Catheter type ventricular assist system

Abstract

The utility model relates to a catheter type ventricular assist system which can provide different flows and is small in trauma, and comprises a single-channel double-cavity cannula and a single-channel single-cavity cannula, the single-channel double-cavity cannula comprises an inner tube and an outer tube, the near end of the inner tube is communicated with an inlet tube of a blood pump, and an outlet tube of the blood pump is communicated with the near end of the outer tube or the near end of the single-channel single-cavity cannula. Blood is sucked in from the blood inflow port at the far end of the inner tube and flows out from the blood outflow port at the far end of the outer tube to form a small-flow circulation auxiliary system, and blood is sucked in from the blood inflow port at the far end of the inner tube and flows out from the opening at the far end of the single-channel single-cavity cannula to form a large-flow circulation auxiliary system. By means of the mode that the outer tube and the single-channel single-cavity cannula are switched, one set of ventricle auxiliary device can meet small-flow circulation assistance and large-flow circulation assistance, and the ventricle auxiliary device is suitable for different scenes. In small-flow circulation assistance, the outer tube and the inner tube are single-channel double-cavity intubation tubes, the single-channel double-cavity intubation tubes can be intervened to the designated position only through one incision, trauma is small, and postoperative recovery is fast.

Description

Technical Field

[0001] The utility model relates to the technical field of medical devices, and particularly relates to a catheter-type ventricular assist system. Background Art

[0002] A ventricular assist device is a life support technology used to partially or completely replace the function of a failing heart and belongs to an active blood circulation support device. A left ventricular assist device usually intervenes in a patient's body through a percutaneous implantation method using two separate catheters. The blood pump pumps the blood from other parts from the left ventricle to the aorta. However, the two catheters will cause two traumatic wounds, increasing the risk of surgical infection. Moreover, the pump blood flow of the same set of ventricular assist devices is determined and cannot adapt to the different needs of patients. Content of the Utility Model

[0003] The purpose of the utility model is to provide a catheter-type ventricular assist system that can provide different flows and has less trauma.

[0004] To achieve the above purpose, the technical solution adopted by the utility model is: a catheter-type ventricular assist system, including a single-channel double-lumen cannula, a single-channel single-lumen cannula, and a blood pump. The single-channel double-lumen cannula includes an inner tube and an outer tube. The proximal end of the inner tube communicates with the inlet tube of the blood pump, and the blood pump outlet tube communicates with the proximal end of the outer tube or the proximal end of the single-channel single-lumen cannula. The blood is inhaled from the blood inlet at the distal end of the inner tube and flows out from the blood outlet at the distal end of the outer tube to form a small-flow circulation assist system. The blood is inhaled from the blood inlet at the distal end of the inner tube and flows out from the distal opening of the single-channel single-lumen cannula to form a large-flow circulation assist system.

[0005] The outer tube is a flexible membrane. The distal end of the flexible membrane is welded and fixed to the outer wall of the inner tube. The proximal end is pulled out from the inner tube to form a branch structure and the boundary is sealed. The annular chamber between the inner tube and the outer tube forms a blood return chamber. The blood outlet is opened at the distal end of the flexible membrane.

[0006] The outer tube is a flexible tube. The proximal end of the outer tube is pulled out from the inner tube to form a branch structure and the boundary is sealed. The distal end of the flexible tube is embedded with a nitinol wire braid and fixed to the inner tube. The annular chamber between the inner tube and the outer tube forms a blood return chamber. The blood outlet is opened at the distal position of the flexible tube.

[0007] The inner tube is made of materials with different stiffnesses in its length direction, or the inner tube is made of the same material and is embedded with a reinforcing bracket in the distal tube section. The reinforcing bracket is a nitinol alloy braid or a nitinol alloy spiral wire.

[0008] The inner cross-sectional area of the single-channel single-lumen cannula is larger than the effective cross-sectional area of the chamber between the inner and outer tubes. The pump blood flow of the small-flow circulation assist system is 1 L / min, and the flow of the large-flow circulation assist system is 3 L / min.

[0009] A plurality of the blood outlets are uniformly arranged at intervals in the circumferential direction, and a flow guiding member is arranged at the blood outlet. The flow guiding member guides the blood flow direction to flow downstream from the descending aorta.

[0010] The flow guiding member is arranged in a segmented manner outside the blood outlet, and is integrally in the shape of a valve, and is warped under the impact of blood.

[0011] The flow guiding member is an integral horn-shaped structure, and the large-mouth side faces the proximal end and covers the periphery of the blood outlet.

[0012] A two-position three-way electromagnetic valve is connected to the outlet pipe of the blood pump. The inlet of the two-position three-way electromagnetic valve is connected to the outlet pipe, and the two outlets are respectively connected to the proximal end of the outer pipe and the proximal end of the single-channel single-lumen cannula. When the two-position three-way electromagnetic valve is powered off, the outlet pipe of the blood pump is communicated with the outer pipe; when the two-position three-way electromagnetic valve is powered on, the outlet pipe of the blood pump is communicated with the single-channel single-lumen cannula.

[0013] In the above solution, at least the following beneficial effects are achieved:

[0014] By switching between the outer pipe and the single-channel single-lumen cannula, a set of ventricular assist devices can be used to meet small-flow circulation assistance and large-flow circulation assistance, and adapt to different scenarios.

[0015] The pump blood flow of the small-flow circulation assistance system is 1 L / min, and the flow of the large-flow circulation assistance system is 3 L / min, corresponding to the blood flow under typical physiological pressures.

[0016] In small-flow circulation assistance, the outer pipe and the inner pipe are single-channel double-lumen cannulas, and the overall diameter is small. Only one incision needs to be made at the femoral artery, and the single-channel double-lumen cannula can be inserted into the designated position, with small trauma and quick postoperative recovery.

[0017] By energizing and de-energizing the two-position three-way electromagnetic valve, the rapid and stable switching between the outer pipe and the single-channel single-lumen cannula can be achieved.

[0018] When large-flow circulation assistance is required, during the entire process of inserting the single-channel single-lumen cannula, the blood supply of the small-flow circulation assistance system does not stop, and vice versa, ensuring the blood supply of the human body.

[0019] Using a flexible film as the outer pipe can reduce the blood damage and the tension of the incision at the femoral artery while protecting the incision. Description of the Drawings

[0020] Figure 1 It is a schematic diagram of the overall structure of the single-channel double-lumen cannula and the single-channel single-lumen cannula;

[0021] Figure 2Schematic diagram of the usage state of a catheter-based ventricular assist system inserted into the heart;

[0022] Figure 3 Schematic diagram of the structure of the single-channel double-lumen cannula in Embodiment 1;

[0023] Figure 4 Schematic diagram of the structure of the single-channel double-lumen cannula in Embodiment 2;

[0024] Figure 5 、 Figure 6 is Figure 4 partial enlarged schematic diagram in

[0025] Figure 7 Schematic diagram of the structure of the blood pump;

[0026] Figure 8 Schematic diagram of the overall structure of an embodiment of the ventricular assist system. Detailed implementation manners

[0027] For the convenience of understanding, first, we define the directions involved in the following text: "proximal" and "near side" refer to the side close to the operator / doctor, and "distal" and "far side" refer to the side far from the operator / doctor, that is, the side close to the heart. The following combines Figures 1-7 to further elaborate on the present invention in detail.

[0028] As Figure 1 、 Figure 2 shown, a catheter-based ventricular assist system includes a single-channel double-lumen cannula 10, a single-channel single-lumen cannula 20, and a blood pump 30. The single-channel double-lumen cannula 10 includes an inner tube 11 and an outer tube 12. The proximal end of the inner tube 11 communicates with the inlet tube 31 of the blood pump 30, and the outlet tube 32 of the blood pump 30 communicates with the proximal end of the outer tube 12 or the proximal end of the single-channel single-lumen cannula 20. Blood is inhaled from the blood inlet a at the distal end of the inner tube 11 and flows out from the blood outlet b at the distal end of the outer tube 12 to form a small-flow circulation assist system. Blood is inhaled from the blood inlet a at the distal end of the inner tube 11 and flows out from the distal opening of the single-channel single-lumen cannula 20 to form a large-flow circulation assist system.

[0029] Working process of the small-flow circulatory assist system: The proximal end of the inner tube 11 is connected to the inlet tube 31 of the blood pump 30, and the proximal end of the outer tube 12 is connected to the outlet tube 32 of the blood pump 30. The single-channel double-lumen cannula 10 is inserted through the femoral artery incision. The inner tube 11 is inserted into the left ventricle. As the inner tube 11 reaches the ventricle, the blood outlet b of the outer tube 12 exactly reaches the position of the descending aorta. The blood pump 30 is started. The blood in the ventricle is sucked into the inner tube 11 from the blood inlet a, returns from the annular chamber between the inner tube 11 and the outer tube 12 after extracorporeal circulation by the blood pump 30, and finally enters the descending aorta from the blood outlet b at the distal end of the outer tube 12, and then supplies blood to the whole body through the branch blood vessels on the artery. Only one incision needs to be made at the femoral artery to insert the single-channel double-lumen cannula 10 to the specified position, with less trauma and quick postoperative recovery. The outer diameter of the entire single-channel double-lumen cannula 10 is limited by the inner diameter of the femoral artery vessel. Coupled with the inner tube 11 inside the outer tube 12, only the annular chamber between the two can transport blood, and the effective interface area is slightly smaller. Therefore, the blood flow transported under this structure is small.

[0030] Working process of the large-flow circulatory assist system: The proximal end of the inner tube 11 is connected to the inlet tube 31 of the blood pump 30, and the proximal end of the single-channel single-lumen cannula 20 is connected to the outlet tube 32 of the blood pump 30. The single-channel double-lumen cannula 10 is inserted through the left femoral artery incision. The inner tube 11 is inserted into the left ventricle. The single-channel single-lumen cannula 20 is inserted through the right femoral artery incision to the position of the descending aorta. The blood pump 30 is started. The blood in the ventricle is sucked into the inner tube 11 from the blood inlet a, and then enters the descending aorta from the distal opening of the single-channel single-lumen cannula 20 after extracorporeal circulation by the blood pump 30, and then supplies blood to the whole body through the branch blood vessels on the artery. In this solution, incisions need to be made on both femoral arteries to insert the inner tube 11 and the single-channel single-lumen cannula 20 to the specified positions respectively, but the trauma is also small and the postoperative recovery is fast. Since the inner cavity of the single-channel single-lumen cannula 20 has a large effective cross-sectional area, large-flow pumping can be achieved.

[0031] By switching between the outer tube 12 and the single-channel single-lumen cannula 20, a set of ventricular assist devices can meet small-flow circulatory assistance and large-flow circulatory assistance, adapting to different scenarios. And in small-flow circulatory assistance, the outer tube 12 and the inner tube 11 are single-channel double-lumen cannulas, with a smaller overall diameter. Only one incision needs to be made at the femoral artery to insert the single-channel double-lumen cannula 10 to the specified position, with less trauma and quick postoperative recovery. Embodiment

[0032] Refer to Figure 3, the outer tube 12 is a flexible film, such as a TPU film. The distal end of the flexible film is welded and fixed to the outer wall of the inner tube 11, and the proximal end is drawn out from the inner tube 11 to form a branch structure and the boundary is sealed. The annular chamber between the inner tube 11 and the outer tube 12 forms a blood return chamber, and the blood outlet b is opened at the distal end of the flexible film. The flexible film is folded and wrapped around the outer periphery of the inner tube 11 during intervention and removal. The diameter of the entire single-channel double-chamber cannula 10 is small, and the damage to blood vessels during intervention is small. During normal blood pumping, due to the soft characteristics of the film, on the one hand, it can reduce blood damage, and on the other hand, it can reduce the tension of the incision at the femoral artery. The film part at the incision expands, and the film in other parts expands completely. That is to say, the inner diameter of the flexible film at the incision is smaller than the inner diameter of the flexible film segment outside the body and also smaller than the inner diameter of the flexible film segment inside the blood vessel. Embodiment

[0033] Participate Figures 4-5 , the outer tube 12 is a flexible tube, such as a TPU tube, with a smooth surface, good elasticity and flexibility. The proximal end of the outer tube 12 is drawn out from the inner tube 11 to form a branch structure and the boundary is sealed. A nickel-titanium wire braided mesh 121 is embedded at the distal end of the flexible tube and fixed to the inner tube 11. The firm connection between the two can be achieved by gluing and / or fixing rings. The annular chamber between the inner tube 11 and the outer tube 12 forms a blood return chamber, and the blood outlet b is opened at the distal position of the flexible tube. Adding a nickel-titanium wire braided mesh 121 at the distal end of the flexible tube can ensure the firm connection and the smoothness of the blood outlet b.

[0034] The inner tube 11 is made of materials with different stiffnesses in its length direction, or the inner tube 11 is made of the same material and a reinforcing bracket 111 is embedded in the distal tube section (at least at the bending part and the distal position), such as Figure 6 shown, to prevent the inner tube 11 from collapsing during suction and bending during the inner tube 11's bending. The reinforcing bracket 111 is a nickel-titanium alloy braided mesh or a nickel-titanium alloy spiral wire. Nickel-titanium alloy has shape memory characteristics and can be pre-shaped outside the body to meet the human physiological structure.

[0035] Corresponding to typical physiological pressures, such as the minimum blood flow rate of 1 L / min and the maximum blood flow rate of 3 L / min under a blood pressure of 90 mmHg, the diameters of the inner tube 11, the outer tube 12, and the single-channel single-chamber cannula 20 need to be adapted to the flow rate. Therefore, the inner cross-sectional area of the single-channel single-chamber cannula 20 is larger than the effective cross-sectional area of the chamber between the inner tube 11 and the outer tube 12. The pump blood flow rate of the small-flow circulatory assist system is 1 L / min, and the flow rate of the large-flow circulatory assist system is 3 L / min.

[0036] To improve the uniformity of blood injection into the descending aorta, a plurality of blood outlets b are evenly arranged at intervals in the circumferential direction. The blood outlets b are as close as possible to the distal end to avoid forming a blood recirculation area. To adjust the blood flow direction, a flow guide member (not shown in the figure) is provided at the blood outlet b. The flow guide member guides the blood flow direction to flow from the descending aorta downstream, which is consistent with the blood flow direction pumped out by the heart itself, conforms to hemodynamics, and can also prevent the blood from directly hitting the blood vessel wall and protect the blood vessels.

[0037] There are many ways to set the flow guide member. One of them is: the flow guide member is arranged in a segmented manner outside the blood outlet b, and the whole is in a valve shape, and is warped under the impact of blood. The segmented flow guide member can not only guide the blood flow, but also the gap between different valves allows the original blood to flow, and has no influence on the blood flow pumped out by the heart itself.

[0038] Another embodiment of the flow guide member is: the flow guide member is an integral horn-shaped structure, and the large-mouth side faces the proximal end and covers the periphery of the blood outlet. The flow guide member with this structure has a simple structure and simple assembly. However, since it surrounds the whole circumference, it may slightly affect the blood flow pumped out by the heart itself, but it will not block the blood flow of this part.

[0039] Since the outer tube 12 and the single-channel single-cavity cannula 20 are used alternatively / switched, as an embodiment, as Figure 8 shown, a two-position three-way solenoid valve 40 is connected to the outlet pipe 32 of the blood pump 30. The inlet of the two-position three-way solenoid valve 40 is connected to the outlet pipe 32, and the two outlets are respectively connected to the proximal end of the outer tube 12 and the proximal end of the single-channel single-cavity cannula 20. When the two-position three-way solenoid valve 40 is powered off, the outlet pipe 32 of the blood pump 30 is communicated with the outer tube 12; when the two-position three-way solenoid valve 40 is powered on, the outlet pipe 32 of the blood pump 30 is communicated with the single-channel single-cavity cannula 20. By energizing and de-energizing the two-position three-way solenoid valve 40, the rapid and stable switching between the outer tube 12 and the single-channel single-cavity cannula 20 can be realized. If it is found that the blood supply is insufficient or other emergencies occur and a large-flow blood supply is required after pumping blood for a period of time using a small-flow circulatory assist system, the single-channel single-cavity cannula 20 can be inserted into the descending aorta position through the femoral artery on the other side, and then switched to the large-flow circulatory assist system. During the whole process of inserting the single-channel single-cavity cannula 20, the blood supply of the small-flow circulatory assist system does not stop to ensure the blood supply of the human body.

[0040] When the small-flow circulation assistance system can meet the human blood flow requirements, the single-channel single-lumen cannula 20 can not be installed on the two-way three-way solenoid valve 40, and the whole device has a simple structure. When a large-flow circulation assistance system is needed to supply blood, the single-channel single-lumen cannula 20 is then intervened. After being connected to the designated position, the single-channel single-lumen cannula 20 is installed on the two-way three-way solenoid valve 40. When the human body function recovers and only small-flow circulation assistance is needed, it can be quickly switched. To further reduce the damage to blood, the passage switching in the valve cavity of the two-way three-way solenoid valve 40 can be realized through a flexible diaphragm, which can not only prevent blood from passing through but also avoid blood damage.

[0041] The blood pump 30 can be a centrifugal pump, a magnetic levitation pump, an electromagnetic drive pump, or even a piston pump, a peristaltic pump, etc. The blood pump 30 is located outside the body, which greatly improves the reliability of the whole assistance device and reduces vascular complications. If necessary, the flow rate can be pulsatile instead of continuous to mimic the natural action of the heart. The inner and outer surfaces of the single-channel double-lumen cannula 10 and the single-channel single-lumen cannula 20 can be coated with an anticoagulant coating, such as heparin or a superhydrophobic coating.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered by the scope of the claims and the description of the present invention.

Claims

1. A catheter-type ventricular assist system, characterized in that: The invention comprises a single-channel double-lumen cannula (10) and a single-channel single-lumen cannula (20). The single-channel double-lumen cannula (10) comprises an inner tube (11) and an outer tube (12). The proximal end of the inner tube (11) is communicated with an inlet tube (31) of a blood pump (30). The outlet tube (32) of the blood pump (30) is communicated with the proximal end of the outer tube (12) or the proximal end of the single-channel single-lumen cannula (20). Blood is sucked from a blood inlet (a) at the distal end of the inner tube (11) and flows out from a blood outlet (b) at the distal end of the outer tube (12) to form a small-flow circulation auxiliary system. Blood is sucked from a blood inlet (a) at the distal end of the inner tube (11) and flows out from a distal opening of the single-channel single-lumen cannula (20) to form a large-flow circulation auxiliary system.

2. The catheter-based ventricular assist system according to claim 1, characterized in that: The outer tube (12) is a flexible membrane, the distal end of the flexible membrane is welded to the outer wall of the inner tube (11), the proximal end is withdrawn from the inner tube (11) to form a branch structure, and the boundary is sealed, the annular chamber between the inner tube (11) and the outer tube (12) forms a blood return chamber, and the blood outflow port (b) is opened at the distal end of the flexible membrane.

3. The catheter-based ventricular assist system according to claim 1, characterized in that: The outer tube (12) is a soft tube. The proximal end of the outer tube (12) is pulled away from the inner tube (11) to form a branch structure and the boundary is sealed. The distal end of the soft tube is embedded with a nickel-titanium wire braided mesh (121) and is fixed to the inner tube (11). The annular chamber between the inner tube (11) and the outer tube (12) forms a blood return chamber. The blood outflow port (b) is opened at the distal end of the soft tube.

4. The catheter-based ventricular assist system according to claim 1, characterized in that: The inner tube (11) is made of materials with different rigidity in its length direction, or the inner tube (11) is made of the same material and a reinforcing bracket (111) is embedded in the distal tube, wherein the reinforcing bracket (111) is a nickel-titanium alloy braided mesh or a nickel-titanium alloy spiral wire.

5. The catheter-based ventricular assist system according to claim 1, characterized in that: The inner cavity cross-sectional area of ​​the single-channel single-lumen cannula (20) is larger than the effective cross-sectional area of ​​the chamber between the inner tube (11) and the outer tube (12); the blood pumping flow rate of the small-flow circulation auxiliary system is 1 L / min, and the flow rate of the large-flow circulation auxiliary system is 3 L / min.

6. The catheter-type ventricular assist system according to claim 2 or 3, characterized in that: The blood outflow outlets (b) are arranged uniformly and spaced apart in a plurality along the circumferential direction, and a flow guide is arranged at the blood outflow outlet (b), and the flow guide guides the blood to flow from the descending aorta to the downstream.

7. The catheter-based ventricular assist system according to claim 6, characterized in that: The guide member is arranged in a segmented manner outside the blood outflow outlet (b) and is valve-shaped, and is warped under the impact of blood.

8. The catheter-based ventricular assist system according to claim 6, characterized in that: The guide piece is an integral trumpet-shaped structure, with the wide mouth side facing the proximal end and arranged on the periphery of the blood outflow outlet (b).

9. The catheter-based ventricular assist system according to claim 1, characterized in that: The outlet pipe (32) of the blood pump (30) is connected to a two-position three-way solenoid valve (40); the inlet of the two-position three-way solenoid valve (40) is connected to the outlet pipe (32), and the two outlets are respectively connected to the proximal end of the outer pipe (12) and the proximal end of the single-channel single-lumen cannula (20); when the two-position three-way solenoid valve (40) is powered off, the outlet pipe (32) of the blood pump (30) is in communication with the outer pipe (12); when the two-position three-way solenoid valve (40) is powered on, the outlet pipe (32) of the blood pump (30) is in communication with the single-channel single-lumen cannula (20).

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