A minimally invasive catheter-based right ventricular assist device

Abstract

The present invention discloses a minimally invasive catheter-type right ventricular assist device. It comprises a cannula, an elastic metal support, a flexible film, an expandable-contractible balloon and a guide wire. The cannula is sequentially divided into a front section, a middle section and a tail section. The front section of the cannula is provided with a plurality of first inflow holes. The middle section of the cannula is a corrugated hose. The tail section of the cannula is provided with an outflow hole and a one-way valve is provided inside the tail section to control the one-way outflow of blood from the middle section to the tail section of the cannula. The elastic metal support is tightly attached to the outer surface of the cannula front section and limits deformation of the cannula front section. The flexible film is connected to the inner wall surface of the cannula front section, and its elastic modulus is smaller than that of the cannula front section. The flexible film surface is provided with a plurality of second inflow holes. The second inflow holes are arranged alternately with the first inflow holes and are located at non-overlapping positions. The expandable-contractible balloon is built into the cavity of the cannula front section to control blood intake and discharge. The guide wire passes through the cannula and extends from the tail section of the cannula.

Description

Technical Field

[0001] The present invention relates to a minimally invasive catheter-type right ventricular assist device, belonging to the field of medical devices. Background Art

[0002] Acute right ventricular failure is a life-threatening disease with a poor prognosis, which remains an unresolved clinical problem. Neither inotropic drugs nor the use of intra-aortic balloon pump (IABP) can reduce the extremely high morbidity and mortality.

[0003] Right ventricular failure may be caused by right ventricular infarction, heart transplantation, or left ventricular assist device implantation. For this problem, a right ventricular assist device is a reasonable treatment option. Summary of the Invention

[0004] The purpose of the present invention is to provide a minimally invasive catheter-type right ventricular assist device that can provide patients with pulsatile blood flow, with a small surgical incision, and can improve the patient's postoperative recovery effect.

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

[0006] A minimally invasive catheter-type right ventricular assist device comprises a cannula, an elastic metal stent, a flexible film, an expandable-contractible balloon and a guide wire; wherein,

[0007] The cannula is divided into a front section, a middle section, and a tail section in sequence. The front section of the cannula is provided with a plurality of first inflow holes; the middle section of the cannula is a corrugated hose that can be adjusted in any direction to adapt to complex blood vessels; the tail section of the cannula is provided with an outflow hole and a one-way valve inside the hole to control the one-way outflow of blood from the middle section to the tail section.

[0008] The elastic metal bracket is tightly attached to the outer surface of the front section of the cannula and limits the deformation of the front section of the cannula;

[0009] The flexible film is connected to the inner wall surface of the front section of the sleeve, and its elastic modulus is smaller than the elastic modulus of the front section of the sleeve. A plurality of second inflow holes are opened on the surface of the flexible film; the second inflow holes are arranged alternately with the first inflow holes and are located at positions that do not overlap each other;

[0010] An expandable and deflable balloon is built into the front cavity of the cannula to control blood suction and discharge;

[0011] The guide wire passes through the cannula along the front section, the middle section and the tail section of the cannula in sequence and extends out from the tail section of the cannula.

[0012] According to one embodiment of the present invention, the tail section of the cannula is provided with an outflow hole. The shape of the outflow hole can be any shape, but circular or elliptical is preferred. The area of ​​a single outflow hole is in the range of 20-30 mm2. The outflow holes are evenly arranged 360 degrees along the circumference of the cannula and are arranged in multiple layers axially at the same time. The number of layers is 2-4 and the number of outflow holes in each layer is equal. The outflow holes in each adjacent layer are staggered to ensure that blood can flow out from any direction.

[0013] According to one embodiment of the present invention, the one-way valve provided inside the tail section of the cannula may be a duckbill valve to ensure that blood can flow out in one direction.

[0014] According to one embodiment of the present invention, the middle section of the sleeve is corrugated, and the corrugated structure can be transversely or spirally wound. The material is soft and the angle can be changed arbitrarily to adapt to the blood vessel path. The outer diameter ranges from 10-12 mm.

[0015] According to one embodiment of the present invention, the elastic metal support structure is in a woven mesh shape, which can resist radial pressure and prevent radial deformation of the front section of the sleeve; the material of the elastic metal support can be selected from alloys with good biocompatibility and superelasticity such as nickel titanium or cobalt chromium.

[0016] According to one embodiment of the present invention, the size of a single small hole in the first inflow small hole on the front surface of the sleeve is 3-8 mm. 2 The small holes are circular in shape, and are evenly arranged 360 degrees along the circumference of the casing and arranged in multiple layers axially at the same time, with the number of layers being 6-10, and the number of small holes flowing into each layer is equal.

[0017] According to one embodiment of the present invention, the flexible membrane comprises a circular membrane of a certain length along the axial direction, and the thickness of the flexible membrane ranges from 0.05 to 0.3 mm. The size of the second inlet aperture is equal to or smaller than that of the first inlet aperture. The second inlet apertures are uniformly arranged 360 degrees along the circumference of the flexible membrane and are arranged in multiple layers axially. Preferably, the number of flexible membranes is 2 to 4, with at least one flexible membrane positioned at each end of the front section of the sleeve.

[0018] According to the above technical solution of the present invention, the front section of the cannula and the flexible film form an inflow one-way valve, and blood can flow in from the first inflow hole and the second inflow hole in sequence. If the blood has a tendency to flow back through the second inflow hole, the flexible film is softer than the front section of the cannula, so that the flexible film is pressed against the inner wall surface of the front section of the cannula by the blood with the tendency to flow back. At the same time, the first inflow hole and the second inflow hole are arranged alternately and there is no overlap between the two inflow holes, so that a good seal is formed on the surface of the front section of the cannula.

[0019] According to one embodiment of the present invention, the length of the expandable-contractible balloon is equal to or slightly smaller than the front section of the cannula, and fluid is injected or pumped into the balloon at a certain frequency to cause it to expand or contract, thereby enabling blood to flow out or in; the fluid injected therein may be saline, silicone oil or helium.

[0020] According to one embodiment of the present invention, the outer diameter of the front section of the sleeve is 15-18 mm.

[0021] Beneficial effects of the present invention:

[0022] The device's operating principle is to periodically expand the balloon radially at a specific frequency. This expansion exerts pressure on the outer surface of the balloon, which then exits the device through the outlet orifice, allowing blood to perfuse various organs. This catheter-based right ventricular assist device can be minimally invasively implanted percutaneously via the inferior or superior vena cava, minimizing the surgical incision area. Furthermore, the balloon's cyclical contraction and expansion enhances blood flow pulsatility, thereby improving organ perfusion.

[0023] The present invention periodically controls the contraction and expansion of the balloon at a specific frequency to achieve blood flow in and out. This design principle can improve blood flow pulsatility, enhance organ perfusion, and reduce other complications. Furthermore, the catheter-based design of the present invention can reduce the surgical incision on the patient, thereby improving postoperative recovery. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic structural diagram of the right ventricular assist device of the present invention.

[0025] Figure 2 It is a schematic diagram showing the changes of the flexible film when blood flows in. The direction of the arrow in the figure indicates the direction of blood inflow.

[0026] Figure 3 It is a schematic diagram of the structure of the flexible film.

[0027] Figure 4 It is a schematic diagram of the connection method between the elastic metal bracket and the front section of the sleeve.

[0028] Figure 5 It is a cross-sectional view of the middle and tail sections of the casing.

[0029] Figure 6 It is a structural diagram of the front section of the casing.

[0030] Figure 7 It is a structural diagram of an elastic metal bracket.

[0031] Figure 8 This is a schematic diagram of the effect of implanting the right ventricular assist device of the present invention through the inferior vena cava.

[0032] Figure 9 This is a schematic diagram of the effect of implanting the right ventricular assist device through the superior vena cava of the present invention. DETAILED DESCRIPTION

[0033] The specific embodiments of the present invention are further described in detail below with reference to the accompanying drawings.

[0034] It should be noted that, in the textual description of the present invention, terms such as "front", "middle", and "back" indicating directions or positional relationships are given based on the relative positional relationship between the device and the pulmonary artery. The position of the device close to the pulmonary artery is expressed as "back", and the position away from the pulmonary artery is expressed as "middle" and "front" respectively. This is merely for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be understood as a limitation on the present invention.

[0035] like Figures 1 to 5 As shown, the catheter-type right ventricular assist device of the present invention includes a cannula 1, an elastic metal stent 2, an expandable-contractible balloon 3, a guide wire 4 and a flexible film 5. The cannula 1 includes a cannula tail section 11, a cannula middle section 12 and a cannula front section 13 in order; the cannula tail section 11 is placed in the pulmonary artery, the cannula middle section 12 is located in the right atrium and right ventricle, and the cannula front section 13 is located in the superior venous cavity or the inferior venous cavity. The cannula tail section 11 and the cannula middle section 12 are made of soft materials and can be adjusted at any angle to adapt to tortuous blood vessels. The elastic metal stent 2 is tightly attached to the outer surface of the cannula front section 13 and limits the deformation of the cannula front section 13; the flexible film 5 is connected to the inner wall surface of the cannula front section 13, and its elastic modulus is smaller than the elastic modulus of the cannula front section 13. The front section 13 of the cannula is provided with a plurality of first inflow holes 131, and the surface of the flexible film 5 is provided with a plurality of second inflow holes 51; the second inflow holes 51 and the first inflow holes 131 are arranged alternately and in non-overlapping positions. The rear section 11 of the cannula is provided with an outflow hole 111, and a one-way valve 112 is provided therein to control the unidirectional outflow of blood from the middle section 12 to the rear section 11 of the cannula. An inflatable and deflationary balloon 3 is built into the cavity of the front section 13 of the cannula to control the intake and discharge of blood. A guide wire 4 can pass through the cannula 1. The guide wire's main function is to achieve angiographic visualization to facilitate observation during surgery, while also enabling the device to be accurately transported to a designated location and fixed.

[0036] like Figure 2 and 4As shown, the first inflow holes 131 defined in the front section 13 of the cannula are evenly arranged along the circumference. The size and number of layers of the individual inflow holes can be equal to those of the second inflow holes 51. When blood shows a tendency to flow backward, the first inflow holes 131 on the surface of the front section 13 of the cannula must be completely covered by the flexible film 5, and the first inflow holes 131 and the second inflow holes 51 must not overlap. The elastic modulus of the flexible film 5 is smaller than that of the front section 13 of the cannula, and the first inflow holes 131 and the second inflow holes 51 are spatially staggered. This design is intended to reduce blood flow resistance and prevent blood backflow, acting as a one-way valve. The specific principle is: when blood in the blood vessel tends to backflow, because the flexible film 5 is softer than the front section 13 of the cannula, the flexible film 5 will be pressed by the blood and tightly adhere to the inner wall surface of the front section 13 of the cannula. At the same time, because the first inflow holes 131 and the second inflow holes 51 are staggered, the first inflow hole 131 will be completely covered by the flexible film 5, so that there will be no gaps for blood to flow back into the vein.

[0037] like Figure 3 As shown, the flexible film 5 is a circular ring with a certain axial length, which is between 60-100mm. The thickness of the flexible film 5 is between 0.05-0.3mm. The material can be made of a polymer material with good compatibility such as polyurethane, silicone rubber, high-density polyethylene film (DHPE). The surface of the flexible film 5 is provided with a second inflow hole 51, and the size of each hole is between 3-8mm. 2 The holes are circular in shape. Second inlet holes 51 are evenly distributed within the circumference of the flexible film 5 and arranged in multiple layers along the axial direction, with the number of layers ranging from 6 to 10. The flexible film end edge 52 is secured to the cannula front section 13 and the elastic metal support 2, which can be secured by adhesive bonding. Blood leakage is prevented from occurring at the flexible film end edge 52, ensuring a complete seal.

[0038] like Figure 5 As shown, the cannula tail section 11 has an inner diameter of 8-9 mm and houses a one-way valve 112 shaped like a duckbill valve. The one-way valve 112 can be positioned anywhere between the outflow orifice 111 and the cannula midsection 12. The cannula midsection 12 is corrugated. The corrugations can be arranged horizontally or spirally. The material is flexible and can be adjusted at any angle to accommodate the vascular path. The inner diameter is equal to that of the cannula tail section 11.

[0039] like Figure 6 As shown, the sleeve tail section 11 is provided with an outflow hole 111. The shape of the outflow hole 111 can be any shape, with circular and elliptical shapes being the best. The area of ​​a single outflow hole 111 is in the range of 20-30 mm. 2The outflow holes are evenly spaced 360 degrees around the cannula and arranged in multiple layers axially. The number of layers ranges from 2 to 4, with each layer having an equal number of outflow holes. The outflow holes between adjacent layers are staggered to ensure blood can flow in from any direction. The cannula's tail section 11 is provided with a tapered tip 113 with a small hole to allow for the passage of a percutaneously inserted 0.035-inch guide wire 4.

[0040] like Figure 7 As shown, the elastic metal stent 2 is made of a woven mesh of wire 21 made of a memory alloy. The memory alloy can be made of a material with superelasticity and good biocompatibility, such as nickel-titanium or cobalt-chromium alloy. The elastic metal stent 2 can be radially or rotationally symmetrical, with a larger diameter in the middle than in the sides, and the outer envelope ends 22 on both sides are designed to be circular. The wire diameter of the wire 21 is between 0.3 and 0.5 mm. The length of the elastic metal stent 2 should be equal to the length of the front section 13 of the cannula. The elastic metal stent 2 can withstand radial pressure, preventing radial deformation of the front section of the cannula.

[0041] like Figure 2 As shown, the blood flow rate depends on the volume of the cannula lumen 133, and thus can be adjusted by varying the inner diameter and length of the cannula front section 13. Furthermore, the blood flow rate also depends on the number of flexible membranes 5 and the corresponding number of first inlet holes 131 and second inlet and outlet holes 51. The number of flexible membranes 5 ranges from 2 to 4, and it is essential to provide flexible membranes 5 at both ends of the cannula front section 13. This design ensures that blood passing through the first inlet holes 131 and second inlet holes 51 can better perfuse the pulmonary artery.

[0042] like Figure 8 and Figure 9 As shown, the device of the present invention can be minimally invasively implanted percutaneously through the inferior vena cava or superior vena cava, passing through the right atrium and right ventricle, and finally the tail section 11 of the cannula is extended into the pulmonary artery. The blood in the right atrium and right ventricle (the blood flow direction is shown by the arrow in the figure) is sucked into the device through the expandable-contractible balloon 3, and then discharged from the catheter for perfusion of various organs. The working principle of the present invention is: fluid is injected into the balloon 3 according to a specific cycle, so that the diameter of the outer surface of the balloon 3 becomes larger and the size is close to the inner diameter of the front section 13 of the cannula. At this time, the outer surface of the balloon generates a certain pressure on the blood, and the blood flows out along the outflow hole 111. The outflow hole 111, the first inflow hole 131 and the second inflow hole 51 can be manufactured by stamping or laser processes.

[0043] The advantages of the present invention are:

[0044] The present invention realizes blood suction and discharge by means of balloon contraction or expansion, which can enhance blood flow pulsatility and improve the blood perfusion effect of various organs; since the present invention adopts a catheter-type structure, minimally invasive implantation can be used to reduce the risk of surgical wounds and related complications in patients.

[0045] Finally, it should be noted that the above are all preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A minimally invasive catheter-based right ventricular assist device, characterized by: It includes a cannula, an elastic metal stent, a flexible film, an expandable and contractible balloon and a guide wire; wherein, The cannula is divided into a front section, a middle section, and a tail section in sequence. The front section of the cannula is provided with a plurality of first inflow holes, which are evenly arranged 360 degrees along the circumference of the cannula and arranged in multiple layers axially. The middle section of the cannula is a corrugated hose that can be arbitrarily adjusted in direction to adapt to complex blood vessels. The tail section of the cannula is provided with an outflow hole and a one-way valve inside the hole to control the one-way outflow of blood from the middle section to the tail section of the cannula. The elastic metal bracket is tightly attached to the outer surface of the front section of the cannula and limits the deformation of the front section of the cannula; The flexible film is connected to the inner wall surface of the front section of the sleeve, has an elastic modulus smaller than that of the front section of the sleeve, and has a plurality of second inlet holes formed on the surface of the flexible film; the second inlet holes are arranged alternately with the first inlet holes and are located at positions that do not overlap; the size of the second inlet holes is equal to or smaller than the size of the first inlet holes; the second inlet holes are uniformly arranged 360 degrees around the circumference of the flexible film and are also arranged in multiple layers axially; An expandable and deflable balloon is built into the front cavity of the cannula to control blood suction and discharge; The guide wire passes through the cannula along the front section, the middle section and the tail section of the cannula in sequence and extends out from the tail section of the cannula.

2. The minimally invasive catheter-based right ventricular assist device according to claim 1, wherein: The shape of the outflow hole of the tail section of the sleeve is circular or elliptical, and the area of ​​a single outflow hole ranges from 20 to 30 mm. 2 The outflow holes are evenly arranged 360 degrees along the circumference of the sleeve and arranged in multiple layers axially at the same time. The number of layers is 2-4 and the number of outflow holes in each layer is equal. The outflow holes in each adjacent layer are staggered.

3. The minimally invasive catheter-based right ventricular assist device according to claim 1, wherein: A duckbill valve is provided inside the tail section of the casing.

4. The minimally invasive catheter-based right ventricular assist device according to claim 1, wherein: The middle section of the sleeve is corrugated, and the corrugated structure is wound horizontally or spirally. The material is soft and the angle can be changed arbitrarily to adapt to the blood vessel path. The outer diameter ranges from 10 to 12 mm.

5. The minimally invasive catheter-based right ventricular assist device according to claim 1, wherein: The elastic metal support structure is in a woven mesh shape and is made of nickel-titanium alloy or cobalt-chromium alloy with good biocompatibility and superelasticity.

6. The minimally invasive catheter-based right ventricular assist device according to claim 1, wherein: The size of each small hole in the first inflow small hole on the front surface of the sleeve is 3-8mm 2 The shape of the small holes is circular, the number of axially arranged layers of small holes is 6-10, and the number of small holes flowing into each layer is equal.

7. The minimally invasive catheter-based right ventricular assist device according to claim 1, wherein: The flexible film has a circular film with a certain length along the axial direction, and the thickness of the flexible film is in the range of 0.05-0.3 mm.

8. The minimally invasive catheter-based right ventricular assist device according to claim 7, wherein: The number of the flexible films is 2-4, and at least one flexible film is provided at each of the two ends of the front section of the sleeve.

9. The minimally invasive catheter-based right ventricular assist device according to claim 1, wherein: The length of the expandable-contractible balloon is equal to or slightly smaller than the front section of the cannula; the fluid injected into the balloon is physiological saline, silicone oil or helium.

10. The minimally invasive catheter-based right ventricular assist device according to claim 1, wherein: The outer diameter of the front section of the sleeve is 15-18 mm.

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