In-line blood pump

Abstract

The application aims to provide a series blood pump with large flow and small hemolysis, comprising a blood flow channel and a pumping unit, one end of the blood flow channel is provided with a blood inflow port, the other end is provided with a blood outflow port, the pumping unit comprises an impeller and a motor set for driving the impeller to rotate, the blood pump is used in the process of interventional heart through blood vessels, the plurality of motors are separated from each other, the length of the continuous rigid section is reduced, and therefore the over-bending requirement of the blood vessel can be met; after reaching the designated position in the heart, the connecting mechanism drives the adjacent motors to be connected into a whole, that is, the torques of the plurality of motors are superposed, and therefore a larger load-impeller can be driven to rotate, so that the pumping flow of the blood pump is increased. Under the premise that the flow meets the human body demand, the rotating speed of the series blood pump can be greatly reduced compared with the common blood pump, and therefore the hemolysis can be further reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical devices, in particular to a series blood pump. BACKGROUND

[0002] The occurrence of cardiovascular diseases can lead to heart failure, which is manifested as the systolic and / or diastolic function of the heart being impaired, the heart being unable to fully discharge the venous blood back into the heart, causing blood to accumulate in the ventricle, blood perfusion being insufficient in the arterial intervention type heart-kidney combined auxiliary system, causing circulatory disorders of the heart, and triggering organ failure and even shock, etc.

[0003] The blood pump can be inserted into the interior of the patient's heart via the patient's blood vessels, so that the blood can flow through the blood pump and into the arterial blood vessels. During the pumping process, the blood flow rate and blood flow volume need to be considered to meet the physiological needs of the human body. At the same time, in order to prevent damage to the blood vessels and the corresponding organs, the diameter and length of the blood pump and the impeller of the blood pump are limited, which limits the torque of the blood pump. In addition, the speed of the blood pump during the pumping process should not be too fast, otherwise the structure of the blood cells will be damaged. Under the condition that the speed of the blood pump is constant, in order to reduce the blood flow rate and increase the blood delivery volume, the blades of the impeller are expanded in the heart after the impeller enters the heart, so that the overall size of the impeller is increased. However, the torque of the given blood pump cannot drive the enlarged impeller, which will also cause the blood pump to heat and cause blood coagulation. In addition, the structure of the blade is complex and not conducive to operation, and there are safety hazards. SUMMARY

[0004] The purpose of the present application is to provide a series blood pump with large flow rate and small hemolysis.

[0005] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows: a series blood pump, comprising a blood flow channel and a pumping unit, one end of the blood flow channel is provided with a blood inlet, and the other end is provided with a blood outlet, the pumping unit comprises an impeller and a motor set for driving the impeller to rotate, the motor set comprises a plurality of series-connected motors, and a connecting mechanism is arranged between adjacent motors, the connecting mechanism drives the adjacent motors to be connected as a whole or drives the adjacent motors to be separated from each other.

[0006] The motor shaft of the motor protrudes to the outside of the motor, the connecting mechanism comprises a compression spring arranged between the motor shafts, the compression spring provides an elastic force to drive the two motor shafts to move away from each other, and an electromagnet is further arranged at the end of the motor shaft, the magnetic attraction force of the electromagnet in the energized state overcomes the elastic force of the compression spring to drive the two motor shafts to attract and connect as one shaft.

[0007] The connecting mechanism also includes protruding claws on the motor shaft. When the magnet is energized, the protruding claws at the ends of adjacent motor shafts engage and lock together.

[0008] There are two motors. The impeller is located at the far end of the first motor. The impeller has a foldable structure. The proximal end of the blood flow channel is connected to an expandable and contractible shell. One end of the shell is fixed to the proximal end of the blood flow channel, and the other end is axially sliding and circumferentially limiting with a conduit located near the motor. When the electromagnet is de-energized, the foldable impeller is placed in the blood flow channel in a folded state. When the electromagnet is energized, the first motor moves to the proximal end and connects with the second motor located at the far end. The foldable impeller is located in the expanded shell in an open state.

[0009] The shell includes a grid-like support made of shape memory alloy material and a thin film covering the inner and / or outer and / or interlayer of the support. After being covered by the thin film, it forms a hollow tubular protective peripheral wall structure of the shell. An opening is made in the proximal end of the thin film of the support to form a blood outflow outlet.

[0010] The foldable impeller includes a rigid hub and blades disposed on the outer periphery of the rigid hub. The motor shaft of the first motor extends to the outside of the rigid hub to form a protruding section. The protruding section is fixed on a fixed ring. The fixed ring includes an outer ring and an inner ring arranged coaxially and fixed to each other by a connecting rib. The outer wall of the outer ring forms a sliding fit with the blood flow channel. The protruding section is inserted into the inner ring and forms a fixed connection.

[0011] The foldable impeller includes a rigid hub and blades disposed on the outer periphery of the rigid hub. The motor shaft of the first motor extends to the outside of the rigid hub to form a protruding section. The protruding section and the fixed ring fixed in the blood flow channel form an axial sliding fit. The fixed ring includes an outer ring and an inner cylinder arranged coaxially, which are fixed together by a connecting rib. The outer ring is fixed to the inner wall of the blood flow channel, and the protruding section is inserted into the inner cavity of the inner cylinder to form a sliding fit.

[0012] There are two motors. The impeller is located at the far end of the first motor. The impeller is a rigid structure. The blood flow mask is located on the outer periphery of the impeller and is fixedly connected to the first motor. When the electromagnet is energized, the second motor located on the near side moves to the far end and is connected to the first motor.

[0013] The first motor and the second motor have the same structure. A magnetic levitation bearing is provided between the stator and the rotor of the first motor. The inner ring of the magnetic levitation bearing is fixed to the end face of the rotor, and the outer ring is fixed to the end face of the stator. The gap between the stator and the rotor forms a flushing channel.

[0014] In the above scheme, during the transvascular intervention of the blood pump into the heart, the multiple motors are isolated, meaning the length of the continuous rigid section is reduced, thus meeting the requirements for navigating the bends of the blood vessel. Once at the designated location within the heart, the connecting mechanism drives adjacent motors to connect as a whole, meaning the torque of multiple motors is superimposed, thereby driving a larger load—the impeller—and increasing the pump's flow rate. Provided the flow rate meets the body's needs, the series-connected blood pump can significantly reduce its rotational speed compared to a conventional blood pump, thus further reducing hemolysis. Attached Figure Description

[0015] Figure 1 This is a diagram of the blood pump's external shape.

[0016] Figure 2 for Figure 1 A sectional view;

[0017] Figure 3 This is a sectional view of the generator set;

[0018] Figure 4 This is a schematic diagram of the connecting mechanism;

[0019] Figure 5 This is a schematic diagram of the shell structure;

[0020] Figure 6 This is a schematic diagram of the fixed ring structure. Detailed Implementation

[0021] To facilitate understanding, we will first define the terms "proximal" and "proximal" as used below: "proximal" refers to the side closest to the operator / doctor, while "distal" refers to the side furthest from the operator / doctor, i.e., the side closest to the heart. The following will combine these definitions... Figures 1-6 The present invention will be described in further detail below.

[0022] like Figure 1 , Figure 2 As shown, a series-connected blood pump includes a blood flow channel 10 and a pumping unit. One end of the blood flow channel 10 is provided with a blood inlet 11 and the other end is provided with a blood outlet 12. The pumping unit includes an impeller 20 and a motor set 30 for driving the impeller 20 to rotate. The motor set 30 has multiple motors 31 connected in series. A connecting mechanism 32 is provided between adjacent motors 31. The connecting mechanism 32 drives adjacent motors 31 to connect into a whole or drives adjacent motors 31 to separate from each other.

[0023] The principle and usage of this invention are as follows: During the transvascular intervention of the blood pump into the heart, the multiple motors 31 are isolated from each other, meaning the length of the continuous rigid section is reduced, thus meeting the requirements for navigating the bends of the blood vessel. Once at the designated location within the heart, the connecting mechanism 32 drives adjacent motors 31 to connect as a whole. This means the torque of the multiple motors 31 is superimposed, thereby driving a larger load—the impeller 20—to rotate, thus increasing the pumping flow rate. While ensuring the flow rate meets the body's needs, the series-connected blood pump can significantly reduce its rotational speed compared to a conventional blood pump, thus further reducing hemolysis.

[0024] To achieve separation and connection between adjacent motors 31, see [reference] Figure 4 The motor shaft 311 of the motor 31 protrudes to the outside of the motor 31. The connecting mechanism 32 includes a compression spring 321 disposed between the motor shafts 311. The compression spring 321 provides elastic force to drive the two motor shafts 311 away from each other. An electromagnet 322 is also disposed at the end of the motor shaft 311. When the electromagnet 322 is energized, the magnetic attraction force overcomes the elastic force of the compression spring 321, driving the two motor shafts 311 to attract each other and connect as a single shaft. When the electromagnet 322 is de-energized, the motor shafts 311 are only subjected to the elastic force of the compression spring 321, which drives the two motor shafts 311 to separate. At the same time, the compression spring 321 has a certain bending deformation capability, thus enabling the use of the curved shape of a blood vessel. When the electromagnet 322 is energized, the magnetic attraction force between the electromagnets 322 is large, overcoming the elastic force of the compression spring 321 and attracting them together. At this time, the compression spring 321 also acts as a guide, ensuring that the two motor shafts 311 are correctly attracted together.

[0025] To ensure the synchronicity of the rotation of the two motor shafts 311, the connecting mechanism 32 further includes protrusions 323 on the motor shafts 311. When the magnet is energized, the protrusions 323 at the ends of adjacent motor shafts 311 engage and lock, preventing relative rotation between the two motor shafts 311. The magnetic attraction force of the electromagnet 322 limits the axial movement of the two motor shafts 311, while the protrusions 323 limit their circumferential movement, thus ensuring synchronous rotation of the motor shafts 311, allowing multiple motors 31 to jointly drive the impeller 20 to rotate.

[0026] Blood pumps are classified into two different structural forms depending on whether the impeller 20 is a foldable structure.

[0027] Example 1

[0028] Considering the actual flow requirements of the blood pump, two motors 31 are sufficient to meet the blood pumping requirements of the human body. The impeller 20 is located at the distal end of the first motor 31a. The impeller 20 has a foldable structure. The proximal end of the blood flow channel 10 is connected to an expandable and contractible housing 40. One end of the housing 40 is fixed to the proximal end of the blood flow channel 10, and the other end is connected to the conduit 50 located at the proximal end of the motor 31 to form an axial sliding and circumferential limiting fit. When the electromagnet is de-energized, the foldable impeller 20 is placed in the blood flow channel 10 in a folded state. When the electromagnet is energized, the first motor 31a moves to the proximal end and connects with the second motor 31b located at the distal end. The foldable impeller 20 is located in the expanded housing 40 in an open state. As we all know, when a blood pump is inserted into the heart via a blood vessel, it relies on a sheath. Due to the constraint of the sheath, the housing 40 contracts, the electromagnet is not energized, and the elastic force of the compression spring 321 drives the two motors 31 to separate. The impeller 20 is inside the blood flow channel 10, and the blades of the impeller 20 are folded due to the constraint of the blood flow channel 10. The outer diameter of the blood pump is small, reducing damage to the blood vessel. After the sheath is removed, the constraint on the housing 40 is released, and it expands. At this time, the electromagnet is energized, and the first motor 31a moves to the second motor 31b and connects with it. The impeller 20 enters the housing 40 from the blood flow channel 10, opening up to achieve high-flow pumping.

[0029] To enable the expansion and contraction of the shell 40, the shell 40 includes a mesh-like support 41 made of shape memory alloy material and a thin film 42 covering the inner and / or outer and / or interlayer layers of the support 41. The thin film 42 also has the characteristic of being expandable and contractable, thus ensuring that it can expand or contract synchronously with the support 41 while forming a blood channel. After being covered by the thin film 42, it forms a hollow tubular protective peripheral wall structure of the shell. An opening is formed in the thin film 42 at the proximal end of the support 41 to form a blood outlet 12. The blood outlet 12 is located at the proximal end of the thin film 42 to avoid the existence of a blood recirculation area, that is, blood flows from the blood channel to the nearest end area and then returns to flow out from the blood outlet 12, which would cause energy loss.

[0030] In Embodiment 1, the cooperation between the foldable impeller 20 and the blood flow channel 10 can be achieved in at least two ways.

[0031] The first type is as follows: The foldable impeller 20 includes a rigid hub and blades disposed on the outer periphery of the rigid hub. The motor shaft 311 of the first motor 31a protrudes to the outside of the rigid hub to form a protruding section 311a. The protruding section 311a is fixed on a fixing ring 33. The fixing ring 33 includes an outer ring 331 and an inner ring 332 arranged coaxially. The outer ring 331 and the inner ring 332 are fixed together by a connecting rib 333. The outer wall of the outer ring 331 is in sliding fit with the blood flow channel 10. The protruding section 311a is inserted into the inner ring 332 and forms a fixed connection. That is, the motor shaft 311 is fixedly connected to the fixing ring 33, and the fixing ring 33 is in axial movement and circumferential rotation fit with the blood flow channel 10 to realize the movement of the first motor 31a.

[0032] The second type is as follows: The foldable impeller 20 includes a rigid hub and blades disposed on the outer periphery of the rigid hub. The motor shaft 311 of the first motor 31a protrudes to the outside of the rigid hub to form a protruding section 311a. The protruding section 311a and the fixing ring 33 fixed in the blood flow channel 10 form an axial sliding fit. The fixing ring 33 includes an outer ring 331 and an inner cylinder 334 arranged coaxially. The two are fixed together by a connecting rib 333. The outer ring 331 is fixed to the inner wall of the blood flow channel 10. The protruding section 311a is inserted into the inner cavity of the inner cylinder 334 and forms a sliding fit. That is, the fixing ring 33 is fixed in the blood flow channel 10, and the motor shaft 311 and the fixing ring 33 form an axial movement and circumferential rotation fit to realize the movement of the first motor 31a. The inner cylinder 334 has a certain length in the axial direction, and the motor shaft 311 can move axially in the inner cylinder 334. In addition, the distal end face of the inner cylinder 334 is closed to prevent blood from entering the inner cylinder 334 and causing blood damage and thrombosis.

[0033] Example 2

[0034] Two motors 31 are provided. The impeller 20 is located at the distal end of the first motor 31a. The impeller 20 is a rigid structure. The blood outlet 12 covers the outer periphery of the impeller 20 and is fixedly connected to the first motor 31a. When the electromagnet is energized, the second motor 31b located nearby moves to the distal end and becomes integrated with the first motor 31a. In this embodiment, the impeller 20 is a non-foldable structure (not shown in the figure), thus eliminating the need to consider expansion and contraction, resulting in a simpler structure. However, the impeller 20 is relatively smaller, and the blood pumping flow rate is lower than in Embodiment 1.

[0035] The first motor 31a and the second motor 31b have the same structure. A magnetic levitation bearing 314 is provided between the stator 312 and the rotor 313 of the first motor 31a. The inner ring of the magnetic levitation bearing 314 is fixed to the end face of the rotor 313, and the outer ring is fixed to the end face of the stator 312. The gap between the stator 312 and the rotor 313 forms a flushing channel. Blood flows through the flushing channel, carrying away the heat generated when the motor 31 rotates.

[0036] The working process of the blood pump in this invention is as follows:

[0037] Initially, the first motor 31a and the second motor 31b are separated by the compression spring 321, and the impeller 20 is retracted and placed inside the blood flow channel 10. When the entire system needs to be introduced into the body, firstly, the blood pump is inserted into the blood vessel under the constraint of the sheath. After the insertion is completed, the sheath is withdrawn, and the housing 40 expands after being unconstrained by the sheath. Then, the magnetic block on the connecting mechanism 32 is energized, causing the first motor 31a to move towards the second motor 31b. The two protrusions 323 mesh with each other, and the adjacent motor shafts 311 merge into one shaft. At the same time, the impeller 20 moves with the first motor 31a and moves out of the blood flow channel 10. At this time, the blades of the impeller 20 expand radially without the constraint of the blood flow channel 10. Then, the motor group controls the speed through current, so that the torque of each motor is concentrated on the same shaft, and drives the expanded impeller 20 to rotate. Blood first enters the blood flow channel 10 and the housing 43 sequentially from the blood inlet 11, and then is ejected from the blood outlet 12.

[0038] Of course, those skilled in the art will recognize that the present invention is not limited to the details of the exemplary embodiments described above, but also includes the same or similar structures that can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0039] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A series-connected blood pump, comprising a blood flow channel (10) and a pumping unit, wherein one end of the blood flow channel (10) is provided with a blood inlet (11) and the other end is provided with a blood outlet (12), characterized in that: The pumping unit includes an impeller (20) and a motor set (30) for driving the impeller (20) to rotate. The motor set (30) has multiple motors (31) connected in series. A connecting mechanism (32) is provided between adjacent motors (31). The connecting mechanism (32) drives adjacent motors (31) to connect into a whole or drives adjacent motors (31) to separate from each other. The motor shaft (311) of the motor (31) protrudes to the outside of the motor (31). The connecting mechanism (32) includes a compression spring (321) disposed between the motor shafts (311). The compression spring (321) provides a spring force to drive the two motor shafts (311) to move away from each other. An electromagnet (322) is also provided at the end of the motor shaft (311). When the electromagnet (322) is energized, the magnetic attraction force overcomes the spring force of the compression spring (321) to drive the two motor shafts (311) to attract each other and connect to the same shaft. The connecting mechanism (32) also includes a claw (323) disposed on the motor shaft (311). When the magnet is energized, the claws (323) at the ends of adjacent motor shafts (311) engage and lock together.

2. The series-connected blood pump according to claim 1, characterized in that: There are two motors (31). The impeller (20) is located at the far end of the first motor (31a) located at the far side. The impeller (20) is a foldable structure. The proximal end of the blood flow channel (10) is connected to an expandable and contractible shell (40). One end of the shell (40) is fixed to the proximal end of the blood flow channel (10), and the other end is connected to the conduit (50) located at the proximal end of the motor (31) to form an axial sliding and circumferential limiting fit. When the electromagnet is de-energized, the foldable impeller (20) is placed in the blood flow channel (10) in a folded state. When the electromagnet is energized, the first motor (31a) moves to the proximal end and is connected to the second motor (31b) located at the far side. The foldable impeller (20) is located in the expanded shell (40) in an open state.

3. The series-connected blood pump according to claim 2, characterized in that: The shell (40) includes a grid-like support body (41) made of shape memory alloy material and a thin film (42) covering the inner and / or outer and / or interlayer of the support body (41). After being covered by the thin film (42), the shell forms a hollow tubular protective peripheral wall structure. The proximal end of the thin film (42) of the support body (41) has an opening to form a blood outlet (12).

4. The series-connected blood pump according to claim 2, characterized in that: The foldable impeller (20) includes a rigid hub and blades disposed on the outer periphery of the rigid hub. The motor shaft (311) of the first motor (31a) extends to the outside of the rigid hub to form a protruding section (311a). The protruding section (311a) is fixed on a fixing ring (33). The fixing ring (33) includes an outer ring (331) and an inner ring (332) arranged coaxially. The two are fixed together by a connecting rib (333). The outer wall of the outer ring (331) is in sliding fit with the blood flow channel (10). The protruding section (311a) is inserted into the inner ring (332) and forms a fixed connection.

5. The series-connected blood pump according to claim 2, characterized in that: The foldable impeller (20) includes a rigid hub and blades disposed on the outer periphery of the rigid hub. The motor shaft (311) of the first motor (31a) extends to the outside of the rigid hub to form a protruding section (311a). The protruding section (311a) and the fixed ring (33) fixed in the blood flow channel (10) form an axial sliding fit. The fixed ring (33) includes an outer ring (331) and an inner cylinder (334) arranged coaxially. The two are fixed together by a connecting rib (333). The outer ring (331) is fixed to the inner wall of the blood flow channel (10). The protruding section (311a) is inserted into the inner cavity of the inner cylinder (334) and forms a sliding fit.

6. The series-connected blood pump according to claim 1, characterized in that: There are two motors (31). The impeller (20) is located at the far end of the first motor (31a) located at the far side. The impeller (20) is a rigid structure. The blood outlet (12) is covered on the outer periphery of the impeller (20) and is fixedly connected to the first motor (31a). When the electromagnet is energized, the second motor (31b) located at the near side moves to the far end and is connected to the first motor (31a).

7. The series blood pump according to claim 2 or 6, characterized in that: The first motor (31a) and the second motor (31b) have the same structure. A magnetic levitation bearing (314) is provided between the stator (312) and the rotor (313) of the first motor (31a). The inner ring of the magnetic levitation bearing (314) is fixed to the end face of the rotor (313), and the outer ring is fixed to the end face of the stator (312). The gap between the stator (312) and the rotor (313) forms a flushing channel.

Images