CN114768083A

CN114768083A - Impeller shaft supporting structure of external drive ventricular assist device

Info

Publication number: CN114768083A
Application number: CN202210473221.5A
Authority: CN
Inventors: 孙英贤
Original assignee: First Hospital of China Medical University
Current assignee: First Hospital of China Medical University
Priority date: 2022-04-29
Filing date: 2022-04-29
Publication date: 2022-07-22

Abstract

The invention relates to the field of medical instruments, in particular to an impeller shaft supporting structure of an in vitro driving ventricular assist device, which comprises a supporting sleeve, wherein the front end of the supporting sleeve is connected with a pump blood vessel, the rear end of the supporting sleeve is connected with a guide pipe, an impeller shaft penetrates through the supporting sleeve and then is connected with a transmission shaft in the guide pipe, the front end of the supporting sleeve is provided with a front limiting element, the rear end of the supporting sleeve is provided with a rear limiting element, a sleeve inner cavity is formed between the front limiting element and the rear limiting element, a rotary supporting element for supporting the impeller shaft is arranged in the sleeve inner cavity, a spacer sleeve is arranged between every two adjacent rotary supporting elements, the front limiting element, the rear limiting element, the rotary supporting element and the impeller shaft are in clearance fit, one side of the guide pipe is provided with a liquid inlet pipe, and the liquid inlet pipe is communicated with the sleeve inner cavity. The invention realizes the impeller shaft suspension effect by filling liquid in the supporting sleeve, does not increase the partial volume of the impeller rotor part of the blood pump additionally, and can realize the timely flushing of the inner cavity of the sleeve while avoiding the blood infiltration.

Description

Impeller shaft supporting structure of external drive ventricular assist device

Technical Field

The invention relates to the field of medical instruments, in particular to an impeller shaft supporting structure of an external drive ventricular assist device.

Background

In medical clinics, when the cardiac function of a patient is seriously damaged, such as in acute myocardial infarction complicated by heart failure and cardiogenic shock, when the patient needs to be treated regularly or intervened, or before and after surgery, complications occur, and the like, the heart needs to be circularly supported, so that the patient can pass through a dangerous period. To meet the above therapeutic needs, ventricular assist devices have been developed.

At present, the ventricular assist device mainly comprises an in-vivo driving mode and an in-vitro driving mode, wherein the in-vivo driving mode generally adopts a mode of arranging a micro motor in a pump tube, but the integral diameter of a catheter is increased due to arrangement of a motor assembly and the like in a body, the trauma to blood vessels is large, and bleeding is easy to occur, so that the driving device is arranged outside the body of the human body and is a better scheme for solving the problem, for example, an axial flow ventricular assist device with an external driving mode is disclosed in Chinese patent invention CN 110237327A.

However, no matter in-vivo driving or in-vitro driving, the rotation supporting part of the impeller still has some defects, for example, because the impeller is in a blood pumping state of high-speed rotation, the friction between the impeller shaft and the related supporting element is large, the abrasion is fast, the service life of elements such as a bearing and the like is influenced, the service life of equipment is further influenced, after the rotation supporting element is abraded, on one hand, a gap is generated between the rotation supporting element and the impeller shaft, blood is easy to permeate into a blood pump conduit through the gap, on the other hand, after the supporting element is abraded, tiny debris impurities are generated, and if the debris impurities cannot be discharged in time, the debris impurities enter a human body through the gap between the impeller shaft and the supporting element, and adverse effects are generated.

In order to solve the above problems, a hydromagnetic suspension type impeller shaft supporting structure is provided in the prior art to enable an impeller to realize suspension support, for example, chinese patent of invention with an authorization publication number of CN204106667U discloses a hydromagnetic suspension type axial blood pump, wherein a lantern ring outer wall is provided outside a rotor, a flow inlet and a flow outlet are formed between the lantern ring outer wall and a pump pipe inner wall, the flow inlet is larger than the flow outlet, blood is squeezed to generate hydraulic pressure on the periphery of the outer wall of the lantern ring of a spiral groove, thereby enabling the impeller to realize radial hydraulic suspension, and a soft magnetic ring is provided behind a coil winding outside the pump pipe and an iron core, and has an axial backward attraction force on annular magnetic steel, thereby realizing axial magnetic suspension. However, the structure is in an in-vivo driving mode, the overall diameter of a pump pipe is large, the problem of large vessel trauma and the like can still be caused, and the suspension structure design mainly aims at the impeller and rotor blade part, and the diameter of the blood pump can be further increased through the suspension structure design.

The chinese patent publication No. CN111097077A discloses an external magnetic drive liquid suspension axial-flow blood pump, which is driven in vitro, so that the structure of stator winding, iron core, etc. is omitted, but the structure is designed for the impeller and rotor blade, a convergent wedge-shaped groove is formed between the impeller top edge and the pump cavity, the liquid generates the hydraulic pressure after entering the wedge-shaped groove to realize the radial suspension effect, and the rotor magnetic steel is arranged in the wedge-shaped groove.

Disclosure of Invention

The invention aims to provide an impeller shaft supporting structure of an extracorporeal drive ventricular assist device, which realizes the suspension effect of an impeller shaft by filling liquid in a supporting sleeve, reduces the friction between the impeller shaft and a rotating supporting element during rotation, prolongs the service life of equipment, does not increase the partial volume of an impeller of a blood pump additionally due to the supporting design of the impeller shaft, and can realize the timely flushing of the inner cavity of the sleeve while avoiding blood from permeating into a catheter of the blood pump.

The purpose of the invention is realized by the following technical scheme:

the utility model provides an external drive ventricle auxiliary device impeller shaft bearing structure, includes the support sleeve, just the support sleeve front end links to each other with the pump blood vessel, the rear end links to each other with the pipe, and the impeller shaft passes be connected with the transmission shaft in the pipe behind the support sleeve, the support sleeve front end is equipped with preceding limit element, the rear end is equipped with back limit element, just form the sleeve pipe inner chamber between preceding limit element and the back limit element, be equipped with the support in the sleeve pipe inner chamber the rotation support component of impeller shaft, and be equipped with the spacer between the adjacent rotation support component, preceding limit element, back limit element, rotation support component with be clearance fit between the impeller shaft, pipe one side is equipped with the feed liquor pipe, just the feed liquor pipe with sleeve pipe inner chamber intercommunication.

The impeller comprises an impeller shaft, a front limiting element and a rear limiting element, wherein the front end of the impeller shaft is provided with a shaft disc, the front limiting element is provided with a shaft disc cavity, the shaft disc is arranged in the shaft disc cavity, and a gap is formed between the shaft disc and the wall of the shaft disc cavity.

The front limiting element comprises a front blocking block and a front limiting sleeve, the rear limiting element is a rear limiting sleeve, the sleeve inner cavity is formed between the front limiting sleeve and the rear limiting sleeve, the front blocking block is arranged on one side, far away from the sleeve inner cavity, of the front limiting sleeve, and the shaft disc cavity is formed in the front blocking block.

And a sealing groove group is arranged on the front plugging block and is arranged on one side of the shaft disc cavity, which is far away from the inner cavity of the sleeve.

The utility model discloses a pipe suction device, including pipe inner chamber, pipe rear end, actuating mechanism, pipe inner chamber, pipe rear end is equipped with a actuating mechanism, actuating mechanism includes the casing and locates the inside drive arrangement of casing, the inside transmission shaft of pipe with drive arrangement links firmly, be equipped with the suction mouth of being connected with suction device on the casing, just the suction mouth pass through the pipeline with pipe inner chamber intercommunication.

The rotary supporting elements in the inner cavity of the sleeve are bearings, and a middle spacer sleeve is arranged between every two adjacent bearings.

A first bearing and a second bearing are arranged in the inner cavity of the sleeve, the first bearing is sleeved on the front portion of the impeller shaft, the second bearing is sleeved on the rear portion of the impeller shaft, and a middle spacer sleeve is arranged between the first bearing and the second bearing.

The rotary supporting elements in the inner cavity of the sleeve are balls, each group of balls are arranged along the circumferential direction of the impeller shaft, and two adjacent groups of balls are separated by a limiting spacer bush.

The invention has the advantages and positive effects that:

1. the invention has a liquid inlet pipe on one side of the conduit and is communicated with the sleeve inner cavity in the support sleeve, and each support element is in clearance fit with the impeller shaft, the liquid flows into the sleeve inner cavity through the liquid inlet pipe and fills the clearance between the support element and the impeller shaft to realize the radial suspension effect of the impeller shaft, the shaft disc on the impeller shaft is accommodated in the shaft disc cavity on the front block to realize the axial limit, and simultaneously the shaft disc cavity is filled with the liquid filling liquid and acts with the shaft disc on the impeller shaft to realize the axial suspension effect of the impeller to replace the magnetic axial suspension design in the prior art, thereby reducing the contact friction between the impeller shaft and the rotary support element when rotating, prolonging the service life of the equipment.

2. According to the invention, the supporting sleeve is additionally arranged between the pump blood vessel and the head end of the conduit, the supporting sleeve is internally provided with a plurality of rotary supporting elements for assisting in supporting the impeller shaft, and because the clearance between the supporting elements and the impeller shaft is limited, the supporting elements form a similar liquid film filling effect, the impeller shaft may be contacted with the supporting elements when rotating at a high speed, but the arrangement of the rotary supporting elements can ensure the real-time rotation state of the impeller shaft, and the arrangement of the plurality of rotary supporting elements ensures the stable support of the impeller shaft.

3. The liquid inlet pipe is used for filling liquid into the inner cavity of the sleeve, and the liquid in the inner cavity of the sleeve can flow out from a gap between the rear limiting element and the impeller shaft through the action of the suction device to realize the flushing effect.

4. The front plugging block is provided with the sealing groove group to ensure sealing, and meanwhile, the pressure balance between the liquid-filled liquid and the blood in the front plugging block can be ensured by matching with a pressure sensor or a CFD simulation mode and the like, so that the blood is prevented from entering the catheter.

Drawings

FIG. 1 is a schematic structural diagram of one embodiment of the present invention,

figure 2 is a schematic structural view of another embodiment of the present invention,

figure 3 is an enlarged schematic view of the junction of the support sleeve and the pump vessel of figure 1,

FIG. 4 is a schematic structural diagram of an extracorporeal drive ventricular assist device using the present invention,

figure 5 is a schematic view of the drive mechanism of figure 4,

fig. 6 is a simulated pressure cloud of the cross-section at a in fig. 3.

The device comprises a support sleeve 1, a sleeve inner cavity 101, a middle spacer bush 102, a front blocking block 2, a shaft disc cavity 201, a sealing groove group 202, a front limiting bush 3, a first bearing 4, an impeller shaft 5, a shaft disc 501, a second bearing 6, a rear limiting bush 7, a guide pipe 8, a transmission shaft 9, a liquid inlet pipe 10, a pump blood pipe 11, an impeller 12, a limiting spacer bush 13, a ball 14, a driving mechanism 15, a driving device 151 and a suction port 152.

Detailed Description

The present invention will be described in more detail with reference to the accompanying drawings.

As shown in fig. 1 to 5, the present invention comprises a support sleeve 1, wherein the front end of the support sleeve 1 is connected with a pump vessel 11, the rear end of the support sleeve is connected with a guide tube 8, an impeller 12 is arranged in the pump vessel 11, an impeller shaft 5 at the rear side of the impeller 12 passes through the support sleeve 1 and then is connected with a transmission shaft 9 arranged in the guide tube 8, the front end of the support sleeve 1 is provided with a front limiting element, the rear end of the support sleeve 1 is provided with a rear limiting element, a sleeve cavity 101 is formed between the front limiting element and the rear limiting element, a rotary supporting element for supporting the impeller shaft 5 is arranged in the sleeve cavity 101, a spacer is arranged between adjacent rotary supporting elements, the front limiting element, the rear limiting element and the spacer are matched to limit the axial displacement of each rotary supporting element, the front limiting element, the rear limiting element and the rotary supporting element are all sleeved on the impeller shaft 5 and are in clearance fit with the impeller shaft 5, a liquid inlet pipe 10 is arranged on one side of the guide pipe 8, the liquid inlet pipe 10 is communicated with the inner cavity 101 of the sleeve, a shaft disc 501 is arranged at the front end of the impeller shaft 5, a shaft disc cavity 201 is arranged on the front limiting element, the shaft disc 501 is arranged in the shaft disc cavity 201, and a gap is also formed between the shaft disc 501 and the wall of the shaft disc cavity 201 to realize liquid filling. As shown in figure 1, when the impeller shaft suspension device works, liquid enters the inner cavity 101 of the sleeve through the liquid inlet pipe 10 and fills the whole inner cavity 101 of the sleeve, and the impeller shaft 5, the front limiting element, the rear limiting element and the rotary supporting element are in clearance fit, so that the impeller shaft 5 can realize a radial suspension effect after the clearance is filled with the liquid, and meanwhile, the shaft disc cavity 201 is filled with the liquid and generates a tendency of axial extrusion on the shaft disc 501, so that the axial suspension effect of the impeller shaft 5 is realized. The liquid filling liquid is normal saline or other liquid harmless to human body, even if a small amount of liquid enters into human body, the liquid in the inner cavity 101 of the sleeve can flow out into the inner cavity of the conduit 8 through a gap between the rear limiting element and the impeller shaft 5, as shown in fig. 1, so that a small amount of friction debris or other impurities generated in the inner cavity 101 of the sleeve can be flushed out of the support sleeve 1.

As shown in fig. 1-2, the front limiting element at the front end of the supporting sleeve 1 comprises a front blocking block 2 and a front limiting sleeve 3, the rear limiting element at the rear end of the supporting sleeve 1 is a rear limiting sleeve 7, the sleeve inner cavity 101 is formed between the front limiting sleeve 3 and the rear limiting sleeve 7, the front blocking block 2 is arranged on one side, away from the sleeve inner cavity 101, of the front limiting sleeve 3, and the shaft disc cavity 201 is arranged on the front blocking block 2.

As shown in fig. 1-2, a sealing groove group 202 is disposed on the front block 2, and the sealing groove group 202 is disposed on a side of the shaft disc cavity 201 away from the casing inner cavity 101, so that when the impeller 12 rotates, the sealing groove group 202 is filled with liquid to achieve a dynamic sealing effect.

As shown in fig. 4 to 5, a driving mechanism 15 is disposed at the rear end of the conduit 8, the driving mechanism 15 includes a housing and a driving device 151 disposed inside the housing, the conduit 8 is fixedly connected to the housing, the transmission shaft 9 inside the conduit 8 is fixedly connected to the driving device 151, the driving device 151 transmits torque through the transmission shaft 9 to further drive the impeller shaft 5 to rotate, which is a technique known in the art, a suction port 152 connected to a suction device is disposed on the housing, the suction port 152 is communicated with the inner cavity of the conduit 8 through a pipeline, and liquid in the inner cavity 101 of the casing flows along the inner cavity of the conduit 8 through the action of the suction device to be discharged, so as to achieve the purpose of flushing. The driving device 151 and the suction device are well known in the art, and the driving device 151 may employ a motor, an electric motor, or the like, and the suction device may employ a suction pump, or the like. As shown in fig. 5, the rear end of the liquid inlet pipe 10 provided on one side of the guide pipe 8 is connected to a liquid inlet device. The liquid inlet device controls the liquid filling flow rate of the liquid inlet pipe 10, although liquid flows out from a gap between the rear limiting sleeve 7 and the impeller shaft 5 for flushing, the inner cavity 101 of the sleeve can be ensured to be filled with the liquid as long as the liquid filling flow rate is higher than the liquid outlet flow rate. The liquid inlet device can adopt a liquid pump and other devices.

As shown in FIGS. 1-3, the present invention can select different rotation support elements according to the requirement.

The first embodiment is as follows:

as shown in fig. 1, in this embodiment, the impeller shaft 5 is supported by bearings, the first bearing 4 and the second bearing 6 are disposed in the inner cavity 101 of the sleeve, the intermediate spacer 102 is disposed between the first bearing 4 and the second bearing 6, the first bearing 4 supports the front portion of the impeller shaft 5, the second bearing 6 supports the rear portion of the impeller shaft 5, and the front blocking block 2, the front limiting sleeve 3, the intermediate spacer 102 and the rear limiting sleeve 7 realize axial limiting of the two bearings, when the inner cavity 101 of the sleeve between the two bearings is filled with liquid, the liquid simultaneously fills gaps between the front limiting sleeve 3, the first bearing 4, the second bearing 6, the rear limiting sleeve 7 and the impeller shaft 5 and the hub cavity 201, thereby realizing a suspension effect of the impeller shaft 5, reducing contact friction between the impeller shaft 5 and the two bearings when rotating at a high speed, and prolonging service life of the device, meanwhile, as shown in fig. 3, the sealing groove group 202 on the front blocking piece 2 can achieve a dynamic sealing effect, so that blood is prevented from flowing into the inner cavity 101 of the cannula, and the liquid-filled liquid can maintain a certain liquid pressure to balance the blood pressure, so that blood is prevented from flowing into the support cannula 1, as shown in fig. 3, pressure sensors can be arranged at the position a and the position B as required to monitor the blood pressure and the liquid-filled liquid pressure in real time, so that the pressure balance at the two sides of the front blocking piece 2 is ensured, and further, when the impeller pumps blood, the blood cannot enter the inner cavity 101 of the cannula. Both the pressure sensor and the CFD simulation are well known in the art. In addition, as shown in fig. 1, in this embodiment, the cannula lumen 101 with different volumes can be designed by designing the first bearing 4, the second bearing 6 and the middle spacer 102 with different length specifications according to actual needs, so as to change the pressure range of the liquid filled in the cannula lumen 101, and the design is more flexible.

In operation, the liquid in the lumen 101 of the cannula can flow out from the gap between the rear limiting sleeve 7 and the impeller shaft 5 into the lumen of the catheter 8 by the suction device and flush the lumen 101 of the cannula.

The second embodiment:

as shown in fig. 2, the present embodiment is different from the first embodiment in that: in the embodiment, the impeller shaft 5 is supported by the balls 14 to rotate, each group of balls 14 is arranged along the circumferential direction of the impeller shaft 5, two adjacent groups of balls 14 are separated by the limiting spacer bush 13 sleeved on the impeller shaft 5 to realize axial limiting, a gap is also arranged between the limiting spacer bush 13 and the impeller shaft 5, and the same suspension effect as that in the first embodiment can be realized after liquid filling liquid is injected into the inner cavity 101 of the sleeve.

Example three: the difference between this embodiment and the first embodiment is: in this embodiment, the structure of the hub cavity 201 and the hub 501 on the front blocking piece 2 can be omitted, and the impeller shaft 5 only realizes radial suspension, wherein as shown in fig. 4, the front end shaft of the impeller 12 is rotationally connected with and limited in front of the pump vessel 11.

Claims

1. The utility model provides an external drive ventricular assist device impeller shaft bearing structure which characterized in that: comprises a support sleeve (1), the front end of the support sleeve (1) is connected with a pump blood vessel (11), the rear end is connected with a conduit (8), an impeller shaft (5) passes through the support sleeve (1) and then is connected with a transmission shaft (9) in the conduit (8), the front end of the supporting sleeve (1) is provided with a front limiting element, the rear end is provided with a rear limiting element, a sleeve inner cavity (101) is formed between the front limiting element and the rear limiting element, a rotary supporting element for supporting the impeller shaft (5) is arranged in the sleeve inner cavity (101), and a spacer sleeve is arranged between the adjacent rotating support elements, the front limiting element, the rear limiting element, the rotating support elements and the impeller shaft (5) are in clearance fit, a liquid inlet pipe (10) is arranged on one side of the conduit (8), and the liquid inlet pipe (10) is communicated with the inner cavity (101) of the sleeve.

2. An in vitro driving ventricular assist device impeller shaft support structure according to claim 1, wherein: the impeller shaft (5) front end is equipped with hub (501), preceding spacing spare is equipped with hub chamber (201), hub (501) are located in hub chamber (201), and be equipped with the clearance between hub (501) and the chamber wall in hub chamber (201).

3. An in vitro driving ventricular assist device impeller shaft support structure according to claim 2, wherein: preceding stopper piece includes preceding stop block (2) and preceding stop collar (3), back stop collar (7) are back stop collar (7), form between preceding stop collar (3) and back stop collar (7) sleeve pipe inner chamber (101), preceding stop block (2) are located preceding stop collar (3) and are kept away from sleeve pipe inner chamber (101) one side be equipped with on preceding stop block (2) reel chamber (201).

4. An extracorporeal drive ventricular assist device impeller shaft support structure as claimed in claim 3, wherein: the front plugging block (2) is provided with a sealing groove group (202), and the sealing groove group (202) is arranged on one side, far away from the inner cavity (101) of the sleeve, of the shaft disc cavity (201).

5. An in vitro driving ventricular assist device impeller shaft support structure according to claim 1, wherein: the utility model discloses a pipe, including pipe (8), pipe (8) rear end, actuating mechanism (15) include the casing and locate inside drive arrangement (151) of casing, inside transmission shaft (9) of pipe (8) with drive arrangement (151) link firmly, be equipped with suction opening (152) of being connected with suction device on the casing, just suction opening (152) pass through the pipeline with pipe (8) inner chamber intercommunication.

6. An in vitro driving ventricular assist device impeller shaft support structure according to claim 1, wherein: the rotary supporting elements in the inner cavity (101) of the sleeve are bearings, and a middle spacer sleeve (102) is arranged between the adjacent bearings.

7. An in vitro driving ventricular assist device impeller shaft support structure according to claim 6, wherein: a first bearing (4) and a second bearing (6) are arranged in the inner cavity (101) of the sleeve, the first bearing (4) is sleeved on the front portion of the impeller shaft (5), the second bearing (6) is sleeved on the rear portion of the impeller shaft (5), and a middle spacer sleeve (102) is arranged between the first bearing (4) and the second bearing (6).

8. An extracorporeal drive ventricular assist device impeller shaft support structure as claimed in claim 1, wherein: the rotary supporting elements in the sleeve inner cavity (101) are balls (14), each group of balls (14) is arranged along the circumferential direction of the impeller shaft (5), and two adjacent groups of balls (14) are separated by a limiting spacer sleeve (13).