CN116328175A - A minimally invasive catheter-type left ventricular assist device - Google Patents

Abstract

The invention discloses a minimally invasive catheter type left ventricle auxiliary device. It comprises a sleeve, an elastic metal bracket, a flexible film, an inflatable-contractible saccule and a guide wire; the sleeve is sequentially divided into a front section, a middle section and a tail section in sequence, the front section of the sleeve is provided with a plurality of inflow small holes, and a one-way valve is arranged in the front section of the sleeve to control the blood to flow in one way from the front section of the sleeve to the middle section of the sleeve; the middle section of the sleeve is a bending pipe with the direction capable of being changed at will; a plurality of first outflow small holes are formed in the surface of the tail section of the sleeve; the elastic metal bracket is tightly attached to the outer surface of the sleeve tail section and limits the deformation of the sleeve tail section; the outer surfaces of the elastic metal bracket and the sleeve tail section are connected with a flexible film, the elastic modulus of the flexible film is smaller than that of the sleeve tail section, a plurality of second outflow small holes are formed on the surface of the flexible film, and the flexible film and the first outflow small holes are arranged in a staggered manner and are positioned at positions which are not overlapped with each other; an inflatable-deflatable balloon is arranged in the tail section of the sleeve; the guide wire extends through the entire cannula and out from the cannula front section.

Description

A minimally invasive catheter-type left ventricular assist device

technical field

The invention relates to a minimally invasive catheter type left ventricular assist device, which belongs to the field of medical devices.

Background technique

Ventricular assist device is a common clinical treatment for critically ill heart failure, among which left ventricular assist device is the most common. At present, the left ventricular assist device is mainly based on the magnetic levitation centrifugal blood pump, but the working principle of the high-speed rotation of its metal impeller, on the one hand, will generate high shear stress on the blood, which will cause complications such as hemolysis and thrombosis, and seriously endanger the life of the patient. ; At the same time, the implantation of the magnetic levitation centrifugal blood pump will cause a large surgical wound to the patient, which is not conducive to the postoperative recovery of the patient; lead to other related complications.

Therefore, it is necessary to develop a new type of left ventricular assist device, which can not only reduce complications such as hemolysis and thrombosis, but also reduce surgical wounds of patients, thereby improving the postoperative rehabilitation effect of patients.

Contents of the invention

The purpose of the present invention is to provide a minimally invasive catheter-type left ventricular assist device, which can not only reduce complications such as hemolysis and thrombus, but also reduce surgical wounds of patients, thereby improving the postoperative rehabilitation effect of patients.

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

A minimally invasive catheter-type left ventricular assist device, which includes a sleeve, an elastic metal stent, a flexible membrane, an expandable-contractable balloon and a guide wire; wherein,

The cannula is divided into the front section, the middle section and the tail section in sequence. The front section of the cannula is provided with a plurality of small inflow holes, and a one-way valve is installed inside the front section of the cannula to control the one-way inflow of blood from the front section of the cannula to the middle section of the cannula; The middle section of the casing is a bent tube that can change direction arbitrarily to adapt to the complex pipeline of blood vessels; the surface of the tail section of the casing is provided with multiple first outflow holes;

The elastic metal bracket is tightly attached to the outer surface of the casing tail section and limits the deformation of the casing tail section; a flexible film is connected between the elastic metal bracket and the outer surface of the casing tail section, and its elastic modulus is smaller than that of the casing tail section Modulus, the surface of the flexible film is provided with a plurality of second outflow holes, and the second outflow holes are alternately arranged with the first outflow holes and are located in non-overlapping positions;

An inflatable-deflation balloon is built in the end of the cannula to control blood inhalation and discharge;

The guide wire runs through the entire casing along the tail section, the middle section of the casing, and the front section of the casing in sequence, and protrudes from the front section of the casing.

According to one embodiment of the present invention, the shape of the inflow hole opened in the front section of the sleeve can be any shape, but it is preferably circular or oval. The area of a single inflow hole is in the range of 20-30 mm The holes are evenly arranged 360 degrees along the circumference of the casing and are arranged in multiple layers axially at the same time. Can flow in from any direction.

According to an embodiment of the present invention, the inner diameter of the front section of the cannula is 8-9 mm, and the one-way valve is a duckbill valve, which ensures that blood can flow in one direction.

According to an embodiment of the present invention, the middle section of the cannula is corrugated, made of soft material, and the angle can be changed arbitrarily to adapt to the blood vessel path. The inner diameter is equal to the size of the front section of the cannula, and the outer diameter is in the range of 12-14mm.

According to one embodiment of the present invention, the structure of the elastic metal bracket is in the form of a mesh, which can resist radial pressure and prevent the radial deformation of the tail section of the casing; the elastic metal bracket can be made of nickel titanium or cobalt chromium, etc. An alloy with good biocompatibility and superelasticity.

According to an embodiment of the present invention, the size of the first outflow small holes opened on the surface of the tail section of the casing is 3-8mm ² , the shape of the small holes is circular, and the small holes are evenly arranged along the circumference of the casing at 360 degrees And at the same time, multiple layers are axially arranged, the number of layers is 6-10, and the number of outflow holes in each layer is equal.

According to one embodiment of the present invention, 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; It is equal to or smaller than the size of the first outflow small hole; the second outflow small hole is uniformly arranged 360 degrees along the circumferential direction of the flexible film and simultaneously arranged in multiple layers axially.

According to the above technical solution of the present invention, the tail section of the sleeve and the flexible film form an outflow one-way valve, and blood can flow out from the first outflow hole and the second outflow hole in sequence; Hole regurgitation tendency, because the flexible membrane is softer than the casing tail section, the flexible membrane will be pressed against the surface of the sleeve tail section by blood with a tendency to flow back; at the same time, the first outflow The small holes and the second outflow small holes are arranged alternately and there can be no overlapping positions between the two outflow small holes, so that a good seal will be formed on the outer surface of the casing tail section.

According to one embodiment of the present invention, the length of the expandable-deflation balloon is equal to or slightly less than the length of the tail section of the cannula; inject or suck fluid into the balloon according to a certain frequency to make it expand or deflate , which in turn enables blood outflow or inflow. The fluid injected into it can be physiological saline, silicone oil or helium.

According to an embodiment of the present invention, the number of flexible films is 2-4, and flexible films are respectively connected at least at both ends of the tail section of the casing.

According to one embodiment of the present invention, the outer diameter of the tail section of the casing is 15-18mm.

Beneficial effects of the present invention:

The left ventricular assist device of the present invention does not rely on the high-speed rotating impeller to transport blood, but controls the expansion and contraction of the balloon according to a certain frequency to realize the inflow and outflow of blood. This design principle has less shear stress on the blood than a magnetic levitation centrifugal blood pump, reduces the risk of hemoglobin dissociation and platelet activation, reduces the risk of complications such as hemolysis and thrombosis, and improves blood compatibility in the human body; At the same time, the balloon has the characteristics of periodic contraction and expansion, which can improve the pulsation of blood flow and enhance the perfusion effect of various organs to reduce other complications; on the other hand, the left ventricular assist device of the present invention is designed as a catheter type, which can The arterial minimally invasive implantation can reduce the surgical wound area of the patient, thereby improving the postoperative rehabilitation effect of the patient.

Description of drawings

Fig. 1 is a schematic diagram of the structure of the left ventricular assist device of the present invention.

Figure 2 is a schematic diagram of the front section of the casing.

Fig. 3 is a schematic diagram of the structure of the flexible film.

Fig. 4 is a schematic diagram of the structure of the elastic metal support.

Fig. 5 is a schematic diagram of the structure of the inflatable-deflated balloon.

Fig. 6 is a schematic diagram of blood outflow in the tail section of the cannula.

Fig. 7 is a schematic diagram of the internal structure of the front section of the casing and the middle section of the casing.

Fig. 8 is a schematic diagram showing the spatial positional relationship between the first outflow hole and the second outflow hole.

Fig. 9 is a schematic diagram of the implantation effect of the left ventricular assist device of the present invention.

Detailed ways

The specific implementation manners of the present invention will be described in further detail below in conjunction with the accompanying drawings.

It should be noted that, in the textual description of the present invention, terms such as "front", "middle", and "rear" indicating direction or positional relationship are given based on the relative positional relationship between the device and the ventricle. The position of the device close to the ventricle is expressed as "anterior", and the position farther from the ventricle is expressed as "middle" and "posterior", which is for convenience of description only, and does not indicate or imply that the device or element must have a specific orientation, in order to Specific orientation configurations and operations, therefore, are not to be construed as limitations on the invention.

As shown in FIGS. 1 to 7 , the catheter-type left ventricular assist device of the present invention includes a sleeve 1 , a flexible membrane 2 , an elastic metal stent 3 , an expandable-deflate balloon 4 and a guide wire 5 . The cannula 1 sequentially includes a cannula front section 11, a cannula middle section 12 and a cannula tail section 13; the cannula front section 11 is placed in the left ventricle A, the cannula middle section 12 is located in the aortic arch, and the cannula tail section 13 is located in the descending aorta . The front section 11 of the cannula and the middle section 12 of the cannula are made of soft material, and the angle can be adjusted arbitrarily to adapt to circuitous and tortuous blood vessel lines. The front section 11 of the casing is provided with a plurality of small inflow holes 111, and a one-way valve 112 is provided inside the front section 11 of the casing to control the one-way inflow of blood from the front section 11 of the casing to the middle section 12 of the casing; a first outflow hole 131. The elastic metal bracket 3 is tightly attached to the outer surface of the casing tail section 13 and limits the deformation of the casing tail section 13; a flexible film 2 is connected to the elastic metal bracket 3 and the outer surface of the casing tail section 13, and its elastic modulus is less than The elastic modulus of the casing tail section 13, the surface of the flexible film 2 has a plurality of second outflow small holes 21, the second outflow small holes 21 and the first outflow small holes 131 are arranged alternately and are located at non-overlapping positions; The tube tail section 13 has a built-in expandable-deflate balloon 4, which is used to control blood inhalation and discharge. The area surrounded by the outer surface of the expandable-deflate balloon 4 and the inner surface of the sleeve tail section is the core area of the flow channel . The guide wire 5 runs through the entire casing along the casing tail section 13 , the casing middle section 12 , and the casing front section 11 in sequence, and protrudes from the casing front section 11 to form a helical shape of a certain length. The function of the guide wire is mainly to achieve angiographic visualization, so as to facilitate observation during surgery, and at the same time, it can accurately deliver the device to the designated position and fix it.

As shown in FIG. 2 , the front section 11 of the sleeve is provided with an inflow hole 111 , and the shape of the inflow hole 111 can be any shape, with circular and elliptical shapes being optimal. The area of a single inflow hole 111 is in the range of 20-30mm ² , the inflow holes are evenly arranged along the circumference of the casing at 360 degrees and multi-layers are arranged axially at the same time, the number of layers is 2-4 and the number of inflow holes in each layer is equal, The small inflow holes of each adjacent two layers are arranged alternately to ensure that blood can flow in from any direction. The front section 11 of the cannula is provided with a tapered tip 113, and the tapered tip 113 has a small hole, allowing the 0.035-inch guide wire 5 inserted percutaneously to pass through.

As shown in Figure 3, the flexible film 2 is a circular ring with a certain axial length, the axial length is between 60-100mm, the thickness of the flexible film 2 is between 0.05-0.3mm, and the material can be polyurethane (Polyurethane) , silicone rubber, high-density polyethylene film (DHPE) and other polymer materials with good compatibility. The surface of the flexible film 2 is provided with a second outflow small hole 21, the size of a single small hole is 3-8mm ² , and the shape of the small hole is circular. The second outflow holes 21 are evenly arranged in the circumference of the flexible film 2 and arranged in multiple layers along the axial direction, the number of layers is 6-10. The end edge 22 of the flexible film is fixed with the casing tail section 13 and the elastic metal bracket 3, and the fixing method can be by bonding. The end edge 22 of the flexible film does not allow blood to leak and is completely sealed.

As shown in Figure 4, the elastic metal stent 3 is made of wire 31 of a mesh-shaped memory alloy material, and the memory alloy material can be made of materials with superelasticity and good biocompatibility such as nickel-titanium or cobalt-chromium alloy . The elastic metal bracket 3 is radially symmetrical or rotationally symmetrical, the diameter of the middle part is larger than that of the two sides, and the shape of the outer envelope ends 32 on both sides is designed to be circular. The wire diameter of the metal wire 31 is between 0.3-0.5 mm, and the length of the elastic metal support 3 should be equal to the length of the casing tail section 13 . The elastic metal bracket 3 can resist radial pressure and prevent radial deformation of the tail section of the casing.

As shown in FIG. 5 , the expandable-deflation balloon 4 is composed of a balloon inlet tube 41 and a balloon 42 , and is placed in the lumen 133 of the tail section of the sleeve through the inlet 132 of the tail section of the sleeve. Periodically inject physiological saline, silicone oil or helium gas into the balloon 42 through the balloon inlet tube 41 or suck out the balloon 42 according to a certain frequency. The injection method can be a micro piston pump or a gear pump (not shown in the figure) , The injection pressure is 0.1-0.2MPa. The length of the inflatable-deflation balloon 4 is equal to or slightly smaller than the tail section of the sleeve, and the outer diameter of the tail section of the sleeve is 15-18mm.

As shown in Figure 6, the surface of the casing tail section 13 is provided with first outflow holes 131, and the first outflow holes 131 are uniformly arranged in the circumferential direction, and the size and number of layers of a single outflow hole can be equal to that of the second outflow holes 21 . The first outflow hole 131 on the surface of the casing tail section 13 must be completely covered by the flexible film 2 , and the first outflow hole 131 and the second outflow hole 21 cannot overlap. The elastic modulus of the flexible film 2 is smaller than that of the casing tail section 13, and the first outflow holes 131 and the second outflow holes 21 are arranged alternately in space. This design purpose is to reduce blood flow resistance and prevent blood backflow. Play the role of a one-way valve, the specific principle is: when the blood in the blood vessel tends to flow back, because the material of the flexible membrane 2 is softer than the tail section 13 of the sleeve, the flexible membrane 2 will be pressed by the blood and cling to the sleeve On the surface of the tail section 13, due to the staggered arrangement of the first outflow holes 131 and the second outflow holes 21, as shown in Figure 8, the first outflow holes 131 will be completely covered by the flexible film 2, so that there will be no gaps so that The blood flows back into the cannula 1 .

On the one hand, the blood discharge depends on the volume of the sleeve lumen 133, so the blood discharge can be adjusted by changing the inner diameter and length of the sleeve tail section 13; secondly, the blood discharge also depends on the number of flexible membranes 2, And the number of corresponding first outflow small holes 131 and second outflow small holes 21 . The number of flexible membranes 2 is 2-4, and it is necessary to be provided with flexible membranes 2 at both ends of the sleeve tail section 13, as shown in Figure 6, so that the design can ensure that when the blood passes through the first outflow hole 131 and the second When it flows out of the small hole 21, it can better perfuse the aortic arch, descending aorta, and venous branches. The inner wall surface 134 of the cannula tail section 13 should be smooth to facilitate blood flow.

As shown in Figure 7, the inner diameter of the front section 11 of the casing is 8-9 mm, and a one-way valve 112 is provided inside, which is the same shape as the duckbill valve. The one-way valve 112 is located between the inflow hole 111 and the middle section 12 anywhere in between. The bent tube of the middle section 12 of the cannula is corrugated, the material is soft, and the angle can be changed arbitrarily to adapt to the blood vessel path. The inner diameter D2 is equal to the size of the front section 11 of the cannula, and the outer diameter D1 is in the range of 12-14mm.

As shown in Figure 9, the device of the present invention is minimally invasively implanted percutaneously through the femoral artery, through the descending aorta, aortic arch, and ascending aorta, and finally the front section 11 of the cannula is inserted into the left ventricle A, and a negative pressure is generated in the cannula by contracting the balloon. Pressure; the blood in the left ventricle A enters the cannula through the inflow hole, and then inflates the balloon to make its outer surface face the blood to generate pressure, and the blood is discharged from the device to achieve organ perfusion. The working principle of the present invention is: inject fluid into the balloon 42 according to a specific period, so that the diameter of the outer surface of the balloon 42 becomes larger and the size is close to the inner diameter of the casing tail section 13 . At this time, the outer surface of the balloon 42 produces a certain pressure on the blood, and the blood flows out along the first outflow hole 131. Due to the blood pressure, the flexible film 2 is pushed out toward the outer surface of the casing tail section 13, and the blood flows out along the second outlet hole 13. The outflow orifice 21 flows into the blood vessel. The inflow hole 111 , the first outflow hole 131 and the second outflow hole 21 can be manufactured by punching or laser technology.

The advantages of the present invention are:

The left ventricular assist device of the present invention does not rely on the high-speed rotating rotor to transport blood, but realizes the blood suction and discharge device through the contraction or expansion of the balloon, reduces the blood shear stress, improves the anti-hemolysis and thrombus performance of the blood, and the catheter The simple internal structure can reduce blood stagnation, backflow and other phenomena; on the other hand, the balloon expands and contracts according to a certain frequency, which can enhance the pulsation of blood flow and improve the effect of blood perfusion in various organs; because the left ventricular assist device of the present invention With the catheter structure, minimally invasive implantation can be used to reduce the incidence of surgical wounds and related complications in patients.

Finally, it should be noted that the above are all preferred implementation modes of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention shall be Included within the protection scope of the present invention.

Claims (10)

1. A minimally invasive catheter-type left ventricular assist device, characterized in that: it comprises a sleeve, an elastic metal bracket, a flexible film, an inflatable-contractible saccule and a guide wire; wherein,,

the sleeve is sequentially divided into a front section, a middle section and a tail section in sequence, the front section of the sleeve is provided with a plurality of inflow small holes, and a one-way valve is arranged in the front section of the sleeve to control the blood to flow in one way from the front section of the sleeve to the middle section of the sleeve; the middle section of the sleeve is a bending pipe with the direction capable of being changed at will; a plurality of first outflow small holes are formed in the surface of the tail section of the sleeve;

the elastic metal bracket is tightly attached to the outer surface of the sleeve tail section and limits the deformation of the sleeve tail section; the outer surfaces of the elastic metal support and the sleeve tail section are connected with a flexible film, the elastic modulus of the flexible film is smaller than that of the sleeve tail section, a plurality of second outflow small holes are formed in the surface of the flexible film, and the second outflow small holes and the first outflow small holes are arranged in a staggered mode and are located at positions which are not overlapped with each other;

an inflatable-deflatable balloon is arranged in the tail section of the sleeve and is used for controlling the suction and discharge of blood;

the guide wire sequentially penetrates through the whole sleeve along the sleeve tail section, the sleeve middle section and the sleeve front section and extends out of the sleeve front section.

2. The minimally invasive ducted left ventricular assist device of claim 1 wherein: the shape of the inflow small hole formed at the front section of the sleeve is round or oval, and the area of the single inflow small hole is 20-30mm ² The inflow small holes are uniformly arranged along the circumferential direction of the sleeve by 360 degrees and axially arranged in multiple layers at the same time, the number of layers is 2-4, the quantity of inflow small holes of each layer is equal, and the inflow small holes of every two adjacent layers are staggered.

3. The minimally invasive ducted left ventricular assist device of claim 1 wherein: the inner diameter of the front section of the sleeve is 8-9mm, and the one-way valve is a duckbill valve.

4. The minimally invasive ducted left ventricular assist device of claim 1 wherein: the middle section of the sleeve is corrugated, the material is soft, the angle can be changed at will to adapt to the vascular path, the inner diameter size is equal to the front section size of the sleeve, and the outer diameter size is in the range of 12-14mm.

5. The minimally invasive ducted left ventricular assist device of claim 1 wherein: the elastic metal bracket structure is in a woven net shape, and is made of nickel-titanium alloy or cobalt-chromium alloy with good biocompatibility and super elasticity.

6. The minimally invasive ducted left ventricular assist device of claim 1 wherein: the size of the first outflow small hole formed on the surface of the sleeve tail section is 3-8mm ² The shape of the small holes is round, the small holes are uniformly arranged along the circumferential direction of the sleeve by 360 degrees and axially arranged in multiple layers at the same time, the number of layers is 6-10, and the number of the small holes flowing out from each layer is equal.

7. The minimally invasive ducted left ventricular assist device of claim 1 wherein: the flexible film is provided with a circular ring film with a certain length along the axial direction, and the thickness of the flexible film ranges from 0.05 mm to 0.3mm; the second outflow small hole with the size equal to or smaller than that of the first outflow small hole is formed on the flexible film; the second outflow apertures are uniformly aligned 360 degrees along the circumference of the flexible film and simultaneously axially aligned in multiple layers.

8. The minimally invasive ducted left ventricular assist device of claim 1 wherein: the length of the inflatable-deflatable balloon is equal to or slightly less than the length of the sleeve tail section; the fluid injected into the container is normal saline, silicone oil or helium.

9. The minimally invasive ducted left ventricular assist device of claim 7 wherein: the number of the flexible films is 2-4, and the flexible films are respectively connected at least at the two ends of the tail section of the sleeve.

10. The minimally invasive ducted left ventricular assist device of claim 4 wherein: the outer diameter of the tail section of the sleeve is 15-18mm.

Images