Dual-balloon left ventricular assist device

Abstract

The application discloses a double-balloon left ventricular assist device, which comprises an inlet pipe, an external balloon, an elastic support, an internal 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 blood flow; the external balloon has a folding and expanding state; during transportation, the external balloon is in the folding state and can be accommodated into a delivery sleeve; when reaching a designated position, the external balloon is in the expanding state; the elastic support is attached to the surface of the external balloon, and elastic deformation of the elastic support enables the external balloon to switch between the folding and expanding states; in the expanding state, the elastic support can provide radial support force, so that the external balloon expands and keeps a fixed volume; the internal balloon is arranged inside the external balloon and is contracted and expanded by injecting gas or liquid, so that the volume of the internal balloon and the internal cavity of the external balloon periodically changes and is used for blood suction and discharge; 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 devices (PMADs) are life-support technologies used to treat critically ill cardiovascular patients. They are widely used in interventional treatments for complex, high-risk coronary artery disease and cardiogenic shock. Currently, the most widely used PMAD devices in clinical practice are micro-axial flow blood pumps.

[0003] A micro-axial-flow blood pump delivers blood to the aortic valve via the femoral or axillary arteries. The pump's inlet is in the left ventricle, and its outlet is in the ascending aorta. A motor drives the pump's rotor to rotate at high speed, performing work on the blood, which is then pumped into the ascending aorta through the inlet cannula. While this micro-axial-flow blood pump provides active forward blood flow, directly reducing left ventricular preload, decreasing myocardial oxygen consumption, and increasing cardiac output, the high shear stress generated by the high-speed rotation of the pump's rotor poses a high risk of blood damage. Furthermore, the pump provides a continuous flow of blood, which is detrimental to maintaining vascular elasticity. Summary of the Invention

[0004] The purpose of the present invention is to solve the above problems and 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 solutions:

[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 stent 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 stent can provide radial support force, allowing the external balloon to expand and maintain a fixed volume;

[0010] The inner balloon is placed inside the outer balloon and is compressed and expanded by injecting gas or liquid, so that the volume of the inner and outer balloon cavities 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 into 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 both sides of the external balloon. 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 via a delivery sheath via femoral or axillary artery puncture. The inlet tube is located within the left ventricle, and the balloon is positioned within the ascending aorta. During percutaneous delivery, the outer balloon is folded and pushed through the delivery sheath. Upon reaching the designated location, the outer balloon expands, creating a defined internal space. The inner balloon periodically contracts and expands, combining inflow and outflow channels with a one-way valve to achieve directional pumping of blood from the left ventricle to the ascending aorta, increasing cardiac output.

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

[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 provided 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 fitted with the inner ring of the first connector and 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 and internal balloons, causing less damage to the blood;

[0024] (2) Produce active forward, pulsatile blood flow, effectively reduce cardiac load and improve the perfusion effect 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 Schematic diagram of the structure 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 of 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 in the expanded balloon state.

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

[0030] Figure 5 Schematic diagram of the first connector of the double-balloon left ventricular assist device of the present invention.

[0031] Figure 6A Schematic diagram of the second connector of the double-balloon left ventricular assist device of the present invention.

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

[0033] Figure 7 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 in operation.

[0035] Figure 9 Schematic diagram of blood flow during the inhalation process of the double-balloon left ventricular assist device of the present invention.

[0036] Figure 10 This is a schematic diagram of the double-balloon left ventricular assist device of the present invention in a filled lumen state.

[0037] Figure 11 Schematic diagram of blood flow during the discharge process of the double-balloon left ventricular assist device of the present invention.

[0038] In the picture:

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

[0040] 11 inflow window; 12 guide wire passage 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.

[0045] To make the above-mentioned objects and features of the present invention more obvious and understandable, specific embodiments 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, which shows 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 bracket 3, the external balloon can maintain a fixed volume. The elastic bracket 3 is evenly and tightly attached to the surface of the external balloon 2. The connection between the elastic bracket and the external balloon is achieved through the manufacturing process of the coated bracket. The elastic bracket is in the shape of a wire or a mesh and is made of nickel-titanium alloy wire with biocompatibility and superelasticity. The elastic deformation of the elastic bracket enables the external balloon to switch between folded and expanded states. In the expanded state, the elastic bracket 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 designated 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 expansion and contraction of the internal balloon 4 can be achieved 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. When filled, its shape can change slightly with the increase of internal pressure. The material is nylon or polyethylene terephthalate. A diaphragm 41 is provided 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. There are multiple small holes 411 on the diaphragm 41, 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. 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. The inflow channel of the inlet tube 1 is connected to the inner cavity of the external balloon 2, which can realize the suction of blood from the left ventricle into the inner cavity. The inner ring 512 of the first connector 51 is loosely matched with the catheter 6. 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. 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 separates the inner ring and the outer ring into multiple outlets. The second connector is also provided with a one-way valve 524. Figure 6B The one-way valve 524 is in a circular shape, and its inner side is bonded and fixed to the inner ring 522 of the second connecting member. The overall outer diameter is set to be larger than the inner diameter of the outer ring of the second connecting member, so that the outer side is in contact with the inner wall of the outer ring 521 of the second connecting member. The one-way valve 524 is made of silicone rubber, and the pressure difference on both sides is used to realize the opening and closing of 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 set 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. The guidewire cavity 62 is used to guide the guidewire through, facilitating the delivery of the device to a designated location via the catheter. The medium cavity 61 is connected to the first chamber 42 of the internal balloon 4 through the connecting holes 63. The distal end of the catheter 6 ends at the first connector, and the proximal end extends outside the body. The catheter 6 is loosely fitted 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 This is a schematic diagram of the percutaneous delivery of the device. The inlet tube 1 and the balloon part are both flexible and can pass through complex vascular environments. 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 outer 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 from the internal balloon, so that the volume between the internal balloon and the outer 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 dual-balloon left ventricular assist device 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 cavity of the catheter 6, while the second chamber 43 is not directly connected to the catheter 6 and can only flow medium through the holes in the diaphragm. This design makes the first chamber respond faster than the second chamber during expansion and contraction. Figure 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, causing blood to be sucked into the outside of the first chamber through the inlet tube 1. Then the second chamber contracts, causing the blood outside the first chamber to be sucked 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. Figure 10 ; Figure 11 This diagram illustrates blood flow during the discharge process of the device. During the inflation of the internal balloon 4, the first chamber expands faster than the second chamber. The first chamber expands first, pushing the blood outside toward the outside of the second chamber. The second chamber then expands, forcing the blood outside through the second connector's outlet channel and into the ascending aorta. This design offers the advantage of directional blood intake and discharge, high pumping efficiency, and enhanced blood compatibility.

[0054] The double-balloon left ventricular assist device of an 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 inflow and outflow channels and a 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 outer balloon, an elastic support, an inner balloon, a catheter and connectors; 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 stent 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 stent can provide radial support force, allowing the external balloon to expand and maintain a fixed volume; The inner balloon is placed inside the outer balloon and is compressed and expanded by injecting gas or liquid, so that the volume of the inner and outer balloon cavities 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 into the body via a 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 both 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 a puncture of the femoral artery or axillary artery, wherein the inlet tube is located in the left ventricle and the balloon is located in the ascending aorta. During the percutaneous delivery process, the external balloon is in a folded state and the entire balloon can be pushed through the escort sheath. When it reaches the designated position, the external balloon is in an expanded state, forming a certain internal space. The internal balloon periodically contracts and expands, and combined with the inflow and outflow channels and the one-way valve, it realizes the 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, wherein: The inner balloon includes a first chamber and a second chamber, and the two chambers are connected through 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 includes an outer ring and an inner ring, and a plurality of partition plates are provided 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, wherein: 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, wherein: The catheter is loosely fitted with the inner ring of the first connector and 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.

9. The double-balloon left ventricular assist device according to claim 1, wherein: The medium cavity of the catheter is in communication with the first cavity of the inner 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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