 shows the relationship between the pump discharge amount (cumulative) and the amount of hemoglobin released by hemolysis. From the graph shown in the same figure, it can be seen that the amount of hemolysis is extremely small in the pump with a rotor having an exit angle β≒50° compared to other pumps. The curved blades 6 are preferably formed substantially perpendicularly on the support 5, but may be formed with a certain inclination. It is preferable to form such curved blades 6 on the support body 5 at equal intervals, and although the number of blades is not particularly limited, it is usually good to set it to about 6 blades. Further, the height of the curved vane 6 is determined depending on the size of the pump, the discharge amount, etc., but it is preferably about 5 to 10 mm when used in place of a roller pump.
If it is less than 5 mm, sufficient discharge volume will not be obtained, and 10
This is because if it exceeds mm, the size will increase. The thickness of the curved blade 6 is appropriately determined in consideration of strength and the like. The supporting body 5 and the curved blades 6 may be made of any material as long as it is lightweight, has sufficient strength, and is suitable for reducing hemolysis. Preferred examples include acrylic resin, etc. can be mentioned. The support body 5 and the curved blade 6 are preferably formed integrally. The surfaces of the support 5 and the curved blades 6 are preferably coated with segmented polyurethane (SPU) for antithrombotic treatment. At the same time, it is preferable to coat the space 2 that accommodates the rotor. Support body 5 and curved blade 6 as explained above
The rotor is rotatably housed in a space 2 of a housing 1, as shown in FIG. For reasons such as obtaining high pump efficiency, the space 2 is preferably shaped to correspond to the rotating body when the rotor is rotated, and is approximately cylindrical, but the upper part of the space 2 is sloped. Good too. At the center of the upper part of the housing, a blood inlet 3 is provided which communicates with the inside of the space 2 in the axial direction of the rotor, which will be described later. A soft vinyl chloride tube or the like is connected to this blood inlet 3. Further, a blood outflow port 4 communicating with the inside of the space 2 is provided in the tangential direction of the cylindrical portion of the cylindrical space 2 of the housing. Similarly, a soft vinyl chloride tube or the like is connected to this blood outlet 4. Blood is introduced from the blood inlet 3 into the space 2 above the apex of the support of the rotor, is accelerated by the rotation of the rotor, and is sent out from the blood outlet 4. As shown in FIG. 1, a rotating shaft 7 is fixed to the rotor, and the rotating shaft 7 is supported by a bearing 8 fitted into the housing 1. As shown in FIG. In addition, in order to prevent blood in the space 2 from leaking from the shaft hole of the rotating shaft 7, a seal ring 9 is attached to the shaft hole.
It is preferable to insert the Such a rotor is rotated by the drive of a motor 10 attached below the housing 1. The rotating shaft 7 and the motor shaft are directly connected, and the tip of the rotating shaft 7 is loosely fitted to the shaft of the motor 10 via the coupler 11, so that only the rotational force of the motor 10 is transmitted. preferable. This allows the housing 1 and the motor 10 to be detachably attached, which is convenient. It is preferable to use a small and high-performance motor as the motor 10, and in the case of an artificial heart-lung circuit, it is preferable that the maximum flow rate of the pump is about 12/min. Specific Effects of the Invention The specific effects of the invention will be explained below with reference to FIGS. 1 to 4. When a voltage is applied to the terminal 12 of the motor 10, the motor 10 is driven and the rotor is rotated. The rotation direction of the rotor is the direction of the arrow in FIG. Blood is introduced into the space 2 from the blood inlet 3 by the rotation of the rotor. The blood introduced into the space 2 forms a blood flow 13 that radially spreads from the vicinity of the conical apex of the support 5. At this time, since the support body 5 is conical and the curved blades 6 are formed up to the vicinity of the outer peripheral edge of the support body 5, no vortex flow 14 as shown in FIG. 3 is generated. Further, the blood flow 13 flows along the curved surface 63 due to the high speed rotation of the curved blade 6, but since the entrance angle and exit angle of the curved blade 6 are limited as described above, hemolysis is less likely to occur. The blood accelerated by the rotation of the rotor is discharged from the blood outlet 4 and circulates within the blood circulation circuit. Due to the above-mentioned action, even if the blood pump is operated continuously and blood is circulated for a long time, hemolysis hardly occurs. Specific Effects of the Invention According to the blood pump of the present invention, the curved blades are formed up to the vicinity of the outer peripheral edge of the conical support, thereby preventing the generation of eddy currents and thereby preventing hemolysis. Further, by limiting the entrance angle and exit angle of the curved blade to 10-30° and 40-60°, respectively, damage caused by blood cells in the blood being rubbed against the curved surface of the curved blade can be minimized. Therefore, the blood pump of the present invention significantly reduces the cumulative amount of hemolysis and can be used for long-term blood circulation. Furthermore, since the blood pump of the present invention is small, the amount of priming can be reduced, and the pump efficiency is extremely high, making it possible to circulate blood at a large flow rate with low power consumption. Example of the invention (Example 1) A rotor having the shape shown in FIG. 4 was created. Its specifications were as follows. The support had a diameter of 40 mm and an apex angle of 140°. The curved blades were formed from a position 3 mm from the top to the outer peripheral edge of the support. The entrance angle α of the curved blades was 20°, the exit angle β was 50°, and the number of blades was 6. These supports and curved blades were integrally molded using acrylic resin. (Comparative Example 1) A rotor having the shape (open type) shown in FIG. 3 was created. Its specifications were as follows. The support had a diameter of 20 mm and an apex angle of 140°, and the curved blades were formed from a position 3 mm from the top to a position protruding 10 mm from the outer peripheral edge of the support. The rest was the same as in Example 1. Blood pumps A and B were created in which the rotors of Example 1 and Comparative Example 1 were mounted in housings. These pumps A and B were operated continuously under the following conditions, and the relationship between the pump discharge amount (cumulative) and the amount of hemolysis (amount of free hemoglobin) was investigated. The results are shown in Figure 5. Motor rotation speed is 2500r.pm, load is 100mmHg,
The flow rate was 2/min. As is clear from the graph in Figure 5, pump A
It was confirmed that the amount of hemolysis in (Example 1) was significantly smaller than that in Pump B (Comparative Example 1). Next, let the entrance angle α of the curved blade be 20°, and the exit angle β
An experiment was conducted to investigate the amount of hemolysis when various changes were made. β = 50° (example of the present invention), β = 20° (comparative example 2), respectively.
A blood pump equipped with a rotor of β=90° (Comparative Example 3) was operated continuously, and the amount of free hemoglobin (cumulative) was measured. Note that the specifications of the rotor were the same as in Example 1 described above except for the exit angle β. The conditions of the pump used in the experiment were: motor rotation speed: 2500r.pm, load 100mmHg, flow rate: 2/
It was min. The results of this experiment are shown in Table 1. In addition, the amount of hemolysis is pump discharge amount (cumulative) 100,
Free hemoglobin amount (mg) at 200, 300
was measured.

[Table] As is clear from the above results, it was confirmed that when the blood pump of the present invention was used, the amount of hemolysis was significantly small. Next, we conducted the following experiment to examine the performance of the blood pump. The entrance angle α of the curved blade is 20°, and the exit angle β is 20°.
Three types of rotors, 20°, 50°, and 90°, were created, and these were attached to a blood pump with the same specifications as described above.
These pumps were operated at 3600rpm for 10 minutes,
The flow characteristics were investigated under loads of 50mmHg, 100mmHg, and 150mmHg. The results are shown in FIG. As is clear from the graph of FIG. 7, the blood pump of the present invention had a large pump discharge flow rate and was found to have high performance.

[Brief explanation of drawings]

FIG. 1 is a partially sectional front view of the blood flow pump of the present invention. FIG. 2 is a plan view showing the structure of a rotor used in the blood pump of the present invention. FIG. 3 is a side view showing the state of blood flow in the open rotor. FIG. 4 is a side view showing the state of blood flow in the rotor used in the blood pump of the present invention. FIG. 5 is a graph showing the relationship between the pump discharge amount (cumulative) and the amount of free hemoglobin for blood pumps A and B equipped with the rotors shown in FIGS. 4 and 3. FIG. 6 is a graph showing the relationship between the pump discharge amount (cumulative) and the amount of free hemoglobin for blood pumps equipped with rotors having curved blade exit angles β of 20°, 50°, and 90°, respectively. FIG. 7 is a graph showing the relationship between the outlet angle β of the curved vane and the discharge flow rate of the pump. Explanation of symbols, 1...Housing, 2...Space,
3...Blood inflow port, 4...Blood outflow port, 5...Support, 51...Support outer peripheral edge, 6...Curved blade, 61...Blood inflow side, 62...Blood outflow side,
63... Curved surface, 7... Rotating shaft, 8... Bearing, 9... Seal ring, 10... Motor, 11
...Coupler, 12...Terminal, 13...Blood flow,
14... vortex.

Claims (1)

[Claims for Utility Model Registration] A substantially conical support, and an entrance angle of 10 to 30° and an exit angle from a position a predetermined distance away from the apex on the curved surface of the support to the vicinity of the outer peripheral edge of the support. a rotor having a plurality of curved blades radially arranged at an angle of 40 to 60 degrees; a housing having a space for rotatably housing the rotor; and a housing provided in the axial direction of the rotor of the housing; a blood inlet for introducing blood toward the vicinity of the apex of the substantially conical support; a blood inlet provided in the tangential direction of the housing in the tangential direction of the rotor rotation direction or close to the tangential direction; A blood pump comprising: a blood outlet for discharging blood; and a drive means for rotating the rotor.