WO2018135478A1

WO2018135478A1 - Pump

Info

Publication number: WO2018135478A1
Application number: PCT/JP2018/000989
Authority: WO
Inventors: 森武寿; 畑優; 野尻利彦
Original assignee: テルモ株式会社
Priority date: 2017-01-18
Filing date: 2018-01-16
Publication date: 2018-07-26
Also published as: JPWO2018135478A1; JP7150616B2

Abstract

This pump (10) is provided with: an impeller (12) which rotates to deflect, in a direction intersecting an axis, a flow traveling in the axial direction; a housing (14) which surrounds the impeller (12); and straightening plates (44) which are provided between the impeller (12) and the housing (14), and which deflect the flow traveling in the direction intersecting the axis (a) generated by the impeller (12). The straightening plates (44) are provided with straightening starting portions (44a) which are provided next to the outer circumference of the impeller (12).

Description

pump

The present invention relates to a pump including a rectifying plate that rectifies a flow from an impeller.

Heart failure is a condition in which the blood volume necessary for metabolism in the whole body tissue cannot be ejected from the heart due to a decrease in cardiac function. When cardiac function is significantly reduced, it is necessary to assist cardiac output. In recent years, blood pumps (auxiliary pumps) that are inserted into the heart percutaneously have been developed.

The pump disclosed in US Pat. No. 9,308,302 is composed of an axial flow type impeller, a housing surrounding the impeller, and a plurality of blades disposed adjacent to the downstream side (proximal direction side) of the impeller. A stator (rectifier plate), and is configured to rectify the flow from the impeller by the stator.

In the pump of U.S. Pat. No. 9,308,302, in the impeller, housing, and rectifying plate of the axial flow pump, the flow caused by the impeller does not occur unless the clearance between the impeller and the housing is reduced. Can not be placed. In other words, the current plate cannot be adjacent to the radial direction of the impeller. Therefore, the current plate is only adjacent in the axial direction of the impeller, and the flow generated by the impeller cannot be sufficiently captured by the current plate, so that a sufficient pump function is not exhibited.

The present invention has been made in consideration of such problems. The flow by the impeller of the mixed flow pump or the centrifugal pump is generated without reducing the clearance between the impeller and the housing. Therefore, the present invention efficiently captures the flow generated by the impeller by the flow straightening plate that rectifies the flow in the direction intersecting the axis generated by the impeller adjacent to the radial direction of the impeller. It is an object of the present invention to provide a pump that can exhibit good pump performance.

In order to achieve the above object, the present invention provides an impeller that deflects axial flow in a direction intersecting the axis with rotation, a housing that surrounds the impeller, and an impeller disposed between the impeller and the housing. A rectifying plate that deflects a flow in a direction intersecting the axis generated by the impeller, and the rectifying plate has a rectification start portion disposed adjacent to an outer peripheral portion of the impeller. It is characterized by.

According to the pump configured as described above, the rectifying plate that deflects the flow in the axial direction in the direction intersecting the axis by the impeller and deflects the flow from the impeller is located beside the impeller (outside in the radial direction). The rectification start part is arranged in the. For this reason, when the outer peripheral part of an impeller and the position of a baffle plate adjoin, the flow which the baffle plate produced by the impeller can be caught efficiently, and it becomes possible to exhibit favorable pump performance.

The rectifying plate may protrude inward from the inner peripheral surface of the housing.

The pump may include a support member disposed inside the housing, and the rectifying plate may protrude outward from an outer peripheral surface of the support member.

The rectification start portion may extend in a circumferential direction around the axis or in a direction inclined with respect to the circumferential direction.

With this configuration, the flow from the impeller can be efficiently deflected by the rectification start unit.

The rectifying plate may deflect the flow in the direction intersecting the axis in the axial direction.

With this configuration, since the flow from the impeller is deflected in the axial direction by the rectifying plate, even better pump performance can be exhibited.

The rectifying plate may have a rectification end portion disposed downstream of the rectification start portion and the impeller.

This configuration makes it possible to increase the rectification distance and to fully demonstrate the rectification function of the rectifying plate.

The rectification end portion may extend in the axial direction.

With this configuration, since the flow from the impeller is deflected in the axial direction by the rectification end portion, it becomes possible to exhibit even better pump performance.

The rectifying plate may include an intermediate rectifying unit that is positioned downstream of the impeller and extends in a direction inclined with respect to the circumferential direction between the rectifying start unit and the rectifying end unit. Good.

With this configuration, since the flow from the impeller is gradually deflected to the axial flow, a better rectification function can be exhibited.

The rectification start unit, the intermediate rectification unit, and the rectification end unit may be connected in series.

With this configuration, the flow from the impeller is rectified seamlessly from the rectification start portion to the rectification end portion, so that a further excellent rectification function can be exhibited.

A plurality of the current plates may be arranged at intervals in the circumferential direction.

With this configuration, a sufficient rectification function is exhibited and a better pump performance can be obtained.

The impeller may have blades arranged radially, and the number of the rectifying plates may be larger than the number of blades in the circumferential direction.

The pump may have the form of a centrifugal pump that deflects the axial flow in the radial direction by the impeller.

By being a centrifugal pump, the effect of the present invention is exhibited more satisfactorily.

The pump may be in the form of a blood pump that is inserted into the heart to assist in reducing cardiac function.

∙ It can contribute effectively to the improvement of heart failure symptoms by being applied to blood pumps.

According to the pump of the present invention, the rectifying plate is disposed between the impeller and the housing, and the rectifying plate that deflects the flow from the impeller includes the rectification start portion disposed directly beside the impeller (outside in the radial direction). Have. For this reason, the flow pushed out to the outer periphery direction of an impeller can be caught efficiently, and it is possible to exhibit favorable pump performance.

It is structure explanatory drawing of the pump which concerns on embodiment of this invention. It is sectional drawing along the axial direction of the housing (the part in which the baffle plate was provided, and its peripheral part) of the said pump. It is the perspective view which looked at the said housing from the base end side. FIG. 4 is a front view of the housing viewed from the front end side (a cross-sectional view taken along line IV-IV in FIG. 2). It is explanatory drawing at the time of use of the said pump.

Hereinafter, preferred embodiments of the pump according to the present invention will be given and described with reference to the accompanying drawings.

A pump 10 according to this embodiment shown in FIG. 1 is inserted into the heart of a patient whose cardiac function has been significantly reduced, such as heart failure, for example, and is used for assisting cardiac output. It is configured as a pump 10A. The pump 10 includes an impeller 12, a hollow cylindrical housing 14 that surrounds the impeller 12, a drive shaft 16 that rotationally drives the impeller 12, and a catheter 18 through which the drive shaft 16 is inserted. The pump 10 is a long device having flexibility as a whole.

The impeller 12 has a hub 22 that forms the center of the impeller 12 and a blade structure 23 provided on the hub 22. In the present embodiment, the impeller 12 is a centrifugal pump impeller configured to deflect an axial flow in a radial direction. Therefore, the pump 10 is configured as a centrifugal pump. The pump 10 may be configured as a mixed flow pump in which the flow discharged by the impeller 12 is inclined with respect to the axial direction.

The hub 22 is connected and fixed to the tip of the drive shaft 16 and is driven to rotate about the axis a by the drive shaft 16. In addition, since the axis of the impeller 12 coincides with the axis a of the hub 22, it may be hereinafter referred to as “axis a of the impeller 12”.

The blade structure 23 includes a plurality of blades 26 in the axial direction, and a plurality of blades 26 are arranged at intervals in the circumferential direction around the axis a (hereinafter simply referred to as “circumferential direction”). Has been. A blade row 25 is constituted by a plurality of blades 26 extending (projecting) radially from the hub 22 in each stage. Note that the blade structure 23 may have the blade row 25 in only one stage in the axial direction.

In FIG. 1, the housing 14 is a hollow member having a distal end opening 14a and a proximal end opening 14b, and is a flexible member. The distal end opening 14a is a blood inflow port, and the proximal end opening 14b is a blood outflow port. The impeller 12 is rotatably disposed in the base end portion 14 c of the housing 14. Specifically, the base end portion 14 c of the housing 14 has an annular bulging portion 14 d surrounding the impeller 12.

A flexible tip member 42 is connected to the tip of the housing 14 via a plurality of connecting members 40 arranged in the circumferential direction. The plurality of connecting members 40 support the flexible tip member 42. The tip of the flexible tip member 42 is curved. A space 41 is formed between the plurality of connecting members 40, and blood can flow into the housing 14 from the tip opening 14 a through the space 41.

The proximal end portion 14 c of the housing 14 is supported by a support member 19 provided at the distal end portion of the catheter 18. The support member 19 is disposed in the base end portion 14 c (annular bulging portion 14 d) of the housing 14, and forms an annular fluid discharge path 21 extending in the axial direction between the support member 19 and the housing 14. Yes. The outer diameter of the support member 19 is set to be substantially the same as the outer diameter of the impeller 12. The outer diameter of the support member 19 may be set to be equal to or larger than the outer diameter of the impeller 12.

The base end portion 14c of the housing 14 and the support member 19 are connected by a plurality of connection members (rims) (not shown) arranged at intervals in the circumferential direction, whereby the housing 14 is supported so as not to rotate. Therefore, the housing 14 is a stationary part that does not rotate during operation of the pump 10.

The pump 10 includes an impeller 12, a hollow cylindrical housing 14 surrounding the impeller 12, a drive shaft 16 that rotationally drives the impeller 12, a catheter 18 through which the drive shaft 16 is inserted, and a sheath 20 through which the catheter 18 is inserted. With. The distal end portion of the drive shaft 16 protrudes from the support member 19 in the distal direction. The hub 22 of the impeller 12 is connected to the tip of the drive shaft 16 protruding from the support member 19. The drive shaft 16 is rotatably supported by a bearing portion (not shown) disposed inside the support member 19. The drive shaft 16, the catheter 18, and the sheath 20 extend to the proximal end side of the pump 10, and are all long members having flexibility.

Although not shown in detail, the drive shaft 16 is connected to an actuator (such as a motor) on the base end side (hand side) of the pump 10 and is driven to rotate by the actuator.

Between the impeller 12 and the housing 14, a rectifying plate 44 that deflects the flow in the direction intersecting the axis a generated by the impeller 12 is disposed. Specifically, a plurality of rectifying plates 44 are provided on the inner peripheral surface of the annular bulging portion 14 d surrounding the impeller 12 in the housing 14 at intervals in the circumferential direction. The plurality of rectifying plates 44 are arranged at equal intervals in the circumferential direction, and project radially inward from the inner circumferential surface of the annular bulging portion 14d. The rectifying plate 44 may be provided on the outer peripheral surface 19a of the support member 19 (may protrude radially outward from the outer peripheral surface 19a).

In the present embodiment, the number of blades 26 in the circumferential direction of the impeller 12 (the number of blades 26 constituting each blade row 25) is 4, and the number of rectifying plates 44 in the circumferential direction is 7. Therefore, the number of rectifying plates 44 is larger than the number of blades 26 in the circumferential direction. The number of rectifying plates 44 may be equal to or less than the number of blades 26 in the circumferential direction.

The rectifying plate 44 has a portion parallel to the axis a. The current plate 44 has a portion inclined with respect to the circumferential direction. The current plate 44 has a bent portion between the distal end and the proximal end. The rectifying plate 44 has a region overlapping with the impeller 12 and a region not overlapping with the impeller 12 in the axial direction. The current plate 44 has a plurality of regions arranged at different circumferential positions. Hereinafter, the configuration of the rectifying plate 44 will be specifically described.

As shown in FIGS. 2 and 3, the rectifying plate 44 includes a rectification start portion 44 a disposed adjacent to the outer peripheral portion of the impeller 12, and a rectification end disposed on the downstream side of the rectification start portion 44 a and the impeller 12. Unit 44b, and an intermediate rectification unit 44c disposed between the rectification start unit 44a and the rectification end unit 44b. The rectification start portion 44 a is a portion constituting the tip region of the rectification plate 44 and faces the outer peripheral portion of the impeller 12 in the radial direction. That is, the rectification start portion 44 a is disposed on the radially outer side of the outer peripheral portion of the impeller 12.

As shown in FIG. 2, the most advanced portion of the rectification start portion 44 a (the most advanced portion of the rectifying plate 44) is the most advanced portion of the wing structure 23 (the most advanced portion of the blade 26 on the tip side) and the wing structure 23. It is located between the most proximal end portion (most proximal end portion of the blade 26 on the proximal end side). More specifically, the most distal end portion of the rectification start portion 44a is located in a region overlapping with the outer end of the tip-side blade 26 in the axial direction. Note that the most distal portion of the rectification start portion 44a may be located in a region overlapping with the outer end of the blade 26 on the base end side in the axial direction.

As shown in FIG. 4, a radial clearance CL (space) is provided between the outer peripheral portion of the impeller 12 (the radially outer end of the blade 26) and the radially inner end of the rectification start portion 44a. Yes. The clearance CL is preferably set in a range in which the outer peripheral portion of the impeller 12 does not come into contact with the current plate 44 when the impeller 12 rotates. For example, the clearance CL is set to 0.1 to 2 mm, and preferably set to 0.5 to 1 mm. Is done.

2 and 3, the rectification start portion 44a extends in a direction inclined with respect to the circumferential direction. Specifically, the rectification start portion 44a is inclined so as to be displaced in the proximal direction toward the rotation direction (arrow R direction) of the impeller 12. The rectification start unit 44a may extend in a direction parallel to the circumferential direction.

The rectification end portion 44 b is a portion constituting the proximal end region of the rectifying plate 44 and faces the outer peripheral surface 19 a of the support member 19 in the radial direction. The position of the rectification end unit 44b is different from the position of the rectification start unit 44a in the circumferential direction. Specifically, the rectification end portion 44b is located closer to the rotation direction side of the impeller 12 than the rectification start portion 44a.

The radially inner end of the rectification end portion 44 b is in contact with the outer peripheral surface 19 a of the support member 19. The radially inner end of the rectification end portion 44b may not be in contact with the outer peripheral surface 19a of the support member 19 (between the radial inner end of the rectification end portion 44b and the outer peripheral surface 19a of the support member 19). Radial clearance (space) may be present). In this case, the clearance is preferably set as small as possible.

The rectification end portion 44b extends in parallel with the axis a of the impeller 12. Note that the rectification end portion 44b may extend in a direction inclined with respect to the axis a of the impeller 12 (a direction inclined with respect to the circumferential direction).

The intermediate rectifying unit 44c is a part constituting an intermediate region of the rectifying plate 44, and is located on the downstream side of the impeller 12 and extends in a direction inclined with respect to the circumferential direction. The intermediate rectification unit 44c is curved in an arc between the rectification start unit 44a and the rectification end unit 44b. Accordingly, the intermediate rectification unit 44c smoothly connects the proximal end of the rectification start unit 44a and the distal end of the rectification end unit 44b that are different in circumferential direction position.

In this embodiment, the rectification start portion 44a, the intermediate rectification portion 44c, and the rectification end portion 44b have the same protruding height from the inner peripheral surface 15 of the housing 14 (the inner peripheral surface of the annular bulging portion 14d). Accordingly, the rectifying plate 44 has a constant protrusion height from the distal end to the proximal end. The rectification start portion 44a, the intermediate rectification portion 44c, and the rectification end portion 44b may have different protrusion heights from the inner peripheral surface 15 of the housing 14.

In the present embodiment, the rectification start unit 44a, the intermediate rectification unit 44c, and the rectification end unit 44b have the same thickness (plate thickness). Therefore, the rectifying plate 44 has a constant thickness from the distal end to the proximal end. Note that the rectification start unit 44a, the intermediate rectification unit 44c, and the rectification end unit 44b may have different thicknesses. In this case, the thickness of the rectifying plate 44 may decrease from the distal end toward the proximal end or from the proximal end toward the distal end.

In this embodiment, the rectification start unit 44a, the intermediate rectification unit 44c, and the rectification end unit 44b are connected in series. That is, the rectification start part 44a, the intermediate rectification part 44c, and the rectification end part 44b are integrally formed. The rectifying plate 44 may be divided into a plurality of segments in the axial direction (may be formed discontinuously in the axial direction). In this case, the rectifying plate 44 may be divided into three stages of segments each serving as the rectification start unit 44a, the intermediate rectification unit 44c, and the rectification end unit 44b.

The rectifying plate 44 may have a straight line shape parallel to the axis a from the distal end to the proximal end. The rectifying plate 44 may be inclined with respect to the circumferential direction from the distal end to the proximal end. The rectifying plate 44 may have a straight region in which a distal end region is inclined with respect to the circumferential direction, and an intermediate region and a proximal end region are parallel to the axis a. The rectifying plate 44 may have a linear shape in which the distal end region and the proximal end region are inclined with respect to the circumferential direction, and the intermediate region is parallel to the axis a. The rectifying plate 44 may extend spirally from the distal end to the base end (in this case, only one spiral rectifying plate 44 may be provided, or two or more spiral rectifying plates 44 may be provided. Also good).

Next, the operation of the pump 10 (blood pump 10A) according to this embodiment configured as described above will be described.

The blood pump 10A is inserted, for example, from the artery of the leg (thigh) of the patient whose cardiac function has been lowered, and the distal end of the blood pump 10A is inserted into the heart 48 (in the left ventricle 54) as shown in FIG. Is done. Specifically, the distal end opening 14 a that is the inflow port of the housing 14 is disposed in the left ventricle 54, and the proximal end opening 14 b that is the outflow port of the housing 14 is disposed in the aorta 50.

In FIG. 5, when the impeller 12 is rotationally driven under the action of an actuator (not shown), the blood pump 10A sucks blood from the distal end opening 14a of the housing 14 and draws blood from the proximal end opening 14b of the housing 14. Discharge. This pump action releases pulmonary congestion due to a decrease in the internal pressure of the left atrium 56, reduces the myocardial burden due to a decrease in the internal pressure of the left ventricle 54, reduces myocardial ischemia due to an increase in coronary blood flow, and increases the systemic blood flow. Peripheral circulation dynamics are normalized.

In this case, the pump 10 according to the present embodiment has the following effects.

According to the pump 10, the impeller 12 deflects the axial flow in a direction intersecting the axis a, and the rectifying plate 44 that deflects the flow from the impeller 12 is directly beside the impeller 12 (outside in the radial direction). It has the commutation start part 44a arrange | positioned. The flow by the impeller of the mixed flow pump or the centrifugal pump is generated without reducing the clearance between the impeller and the housing. For this reason, since the outer peripheral part of the impeller 12 and the position of the rectifying plate 44 are adjacent to each other, the rectifying plate 44 can efficiently capture the flow generated by the impeller 12 and can exhibit good pump performance. Become.

The rectifying plate 44 protrudes inward from the inner peripheral surface 15 of the housing 14. With this configuration, a clearance is not formed between the inner peripheral surface 15 of the housing 14 and the rectifying plate 44, so that even better pump performance can be exhibited.

The rectification start portion 44a extends in the circumferential direction around the axis a or in a direction inclined with respect to the circumferential direction. With this configuration, the flow from the impeller 12 can be efficiently deflected by the rectification start unit 44a.

The rectifying plate 44 is configured to deflect the flow in the direction intersecting the axis a in the axial direction. With this configuration, the flow from the impeller 12 is deflected in the axial direction by the rectifying plate 44, so that even better pump performance can be exhibited.

The rectifying plate 44 includes a rectification start portion 44 a and a rectification end portion 44 b disposed on the downstream side of the impeller 12. With this configuration, the rectification distance can be increased and the rectification function of the rectifying plate 44 can be sufficiently exhibited.

The rectification end portion 44b extends in the axial direction. With this configuration, the flow from the impeller 12 is deflected in the axial direction by the rectification end portion 44b, so that even better pump performance can be exhibited.

The rectifying plate 44 includes an intermediate rectifying portion 44c that is located on the downstream side of the impeller 12 and extends in a direction inclined with respect to the circumferential direction between the rectifying start portion 44a and the rectifying end portion 44b. With this configuration, since the flow from the impeller 12 is gradually deflected to the axial flow, a better rectification function can be exhibited.

The rectification start unit 44a, the intermediate rectification unit 44c, and the rectification end unit 44b are connected in series. With this configuration, since the flow from the impeller 12 is rectified seamlessly from the rectification start unit 44a to the rectification end unit 44b, a better rectification function can be exhibited.

A plurality of rectifying plates 44 are arranged at intervals in the circumferential direction. The number of rectifying plates 44 is larger than the number of blades 26 in the circumferential direction. With this configuration, a sufficient rectification function is exhibited, and better pump performance is obtained.

The pump 10 has a form of a centrifugal pump in which an axial flow is deflected radially by an impeller 12. By being a centrifugal pump, the effect of the present invention is more satisfactorily exhibited.

The pump 10 has the form of a blood pump 10A that is inserted into the heart to assist in lowering cardiac function. By applying the present invention to a blood pump, it can effectively contribute to the improvement of symptoms of heart failure.

The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention. The present invention is also applicable to pumps other than medical pumps.

Claims

An impeller (12) for deflecting axial flow in a direction intersecting the axis with rotation;
A housing (14) surrounding the impeller (12);
A rectifying plate (44) disposed between the impeller (12) and the housing (14) and deflecting a flow in a direction intersecting the axis generated by the impeller (12),
The rectifying plate (44) has a rectification start portion (44a) disposed adjacent to the outer peripheral portion of the impeller (12).
A pump (10) characterized in that.
Pump (10) according to claim 1,
The rectifying plate (44) protrudes inward from the inner peripheral surface of the housing (14).
A pump (10) characterized in that.
Pump (10) according to claim 1,
A support member (19) disposed inside the housing (14);
The current plate (44) protrudes outward from the outer peripheral surface of the support member (19).
A pump (10) characterized in that.
The pump (10) according to any one of claims 1 to 3,
The rectification start portion (44a) extends in a circumferential direction around the axis, or in a direction inclined with respect to the circumferential direction.
A pump (10) characterized in that.
The pump (10) according to any one of claims 1 to 4,
The rectifying plate (44) deflects the flow in the direction intersecting the axis in the axial direction.
A pump (10) characterized in that.
The pump (10) according to any one of claims 1 to 5,
The rectifying plate (44) has a rectification end portion (44b) disposed downstream of the rectification start portion (44a) and the impeller (12).
A pump (10) characterized in that.
The pump (10) according to claim 6,
The rectification end portion (44b) extends in the axial direction.
A pump (10) characterized in that.
Pump (10) according to claim 7,
The rectifying plate (44) is positioned downstream of the impeller (12) and inclined with respect to the circumferential direction between the rectification start portion (44a) and the rectification end portion (44b). Having an intermediate rectifying section (44c) extending;
A pump (10) characterized in that.
Pump (10) according to claim 8,
The rectification start part (44a), the intermediate rectification part (44c) and the rectification end part (44b) are connected in series.
A pump (10) characterized in that.
The pump (10) according to any one of claims 1 to 9,
A plurality of the rectifying plates (44) are arranged at intervals in the circumferential direction.
A pump (10) characterized in that.
Pump (10) according to claim 10,
The impeller (12) has radially arranged vanes (26),
The number of the current plates (44) is larger than the number of the blades (26) in the circumferential direction.
A pump (10) characterized in that.
The pump (10) according to any one of claims 1 to 11,
The pump (10) has the form of a centrifugal pump that deflects axial flow radially by the impeller (12).
A pump (10) characterized in that.
The pump (10) according to any one of claims 1 to 12,
The pump (10) has the form of a blood pump (10A) inserted into the heart to assist in reducing cardiac function,
A pump (10) characterized in that.