Double-balloon type left ventricle auxiliary device

Abstract

The invention discloses a double-balloon type left ventricle auxiliary device which comprises an inlet tube, an outer balloon, an elastic support, an inner balloon, a catheter and a connecting piece. The inlet pipe is provided with a plurality of inflow windows and a one-way valve for controlling one-way flow of blood; the outer balloon has a folded state and an expanded state, in the conveying process, the outer balloon is in the folded state and can be contained in the conveying sleeve, and when the outer balloon reaches a designated position, the outer balloon is in the expanded state; the elastic support is attached to the surface of the external balloon, the elastic deformation of the elastic support enables the external balloon to be switched between a folded state and an expanded state, and the elastic support can provide radial supporting force in the expanded state, so that the external balloon is expanded and keeps a fixed volume; the internal balloon is arranged inside the external balloon, and contraction and expansion are realized by injecting gas or liquid, so that the volumes of inner cavities of the internal balloon and the external balloon are periodically changed, and the internal balloon and the external balloon are used for sucking and discharging blood; the catheter is provided with a medium cavity and a guide wire cavity, and the medium cavity is communicated with the internal balloon.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical ventricular assist devices, and in particular relates to a double-balloon left ventricular assist device. Background Art

[0002] Percutaneous mechanical circulatory assist device is a life support technology used to treat critically ill cardiovascular patients. It is widely used in interventional treatment of complex, high-risk coronary artery disease and cardiogenic shock. Currently, the most widely used percutaneous mechanical circulatory assist device in clinical practice is a micro axial flow blood pump.

[0003] The micro-axial flow blood pump is delivered to the aortic valve through the femoral artery or axillary artery. The inlet of the axial flow blood pump is in the left ventricle and the outlet is in the ascending aorta. The motor drives the blood pump rotor to rotate at high speed to do work on the blood, and the blood is pumped into the ascending aorta through the inlet cannula. The micro-axial flow blood pump can provide active forward blood flow, directly reduce the left ventricular preload, reduce myocardial oxygen consumption, and increase cardiac output. However, the high shear stress generated by the high-speed rotation of the blood pump rotor has a high risk of blood damage, and it provides continuous flow of blood, which is not conducive to maintaining vascular elasticity. Summary of the invention

[0004] The purpose of the present invention is to solve the above-mentioned problems and to provide a double-balloon left ventricular assist device that causes less damage to the blood, effectively reduces the heart load, and can improve the perfusion effect of peripheral organs and maintain vascular elasticity.

[0005] To achieve the above object, the present invention adopts the following technical solution:

[0006] A double-balloon left ventricular assist device comprises an inlet tube, an external balloon, an elastic support, an internal balloon, a catheter and a connector;

[0007] The inlet tube has multiple inflow windows and a one-way valve to control the one-way flow of blood;

[0008] The external balloon has a folded state and an expanded state. During the delivery process, the external balloon is in a folded state and can be accommodated in the delivery sleeve. When it reaches the designated position, the external balloon is in an expanded state.

[0009] The elastic support is attached to the surface of the external balloon, and its elastic deformation enables the external balloon to switch between two states: folded and expanded. In the expanded state, the elastic support can provide radial support force, so that the external balloon expands and maintains a fixed volume;

[0010] The inner balloon is arranged inside the outer balloon, and is shrunk and expanded by injecting gas or liquid, so that the volume of the inner cavity of the inner balloon and the outer balloon changes periodically, which is used for blood suction and discharge;

[0011] The catheter has a medium cavity and a guidewire cavity. The medium cavity is connected to the internal balloon and is used to inject and extract gas or liquid into the internal balloon to achieve expansion and contraction of the internal balloon. The guidewire cavity is used to guide the device to be implanted in the body through the guidewire.

[0012] The connecting piece includes a first connecting piece and a second connecting piece, the two connecting pieces are distributed at two positions of the catheter and are fixedly connected to two sides of the external balloon, and the two connecting pieces are provided with inflow and outflow channels for directional pumping of blood flow.

[0013] The device is delivered into the body through a delivery sheath via femoral or axillary artery puncture, where the inlet tube is located in the left ventricle and the balloon is located in the ascending aorta. During percutaneous delivery, the outer balloon is in a folded state and can be pushed through the delivery sheath as a whole. When it reaches the designated position, the outer balloon is in an expanded state, forming a certain internal space. The inner balloon periodically contracts and expands, combined with the inflow and outflow channels and the one-way valve, to achieve directional pumping of blood from the left ventricle to the ascending aorta, thereby increasing cardiac output.

[0014] Furthermore, the elastic support is fixedly connected to the outer balloon surface.

[0015] Furthermore, the elastic support is in the shape of a wire or a mesh, and is made of nickel-titanium alloy wire.

[0016] Furthermore, the inner balloon includes a first chamber and a second chamber, and the two chambers are connected through a diaphragm.

[0017] Furthermore, a small hole is provided on the diaphragm of the inner balloon, and the two chambers achieve the circulation of gas or liquid through the small hole on the diaphragm.

[0018] Furthermore, the connecting member includes an outer ring and an inner ring, and a plurality of partition plates are arranged between the inner and outer rings to form a plurality of inflow and outflow channels; the outer ring of the connecting member is fixedly connected to the external balloon.

[0019] Furthermore, the outflow channel of the second connecting member is provided with a one-way valve for controlling the one-way outflow of blood.

[0020] Furthermore, the catheter is loosely matched with the inner ring of the first connector and is fixedly connected to the inner ring of the second connector. The distance between the two connectors changes with the folding and expansion of the external balloon. The distal end of the catheter stops at the first connector and the proximal end extends outside the body.

[0021] Furthermore, the medium cavity of the catheter is in communication with the first cavity of the internal balloon, so that the expansion and contraction response speed of the first cavity is faster than that of the second cavity.

[0022] The beneficial effects of the present invention are:

[0023] (1) Blood pumping is achieved by periodically changing the volume of the inner cavity formed by the external balloon and the internal balloon, which causes less damage to the blood;

[0024] (2) Produce active forward, pulsatile blood flow, effectively reduce cardiac load and improve the perfusion of peripheral organs and maintain vascular elasticity. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiment of the present invention, the embodiment will be described below with reference to the accompanying drawings.

[0026] Figure 1 It is a schematic structural diagram of the double-balloon left ventricular assist device of the present invention.

[0027] Figure 2 It is a cross-sectional view of the inlet tube in the double-balloon left ventricular assist device of the present invention.

[0028] Figure 3 It is a cross-sectional view of the double-balloon left ventricular assist device of the present invention when the balloon is in the expanded state.

[0029] Figure 4 It is a cross-sectional view of the double-balloon left ventricular assist device of the present invention when the balloon is in a folded state.

[0030] Figure 5 It is a schematic diagram of the first connecting piece of the double-balloon left ventricular assist device of the present invention.

[0031] Fig. 6A It is a schematic diagram of the second connecting piece of the double-balloon left ventricular assist device of the present invention.

[0032] Figure 6B It is a cross-sectional view of the second connecting piece of the double-balloon left ventricular assist device of the present invention.

[0033] Figure 7 It is a schematic diagram of the percutaneous delivery process of the double-balloon left ventricular assist device of the present invention.

[0034] Figure 8 This is a schematic diagram of the double-balloon left ventricular assist device of the present invention when it is working.

[0035] Fig. 9 It is a schematic diagram of blood flow during the inhalation process of the double-balloon left ventricular assist device of the present invention.

[0036] Fig.10 It is a schematic diagram of the double-balloon left ventricular assist device of the present invention in a state where the inner cavity is filled.

[0037] Fig.11 It is a schematic diagram of blood flow during the discharge process of the double-balloon left ventricular assist device of the present invention.

[0038] In the figure:

[0039] 1 inlet tube; 2 external balloon; 3 elastic support; 4 internal balloon; 5 connecting piece; 6 catheter;

[0040] 11 inflow window; 12 guide wire passing hole; 13 one-way valve;

[0041] 41 diaphragm; 42 first chamber; 43 second chamber;

[0042] 51 first connecting member; 52 second connecting member;

[0043] 61 medium cavity; 62 guide wire cavity; 63 connecting hole. DETAILED DESCRIPTION

[0044] The following examples are merely used to illustrate possible implementations of the present invention, but are not intended to limit the scope of the present invention, so it is necessary to explain them first.

[0045] In order to make the above-mentioned objects and features of the present invention more obvious and understandable, the specific implementation modes of the present invention are described in detail below with reference to the accompanying drawings, but the present invention is not limited to the following contents.

[0046] like Figures 1 to 11 As shown, an embodiment of a double-balloon left ventricular assist device of the present invention includes an inlet tube 1, an external balloon 2, an elastic support 3, an internal balloon 4, a connector 5 and a catheter 6.

[0047] The inlet tube 1 of the embodiment of the present invention is arranged at the distal side of the device, including multiple inflow windows 11 at the distal end, a guide wire passing hole 12 and a one-way valve 13. The structure of the one-way valve 13 is similar to a duckbill valve, which can realize one-way suction of blood. The inlet tube 1 is made of flexible material, and the distal end is elliptical, and it has good passability during the sheath guide wire delivery process.

[0048] The external balloon 2 of the embodiment of the present invention is a non-compliant balloon, which can withstand a certain normal pressure without deformation in the filled state. The material can be polyethylene, polyurethane, nylon, etc. Under the support of the elastic support 3, the external balloon can maintain a fixed volume. The elastic support 3 is evenly and tightly attached to the surface of the external balloon 2. The connection between the elastic support and the external balloon is achieved through the manufacturing process of the coated stent. The elastic support is in the shape of a wire or a mesh and is made of a nickel-titanium alloy wire with biocompatibility and superelasticity. The elastic deformation of the elastic support enables the external balloon to switch between a folded state and an expanded state. In the expanded state, the elastic support can provide a certain radial support force, so that the external balloon expands and maintains a fixed volume; during the delivery process, the external balloon is in a folded state and can be accommodated in the delivery sheath. When it reaches the specified position, the external balloon is in an expanded state.

[0049] The internal balloon 4 of the embodiment of the present invention is arranged inside the external balloon 2 and installed on the catheter 5. The internal balloon 4 can be expanded and contracted by injecting and extracting helium, so that the volume of the internal balloon and the external balloon cavity changes periodically, which is used for blood suction and discharge; the internal balloon 4 is a semi-compliant balloon, and its shape can change slightly with the increase of internal pressure in the filled state. The material is nylon or polyethylene terephthalate. A diaphragm 41 is arranged in the middle of the internal balloon 4, which divides the internal balloon into a first chamber 42 and a second chamber 43. The two chambers are connected by the diaphragm. The diaphragm 41 has multiple small holes 411, and the two chambers can realize the circulation of helium through the holes on the diaphragm.

[0050] The connector 5 of the embodiment of the present invention is mainly composed of an inner ring, an outer ring and a partition plate, and is divided into a first connector 51 and a second connector 52 according to different distribution positions. The two connectors are distributed at two positions of the catheter and are fixedly connected to both sides of the external balloon, and the two connectors are provided with inflow and outflow channels for directional pumping of blood flow. The outer ring 511 of the first connector 51 connects the inlet tube 1 and the external balloon 2, and the inflow channel of the inlet tube 1 is connected to the inner cavity of the external balloon 2, so that blood can be sucked from the left ventricle into the inner cavity. The inner ring 512 of the first connector 51 is in clearance fit with the catheter 6, and the first connector 51 can move along the axial direction of the catheter as the external balloon 2 is folded and expanded; the outer ring 521 of the second connector 52 is fixedly connected to the external balloon, and the inner ring 522 is fixedly connected to the catheter, and the proximal end of the second connector is conical in shape. The purpose of this design is to make the device have good passability when withdrawn through the sheath. The partition plate 523 divides the inner ring and the outer ring into multiple outlets, and the second connector is also provided with a one-way valve 524, such as Figure 6B The one-way valve 524 is in a circular shape, and its inner side is bonded and fixed to the second connecting member inner ring 522. The overall outer diameter is set to be larger than the inner diameter of the second connecting member outer ring, so that the outer side is in close contact with the inner wall of the second connecting member outer ring 521. The one-way valve 524 is made of silicone rubber, and the pressure difference on both sides is used to open and close the one-way valve, thereby controlling the one-way outflow of blood.

[0051] The catheter 6 of the embodiment of the present invention includes a medium cavity 61, a guidewire cavity 62 and a group of connecting holes 63. The medium cavity of the catheter is connected to the first chamber of the internal balloon, so that the expansion and contraction response speed of the first chamber is faster than that of the second chamber; the medium cavity 61 is used to inject and extract helium into the internal balloon to achieve expansion and contraction, and the guidewire cavity 62 is used to guide the guidewire to pass through, so as to facilitate the device to be transported to a specified position via the catheter. The medium cavity 61 is connected to the first chamber 42 of the internal balloon 4 through the connecting hole 63. The distal end of the catheter 6 stops at the first connector, and the proximal end extends outside the body. The catheter 6 is gap-matched with the inner ring 512 of the first connector, and is fixedly connected to the inner ring 522 of the second connector. The distance between the two connectors changes with the folding and expansion of the external balloon.

[0052] The double-balloon left ventricular assist device of the embodiment of the present invention has an overall outer diameter of 4 to 5 mm during the delivery process through the sheath. It is implanted into the body through the escort sheath and guide wire. During the delivery process, the inner balloon is in a contracted state, and the outer balloon is in a folded state as the elastic stent contracts. The entire device is delivered through a 16F sheath. Figure 7 The figure is a schematic diagram of the percutaneous delivery of the device. The inlet tube 1 and the balloon part have certain flexibility and can pass through the complex vascular environment. When reaching the designated position, the inlet tube extends into the left ventricle, and the balloon is located in the ascending aorta. At this time, the external balloon 2 is in an expanded state under the support of the elastic bracket, forming an internal space of a certain volume. The internal balloon is expanded and contracted by the infusion and extraction of helium gas in the internal balloon, so that the volume between the internal balloon and the external balloon changes periodically. Combined with the inlet tube 1 and the inflow and outflow channels of the second connecting piece 52 and the one-way valve, blood is pumped from the left ventricle to the ascending aorta. Figure 8 This is a schematic diagram of the device in actual use.

[0053] The double-balloon left ventricular assist device of the embodiment of the present invention has a special design for the inner balloon 4. The diaphragm 41 divides the inner balloon 4 into a first chamber 42 and a second chamber 43. The first chamber 42 is connected to the medium chamber of the catheter 6, and the second chamber 43 is not directly connected to the catheter 6, and the medium can only flow through the hole on the diaphragm. This design makes the response speed of the first chamber faster than that of the second chamber during expansion and contraction. Fig. 9 As shown, during the contraction of the internal balloon 4, the first chamber contracts faster than the second chamber. The first chamber contracts first so that blood is sucked into the outside of the first chamber through the inlet tube 1, and then the second chamber contracts to suck the blood outside the first chamber into the outside of the second chamber. The contraction of the internal balloon is completed and the internal space is filled. The filling state is shown in FIG. Fig.10 ; Fig.11 This is a schematic diagram of the blood flow during the discharge process of the device of the present invention. During the expansion of the internal balloon 4, the first chamber expands faster than the second chamber. The first chamber expands first to squeeze the outer blood to the outside of the second chamber, and then the second chamber expands to make the outer blood flow out of the second connector into the ascending aorta. The advantage of this design is that the balloon has directionality when inhaling and discharging blood, with high pumping efficiency and high blood compatibility.

[0054] The double-balloon left ventricular assist device of the embodiment of the present invention provides active forward, pulsatile blood flow from the left ventricle to the ascending aorta through periodic changes in the inner cavity volume combined with the inflow and outflow channels and the one-way valve, thereby increasing cardiac output, maintaining vascular elasticity, and improving blood circulation levels.

Claims

1. A double-balloon left ventricular assist device, characterized in that: It includes an inlet tube, an external balloon, an elastic support, an internal balloon, a catheter and a connector; The inlet tube has multiple inflow windows and a one-way valve to control the one-way flow of blood; The external balloon has a folded state and an expanded state. During the delivery process, the external balloon is in a folded state and can be accommodated in the delivery sleeve. When it reaches the designated position, the external balloon is in an expanded state. The elastic support is attached to the surface of the external balloon, and its elastic deformation enables the external balloon to switch between two states: folded and expanded. In the expanded state, the elastic support can provide radial support force, so that the external balloon expands and maintains a fixed volume; The inner balloon is arranged inside the outer balloon, and is shrunk and expanded by injecting gas or liquid, so that the volume of the inner cavity of the inner balloon and the outer balloon changes periodically, which is used for blood suction and discharge; The catheter has a medium cavity and a guidewire cavity. The medium cavity is connected to the internal balloon and is used to inject and extract gas or liquid into the internal balloon to achieve expansion and contraction of the internal balloon. The guidewire cavity is used to guide the device to be implanted in the body through the guidewire. The connecting piece includes a first connecting piece and a second connecting piece, the two connecting pieces are distributed at two positions of the catheter and are fixedly connected to two sides of the external balloon, and the two connecting pieces are provided with inflow and outflow channels for directional pumping of blood flow; The device is delivered into the body through a delivery sheath via femoral or axillary artery puncture, where the inlet tube is located in the left ventricle and the balloon is located in the ascending aorta. During percutaneous delivery, the outer balloon is in a folded state and can be pushed through the delivery sheath as a whole. When it reaches the designated position, the outer balloon is in an expanded state, forming a certain internal space. The inner balloon periodically contracts and expands, combined with the inflow and outflow channels and the one-way valve, to achieve directional pumping of blood from the left ventricle to the ascending aorta, thereby increasing cardiac output.

2. The double-balloon left ventricular assist device according to claim 1, characterized in that: The elastic support is fixedly connected to the outer balloon surface.

3. The double-balloon left ventricular assist device according to claim 2, characterized in that: The elastic support is in the shape of a wire or a mesh, and is made of nickel-titanium alloy wire.

4. The double-balloon left ventricular assist device according to claim 3, characterized in that: The inner balloon comprises a first chamber and a second chamber, and the two chambers are connected via a diaphragm.

5. The double-balloon left ventricular assist device according to claim 4, characterized in that: The diaphragm of the inner balloon is provided with small holes, and the two chambers realize the circulation of gas or liquid through the small holes on the diaphragm.

6. The double-balloon left ventricular assist device according to claim 1, characterized in that: The connecting member comprises an outer ring and an inner ring, and a plurality of partition plates are arranged between the inner and outer rings to form a plurality of inflow and outflow channels; the outer ring of the connecting member is fixedly connected to the external balloon.

7. The double-balloon left ventricular assist device according to claim 1, characterized in that: The outflow channel of the second connecting member is provided with a one-way valve for controlling the one-way outflow of blood.

8. The double-balloon left ventricular assist device according to claim 1, characterized in that: The catheter is loosely matched with the inner ring of the first connector and fixedly connected with the inner ring of the second connector. The distance between the two connectors changes with the folding and expansion of the external balloon. The distal end of the catheter stops at the first connector and the proximal end extends outside the body.

9. The double-balloon left ventricular assist device according to claim 1, characterized in that: The medium cavity of the catheter is in communication with the first cavity of the internal balloon, so that the expansion and contraction response speed of the first cavity is faster than that of the second cavity.

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