阅读说明：本技术 一种灌注液输送装置及其控制方法 (Perfusate conveying device and control method thereof ) 是由 杨智峻 赵贤忠 刘智勇 唐智荣 于 2021-05-07 设计创作，主要内容包括：本发明公开了一种灌注液输送装置及其控制方法,所述灌注液输送装置包括灌注管路,所述灌注管路包括依次相连的灌注管路远端,灌注管路中部和灌注管路近端,所述灌注管路远端通过旋转件连接叶轮,所述灌注管路近端位于体外,所述灌注管路远端形成灌注管路内层腔体和灌注管路外层腔体,所述旋转件位于灌注管路内层腔体内；所述灌注管路近端设置有输入泵,所述灌注管路中部采用多层管或多腔管结构,所述输入泵将灌注液经由灌注管路中部泵送至灌注管路外层腔体,所述灌注管路内层腔体中携带磨损颗粒的灌注液经由灌注管路中部流出至灌注管路近端。本发明能够避免血液大量进入泵血装置传动系统同时,防止磨损颗粒物进入人体。(The invention discloses a perfusion fluid conveying device and a control method thereof, wherein the perfusion fluid conveying device comprises a perfusion pipeline, the perfusion pipeline comprises a far end of the perfusion pipeline, a middle part of the perfusion pipeline and a near end of the perfusion pipeline which are sequentially connected, the far end of the perfusion pipeline is connected with an impeller through a rotating piece, the near end of the perfusion pipeline is positioned outside the body, the far end of the perfusion pipeline forms an inner cavity of the perfusion pipeline and an outer cavity of the perfusion pipeline, and the rotating piece is positioned in the inner cavity of the perfusion pipeline; the filling pipeline near-end is provided with the input pump, filling pipeline middle part adopts multilayer pipe or multi-cavity tube structure, the input pump is with the perfusate via filling pipeline middle part pump sending to the outer cavity of filling pipeline, the perfusate that carries the wear particle in the inner cavity of filling pipeline flows out to the filling pipeline near-end via filling pipeline middle part. The invention can prevent a large amount of blood from entering a transmission system of the blood pumping device and prevent wear particles from entering a human body.)

1. A perfusion liquid conveying device comprises a perfusion pipeline, wherein the perfusion pipeline comprises a far end of the perfusion pipeline, a middle part of the perfusion pipeline and a near end of the perfusion pipeline which are sequentially connected, the far end of the perfusion pipeline is connected with an impeller through a rotating piece, and the near end of the perfusion pipeline is positioned outside a body; the filling pipeline near-end is provided with the input pump, filling pipeline middle part adopts multilayer pipe or multi-cavity tube structure, the input pump is with the perfusate via filling pipeline middle part pump sending to the outer cavity of filling pipeline, the perfusate that carries the wear particle in the inner cavity of filling pipeline flows out to the filling pipeline near-end via filling pipeline middle part.

2. The perfusate conveying device according to claim 1, wherein the rotating member comprises an impeller rotating shaft, a bearing and a transmission twisted wire, the bearing is arranged outside the impeller rotating shaft, the distal end of the impeller rotating shaft is connected with the impeller, and the proximal end of the impeller rotating shaft is connected with the transmission twisted wire.

3. The perfusate conveying device according to claim 2, wherein the near end of the impeller rotating shaft is provided with a near end sealing cover and a near end fixing frame, the far end of the impeller rotating shaft is provided with a far end sealing cover and a far end fixing frame, and the near end fixing frame and the far end fixing frame are externally provided with a shell; the far-end fixing frame and the near-end fixing frame are fixedly connected, the far-end fixing frame and the near-end fixing frame are of hollow structures, and an outer-layer cavity of the perfusion pipeline is formed by an inner side wall surface of the far-end fixing frame, an outer side wall surface of the far-end sealing cover, an outer side wall surface of the near-end sealing cover and an inner side wall surface of the shell; the inner side wall surface of the near-end sealing cover, the inner side of the far-end fixing frame and the inner side of the near-end fixing frame jointly form an inner cavity of the filling pipeline.

4. The perfusion fluid delivery device according to claim 3, wherein the housing is sleeved outside the distal mount and the proximal mount, the impeller shaft penetrates through the distal mount and the proximal mount and is connected to the impeller, the distal mount is provided with a slot, so that a perfusion passage is formed between the distal mount and the inner wall of the housing, the perfusion fluid flows into the outer cavity of the perfusion tube and then is separated into two paths at the proximal end of the impeller, one path flows out from between the proximal end of the impeller and the distal mount to the blood pumping catheter, and the other path flows into the inner cavity of the perfusion tube from the gap between the impeller shaft and the distal seal cover, so that the perfusion fluid returns from the distal end of the perfusion tube and flows to the proximal end of the perfusion tube.

5. The perfusate conveying device according to claim 3, wherein the bearing is a rolling bearing, the outer surface of the rolling bearing is tightly matched and connected with the far-end fixing frame, and a perfusion passage is formed by a gap between the inner ring and the outer ring of the rolling bearing.

6. The perfusate conveying device according to claim 5, wherein the number of the rolling bearings is plural, the plurality of rolling bearings are arranged side by side and are completely positioned in the inner cavity of the perfusion pipeline, the rolling bearing close to the far end abuts against the sealing cover at the far end, and the rolling bearing close to the near end abuts against a shaft shoulder on the rotating shaft of the impeller.

7. The perfusate conveying device according to claim 2, wherein the middle part of the perfusion pipeline comprises an outer sheath and an inner sheath, and the transmission skein is positioned in the inner sheath; one end of the inner sheath pipe is communicated with the inner cavity of the filling pipeline, the other end of the inner sheath pipe is connected to the outside of the body, one end of the outer sheath pipe is communicated with the outer cavity of the filling pipeline, and the other end of the outer sheath pipe is connected with the infusion bag through the input pump.

8. The perfusion fluid delivery device according to claim 2, wherein the middle part of the perfusion pipeline is a multi-cavity tube, the multi-cavity tube at least comprises a perfusion inflow cavity and a perfusion outflow cavity, and the transmission twisted wire is positioned in the perfusion outflow cavity; the perfusion outflow cavity is communicated with the inner cavity of the perfusion pipeline at the far end of the perfusion pipeline, and the perfusion outflow cavity is communicated with the outer cavity of the perfusion pipeline at the far end of the perfusion pipeline.

9. The perfusate delivery device according to claim 1, wherein the input pump is a syringe pump, or a one-way valve is provided at the outlet of the input pump.

10. The perfusion fluid delivery device according to claim 1, wherein the proximal end of the perfusion line further comprises an output pump, and the output pump pumps the perfusion fluid carrying the wear particles in the inner cavity of the perfusion line to the proximal end of the perfusion line through the middle part of the perfusion line.

11. A method of controlling the perfusate delivery device according to claim 10, characterized by comprising the following steps:

the rotating part in the inner cavity of the filling pipeline at the far end of the filling pipeline generates abrasion particles;

opening an input pump positioned outside the body, and pumping the perfusion solution into the outer-layer cavity of the perfusion pipeline at the far end of the perfusion pipeline;

the perfusate is separated into two paths at the near end of the impeller after flowing into the outer cavity of the perfusion pipeline, one path flows out to the blood pumping guide pipe, and the other path returns to flow into the inner cavity of the perfusion pipeline; enabling the perfusion fluid to return from the far end of the perfusion pipeline to flow to the near end of the perfusion pipeline;

opening an output pump positioned outside the body, and discharging the perfusion liquid pump carrying the wear particles in the inner layer cavity of the perfusion pipeline to the near end of the perfusion pipeline;

and controlling the flow of the input pump to be larger than that of the output pump, and controlling the flow of the output pump according to the rotating speed of the impeller.

12. The perfusion fluid delivery apparatus control method according to claim 11, wherein the output pump flow rate control process is as follows:

controlling the flow rate of the input pump to be 5 ml/h-90 ml/h;

acquiring a corresponding table between different rotating speeds and the critical flow of the output pump in advance, and acquiring the critical flow of the current output pump by adopting a table look-up mode; if the current rotating speed is not in the corresponding table, linear interpolation is carried out by adopting the critical flow of the output pump corresponding to the two adjacent rotating speeds;

and controlling the flow of the output pump to be larger than the critical flow and smaller than the flow of the input pump.

Technical Field

The invention relates to an interventional medical instrument and a control method thereof, in particular to a perfusion fluid conveying device and a control method thereof, which are used for realizing the percutaneous auxiliary blood pumping device with a power source positioned outside a body and reducing particles from entering the body.

Background

The percutaneous auxiliary blood pumping device is a device which separately arranges a blood pumping catheter and a driving module and is connected with the blood pumping catheter through a flexible transmission structure, an active driving module is positioned outside the body, and the active driving module drives the blood pumping catheter implanted in the body through the flexible transmission structure to realize the auxiliary blood pumping function.

The active driving module is positioned outside a human body, the near end of the flexible twisted wire needs to be connected with a motor rotating shaft, and the far end of the flexible twisted wire needs to be connected with the impeller rotating shaft in the blood pumping catheter after passing through a complex human body vascular structure. In the entire blood-pumping device, there are both rotating parts, such as: impeller, impeller pivot and transmission hank silk etc. have the mounting that is used for protecting tissues such as blood vessel in the human body, heart, makes it not with rotating member direct contact again, for example: sheath, housing, etc. Because the blood pumping catheter and the transmission system are both positioned in a human body, blood can flow into the transmission system of the blood pumping device from a gap between the rotating part and the fixing part, and the normal work of the transmission system can be influenced by the large amount of blood entering, so that the problems of load increase, transmission failure and the like are caused. On the one hand, in the blood pumping device, abrasion particles may be generated at the transmission device such as the flexible twisted wire and the rotating shaft and the bearing of the impeller, and when the abrasion particles enter a human body, thrombus is formed, so that the life and health of the human body are damaged.

In patent documents CN 108457844 a, CN 105917118A, US8597170B2, CN211693252U and earlier papers published by the company Impella, the perfusion mode and perfusion structure in the blood pumping device are studied, and the problem that blood enters the transmission system of the blood pumping device is effectively solved, and meanwhile, the perfusion liquid has the advantages of lubrication and vibration damping transmission structure. However, the above solutions have some drawbacks with respect to the problem of wear particles.

The liquid path structure adopted in the patent document US8597170B2 does not consider the harm of the abrasion particles possibly entering human body, in the designed liquid path structure, the impeller rotating shaft and the bearing thereof are positioned at the junction of blood and perfusate, and the abrasion particles generated by the impeller rotating shaft and the bearing directly enter the blood to harm human life.

In patent documents CN 108457844 a and CN 105917118A, although the problem of abrasion of particles is mentioned, the above two patent documents consider that "particles start to stagnate in the liquid flow due to a stage where the flow rate of the liquid is slow, so that the transport of particles along the passage can be minimized. That is, the above two patent documents suggest that the particulate matter does not move with the liquid flow due to the low flow rate of the liquid; however, in fact, when the rotation speed of the impeller and the transmission system is more than 10000rpm, the liquid flow in the perfusion cavity can obtain an extremely large radial speed when the working condition is operated, and when the particle size of the particles is less than 10um, Brownian motion can be generated, namely the particles can move due to the thermal motion of water molecules. Whereas the particle size generated in the drive train of the blood-pumping device is mostly smaller than 20 um. It can be seen that in most cases the wear particles will be influenced by the movement of the liquid to move without stagnating in the flow. Therefore, this solution fails to effectively solve the problem of wear particles.

The applicant's earlier patent document CN211693252U proposes a dynamic sealing structure, which uses the dead zone generated by the vortex to seal the cavity, so as to solve the problem of the entry of wear particles into the human body. However, when the rotation speed of the impeller is at a very low level, the sealing effect is reduced, and when the guide pipe is withdrawn and the rotation speed of the impeller is 0, the sealing effect is not even generated.

In the early papers published by the Impella company, a single-cavity structure is adopted, a hydrodynamic bearing is utilized, and magnetic fluid is adopted for sealing, so that the problem of abrasion particles is effectively solved, the blood pumping device mentioned in the papers adopts an in-vivo motor, however, a hollow catheter has no transmission structure, and has essential difference with a percutaneous auxiliary blood pumping device, and the micro in-vivo motor (the maximum outer diameter is less than 4.3 mm) mentioned in the papers belongs to the technical problem, has no reference value, and is difficult to realize on the percutaneous auxiliary blood pumping device.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a perfusion fluid conveying device and a control method thereof, which can prevent a large amount of blood from entering a transmission system of a blood pumping device and prevent abrasion particles from entering a human body.

The technical scheme adopted by the invention for solving the technical problems is to provide a perfusion fluid conveying device which comprises a perfusion pipeline, wherein the perfusion pipeline comprises a far end of the perfusion pipeline, a middle part of the perfusion pipeline and a near end of the perfusion pipeline which are sequentially connected, the far end of the perfusion pipeline is connected with an impeller through a rotating piece, and the near end of the perfusion pipeline is positioned outside the body, wherein the far end of the perfusion pipeline forms an inner cavity of the perfusion pipeline and an outer cavity of the perfusion pipeline, and the rotating piece is positioned in the inner cavity of the perfusion pipeline; the filling pipeline near-end is provided with the input pump, filling pipeline middle part adopts multilayer pipe or multi-cavity tube structure, the input pump is with the perfusate via filling pipeline middle part pump sending to the outer cavity of filling pipeline, the perfusate that carries the wear particle in the inner cavity of filling pipeline flows out to the filling pipeline near-end via filling pipeline middle part.

Further, the rotating part comprises an impeller rotating shaft, a bearing and a transmission twisted wire, the bearing is arranged outside the impeller rotating shaft, the far end of the impeller rotating shaft is connected with the impeller, and the near end of the impeller rotating shaft is connected with the transmission twisted wire.

Furthermore, a near end sealing cover and a near end fixing frame are arranged at the near end of the impeller rotating shaft, a far end sealing cover and a far end fixing frame are arranged at the far end of the impeller rotating shaft, and a shell is arranged outside the near end fixing frame and the far end fixing frame; the far-end fixing frame and the near-end fixing frame are fixedly connected, the far-end fixing frame and the near-end fixing frame are of hollow structures, and an outer-layer cavity of the perfusion pipeline is formed by an inner side wall surface of the far-end fixing frame, an outer side wall surface of the far-end sealing cover, an outer side wall surface of the near-end sealing cover and an inner side wall surface of the shell; the inner side wall surface of the near-end sealing cover, the inner side of the far-end fixing frame and the inner side of the near-end fixing frame jointly form an inner cavity of the filling pipeline.

Further, outside distal end mount and near-end mount were located to the casing cover, the impeller pivot runs through distal end mount and near-end mount and links to each other with the impeller, be provided with the fluting on the distal end mount for form the perfusion route between distal end mount and the shells inner wall, the perfusate flows into to separate into two the tunnel at the impeller near-end behind the outer cavity of perfusion pipeline, flows out to the pump blood pipe between impeller near-end and the distal end mount all the way, and another way flows into perfusion pipeline inlayer cavity from the clearance between impeller pivot and the sealed lid of distal end, makes the perfusate return from the perfusion pipeline distal end and flows to the perfusion pipeline near-end.

Furthermore, the bearing is a rolling bearing, the outer surface of the rolling bearing is tightly matched and connected with the far-end fixing frame, and a gap between an inner ring and an outer ring of the rolling bearing forms a perfusion passage.

Furthermore, the number of the rolling bearings is multiple, the rolling bearings are arranged side by side and are completely positioned in the inner cavity of the filling pipeline, the rolling bearing close to the far end is abutted with the sealing cover at the far end, and the rolling bearing close to the near end is abutted with a shaft shoulder on the rotating shaft of the impeller.

Furthermore, the middle part of the perfusion pipeline comprises an outer-layer sheath pipe and an inner-layer sheath pipe, and the transmission skein is positioned in the inner-layer sheath pipe; one end of the inner sheath pipe is communicated with the inner cavity of the filling pipeline, the other end of the inner sheath pipe is connected to the outside of the body, one end of the outer sheath pipe is communicated with the outer cavity of the filling pipeline, and the other end of the outer sheath pipe is connected with the infusion bag through the input pump.

Furthermore, a multi-cavity pipe is arranged in the middle of the perfusion pipeline, the multi-cavity pipe at least comprises a perfusion inflow cavity and a perfusion outflow cavity, and the transmission twisted wire is positioned in the perfusion outflow cavity; the perfusion outflow cavity is communicated with the inner cavity of the perfusion pipeline at the far end of the perfusion pipeline, and the perfusion outflow cavity is communicated with the outer cavity of the perfusion pipeline at the far end of the perfusion pipeline.

Further, the input pump is a syringe pump, or a one-way valve is arranged at an outlet of the input pump.

Furthermore, the near end of the filling pipeline also comprises an output pump, and the output pump enables the filling liquid carrying the wear particles in the inner cavity of the filling pipeline to flow to the near end of the filling pipeline through the middle pump of the filling pipeline.

The invention also provides a control method of the perfusion fluid conveying device for solving the technical problems, which comprises the following steps: the rotating part in the inner cavity of the filling pipeline at the far end of the filling pipeline generates abrasion particles; opening an input pump positioned outside the body, and pumping the perfusion solution into the outer-layer cavity of the perfusion pipeline at the far end of the perfusion pipeline; the perfusate is separated into two paths at the near end of the impeller after flowing into the outer cavity of the perfusion pipeline, one path flows out to the blood pumping guide pipe, and the other path returns to flow into the inner cavity of the perfusion pipeline; enabling the perfusion fluid to return from the far end of the perfusion pipeline to flow to the near end of the perfusion pipeline; opening an output pump positioned outside the body, and discharging the perfusion liquid pump carrying the wear particles in the inner layer cavity of the perfusion pipeline to the near end of the perfusion pipeline; and controlling the flow of the input pump to be larger than that of the output pump, and controlling the flow of the output pump according to the rotating speed of the impeller.

Further, the flow control process of the output pump is as follows: controlling the flow rate of the input pump to be 5 ml/h-90 ml/h; acquiring a corresponding table between different rotating speeds and the critical flow of the output pump in advance, and acquiring the critical flow of the current output pump by adopting a table look-up mode; if the current rotating speed is not in the corresponding table, linear interpolation is carried out by adopting the critical flow of the output pump corresponding to the two adjacent rotating speeds; and controlling the flow of the output pump to be larger than the critical flow and smaller than the flow of the input pump.

Compared with the prior art, the invention has the following beneficial effects: the invention deposits and isolates the abrasion particles generated by the rotating part by adopting the double-cavity structure of the inner cavity of the perfusion pipeline and the outer cavity of the perfusion pipeline, the rotating part is positioned in the inner cavity of the perfusion pipeline, the middle part of the perfusion pipeline adopts a multilayer pipe structure, perfusion fluid is fed into the outer cavity of the perfusion pipeline by using an input pump, the perfusion fluid does not flow through any abrasion part at the moment, abrasion particles do not enter the perfusion fluid, the perfusion fluid cannot generate any harm when entering the human body, meanwhile, the shunted perfusion fluid enters the inner cavity of the perfusion pipeline, the abrasion particles generated by the rotating part in the cavity are mixed into the perfusion fluid, the perfusion fluid carrying the abrasion particles is continuously pumped out from the outlet of the perfusion pipeline by using the form of active or passive suction in vitro, and the device can prevent a large amount of blood from entering the transmission system of the blood pumping device and simultaneously prevent the abrasion particles from, the safety is high. The invention has wide application range, is not only suitable for the condition that the active driving module is positioned outside the body, but also suitable for the condition that the active driving module is positioned inside the body.

Drawings

FIG. 1 is a schematic structural diagram of a perfusate conveying device in an embodiment of the present invention;

FIG. 2 is a schematic view of the distal end of the infusion line in an embodiment of the present invention;

FIG. 3 is a schematic diagram of a distal cross-sectional structure of a perfusion line in an embodiment of the present invention;

FIG. 4 is a schematic diagram showing a cross-sectional view of a middle portion of a perfusion line using a multi-layer tube according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of a cross-sectional view of a central portion of a perfusion line using a multi-lumen tube in accordance with an embodiment of the present invention;

FIG. 6 is a schematic view of a mid-section of another infusion line using a multi-lumen tube in accordance with an embodiment of the present invention;

FIG. 7 is a schematic flow diagram of the perfusion fluid in an embodiment of the present invention;

FIG. 8 is a graph of critical flow versus rotational speed for an output pump in accordance with an embodiment of the present invention;

FIG. 9 is a graph showing a comparison of particle concentrations before and after active aspiration at a flow rate of 5ml/h for an input pump in an embodiment of the present invention;

FIG. 10 is a graph showing a comparison of particle concentration before and after active aspiration at a flow rate of 30ml/h for an input pump in an embodiment of the present invention;

FIG. 11 is a graph showing a comparison of particle concentration before and after active aspiration at a flow rate of 90ml/h for an infusion pump in accordance with an embodiment of the present invention.

In the figure:

1 filling pipeline far end 2 filling pipeline near end 3 filling pipeline middle part

4-drive twisted wire 5-impeller 6-input pump

7 output pump 8 infusion bag 9 perfusion pipeline outer layer cavity

10 filling pipeline inner layer cavity 11 one-way valve 12 multilayer pipe outer layer cavity

13 multilayer pipe inner layer cavity 14 perfusion inflow cavity 15 perfusion outflow cavity

101 distal mount 102 proximal mount 103 distal seal cap

104 near-end sealing cover 105 shaft shoulder 106 rolling bearing

107 impeller shaft 108 casing

301 inner sheath 302 outer sheath

Detailed Description

The invention is further described below with reference to the figures and examples.

FIG. 1 is a schematic view of a seal configuration in an embodiment of the present invention; fig. 2 is a schematic structural diagram of a rotating shaft with a seal connected with a driving power device in the embodiment of the invention.

Referring to fig. 1 and 2, the perfusion fluid delivery device provided by the present invention includes a perfusion pipeline, the perfusion pipeline includes a distal end 1 of the perfusion pipeline, a middle portion 3 of the perfusion pipeline, and a proximal end 2 of the perfusion pipeline, which are connected in sequence, the distal end 1 of the perfusion pipeline is connected to an impeller 5 through a rotating member, the proximal end 2 of the perfusion pipeline is located outside the body, wherein the distal end 1 of the perfusion pipeline forms an inner cavity 10 of the perfusion pipeline and an outer cavity 9 of the perfusion pipeline, and the rotating member is located in the inner cavity 10 of the perfusion pipeline; the filling line near-end 2 is provided with the input pump 6, 3 multi-layer pipe or multi-cavity tube structures of adoption in the filling line middle part, 6 pumps the perfusate to the outer cavity 9 of filling line via the 3 pump joints in filling line middle part of the input pump, carry the perfusate of wear particle among the inner cavity 10 of filling line to flow out to the filling line near-end 2 via the filling line middle part 3. The invention can provide enough power through the input pump 6 to enable the perfusion fluid carrying the wear particles to flow out, and can also further arrange the output pump 7 at the near end 2 of the perfusion pipeline, wherein the output pump 7 pumps the perfusion fluid carrying the wear particles in the inner layer cavity 10 of the perfusion pipeline to the near end 2 of the perfusion pipeline through the middle part 3 of the perfusion pipeline.

The perfusion fluid conveying device provided by the invention has the advantages that the rotating parts which can generate abrasion particles are possible, such as: the transmission twisted wire, the impeller rotating shaft, the bearing assembly and the like are all positioned in the inner-layer cavity 10 of the filling pipeline. The perfusion liquid in the outer layer cavity 9 of the perfusion pipeline only contacts with the fixing piece, so the perfusion liquid in the outer layer cavity does not carry wear particles, and the perfusion liquid containing the wear particles and the perfusion liquid without the wear particles are effectively separated into two cavities.

With continued reference to fig. 3, specifically, the rotating member includes an impeller rotating shaft 107, a bearing and a transmission hinge 4, the bearing is disposed outside the impeller rotating shaft 107, a distal end of the impeller rotating shaft 107 is connected to the impeller 5, and a proximal end of the impeller rotating shaft 107 is connected to the transmission hinge 4. A near-end sealing cover 104 and a near-end fixing frame 102 are arranged at the near end of the impeller rotating shaft 107, a far-end sealing cover 103 and a far-end fixing frame 101 are arranged at the far end of the impeller rotating shaft 107, and a shell 108 is arranged outside the near-end fixing frame 102 and the far-end fixing frame 101; the far-end fixing frame 101 and the near-end fixing frame 102 are fixedly connected, the far-end fixing frame 101 and the near-end fixing frame 102 are of hollow structures, and an outer-layer cavity 9 of the perfusion pipeline is formed by an inner side wall surface of the far-end fixing frame 101, an outer side wall surface of the far-end sealing cover 103, an outer side wall surface of the near-end sealing cover 104 and an inner side wall surface of the shell 108; the inner side wall surface of the near-end sealing cover 104, the inner side of the far-end fixing frame 101 and the inner side of the near-end fixing frame 102 jointly form a perfusion pipeline inner-layer cavity 10.

According to the perfusate conveying device provided by the invention, the shell 108 is sleeved outside the far-end fixing frame 101 and the near-end fixing frame 102, the impeller rotating shaft 107 penetrates through the far-end fixing frame 101 and the near-end fixing frame 102 and is connected with the impeller 5, and the far-end fixing frame 101 is provided with the slot, so that a perfusion passage is formed between the far-end fixing frame 101 and the inner wall of the shell 108. The groove is formed in the distal fixing frame 101, so that not only the groove structure on the distal fixing frame 101 and the inner wall of the shell 108 together form an outflow channel, but also the deep hole on the distal fixing frame 101 can be easily machined on a plane. The perfusate is separated into two paths at the near end of the impeller 5 after flowing into the outer layer cavity 9 of the perfusion pipeline, one path flows out to a blood pumping catheter from the space between the near end of the impeller 5 and the far end fixing frame 101, and the other path flows into the inner layer cavity 10 of the perfusion pipeline from the gap between the rotating shaft 107 of the impeller and the far end sealing cover 103, so that the perfusate returns from the far end 1 of the perfusion pipeline and flows to the near end 2 of the perfusion pipeline.

According to the perfusate conveying device provided by the invention, the bearing is the rolling bearing 106, the inner surface of the rolling bearing 106 is in tight fit connection with the impeller rotating shaft 107, the outer surface of the rolling bearing 106 is in tight fit connection with the far-end fixing frame 101, a perfusion passage is formed by directly utilizing a gap between an inner ring and an outer ring of the rolling bearing 106, and a gap does not need to be reserved between the bearing and the impeller rotating shaft or a thread groove is formed to ensure perfusion flow, so that radial runout of the impeller can be reduced while the perfusion flow is ensured. If a single rolling bearing is used, the lack of radial positioning may cause radial runout of the impeller during operation. For this purpose, the number of the rolling bearings 106 in the embodiment of the present invention may be multiple, that is, two or more, the multiple rolling bearings 106 are completely located in the inner cavity 10 of the infusion line, the rolling bearing near the distal end abuts against the distal sealing cover 103, and the rolling bearing 107 near the proximal end abuts against the shoulder 105 on the rotating shaft 107 of the impeller. When the rolling bearing 106 is plural in number, the plural rolling bearings 106 are preferably placed side by side in order to reduce the incompressible length in the pipe. When the two bearings are arranged at intervals, the radial runout of the impeller can be reduced, but the incompressible length in the guide pipe can be increased. Because the acting force of the liquid on the impeller causes the rotating shaft 107 of the impeller to have a far-end acting force during the rotation of the impeller, the double bearings are fixed between the far-end sealing cover 103 and the shaft shoulder 105 of the rotating shaft of the impeller by the force, so that the double bearings cannot generate axial jumping in the inner cavity 10 of the perfusion pipeline. Further, when the rolling bearing rotates, the wear particles are mainly distributed to the outer ring side of the rolling bearing due to centrifugal action, and therefore, the distance between the distal seal cover 103 and the impeller rotation shaft 107 is preferably less than half of the sum of the inner diameter and the outer diameter of the rolling bearing; too large a spacing may allow the particles to diffuse out, too small a spacing may allow impeller shaft 107 to encounter distal seal head 103 during high speed rotation.

The perfusion fluid conveying device adopts the rolling bearing, and has the following advantages: 1. compared with the prior art, because the rolling bearing is completely positioned in the perfusion backflow cavity (in the perfusion pipeline inner layer cavity 10), the generated wear particles can be effectively prevented from entering the human body. 2. Compared with the prior art, the rolling bearing is adopted, the filling pipeline passage is formed by utilizing the clearance between the ball bearings, and the backflow flow is ensured without an additional process. 3. Compared with the prior art, the friction coefficient can be greatly reduced by adopting a rolling bearing structure, so that the friction coefficient can reach 0.001 to 0.0015. 4. Compared with the prior art, the impeller has the advantages that the clearance between the impeller rotating shaft and the bearing is lower than 5 microns by adopting the rolling bearing structure, and the radial runout of the impeller rotating shaft is reduced. 5. If a single bearing structure is adopted, the radial runout of the impeller shaft can be caused by insufficient definition of the degree of freedom, and the double rolling bearings play a role in supporting the rotating shaft of the impeller and defining the degree of freedom of the rotating shaft of the impeller.

With continued reference to fig. 4, the middle portion 3 of the infusion line is positioned within the body and is connected to a blood-pumping catheter positioned in the left ventricle of the body after passing through the complex vascular structure of the body. The middle part 3 of the perfusion pipeline comprises an outer-layer sheath 301 and an inner-layer sheath 302, a multilayer pipe inner-layer cavity 13 is arranged in the inner-layer sheath 302, a multilayer pipe outer-layer cavity 12 is formed between the inner-layer sheath 302 and the outer-layer sheath 301, and the transmission hank wire 4 is positioned in the inner-layer sheath 302; inner sheath pipe 302 one end links to each other with filling pipeline inlayer cavity 10 for multilayer pipe inlayer cavity 13 and filling pipeline inlayer cavity 10 are linked together, the other end of inner sheath pipe 301 is connected to external or links to each other with delivery pump 7, the one end of outer sheath pipe 302 links to each other with filling pipeline outer cavity 9, makes multilayer pipe outer cavity 12 and filling pipeline outer cavity 9 be linked together, the other end of outer sheath pipe 302 passes through input pump 6 and links to each other with infusion bag 8. Since the driving wire 4 rotates at high speed and bends with the vascular structure when passing through the complex vascular structure, the driving wire 4 generates wear particles, especially at the bent portion of the wire. The wear particles in the middle 3 of the filling pipeline are mainly generated by a transmission twisted wire positioned in the inner cavity 10 of the filling pipeline, and the filling liquid which is positioned in the inner cavity of the filling pipeline and carries the wear particles is pumped to the near end 2 of the filling pipeline by the pumping action of the output pump 7 positioned at the near end of the filling pipeline. And meanwhile, the perfusion fluid without the wear particles is pumped to the far end 1 of the perfusion pipeline through the outer cavity 9 of the perfusion pipeline by the pumping action of the input pump 6.

The middle part 3 of the perfusion pipeline used in the invention can also be a multi-cavity pipe, and the multi-cavity pipe has a structure with two or more cavities and at least comprises a perfusion inflow cavity 14 and a perfusion outflow cavity 15, as shown in fig. 5 and 6; the transmission twisted wire 4 is positioned in the perfusion outflow cavity 15; the perfusion outflow cavity 15 is communicated with the perfusion pipeline inner-layer cavity 10 at the far end of the perfusion pipeline, and the perfusion outflow cavity 15 is communicated with the perfusion pipeline outer-layer cavity 9 at the far end of the perfusion pipeline.

Because the near end 2 of the perfusion pipeline is positioned outside the body, the invention can conveniently select the input pump 6 and the output pump 7, the input pump 6 pumps the perfusion fluid in the infusion bag 8 into the outer cavity 9 of the perfusion pipeline, and the output pump 7 continuously pumps the perfusion fluid containing wear particles in the inner cavity 10 of the perfusion pipeline. The check valve 11 is used to ensure the one-way flow of the liquid flow and prevent the liquid flow from flowing backwards when the pump fails, and when the pump body has the check valve or has the characteristic of ensuring the single flow of the liquid flow, the check valve is not arranged. The input pump 6 can be a syringe pump, or a one-way valve 11 is arranged at the outlet of the input pump 6; the output pump 7 is an injection pump, or a one-way valve 11 is arranged at the inlet of the output pump 7; the one-way and non-fluctuation of the liquid flow is ensured, and simultaneously, as the injection pump has the characteristic of flow control, a flow sensor or a pressure sensor is omitted.

The perfusate can be glucose heparin solution or normal saline heparin solution, and heparin mainly plays a role in preventing blood coagulation. On the other hand, however, excessive heparin dosage will cause bleeding, and the dosage of heparin has no specific standard, and the principle is to use as little heparin as possible under the condition of ensuring that the tube and the dialyzer do not coagulate blood. Thus, under normal conditions, the filling line inlet flow should be as small as possible. The control method of the perfusate conveying device provided by the invention comprises the following steps:

the rotating member in the inner cavity 10 of the infusion line at the distal end 1 of the infusion line generates wear particles;

an input pump 6 positioned outside the body is opened, and perfusion fluid is pumped into a perfusion pipeline outer layer cavity 9 at the far end 1 of the perfusion pipeline;

the perfusate is separated into two paths at the near end of the impeller 5 after flowing into the outer cavity 9 of the perfusion pipeline, one path flows out to the blood pumping guide pipe, and the other path returns to flow into the inner cavity 10 of the perfusion pipeline; so that the perfusion fluid flows back from the far end 1 of the perfusion pipeline to the near end 2 of the perfusion pipeline;

opening an output pump 7 positioned outside the body, and discharging the perfusion liquid carrying the wear particles in the inner cavity 10 of the perfusion pipeline to the near end 2 of the perfusion pipeline by a pump;

and controlling the flow of the input pump 6 to be larger than that of the output pump 7, and controlling the flow of the output pump according to the rotating speed of the impeller.

FIG. 7 is a schematic flow diagram of the perfusate in the embodiment of the present invention. The infusion line distal fluid circuit boundaries are named out1, out2 and in, and according to the conservation of mass, the infusion line proximal input pump 6 has the same pumping flow as at in, and the infusion line proximal output pump 7 has the same pumping flow as at out 2. Through a plurality of tests, the leakage of the wear particles is only related to the rotating speed of the rotating shaft of the impeller and the flow of the output pump 7, and the critical flow corresponding to different rotating speeds is shown in fig. 8. Whether blood enters the transmission system or not is related to the rotating speed of the rotating shaft of the impeller and the flow difference between the input pump 6 and the output pump 7, and the difference value is not less than 0. The control method of the perfusion fluid conveying device provided by the invention adopts an active suction mode in the perfusion outflow cavity, generates negative pressure on the perfusion outlet side, and continuously pumps the fluid flow in the cavity to the outlet of the perfusion pipeline. Wear particles at the position of the rolling bearing are continuously pumped out from the outlet of the filling pipeline in the mode, and meanwhile, the flow of the outlet of the filling pipeline can be correspondingly adjusted according to the set gears, so that the complex clinical condition can be met.

FIG. 8 shows the minimum flow required for the output pump 7 for the input pump 6 at 20ml/h and 40 ml/h. When the flow rate of the output pump is higher than the critical flow rate shown in the figure, the effect of no abrasion particles entering the human body can be achieved. The output pump 7 flow should not be higher than the input pump 6 flow, which would otherwise result in blood entering the perfusion line. As the flow rate of the inlet pump 6 increases, the corresponding critical flow rate of the outlet pump 7 decreases at the same speed.

When the flow rate of the input pump is 20 ml/h-40 ml/h, the flow rate of the output pump 7 is in a substantially linear positive correlation with the rotating speed, the flow rates of the input pumps are respectively kept at 20ml/h, 30ml/h and 40ml/h and correspond to 10000rpm, 20000 rpm, 30000 rpm, 40000rpm and 50000 rpm, and the corresponding relation between the corresponding critical flow rate and the rotating speed of the output pump is determined as follows:

for different rotation speeds, the output pump 7 needs to be larger than the corresponding value in the table to ensure no wear particle backflow. At the same time, in order to ensure that no blood enters the transmission structure, the flow difference between the input pump 6 and the output pump 7 should be greater than 0. The flow control process of the output pump is as follows: acquiring a corresponding table between different rotating speeds and the critical flow of the output pump in advance, and acquiring the critical flow of the current output pump by adopting a table look-up mode; if the current rotating speed is not in the corresponding table, linear interpolation is carried out by adopting the critical flow of the output pump corresponding to the two adjacent rotating speeds; and controlling the flow of the output pump to be larger than the critical flow and smaller than the flow of the input pump.

When the flow rate of the input pump is lower than 20ml/h, the critical flow rate of the output pump 7 is obviously increased to ensure no wear particles, and the error is larger by adopting linear interpolation. If further control is needed under low flow, the critical flow of the corresponding output pump under more rotating speeds is obtained as much as possible in advance, for example, the critical flow of the corresponding output pump is measured at intervals of 2000 rpm per change in advance, so as to ensure the accuracy of the subsequent linear interpolation control; preferably, a flow rate of more than 5ml/h is recommended for the feed pump 6. The active suction mode can effectively reduce the particle concentration in the perfusion pipeline, taking particles with the particle size being more than or equal to 2 microns as an example, fig. 9, 10 and 11 are respectively schematic diagrams comparing the particle concentration with and without active suction when the input pump flow is 5ml/h, 30ml/h and 90 ml/h. The effect of active aspiration is more pronounced the smaller the input pump volume flow.

When the flow rate of the input pump reaches 90ml/h, the active suction has no effect basically, and the particle requirement can be met only by the natural outflow of the perfusion outflow part. However, since the perfusate entering the human body is a heparin solution to prevent the blood coagulation of the patient, when the perfusate enters too much, the blood of the patient is difficult to coagulate, and a great amount of bleeding is caused. Therefore, when the flow rate of the input pump 6 is increased, the flow rate of the corresponding output pump 7 needs to be increased to make the flow rate of the perfusate entering the human body in a proper range.

Furthermore, when the input pump 6 and the output pump 7 simultaneously select too high a flow rate, the following disadvantages arise: 1. when the output pump 7 fails, it will cause too high a perfusion flow into the body, with the risk of bleeding. 2. The maximum volume of the medical infusion bag is 500ml generally, the length of the product can be higher than 7 days, so that the infusion bag can be repeatedly replaced when the flow of the input pump 6 and the flow of the output pump 7 are too high, and the volume of the waste liquid collecting container is correspondingly increased. It is therefore recommended that the input pump 6 flow should be less than 90ml/h, avoiding the risk of bleeding even when the output pump 7 fails.

In summary, the perfusate conveying device and the control method thereof provided by the invention have the following specific advantages: 1. the rotating part which can generate abrasion particles and the perfusion fluid are separated from the perfusion fluid without the abrasion particles by using the multilayer pipe structure, so that the abrasion particles are prevented from entering a human body; 2. the output pump at the outlet of the filling pipeline adopts a syringe pump, so that the liquid flow is free from fluctuation at an extremely low level of flow; 3. and a reasonable flow control strategy is adopted, and the characteristics of the injection pump are utilized, so that a sensor structure is omitted.

Although the present invention has been described with respect to the preferred embodiments, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.