JP4340182B2 - Blood pump device - Google Patents

Description

  The present invention relates to a blood pump device for feeding blood.

Recently, an example of using a centrifugal blood pump for extracorporeal blood circulation in an oxygenator is increasing. Centrifugal pumps use a system that transmits driving torque from an external motor using magnetic coupling by completely eliminating physical communication between the outside and the blood chamber in the pump and preventing invasion of bacteria. Is used.
As such a centrifugal blood pump, there is a turbo pump disclosed in Japanese Patent Laid-Open No. 4-91396 (Patent Document 1). In the technique disclosed in Patent Document 1, a magnetic coupling is formed by a first permanent magnet provided on one surface of an impeller and a second permanent magnet opposed via a housing, and this second permanent magnet is formed. The impeller is rotationally driven by rotating the rotor to which the magnet is attached. The impeller is attracted to the rotor side, but has a dynamic pressure groove, so that it is slightly away from the inner surface of the housing and in a non-contact state due to the effect of the dynamic pressure bearing formed between the dynamic pressure groove and the inner surface of the housing. Rotate at.

In the case of such a hydrodynamic bearing pump, the load capacity generated by the hydrodynamic groove (the load capacity is a term of bearing and has a dimension of force) and a force against it, for example, for liquid feeding The impeller is kept out of contact with the surrounding surface to prevent hemolysis and thrombus formation.
Further, the present applicant has proposed Japanese Patent Application Laid-Open No. 2003-201992 (Patent Document 2). The centrifugal liquid pump apparatus 1 includes a pump unit 2 having an impeller 21 that rotates within a housing 20, a rotor 31 that includes an impeller suction magnet 33, a motor 34 that rotates the rotor, an electromagnet 41 that sucks the impeller, and an impeller. A main body 5 including a position detecting sensor 42 and a dynamic pressure groove 38 provided on the inner surface of the housing 20 and a control mechanism 6 are provided. The control mechanism 6 has a position sensor output monitoring function 56, an electromagnet current monitoring function 57, and a motor current monitoring function. The control mechanism 6 determines sensor malfunction and electromagnet malfunction using the position sensor output monitoring function and the electromagnet current monitoring function. It operates at the time of detection and has an emergency impeller rotating function for rotating the impeller using the dynamic pressure groove.

Japanese Patent Laid-Open No. 4-91396 JP 2003-201992 A

In the hydrodynamic bearing pump, the impeller is kept in a non-contact state in the blood. However, the pump device of Patent Document 1 cannot know the position of the impeller. Therefore, it cannot be confirmed whether it rotates in a non-contact manner while maintaining a predetermined distance from the surrounding housing surface. In addition, the dynamic pressure groove in the pump device of Patent Document 2 is for emergency use in the event of sensor malfunction, and is not a type that always rotates the impeller using the dynamic pressure by the dynamic pressure groove, The sensor does not measure the position of the impeller in a state where the impeller rotates in a non-contact state with the housing due to the dynamic pressure by the dynamic pressure groove.
Therefore, an object of the present invention is not a magnetic levitation type blood pump, but a blood pump device that uses a so-called dynamic pressure groove to rotate the impeller substantially in a non-contact state with respect to the housing. A blood pump device that can be confirmed is provided.

What achieves the above object is as follows.
(1) A housing having a blood inflow port and a blood outflow port, a pump unit having a magnetic body, an impeller that rotates in the housing and feeds blood, and sucks and rotates the impeller of the pump unit An impeller rotational torque generating portion for causing the impeller rotational torque to be generated, and the pump portion is a dynamic pressure groove provided on an inner surface of the housing on the impeller rotational torque generating portion side or on a surface of the impeller on the impeller rotational torque generating portion side A blood pump device in which the impeller rotates in a non-contact state with respect to the housing, wherein the pump unit rotates in a non-contact state with the housing by a dynamic pressure by the dynamic pressure groove A sensor for measuring the position of the impeller in a state where the impeller is installed, and the magnetic body of the impeller or the magnetic body A permanent magnet that attracts the second magnetic body in a direction opposite to the direction of attraction by the impeller rotational torque generator, and a second inner surface provided on the inner surface of the housing on the permanent magnet side or on the surface of the impeller on the permanent magnet side. A blood pump device comprising a dynamic pressure groove .
( 2 ) The blood pump device according to (1), wherein the sensor is for measuring a flying distance of the impeller in the housing.
( 3 ) The blood pump device according to (1) or (2) , wherein at least three sensors are provided at an equal angle with respect to a central axis of the impeller.

( 4 ) The blood pump device according to any one of (1) to ( 3 ), wherein the blood pump device has a blood viscosity calculation function for calculating blood viscosity using an output of the sensor.
( 5 ) The blood viscosity calculation function uses a rotational speed temporary lowering function for temporarily reducing the impeller rotational speed to a predetermined rotational speed, and a predetermined rotational speed by the rotational speed temporary lowering function using the sensor. The blood according to ( 4 ) above, which has a blood viscosity calculation function for detecting blood oscillation viscosity by detecting the oscillation width of the impeller when the rotation speed of the impeller is reduced. Pump device.
( 6 ) The blood viscosity calculation function includes a storage unit that stores relational data between a swing width of the impeller and blood viscosity at the predetermined rotational speed or a viscosity calculation formula calculated from the relational data, and an output of the sensor. The blood pump device according to ( 5 ), wherein the blood pump device includes a viscosity calculation function for calculating the viscosity from the obtained swing width data and the relation data stored in the storage unit or the viscosity calculation formula.
( 7 ) The said impeller rotational torque generation part is provided with the rotor provided with the magnet for attracting | sucking the 1st magnetic body of the said impeller, and the motor which rotates this rotor (1) thru | or ( 6 ). The blood pump device according to any one of the above.
( 8 ) The impeller rotational torque generating section includes a plurality of stator coils arranged on the circumference for attracting the magnetic body of the impeller and rotating the impeller. The blood pump device according to any one of 6 ).

The blood pump device of the present invention includes a housing having a blood inflow port and a blood outflow port, a pump unit having a magnetic body, an impeller that rotates in the housing and feeds blood, and the impeller of the pump unit. An impeller rotational torque generating part for sucking and rotating the impeller, and the pump part is provided on the inner surface of the housing on the impeller rotational torque generating part side or on the surface of the impeller on the impeller rotational torque generating part side A blood pump device in which the impeller rotates in a non-contact state with respect to the housing, and the pump unit is configured so that the impeller is not in contact with the housing by the dynamic pressure of the dynamic pressure groove. A sensor 45 having a function of measuring the position of the impeller in a state of rotating in a contact state is provided.
For this reason, it is a blood pump device that rotates the impeller in a non-contact state substantially in the housing by utilizing a so-called dynamic pressure groove, and the position of the impeller can be confirmed.

  FIG. 1 is a block diagram including a control mechanism of an embodiment in which the blood pump device of the present invention is applied to a centrifugal blood pump device. FIG. 2 is a front view of an embodiment in which the blood pump device of the present invention is applied to a centrifugal blood pump device. FIG. 3 is a plan view of the blood pump device shown in FIG. 4 is a cross-sectional view taken along line AA in FIG. 5 is a cross-sectional view taken along line BB in FIG. 6 is a cross-sectional view showing a state where the impeller is removed from the cross-sectional view taken along the line B-B in FIG. 4. 7 is a cross-sectional view showing a state where the impeller is removed from the cross-sectional view taken along the line CC of FIG. 8 and 9 are explanatory views for explaining the form of the dynamic pressure groove.

  The blood pump device 1 of the present invention includes a housing 20 having a blood inflow port 22 and a blood outflow port 23, a magnetic body 25, a pump unit 2 having an impeller 21 that rotates in the housing 20 and feeds blood. And an impeller rotational torque generating unit 3 for sucking and rotating the impeller 21 of the pump unit 2. Furthermore, the pump unit 2 includes a first dynamic pressure groove 38 provided on the inner surface of the housing on the impeller rotational torque generating unit 3 side or on the surface of the impeller 21 on the impeller rotational torque generating unit 3 side. The impeller 21 rotates in a non-contact state with respect to the housing 20. The pump unit 2 includes a sensor 45 having a function of measuring the position of the impeller 21 in a state where the impeller 21 rotates in a non-contact state with the housing 20 by the dynamic pressure generated by the dynamic pressure groove 38.

As shown in FIGS. 2 to 7, the blood pump device 1 of this embodiment is a centrifugal blood pump device, and a housing 20 having a blood inflow port 22 and a blood outflow port 23, and rotating within the housing 20. A centrifugal blood pump unit 2 having an impeller 21 for feeding blood by the centrifugal force of time and an impeller rotational torque generating unit 3 for the impeller 21 are provided.
The blood pump device of the present invention is not limited to the centrifugal pump device as described above. For example, an axial flow type or diagonal flow type blood pump device may be used.

In the centrifugal blood pump device 1 of this embodiment, the impeller rotational torque generating unit 3 includes a rotor 31 including a magnet 33 for attracting the magnetic body 25 of the impeller 21 and a motor 34 that rotates the rotor 31. It has become a thing.
As shown in FIG. 4, the impeller 21 rotates without contacting the inner surface of the housing due to the pressure generated by the dynamic pressure groove during rotation.
The housing 20 includes a blood inflow port 22 and a blood outflow port 23, and is formed of a nonmagnetic material. A blood chamber 24 communicating with the blood inflow port 22 and the blood outflow port 23 is formed in the housing 20. An impeller 21 is accommodated in the housing 20. The blood inflow port 22 is provided so as to protrude substantially vertically from the vicinity of the center of the upper surface of the housing 20. The blood inlet port is not limited to such a straight tube, and may be a curved tube or a bent tube. As shown in FIGS. 3 and 5 to 7, the blood outflow port 23 is provided so as to protrude in the tangential direction from the side surface of the housing 20 formed in a substantially cylindrical shape.

  As shown in FIG. 4, a disc-like impeller 21 having a through-hole at the center is housed in a blood chamber 24 formed in the housing 20. As shown in FIGS. 3 and 4, the impeller 21 includes a donut plate-like member (lower shroud) 27 that forms a lower surface, a donut plate-like member (upper shroud) 28 that opens at the center that forms the upper surface, and a gap between the two. A plurality of (for example, seven) vanes 18 formed in A plurality (seven) blood passages 26 partitioned by the adjacent vanes 18 are formed between the lower shroud and the upper shroud. As shown in FIG. 4, the blood passage 26 communicates with the central opening of the impeller 21, starts from the central opening of the impeller 21, and extends so that the width gradually increases to the outer peripheral edge. In other words, the vane 18 is formed between the adjacent blood passages 26. In this embodiment, each blood passage 26 and each vane 18 are provided at equal angular intervals and in substantially the same shape.

As shown in FIGS. 4 and 5, a plurality of (for example, 10 to 40) magnetic bodies 25 (permanent magnets, driven magnets) are embedded in the impeller 21. In this embodiment, the magnetic body 25 is embedded in the lower shroud 27. The magnetic body 25 (permanent magnet) embedded in the impeller is attracted to the opposite side of the blood inflow port 22 by a permanent magnet 33 provided in the rotor 31 of the impeller rotational torque generating unit 3 described later, and is cupped with the rotor. The rotational torque generated by the ring and impeller rotational torque generator is transmitted to the impeller.
Further, by embedding a certain number of magnetic bodies 25 as in this embodiment, sufficient magnetic coupling with the rotor 31 described later can be ensured. The shape of the magnetic body 25 (permanent magnet) is preferably circular.
As shown in FIG. 4, the impeller rotational torque generating unit 3 includes a rotor 31 housed in the housing 20 and a motor 34 for rotating the rotor 31. The rotor 31 includes a plurality of permanent magnets 33 provided on the surface on the blood pump unit 2 side. The center of the rotor 31 is fixed to the rotating shaft of the motor 34. The permanent magnets 33 are provided in plural and at equal angles so as to correspond to the arrangement form (number and arrangement position) of the permanent magnets 25 of the impeller 21.

In addition, in the coupling of the permanent magnet between the impeller and the motor, it is preferable to arrange the permanent magnet so that an attraction force is always generated between the impeller and the motor even if the coupling is disengaged due to an external force. . By doing so, even if the coupling is disengaged and the impeller and the motor are stepped out, since the suction force is generated between them, the coupling is easily restored.
As shown in FIGS. 3 and 4, in this embodiment, the impeller 21 includes a ring-shaped permanent magnet 29. In this embodiment, the permanent magnet 29 is embedded in the upper shroud 28. The embedded permanent magnet 29 attracts the impeller 21 to the side opposite to the impeller rotational torque generating unit 3 (specifically, the rotor) by the second permanent magnet 41. The permanent magnet 29 is disposed so as to have a polarity that generates an attractive force between the permanent magnet 29 and the second permanent magnet 41. Further, the permanent magnet 29 may be composed of a plurality of (for example, 10 to 40) permanent magnets.

In the centrifugal blood pump device 1 of this embodiment, as shown in FIG. 6, the housing 20 includes a housing inner surface that houses the impeller 21 and forms a blood chamber 24, and is disposed on the housing inner surface 20 a on the rotor 31 side. A first dynamic pressure groove 38 is provided. The impeller 21 rotates in a non-contact state due to a dynamic pressure bearing effect formed between the dynamic pressure groove 38 and the impeller 21 generated by rotating at a predetermined number of rotations or more.
Further, as shown in FIGS. 3 and 4, the centrifugal pump unit 2 is fixed to suck an impeller magnetic body 29 (embedded in the upper shroud 28) provided separately from the magnetic body 25. At least one permanent magnet 41 is provided. Specifically, as indicated by broken lines in FIG. 3, a plurality of arc-shaped ones are used as the permanent magnet 41. The impeller 21 is attracted in opposite directions by both the permanent magnet 33 and the permanent magnet 41 of the rotor. The plurality of permanent magnets are arranged at an equal angle with respect to the center of the impeller. The number of permanent magnets 41 may be three or more, for example, four.

The centrifugal pump unit 2 includes a sensor 45 having a function for measuring the position of the impeller 21. Specifically, it has a plurality of position sensors 45 housed in the housing 20. A plurality of (for example, three) position sensors 45 are provided at equal angular intervals with respect to the center of the impeller, and the permanent magnet 41 and the position sensor 45 described above are also provided at equal angular intervals. . By providing the three position sensors 45 in this manner, the rotation axis (z-axis) direction of the impeller 21 and the inclination about the x-axis and the y-axis orthogonal to the rotation axis (z-axis) can be measured. The position sensor 45 detects the gap between the position sensor 45 and the magnetic body 29. As shown in FIG. 1, the detection output of the position sensor 45 is sent to the control unit 51 of the control device 6 that controls the motor current.
The control device 6 includes a sensor unit 57 for the sensor 45, a control unit 51, a power amplifier 52 for the motor, a motor control circuit 53, and a motor current monitoring unit 55.

  The blood pump device preferably has a blood viscosity calculation function for calculating blood viscosity using the output of the position sensor 45. Specifically, the control device 6 has a viscosity measuring function. As the blood viscosity calculation function, for example, the rotational speed temporary lowering function that temporarily reduces the impeller rotational speed to a predetermined rotational speed, and the sensor is used to temporarily rotate the impeller to the predetermined rotational speed by the rotational speed temporary lowering function. There is one that detects the oscillation width of the impeller in a state where the rotational speed is reduced, and calculates the blood viscosity using the oscillation width. The blood viscosity calculation function is a storage unit that stores relational data between the oscillation width of the impeller and blood viscosity at a predetermined rotational speed or a viscosity calculation formula calculated from the relational data, and a fluctuation obtained from the output of the sensor. It is preferable to have a viscosity calculation function for calculating the viscosity from the moving width data and the relation data stored in the storage unit or the viscosity calculation formula.

More specifically, in the blood pump device 1 of this embodiment, the control device 6 has a function of reducing the motor rotational speed to a predetermined rotational speed by adjusting the motor current, and the impeller swing at the predetermined rotational speed. The relationship of the movement (up and down movement of the impeller, expressed as μm Peak to Peak) is stored for different blood viscosities, and the blood viscosity is calculated from the sensor detection result and the motor rotation speed.
If the distance between the position sensor and the impeller is detected by the position sensor 45 at an interval of 120 degrees as shown in FIG. 3 for the impeller rotating with the hydrodynamic bearing, the sensor output is a rotation speed cycle (for example, 0.05 second at 1200 rpm). ) Changes to a sine wave. The sine wave Peak to Peak is the impeller oscillation. For example, in the case of an impeller centrifugal hydrodynamic bearing pump having a diameter of 40 mm, the oscillation is as shown in Table 1 below.

  Here, the state of the outflow port is shown in the case of a pump in the case of Open and Close which are frequently used conditions. Then, at a low rotational speed (in this case, 1000 rpm) at which the dynamic pressure effect on the inflow port side does not appear, the higher the viscosity, the smaller the oscillation. Conversely, at 1500 rpm, the difference in oscillation becomes small due to the dynamic pressure effect on the inflow port side. This relationship is measured in advance for a plurality of viscosities (for example, 2 to 5 mPa · s at 1 mPa · s interval) at a predetermined rotation speed (specifically, 800 to 1200 rpm), and the relational expression obtained from the data or data The data is stored, and the viscosity is calculated from the actually measured swing value and the above data. Swing changes slightly depending on the state of the outflow port, but when used as an auxiliary artificial heart for a living body, the state close to Open or Close can be found from the change in motor current, so the swing at that time can be selected. .

(Table 1)
┌─────┬─────────────┬─────────────┐
│ Outflow port │ Open │ Close │
├─────┼──────┬──────┼──────┬──────┤
│ Viscosity │2mPa ・ s│4mPa ・ s│2mPa ・ s│4mPa ・ s│
│ 1000rpm │ 20 │ 18 │ 25 │ 18 │
│ 1500rpm │ 25 │ 25 │ 27 │ 28 │
└─────┴──────┴──────┴──────┴──────┘

The pump device 1 according to the present invention includes a first dynamic pressure groove 38 provided on the inner surface of the housing on the impeller rotational torque generating unit 3 side or on the surface of the impeller 21 on the impeller rotational torque generating unit 3 side.
As shown in FIG. 6, the first dynamic pressure groove 38 is formed in a size corresponding to the bottom surface (rotor side surface) of the impeller 21. Further, as shown in FIG. 8, the dynamic pressure groove 38 has one end on the periphery (circumference) of a circular portion slightly spaced from the center of the housing inner surface 20a, and is formed in a spiral shape (in other words, curved). It extends so that the width gradually increases to the vicinity of the outer edge of the inner surface 20a (dynamic pressure groove forming portion 39). The dynamic pressure groove 38 is constituted by a dynamic pressure groove group including a large number of isolated dynamic pressure grooves. The respective dynamic pressure grooves 38 have substantially the same shape and are arranged at substantially the same angular intervals. The dynamic pressure groove 38 is a recess, and the depth is preferably about 0.05 to 0.4 mm. About 6 to 36 dynamic pressure grooves are preferably provided. In this embodiment, 16 dynamic pressure grooves are arranged at an equal angle with respect to the central axis of the impeller.

The dynamic pressure groove may be provided not on the housing side but on the rotor side surface of the impeller 21. Also in this case, it is preferable to have the same configuration as the above-described dynamic pressure groove.
Although it is attracted to the impeller rotational torque generating portion 3 side, it has a dynamic pressure groove as described above, so it is formed between the dynamic pressure groove 38 of the housing and the bottom surface of the impeller 21 (or between the dynamic pressure groove of the impeller and the inner surface of the housing). Due to the effect of the hydrodynamic bearing, it is slightly separated from the inner surface of the housing and rotates in a non-contact state to secure a blood flow path between the lower surface of the impeller and the inner surface of the housing. Prevent the occurrence of thrombus.
In this pump device, the dynamic pressure groove 38 includes a first side 38a and a second side 38b that extend from the peripheral edge of the dynamic pressure groove forming portion 39 to the center side and face each other, as shown in FIGS. A third side 38c connecting between one ends of the first side 38a and the second side 38b, and a fourth side 38d connecting between the other ends of the first side 38a and the second side 38b. The first side 38a and the second side 38b are formed by arcs having different centers.

In particular, in this embodiment, the first side 38a and the second side 38b are formed by arcs having different centers and different radii. The dynamic pressure grooves may be formed by arcs having different radii at the same center, or the dynamic pressure grooves may be formed by arcs having the same radius at different centers. However, by forming the dynamic pressure groove with arcs having different centers and radii as described above, when the dynamic pressure groove is formed with arcs having different radii at the same center, and when the dynamic pressure grooves are formed with arcs having the same radius at different centers. Compared with the case where it forms, the width | variety in the peripheral part of the dynamic pressure groove formation part of a dynamic pressure groove can be made wide.
In this embodiment, the third side 38c and the fourth side 38d are formed by arcs having the same center and different radii.

  Referring to FIG. 8, in one dynamic pressure groove of this embodiment, the first side 38 a is formed by a radius Ra arc with the point P 2 outside the groove forming part 39 as the center. The second side 38b is formed by an arc having a radius Rb with the point P3 outside the groove forming portion 39 as the center. Ra varies depending on the size of the pump device, but is preferably 30 to 70 mm. Rb varies depending on the size of the pump device, but is preferably 30 to 70 mm. The distance between P2 and P3 is preferably 3 to 10 mm. The third side 38c is formed by an arc having a radius Rc with the center P1 of the groove forming part 39 as the center. The fourth side 38d is formed by an arc having a radius Rd with the center P1 of the groove forming part 39 as the center. Rc varies depending on the size of the pump device, but is preferably 6 to 18 mm. Rd varies depending on the size of the pump device, but is preferably 15 to 30 mm. Rc is preferably 0.3 to 0.8 of Rd.

Further, the dynamic pressure groove 38 is a sum B (B = Bo + B1) of the width Bo of the peripheral portion and the width B1 of the non-existing dynamic pressure groove between the peripheral edges of the adjacent dynamic pressure grooves 38 and the width Bo shown in FIG. The groove width related value s (s = Bo / B) calculated from the above is 0.6 to 0.8.
Furthermore, in the pump device of this embodiment, the four corners 38e, 38f, 38g, 38h formed by the four sides 38a, 38b, 38c, 38d of the dynamic pressure groove 38 are rounded. The four corners are preferably rounded so as to have an R of at least 0.1 mm.
In the pump device of the present invention, the impeller in the dynamic pressure groove forming portion 38 of the dynamic pressure groove forming portion when the impeller rotates and the distance h1 between the housing and the impeller in the non-existing portion of the dynamic pressure groove forming portion during the rotation of the impeller The groove depth-related value a (a = h1 / h2) calculated from the inter-housing distance h2 is formed to be 1.5 to 2.5.

The dynamic pressure groove 38 has the above-described groove width related value s (s = Bo / B) of 0.6 to 0.8 and the groove depth related value a (a = h1 / h2). However, since the groove width is larger than that of logarithmic dynamic pressure grooves having the same number of dynamic pressure grooves and the groove depth is shallow, Less occurrence.
The pump device 1 preferably includes a second dynamic pressure groove 71 provided on the inner surface of the housing 20 on the permanent magnet 41 side or the surface of the impeller 21 on the permanent magnet 41 side.
As shown in FIG. 7, the second dynamic pressure groove 71 is preferably formed in an outer edge shape substantially the same as the above-described dynamic pressure groove 38. In FIGS. 6 and 7, the direction of rotation of the impeller is indicated by an arrow. As can be seen, the impeller is located on the surface of the dynamic pressure groove in FIGS. 6 and 7. The first dynamic pressure groove 38 and the second dynamic pressure groove 71 have the same spiral direction of the dynamic pressure groove group with respect to the rotation direction of the impeller. In this embodiment, the impeller rotates in the spiral direction on the dynamic pressure groove 38 side, and the impeller also rotates in the spiral direction on the dynamic pressure groove 71.

As shown in FIG. 7, the second dynamic pressure groove 71 is formed in a size corresponding to the upper surface (side surface of the permanent magnet) of the impeller 21. Further, like the one shown in FIG. 8, the dynamic pressure groove 71 has one end on the periphery (circumference) of a circular portion slightly spaced from the center of the housing inner surface 20a, and is spirally (in other words, curved). The width of the housing inner surface 20a extends so as to gradually increase to the vicinity of the outer edge (dynamic pressure groove forming portion). The dynamic pressure groove 71 is constituted by a dynamic pressure groove group including a large number of isolated dynamic pressure grooves. The dynamic pressure grooves 71 have substantially the same shape and are arranged at substantially the same angular intervals. The dynamic pressure groove 71 is a recess, and the depth is preferably about 0.05 to 0.4 mm. About 6 to 36 dynamic pressure grooves are preferably provided. In this embodiment, 16 dynamic pressure grooves are arranged at an equal angle with respect to the central axis of the impeller.
The dynamic pressure groove may be provided not on the housing side but on the surface of the impeller 21 on the permanent magnet side. Also in this case, it is preferable to have the same configuration as the above-described dynamic pressure groove.
Since the second dynamic pressure groove 71 is provided, the impeller may come close to the second dynamic pressure groove side housing when the disturbance or the dynamic pressure by the first dynamic pressure groove becomes excessive. However, since the dynamic pressure resulting from the second dynamic pressure groove is generated, it is possible to prevent the impeller from contacting the second dynamic pressure groove side housing.

  In the illustrated embodiment, the dynamic pressure groove 71 also extends from the peripheral edge of the dynamic pressure groove forming portion 39 to the center side as shown in FIGS. A first side 38a and a second side 38b; a third side 38c connecting one end of the first side 38a and the second side 38b; and the other end of the first side 38a and the second side 38b. The first side 38a and the second side 38b are formed by circular arcs having different centers. In particular, in this embodiment, the first side 38a and the second side 38b are formed by arcs having different centers and different radii. In this embodiment, the third side 38c and the fourth side 38d are formed by arcs having the same center and different radii.

Next, a centrifugal blood pump device according to another embodiment of the present invention will be described.
FIG. 10 is a front view of another embodiment of the centrifugal blood pump device of the present invention. FIG. 11 is a longitudinal sectional view of the centrifugal blood pump apparatus of the embodiment shown in FIG. 12 is a cross-sectional view taken along line DD of the centrifugal blood pump device of FIG. 13 is a bottom view of the centrifugal blood pump apparatus of FIG. In addition, the top view of the centrifugal blood pump apparatus of the Example shown in FIG. 10 is the same as FIG.
The substantial difference between the pump device 50 of this embodiment and the pump device 1 of the above-described embodiment is only the mechanism of the impeller rotational torque generating unit 3. The impeller rotational torque generator 3 in the pump device 50 of this embodiment is of a type that directly drives the impeller without providing a so-called rotor. Also in the pump device 50 of this embodiment, the impeller 21 rotates without contacting the inner surface of the housing due to the pressure generated by the dynamic pressure groove during rotation. In the following description, only differences will be described. The forms of the sensor 45, the dynamic pressure grooves 38 and 71, and the control unit 6 are the same as those in the above-described embodiment.

In the pump device 50 according to this embodiment, the impeller rotational torque generating unit 3 includes a plurality of stator coils 61 housed in the housing 20 as shown in FIGS. 11 and 13. A plurality of stator coils 61 are arranged on the circumference so as to be substantially equiangular with respect to the central axis of the circumference. Specifically, six stator coils are used. As the stator coil, a multi-layer stator coil is used. By switching the direction of the current flowing through each stator coil 61, a rotating magnetic field is generated, and the impeller is attracted and rotated by this rotating magnetic field.
And as shown in FIG. 12, the impeller 21 has a plurality of (for example, 6 to 12) magnetic bodies 25 (permanent magnets, driven magnets) embedded therein. In this embodiment, the magnetic body 25 is embedded in the lower shroud 27. The magnetic body 25 (permanent magnet) embedded in the impeller is attracted to the side opposite to the blood inflow port 22 by the stator coil 61 of the impeller rotational torque generating unit 3 and coupled with the operation of the stator coil 61 and the rotational torque is impeller. To communicate.

In addition, by embedding a certain number of magnetic bodies 25 as in this embodiment, sufficient magnetic coupling with the stator coil 61 can be ensured. The shape of the magnetic body 25 (permanent magnet) is preferably substantially trapezoidal. The magnetic body 25 may be either a ring shape or a plate shape. Moreover, it is preferable that the number and arrangement | positioning form of the magnetic body 25 respond | correspond to the number and arrangement | positioning form of a stator coil. The plurality of magnetic bodies 25 are arranged on the circumference so that the magnetic poles are alternately different and at substantially the same angle with respect to the central axis of the impeller.
Further, in all the embodiments described above, the outer edge shape of the dynamic pressure groove is preferably the above-mentioned one, but is not limited to this, for example, a so-called logarithmic spiral groove as shown in FIG. Also good.

FIG. 1 is a block diagram of an embodiment including a control mechanism of a blood pump device of the present invention. FIG. 2 is a front view of an embodiment of the blood pump device of the present invention. FIG. 3 is a plan view of the blood pump device shown in FIG. 4 is a cross-sectional view taken along line AA in FIG. 5 is a cross-sectional view taken along line BB in FIG. 6 is a cross-sectional view showing a state where the impeller is removed from the cross-sectional view taken along the line B-B in FIG. 4. 7 is a cross-sectional view showing a state where the impeller is removed from the cross-sectional view taken along the line CC of FIG. FIG. 8 is an explanatory diagram for explaining the form of the dynamic pressure groove. FIG. 9 is an explanatory diagram for explaining the form of the dynamic pressure groove. FIG. 10 is a plan view of another embodiment of the blood pump device of the present invention. FIG. 11 is a longitudinal sectional view of the blood pump device of FIG. 12 is a cross-sectional view taken along line DD of the blood pump device of FIG. 13 is a bottom view of the blood pump device of FIG. FIG. 14 is an explanatory view for explaining the form of a logarithmic spiral type dynamic pressure groove.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Blood pump apparatus 2 Pump part 3 Impeller rotational torque generation part 20 Housing 21 Impeller 25 Magnetic body 31 Rotor 34 Motor 38 Dynamic pressure groove 45 Sensor

Claims (8)

A housing having a blood inflow port and a blood outflow port, a pump unit having a magnetic body, and having an impeller that rotates in the housing and feeds blood, and for sucking and rotating the impeller of the pump unit An impeller rotational torque generating unit, and the pump unit further includes a dynamic pressure groove provided on a housing inner surface of the impeller rotational torque generating unit side or a surface of the impeller on the side of the impeller rotational torque generating unit, A blood pump device in which the impeller rotates in a non-contact state with respect to the housing;
The pump unit includes a sensor for measuring the position of the impeller in a state where the impeller rotates in a non-contact state with the housing by a dynamic pressure by the dynamic pressure groove, and the magnetic body of the impeller or the magnetic A permanent magnet that attracts a second magnetic body provided separately from the body in a direction opposite to the direction of attraction by the impeller rotational torque generating unit, and a housing inner surface on the permanent magnet side or a surface on the permanent magnet side of the impeller And a second dynamic pressure groove formed . The blood pump device according to claim 1, wherein the sensor is for measuring a flying distance of the impeller in the housing. The blood pump device according to claim 1 or 2 , wherein at least three sensors are provided so as to be equiangular with respect to a central axis of the impeller. The blood pump device according to any one of claims 1 to 3 , wherein the blood pump device has a blood viscosity calculation function for calculating blood viscosity using an output of the sensor. The blood viscosity calculation function includes a rotational speed temporary lowering function for temporarily reducing the impeller rotational speed to a predetermined rotational speed, and an impeller at a predetermined rotational speed by the rotational speed temporary lowering function using the sensor. The blood pump device according to claim 4 , further comprising a blood viscosity calculation function that detects a swinging width of the impeller in a state where the rotational speed of the impeller is reduced and calculates a blood viscosity using the swinging width. The blood viscosity calculation function includes a storage unit that stores relational data between the oscillation width of the impeller and the blood viscosity at the predetermined rotational speed or a viscosity calculation formula calculated from the relational data, and a fluctuation obtained from the output of the sensor. 6. The blood pump device according to claim 5 , further comprising a viscosity calculation function for calculating a viscosity based on dynamic width data and the relation data stored in the storage unit or a viscosity calculation formula. The impeller rotation torque generating section includes a rotor having a magnet for attracting the first magnetic material of said impeller, as claimed in any one of claims 1 to 6 in which and a motor for rotating the rotor Blood pump device. The impeller rotation torque generating section in any one of the claims 1 to those having a plurality of stator coils arranged on the circumference in order to rotate the impeller 6 sucks the magnetic of the impeller The blood pump device described.

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