JP3364142B2 - Artificial heart valve - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to prosthetic heart valves, and in particular to
The present invention relates to a tricuspid artificial heart valve.

[0002]

Heart valves act as hydraulic valves in a blood circulation system to maintain blood flow in the same direction and control blood flow to the heart. Heart valves lose their function due to lesions or degeneration.

A diseased or degenerated heart valve leads to valvular insufficiency or stenosis. Valve insufficiency is a phenomenon in which blood flows backward because the valve does not close completely, and valve stenosis is a phenomenon in which blood resistance increases because the valve does not open completely. These phenomena increase the load on the heart. In order to reduce the burden on the heart, it is necessary to replace the heart valve with an artificial heart valve by a surgical operation.

Heart valve replacement surgery is a complete and effective treatment for end-stage patients with valvular heart disease. 19 artificial heart valves
Starr Edwards in America in 1966
Since its first commercialization under the name, heart valve replacement surgery has become a routine clinical procedure.

Artificial heart valves are roughly classified into biological valves and mechanical valves.

The biovalve is composed of a drug-treated porcine heart valve and a bovine heart membrane. A porcine heart valve is one that has been removed from the porcine aorta, chemically treated and then fixed to a support under low pressure (0-10 mmHg). The bovine heart thin film is obtained by cutting the bovine heart thin film, chemically treating it, and then sewing it to a support. The biovalve geometry is very similar to that of a normal human aortic valve, so it has excellent dynamic mechanisms of cardiac blood flow, and in the 1970s, about 70% of the clinical market Came to occupy. However, biovalves have limited durability due to calcification. For example, five years after surgery, the biological valve begins to deform and requires re-operation. On the other hand, the mechanical valve has excellent durability and does not require reoperation for many years after the operation. As a result, the share of biovalves in the clinical market has declined, and is now less than 30%. In addition, the biological valve has a physiological calcifi rate.
It is not suitable for young patients because of high cation but is suitable for patients over 65 years old.

On the other hand, mechanical valves are classified into ball valves, tilted single-circle valves and bicuspid valves according to their geometrical structure. None of the mechanical valves can avoid clinical problems such as thrombosis, and therefore, the anticoagulant must be taken for a long period of time.

When the blood flows through the mechanical valve, the occluder located on the blood passage moves, which produces different effects depending on the valve type. That is, a ball valve produces peripheral blood, a tilted single-circle valve produces lateral blood flow, and a bicuspid valve produces central blood flow. Disturbances such as vortex flow, stagnation region, turbulence and cavitation occur behind the closed body in any mechanical valve. These perturbations are believed to be a major factor in thrombus formation. Long-term clinical observations indicate that bicuspid valves are generally less prone to thrombotic forms than tilted single-circle valves and are therefore relatively popular today.
Among them, the SJM (ST. Jude Medical) valve is most widely used. From the point of view of fluid dynamics, blood flowing through the bicuspid valve is more uniform and less turbulent than the other two valves. However, in a bicuspid valve, the two fields cross the center of the valve seat, so the flow field is divided into three jet streams, and due to the non-simultaneous opening and closing of the two valves, Jet flow lacks axial symmetry. This results in an asymmetric velocity distribution and also large velocity gradients and turbulence. In order to improve such a defect, a tricuspid artificial valve has been proposed.

In the first conventional tricuspid artificial valve (see US Pat. No. 4416029, Nov. 2, 1983).
Issued on the 2nd), each valve consists of a disk divided into three parts, and the opening and closing of the valve is controlled by six support rods extending from the inner peripheral side of the valve. When the valves are fully open, the three valves open and extend towards the center of the valve annulus. A wake is formed as blood passes through the support rod and valve.

In the second conventional tricuspid artificial valve (see US Pat. No. 4,820,299, issued Apr. 11, 1989), the valve has an arc shape, and the valve is opened and closed. It is controlled by three hooks on the valve seat.

In a third conventional tricuspid prosthetic valve (see US Pat. No. 5,207,707, issued May 4, 1993), the valve is located inside the annulus. These valves have a flat plate shape, and when the valves are fully opened, a hexagonal opening is formed in the center. In addition, three half-moon shaped openings that are not completely related to the central blood flow are formed in the edge portion of the ring.

In the fourth conventional tricuspid prosthetic valve (see US Pat. No. 5,522,886, June 4, 1996), the valves are arcuate and downstream of these valves. The side has a sinusoidal shape with a convex inside and a concave outside, and the axis of rotation is elliptical so that it can rotate in a concave groove inside the valve seat.

In the fifth conventional tricuspid prosthetic valve (see US Pat. No. 5,628,791, May 13, 1997), the valve is flat.

[0014]

However, in the above-mentioned first to fifth conventional tricuspid artificial valves, there is a problem that the blood flow field at the time of full opening is not ideal and a thrombus is formed. there were.

[0015]

[Means for Solving the Problems] The means for solving the above-mentioned problems are arc-shaped in a center flow type artificial heart valve which is similar to the opening / closing method of the aortic valve in the human body, with the center opened and blood flowing through the center. By using the valve of (1), the curvature of the valve at the time of fully opening is approximated to a circle, and the effective opening area is increased, thereby increasing the blood outflow amount.

Further, by reducing the protrusion height of the valve and reducing the difference in height profile of the valve when the valve is opened, separation of the boundary layer is eliminated under normal pressure, and pressure drop and turbulent flow are suppressed.

Further, the fulcrum of the valve is a small triangular rotation support portion projecting inward of the valve seat, which quickly opens and closes by exploring the rotation and slide system to reduce the generation of circulating flow. The height of the support ring is sufficient to mount the valve and does not affect the pressure drop. This entire design philosophy solves the problem of thrombus formation caused by fluid dynamics and allows the artificial valve to reach the ideal range.

Furthermore, when the valve is closed, the entire valve has a conical appearance. On the other hand, when the valve is opened, the entire valve has a shape with petals opened, and the most preferable flow field is obtained.
The valve consists of three fan-shaped valves with arcs, which prevents the boundary layer from separating when fully open and reduces the pressure differential, thus preventing the formation of a stagnation region and between the blood and the valve when opening and closing. Relieves the shock between blood and the tube wall.

[0019]

1 is a perspective view showing an embodiment of a tricuspid artificial heart valve according to the present invention, in which (A) shows a valve open state and (B) shows a valve closed state. In FIG. 1, the heart valve includes an annular valve seat 300, a valve 400, and a triangular rotation support portion 500 provided on the valve seat 300. The central passageway on the inner surface of the valve seat 300 is the main passageway for blood to flow through the heart valve. The valve seat 300 is primarily designed to secure the valve 400 while reducing interference with blood flow.
The valve 400 includes an upstream curved surface portion 46 and a downstream curved surface portion 45. That is, the valve 400 has a fan-shaped arc surface that is concave on the inflow side and convex on the outflow side. Valve seat 300 and valve 40
0 is supported by inserting the rotating ear-shaped portions 44 formed on the convex portions at both ends of the arc of the valve 400 into the concave portions 33 of the rotation supporting portion 500 of the valve seat 300. This allows the valve 4
00 does not disengage from the valve seat 300 and rotates naturally to control the opening and closing of the valve 400. As a result, the forward flow of blood is promoted and the reverse flow of blood flow is prevented. The rotating ear 44 is a valve 400.
The rotation support portion 500 is rotated in accordance with the change of the curved surface portions 45 and 46, and the recess 33 of the rotation support portion 500 is formed so as to coincide with the rotation of the rotation ear portion 44. At the curved surface on the downstream side of the rotary ear portion 44, when the valve 400 is opened and closed, the curved surface of the rotary ear portion 44 and the recess 33 of the rotation support portion 500 come into contact with each other, so that the valve 40 is closed.
The position of 0 is controlled. On the other hand, in the upstream curved surface of the rotary ear 44, the position of the valve 400 is controlled by the contact between the end surface of the rotary ear 44 and the bottom surface of the recess 33 of the rotary support 500 when the valve 400 is opened and closed.

The valve seat 300 is designed to regulate the smooth opening and closing of the valve 400 and to reduce unwanted protrusions and eliminate flow field obstructions.

FIG. 2 is a top view of the valve seat 300 of FIG.
As the rotation support portion 500, three triangular protrusions are provided on the valve seat 3
00, and a concave portion 33 for supporting the valve 400 is formed in each convex portion.

FIG. 3 is a sectional view of FIG. 2, in which (A) is a sectional view taken along the line AA of FIG. 2 and (B) is a sectional view taken along the line BB of FIG. As shown in FIG. 3, the outer wall 34 of the valve seat 300 is shaped to conform to the structure of the tissue annulus. Further, the outer wall 34 and the inner wall 35 of the valve seat 300 have a smooth shape in order to prevent separation of the flow field and generation of vortices. That is, the edge portion of the valve seat 300 is rounded.

As shown in FIG. 3, the recess 33 of the rotary support 500 of the valve seat 300 is designed so that the rotation of the rotary ear 44 of the valve 400 is smooth. This recess 33 has a straight edge 36 and four curved edges 30, 37, 3
It consists of 8, 39. Each edge 30, 36, 37, 38,
The intersection of 39 is rounded and smooth. The straight edge 36 and the curved edges 30 and 37 have the valve 40 when opened.
0 rotator ears 44 (FIG. 1A) and the curved edges 38, 39 have the rotator ears 44 of valve 400 when closed.
(It corresponds to (A) of FIG. 1). The curves of these curved edges are all quadratic and can be calculated by solving polynomial equations. The plane defined by the edges 30, 36, 37, 38, 39 is parallel to the line BB in FIG. 2 and the edges 30, 36, 37, 38, 39 are perpendicular to the plane inside the recess 33. . As a result, the rotation of the valve 400 is prevented and controlled. Further, R31,
As shown in R32, it is rounded, so that
When the valve is closed, the recess 33 is washed with blood to prevent the formation of a stagnation region and prevent the formation of thrombus.

FIG. 4 is a perspective view of the valve 400 of FIG.
5A is a perspective view seen from the AA plane of FIG. 4, and FIG. 5B is a perspective view seen from the BB plane of FIG. As shown in FIG. 4, the valve 400 is formed by dividing a disk into three parts, and is composed of two straight edges 48, 49 and a curved edge 51. As shown in FIG. 5A, the valve 400 is divided into an upstream curved surface portion 46 and a downstream curved surface portion 45, and the valve 400
Has a uniform thickness 47 throughout. Also, the curved edge 51
Is a quadratic curve.

The straight edges 48, 49 of FIG. 4 are curved as shown in FIG.
0 comrades can match exactly. Curved edge 4
Rounded R is added to the intersection of 8 and the upstream curved surface portion 46,
This prevents the valves from overlapping and facilitates the opening and closing of the valves. Further, the surface 54 adjacent to the curved edges 48, 49 is a vertical surface and is parallel to the BB plane in FIG. Therefore, the surfaces 54 are parallel to the surfaces of the recess 33 and are adjacent to each other by a small distance 55 (see FIG. 6 (B)), so that wear does not occur between these surfaces during valve rotation.

As shown in FIG. 5B, the curved edge 5
Reference numeral 1 is a curved portion of the valve 400. As shown in FIG. 5A, the curved edge 51 is rounded so that the curved surface portion 50
Is formed naturally and intersects the downstream curved surface portion 45 at a line 56. The roundness R prevents the arcuate portion of the downstream curved surface portion 45 and the inner wall 35 of the valve seat 300 from overlapping.

As shown in FIG. 5A, the rotating ears 44 at both ends of the valve 400 adjacent to the surface 54 and the curved surface 50 are ears. Changes in the curved surface 57 of the rotating ear 44 are similar to changes in the curved edge 48. The roundness of the curve 59 of the curved surface portion 50 is indicated by R, and the lower half of this curve 59 coincides with the curved surface 57 of the rotary ear portion 44, which allows the valve 400 to the rotary support portion 500 of the valve seat 300. Fix it. That is, when the valve 400 is opened and closed, the ear-shaped rotary shaft 44 moves in the recess 33 of the rotation support portion 500, so that the valve 40
Controls the opening and closing angle of 0. For example, when the valve is fully open, maximum opening is obtained, and in this embodiment, the valve is center flow, which can reduce boundary layer separation and pressure differentials. In addition, the valve 400 can quickly open and close in response to whether blood flow is on or off to reduce backflow of blood.

The valve 400 is incorporated in the valve seat 300. This incorporation takes advantage of the fact that the valve 400 expands when heated and contracts when cooled, which causes the rotating ear 44 of the valve 400 to move to the valve seat 300.
It is carried out by fitting it into the concave portion 33 of the rotation support portion 500.

A small gap is provided between the rotary ear 44 of the valve 400 and the recess 33 of the rotary support 500 of the valve seat 300, which allows the valve 400 to rotate smoothly in the recess 33. Wear on the contact surface of is reduced. Similarly, a small spacing is also provided between the vertical surface 54 of the valve 300 and the surface of the recess 33 to reduce wear on these contact surfaces. Since the valve 400 is opened by a smooth mechanism, it can be stably opened even if blood flow is small. By providing the rotary ear portion 44, the occupied volume becomes smaller than that in the case where the rotary shaft is provided in the valve 400. Further, the rotating ear-shaped portion 44 is the recess 33 of the rotation supporting portion 500 of the valve seat 300.
The valve 400 is less likely to vibrate because it is in contact with the side surface of the valve.

FIG. 6A is a side view of the artificial valve of FIG. 1A, and FIG. 6B is a view seen from the BB plane of FIG. 6A. During systole of the heart, the blood pressure in the ventricles is higher than that in the aorta. Therefore, the valve 400 receives a positive force,
The valve 400 is rotated along the rotation axis O shown in FIG.
Will open naturally. At this time, the valve 400 and the valve seat 30
It is at a right angle to 0, and therefore, the upstream curved surface portion 46 of the valve 400 and the blood flow direction 60 are parallel. As shown in FIG. 6B, when the valve 400 is fully opened, the resistance of the blood flow through the heart valve is minimum and the opening area is maximum. At the point of contact between the rotary ear 44 of the valve 400 and the surface of the recess 33 of the rotary support 500 of the valve seat 300, the lower half of the rotary ear 44 and the curved edge 38 contact the bottom of the recess 33, and The curved surface 59 of the rotating ear 44 and the curved edge 38 contact the side surface of the recess 33 to control the opening angle of the valve 400.

During the diastole of the heart, the blood pressure in the aorta gradually becomes higher than that in the ventricle, and the valve immediately closes due to the negative pressure and vortices formed in the aorta. That is, when the heart is in diastole, blood flow is reversed. Therefore, in the early stage of the relaxation period, the downstream curved surface portion 45 of the valve 400 acts on the blood flow in the opposite direction, and the valve 400 starts to rotate in the closing direction. At this moment, the drag force of the blood flow on the surface of the valve 400 causes the valve 40 to move.
The closing operation of 0 is promoted. As a result, the valve 400 smoothly rotates along the rotation axis O, and the valve shifts from the open state to the closed state. Here, curved edges R31 and R32 of the recess 33
(See FIG. 3) is formed based on the turning radius of the rotating ear portion 44.

FIG. 7A is a side view of the artificial valve of FIG. 1B, and FIG. 7B is a view seen from the BB plane of FIG. 7A. The upper half of the rotating ear 44 contacts the straight edge 36, the curved edge 37 and the side surface of the bottom surface of the recess 33, and the curved surface 59 of the rotating ear 44 contacts the side surface of the recess 33. Further, as shown in FIG. 7B, when the valve is closed, the curved edge 51 of the valve 400 coincides with the inner wall 35 of the valve seat 300, and further, the straight edge 4 of the valve 400.
8, 49 and their end points 52 coincide with each other to facilitate the end of the valve closing operation.

To summarize the above, the end of the valve opening operation is
(1) Curved edge 3 of the rotating ear portion 44 and the concave portion 33
8 and (2) the curved surface 59 of the rotating ear-shaped portion 44 and the concave portion 3
3 contact with curved edge 39. On the other hand, the end of the valve closing operation is (1) the contact between the portion of the rotating ear portion 44 and the straight edge 36 of the recess 33, and (2) the curved surface 59 of the rotating ear portion 44 and the curved edge 30 of the recess 33. Contact with (3) curved edge 51 of valve 400 and inner wall 35 of valve seat 300, (4) straight edge 48 of valve 400,
This is controlled by the contact of 49 and (5) the contact of the end point 52 of the valve 400, which can reduce the regurgitation of the valve and suppress the leakage of blood flow.

In the valve closed state, the valve 400 forms an angle of 30 ° with the valve seat 300, as shown in FIG. 7 (A). In other words, the valve 400 makes a 60 ° angle with the direction of blood flow. Therefore, the opening / closing angle of the valve 400 is 60 °.

By comparing FIG. 6B and FIG. 7B, it is possible to infer the change of the valve 400 from the open state to the closed state.
That is, since the side of the valve 400 gradually approaches toward the center, the impact of the blood flow on the tube wall is reduced, and therefore the occurrence of turbulence is also suppressed.

Although the preferred embodiment of the present invention has been described above, this does not limit the present invention, and any person skilled in the art can make modifications within the scope of the claims. It includes the possible range.

[0037]

As described above, according to the present invention, since the valve has a fan-shaped arc surface which is concave on the inflow side and convex on the outflow side, the curvature of the valve approaches a circle when fully opened. As a result, an ideal flow field can be obtained, and the effective opening area can be increased. Furthermore, since the protruding height of the valve is small, and therefore the difference in height cross-sectional area of the valve when opening and closing is small, it is possible to prevent separation of the boundary layer and the occurrence of a stagnation region under the forward flow of blood flow. It can also prevent blood pressure drop and turbulent flow. Furthermore, since the fulcrum of the valve is formed by the rotation support portion protruding from the valve seat, the curved valve can be smoothly rotated. Further, the valve can be opened and closed quickly.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a tricuspid artificial heart valve according to the present invention, in which (A) shows a valve open state and (B) shows a valve closed state.

FIG. 2 is a top view of the valve seat of FIG.

3 is a sectional view of FIG. 2, wherein FIG. 3A is a sectional view taken along the line AA of FIG. 2, and FIG. 3B is a sectional view taken along the line BB of FIG.

FIG. 4 is a perspective view of the valve of FIG.

5 is an enlarged view of FIG. 4, (A) of FIG. 5 is a perspective view seen from the AA plane of FIG. 4, and (B) of FIG. 5 is BB of FIG.
It is the perspective view seen from the surface.

6 shows the artificial valve of FIG. 1 (A), FIG. 6 (A) is a side view of the artificial valve of FIG. 1 (A), and FIG. 6 (B) is of FIG. 6 (A). It is the figure seen from the BB surface.

7 shows the artificial valve of FIG. 1 (B), FIG. 7 (A) is a side view of the artificial valve of FIG. 1 (B), and FIG. 7 (B) is of FIG. 7 (A). It is the figure seen from the BB surface.

[Explanation of symbols] 30: Curved edge 33: Recess 34: Outer wall 35: Inner wall 36: Straight edge 37: curved edge 38: curved edge 39: curved edge 44: Rotating ear 45: Downstream curved surface 46: upstream curved surface 47: Thickness 48: Straight edge 49: Straight edge 50: curved surface 51: Curved edge 52: end point 54: surface 55: Distance 56: Line 57: curved surface 58: Rotating ear portion 59: curved surface 60: blood flow direction 61: bottom 300: valve seat 400: valve 500: rotation support R31: Roundness R32: Roundness

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Face of the inventor Fengiku, 3rd floor, No. 6-2 No. 6-2, 3rd floor, 8th Road, Taipei City, Taiwan (56) Bibliography (US, A) US Patent 4254508 (US, A) US Patent 4328592 (US, A) US Patent 4689046 (US, A) US Patent 5628791 (US, A) US Patent 5641324 (US, A) UK Patent Application Publication 2281371 (GB, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) A61F 2/24 WPI (DIALOG)

Claims (15)

(57) [Claims] 1. A central passage for blood is provided on the inner wall (35) side.
A valve seat (300) and a recess (33) formed so as to project toward the inner wall of the valve seat.
A plurality of rotation supporting parts (500), an upstream curved surface part (46) concave on the blood inflow side, and
Plural that have a convex downstream curved surface portion (45) on the blood outflow side
Valve (400), the bottom of each valve being fitted into a corresponding recess of the rotary support.
The opening / closing operation of each valve is restricted by the recess.
And each valve has two straight edges (48,49) and two
Has a curved edge (51) connecting the straight edges of the above, and when the valves are closed, the straight edges of the adjacent valves coincide with each other,
And the curved edge of each valve matches the inner wall of the valve seat.
And a rounded curved edge of each valve . 2. Each valve has a fan-shaped arc surface that is substantially 1/3 of a circle, and two straight edges of each valve are 12
The artificial heart valve according to claim 1 , wherein the artificial heart valve forms an angle of 0 °. 3. The artificial heart valve according to claim 1, wherein the number of the valves is three. 4. A central passage for blood is provided on the inner wall (35) side.
A valve seat (300) and a recess (33) formed so as to project toward the inner wall of the valve seat.
A plurality of rotation supporting parts (500), an upstream curved surface part (46) concave on the blood inflow side, and
Plural that have a convex downstream curved surface portion (45) on the blood outflow side
Valve (400), the bottom of each valve being fitted into a corresponding recess of the rotary support.
The opening / closing operation of each valve is restricted by the recess.
So as to be the bottom rotating ear portion (44) which forms a ear shape der of the valves
And a side surface of the rotating ear has the same shape as a side surface of a straight edge of the valve, and a lower half of the rotating ear has a rounded curved edge of the valve . 5. The artificial heart valve according to claim 4 , wherein the number of the valves is three. 6. A central passage for blood is provided on the inner wall (35) side.
A valve seat (300) and a recess (33) formed so as to project toward the inner wall of the valve seat.
A plurality of rotation supporting parts (500), an upstream curved surface part (46) concave on the blood inflow side, and
Plural that have a convex downstream curved surface portion (45) on the blood outflow side
Valve (400), the bottom of each valve being fitted into a corresponding recess of the rotary support.
The opening / closing operation of each valve is restricted by the recess.
So as to be, the recess, one straight edge (36) and four curves
Defined by edges (30, 37, 38, 39)
An artificial body that has a closed surface, is provided with a rounded portion at the intersection of each edge, and two curved edges of the curved edges are formed based on the radius of gyration in the recess of the rotating ear portion.
Heart valve . 7. The artificial heart valve according to claim 6 , wherein the depth of the recess is larger than the depth of the rotary ear like part accommodated in the recess. 8. The position of the recess, according to claim 7 which is determined on the basis that the turning center of the wall of the recess and the center point on the projecting surface of the valve seat is the same point Artificial heart valve. 9. The portion of the valve seat projecting toward the upstream end is cut away from a plane inclined toward the upstream end so that the plane resembles a triangular plane. a point of intersection of the double wall protrudes a valve seat, to the point where the the end of a side the valve seat blood protruding portion of the valve seat flows intersect each to claim 8 intersecting The artificial heart valve described. 10. A central passage for blood is provided on the inner wall (35) side.
And a recessed portion (33) formed so as to protrude toward the inner wall of the valve seat (300).
A plurality of rotation supporting parts (500), an upstream curved surface part (46) concave on the blood inflow side, and
Plural that have a convex downstream curved surface portion (45) on the blood outflow side
Valve (400), the bottom of each valve being fitted into a corresponding recess of the rotary support.
The opening / closing operation of each valve is restricted by the recess.
And when the valve is fully open, the rotation support should be above the rotation ear.
Lower half of the side that corresponds to the lower half of the recess on the flow-side curved surface
Are in contact with each other, and the downstream curved surface of the rotating ear and the concave
The surface of the upper half of the curved part is vertically face-down
They are in contact with each other, which controls the valve opening operation of the valve seat.
And, when opening and closing of the valve, the rotation corresponding to the side surface of the ear-like portion curved surface with the phase contact with the rotation of the central shaft and the bottom surface of the recess, an artificial heart valve gap is left between the two surfaces. 11. A central passage for blood is provided on the inner wall (35) side.
And a recessed portion (33) formed so as to protrude toward the inner wall of the valve seat (300).
A plurality of rotation supporting parts (500), an upstream curved surface part (46) concave on the blood inflow side, and
Plural that have a convex downstream curved surface portion (45) on the blood outflow side
Valve (400), the bottom of each valve being fitted into a corresponding recess of the rotary support.
The opening / closing operation of each valve is restricted by the recess.
And when the valve is fully open, the rotation support should be above the rotation ear.
Lower half of the side that corresponds to the lower half of the recess on the flow-side curved surface
Are in contact with each other, and the downstream curved surface of the rotating ear and the concave
The surface of the upper half of the curved part is vertically face-down
They are in contact with each other, which controls the valve opening operation of the valve seat.
However , when the valve is fully closed, in the rotation support portion, the curve corresponding to the upper half of the upstream curved surface of the rotating ear portion and the side on the upper half side of the recess are in contact with each other on a side-by-side basis, An artificial heart valve in which a side representing a thickness where a vertical surface corresponding to a side surface and a curved surface corresponding to a side surface of the rotating ear portion contact each other and a straight edge of the recess contact each other on a side-to-side basis. 12. When the valve is fully closed, the curved surface corresponding to the lower half portion of the downstream curved surface portion of the rotary ear portion and the surface obtained by vertically digging the lower half side curve of the concave portion are face-to-face contact with each other. The artificial heart valve according to claim 11 . 13. The arc line segment of the upstream curved surface portion of the valve and the inner wall of the valve seat are face-to-face contact with each other when the valve is fully closed.
The artificial heart valve according to 12 . 14. The artificial heart valve according to claim 13, wherein two sides of the front valve are in face-to-face contact with two sides of another valve when the valve is fully closed. When 15. valve is fully closed, the vertex two sides of the valve intersects the apex of the other two valves, according to claim 14 adjoin at the side opposite sides in the vertical sides representing the thickness Artificial heart valve.