JPH0654868A - Artificial valve for living body - Google Patents

Abstract

PURPOSE:To provide the artificial valve for living bodies with which the side flow passing the peripheral edge of a valve port is obtainable in addition to the main flow passing the central area of the valve port and which has excellent fluid dynamic characteristics, can particularly decrease the pressure difference across the valve and has the characteristic capable of additionally improving the formation of turbulence downstream of the valve. CONSTITUTION:The front edges 2a of valve leaves 2 consisting of an aluminum system part to open a central area 10h and the rear edges 2b of the respective valve leaves 2 part from the peripheral edge 10i of the valve port 10 to open the valve when the valve leaves 2 oscillate in an arrow A direction. The distance connecting the front edge 2a of each valve leaf 2 and the center of the axial part 20 in a direction parallel with a virtual line P2 is designated as L1, the distance connecting the front edge 2a and rear edge 2b of each valve leaf 2 in the direction parallel with the virtual line P2 as L0 and the wing chord length of the value leaf 2 as CO and the max. chamber of the valve leaf 2 as C1, the axial positions of the valve leaves 2 as (%)=(L1/L0)X100 and the curvature of the valve leaves 2 as (%)=(C1/C0)X100. The axial position of the valve leaves 2 is set at about 70% and the curvature of the valve leaves 2 at about 9%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bioprosthetic valve applicable to a heart valve and the like, and more particularly to a bioprosthetic valve which can obtain a main flow passing through the central region of the valve opening as well as a side flow passing through the peripheral edge of the valve opening. Regarding artificial valve.

[0002]

2. Description of the Related Art Conventional artificial valves for living bodies still have problems such as thrombosis and damage during long-term use. Therefore, an artificial valve for a living body having characteristics close to those of the natural valve of the living body is desired. As such an artificial valve for a living body, the present inventors have a substantially ring-shaped valve housing having a circular valve opening, and a set of two rockable leaflets, and swing the leaflets. A center open type has been developed that opens the central region of the valve opening (Japanese Patent Laid-Open No. 63-234965). In this case, since the central region of the valve opening is opened by the leaflets, a central blood flow similar to that of the natural valve of the living body can be obtained, which is advantageous in preventing thrombus.

Further, conventionally, as an artificial valve for a living body, a shaft portion that pivotally supports a valve leaf is translated with respect to a valve housing in addition to the pivotal movement to prevent thrombus near the shaft portion. The one designed is also known (JP-A-56-1610).
47 publication).

[0004]

Further, the present inventors have
As a biological artificial valve that is closer to the natural valve of the living body, in addition to opening the central area of the valve opening to obtain the main flow of blood flow, the peripheral edge of the valve opening is also opened to obtain a secondary flow of blood flow. We are developing the artificial valve. In this bioprosthetic valve, the intermediate portion of the leaflet is pivotally supported by the valve housing by the shaft portion. here,
When the leaflets oscillate in the centrifugal direction, the leading edges of the leaflets move away from each other to open the central region of the valve opening, and the trailing edges of the leaflets move away from the peripheral edge of the valve opening. Speak. With this type, in addition to the main flow passing through the central region of the valve opening, a side flow passing through the peripheral edge of the valve opening is obtained, so an effective washout effect due to the side flow is obtained, and vortices and stagnation around the valve are obtained. It can be effectively avoided, and the antithrombogenicity can be further improved.

The present invention is a further technical advancement of a bioprosthetic valve of the type in which a side flow passing through the periphery of the valve opening is obtained in addition to the main flow passing through the central area of the valve opening described above. It is an object of the present invention to provide an artificial valve for a living body, which has excellent dynamic characteristics, in particular, can reduce the pressure difference before and after the valve, and can further suppress turbulent flow downstream of the valve.

[0006]

Means for Solving the Problems The present inventor speculates that the position, curvature, etc. of the shaft portion of a mechanical artificial valve that opens and closes in response to swinging greatly influences the valve function, and advances the research. The present invention has been completed. That is, the bioprosthetic valve of the present invention is a substantially ring-shaped valve housing having a valve opening,
It is composed of a pair of two having front edges facing each other and arcuate rear edges facing back to each other and extending along the peripheral edge of the valve opening. The intermediate part is pivotally movable in the centrifugal direction and the centripetal direction by the shaft part to the valve housing. It is pivotally supported, and as it swings in the centrifugal direction, each leading edge separates and opens the central region of the valve opening, and each trailing edge separates from the peripheral edge of the valve opening and opens, and in the centripetal direction. The leading edge of each valve closes to close the central region of the valve opening and the trailing edge of each valve closes to the edge of the valve opening, and at least one of the valve housing and the valve leaf. When the valve is closed, it is configured with a stopper portion that tilts each leaflet with respect to an imaginary line that is orthogonal to the axis of the valve opening when the valve is closed. In the cross section, the distance connecting the front edge of the leaflets and the center of the shaft portion in the direction parallel to the imaginary line is L1, and the leaflet in the direction parallel to the imaginary line is L1. The distance connecting the leading and trailing edges and L0,
Let the chord length of the leaflets be C0, and let the maximum camber of the leaflets be C1.
And the axial position of the leaflet (%) = (L1 / L0) × 100 and the curvature of the leaflet (%) = (C1 / C0) × 100, the axial position of the leaflet is 67 to 73%. The curvature of the leaflets is set to 8 to 10%.

In the present invention, the leaflet and the shaft portion may be separate bodies or one body.

[0008]

In the artificial valve for a living body of the present invention, when the valve is opened, a main flow passing through the central region of the valve opening is obtained, and a side flow passing through the peripheral edge of the valve opening is obtained. In the bioprosthetic valve of the present invention, the axial position of the leaflet is set to 67 to 73%, and the curvature of the leaflet is 8 to 10%.
%, The hydrodynamic characteristics are improved.

[0009]

Embodiments of the artificial valve for a living body of the present invention will be described with reference to the drawings. 1 and 2 show the valve closed state. FIG. 3 shows the valve housing 1. As shown in FIGS. 1 and 3, the valve housing 1 has a substantially ring shape having a valve port 10. The valve port 10 is divided into an arc surface 10a, an arc surface 10b, a straight surface 10e, and a straight surface 10f. Mounting hole 1 for valve housing 1
A stopper portion 11 is inserted in a, and the stopper portion 11 is fixed by a set screw 12 screwed into the hole 1b of the valve housing 1. In addition, the valve housing 1, the stopper portion 11,
The set screw 12 is made of stainless steel, and a titanium nitride film having a required thickness, which is expected to have antithrombogenicity, is laminated.

As shown in FIGS. 1 and 2, the leaflets 2 are composed of two pairs. The leaflets 2 have front edges 2a facing each other.
And a rear edge 2b having shapes that face each other and extend along the arc surface 10a of the peripheral edge 10i of the valve opening 10, and further include side surface edges 2e, 2f,
It has an arc edge surface 2i. Further, as shown in FIGS. 1 and 6, a stainless shaft 20 (outer diameter 0.5 mm) is inserted into a hole 2w formed in the side edge 2f as an intermediate portion of the leaflet 2.

In FIG. 6, the trailing edge 2b has an arc center M.
The arc edge surface 2i is formed from the arc center M1 to the radius r2. Further, in FIG. 7, the inner surface 2n and the outer surface 2k of the valve leaf 2 are slightly bulged outward. Further, in FIG. 8, the outer surface 2k of the leaflet 2 has an arc center M.
The inner surface 2n of the leaflet 2 is formed from the arc center M3 to the radius r5.

As shown in FIGS. 4 and 5, the stopper portion 11 has tapered stopper surfaces 11a and 11b and an insertion hole 11d (inner diameter 0.5 mm). Then, as shown in FIG. 5, the shaft portion 20 is inserted into the insertion hole 11 d of the stopper portion 11, so that each valve leaf 2 is moved by the shaft portion 20.
The valve leaflets 2 are swingable in the centrifugal direction, that is, the arrow A1 direction and in the centripetal direction, that is, the arrow A2 direction. In this embodiment, as can be understood from FIG.
Since a gap 14 (about 0.1 mm) is formed between the leaflet 2 and the boundary region 11c of the stopper surfaces 11a and 11b, blood flow (blood in the direction of arrow S in FIG. 5) around the shaft portion 20. )) Washout effect,
This is advantageous for preventing thrombus around the shaft portion 20 and around the stopper portion 11.

Here, as can be understood from FIG. 2, as the leaflets 2 swing in the centrifugal direction, that is, in the direction of arrow A1, the front edges 2a of the leaflets 2 move away from each other and the center of the valve opening 10 is separated. Area 10
h is opened, and the trailing edge 2b of each leaflet 2 is opened at the valve opening 10
The valve is opened apart from the arc surface 10a of the peripheral edge 10i. Further, as the leaflets 2 swing in the centripetal direction, that is, in the direction of the arrow A2, the leading edges 2a of the leaflets 2 approach each other to close the central region 10h of the leaflets 10, and The trailing edge 2b closes the arc surface 10a of the peripheral edge 10i of the valve opening 10 to close the valve. In FIG. 2, the arrow W indicates the direction of blood flow, and therefore W1 indicates upstream and W2 indicates downstream.

Now, FIG. 9 shows a central cross section in the direction connecting the front edge 2a and the rear edge 2b of the leaf 2 in the valve closed state. Here, the front edge 2a means the intersection of the tip of the leaflet 2 and the thickness center line E in the thickness of the leaflet 2. In FIG.
The distance connecting the front edge 2a of the leaflet 2 and the center of the shaft portion 20 in the direction parallel to the imaginary line P2 is L1, and the front edge 2a and the rear edge 2b of the leaflet 2 in the direction parallel to the imaginary line P2 are The connecting distance is L0. Further, the chord length of the leaflets 2 is set to C0, and the leaflets 2
The maximum camper of C1 is C1. Here, as can be understood from FIG. 9, the chord length CO of the leaflet 2 means the shortest distance connecting the start point E1 and the end point E2 (front edge 2a) of the thickness centerline E of the leaflet 2. Also, the maximum camper C1 of the leaflets 2 is
It means the shortest distance between the straight line F connecting the starting point E1 and the end point E2 of the thickness center line E of the leaflet 2 and the maximum curvature point E3 of the thickness center line E.

Here, the axial position (%) of the leaflets 2 = (L1 /
L0) × 100, and curvature (%) of leaflet 2 = (C1 / C
0) × 100. In this embodiment, the axial position of the leaf 2 is set to about 70%, and the curvature of the leaf 2 is set to about 9%. As can be understood from FIG. 5, when the valve is closed, the valve leaf 2 oscillated in the direction of the arrow A2 is moved to the stopper portion 11
Is regulated by the stopper surface 11a. At the time of such valve closing, as shown in FIG. 2, the valve leaf 2 has the axis P1 of the valve port 10.
It is held at an angle θ2 (15 °) with respect to an imaginary line P2 that is orthogonal to. This is because the opening / closing response of the leaflets 2 is performed quickly. Further, as can be understood from FIG. 5, when the valve is opened, the valve leaf 2 has the stopper surface 11b of the stopper portion 11.
Regulated by. When the leaflet 2 is fully opened, the angle of the leaflet 2 with respect to the imaginary line P2 when the valve is fully opened is 62 °.
Is. Here, basically, when the leaflet 2 is fully opened, the tangent line drawn from the starting point E1 of the thickness centerline E of the leaflet 2 to the thickness centerline E is 90 °.

In this embodiment, the leaflets 2 are A1-Zn-Mg.
Aluminum-based metals of the series, namely ultra-super duralumin (JI
S A7056-T6), and a film of aluminum oxide is laminated on the surface thereof by reactive sputtering. The aluminum oxide film has a graded composition so that the outermost surface thereof has a high concentration. Aluminum oxide is biocompatible and blood compatible. It was confirmed that the aluminum oxide had an amorphous structure structurally and was oxygen-rich compositionally. Further, in this embodiment,
Since the leaflets 2 are formed of an Al1-Zn-Mg-based aluminum-based metal, they have good machinability while ensuring durability and strength, and are advantageous in setting the shape of the leaflets. In this embodiment, since reactive sputtering is used as the film forming means, it is possible to form a film at a low temperature, and it is possible to prevent thermal deterioration of the mechanical properties of the aluminum-based metal forming the leaflets 2.

As described above, in the present embodiment, when the valve leaf 2 is opened, the peripheral area 10i of the valve opening 10 is opened in addition to the central area 10h of the valve opening 10, so that the central area of the valve opening 10 is opened. 10h
In addition to the main flow passing through, the secondary flow passing through the peripheral edge 10i of the valve opening 10 can be obtained, vortices and stagnation around the valve can be effectively avoided, and an excellent thrombus prevention effect can be obtained. Further, in this embodiment, the axial position of the leaf 2 is set to about 70%, and the curvature of the leaf 2 is about 9%.
%, The leaflets 2 having improved hydrodynamic characteristics can be obtained, as shown in the test example described later, and a leaflet more similar to a human natural valve can be obtained.

(Test Example) Seven kinds of artificial valves shown in Table 1 were made as trials by using the axial position of the leaflets 2 and the curvature of the leaflets 2 as parameters. That is, the axial position of the leaflets 2 was fixed at 70% and the curvature of the leaflets 2 was changed to 0%, 9%, 11% and 13%, and the curvature of the leaflets 2 was fixed at 9%. Axis position 65%,
Seven types of prototypes were produced, with the changes being 70%, 75%, and 80%. And, as shown in Table 1, each artificial valve is S650.
9, S7000, S7009, S7011, S701
3, S7509 and S8009. Here, for example, in the artificial valve S7009, the numeral 70 indicates the axial position and the numeral 09 indicates the curvature.

[0019]

[Table 1] (1) Test method Using each prototype artificial valve, hydrodynamic characteristic evaluation was performed. In this case, a steady flow test, a constant pressure leak test, and a pulsatile flow test simulating the left ventricular system circulation in vivo were performed as described below. (1-1) Steady flow test As a basic fluid property evaluation, the fluid dynamics after passing through the valve were tested by visualizing the pressure difference before and after the valve in the steady flow. This test was performed by fixing an artificial valve to the tip of an acrylic tube having a length of 250 cm, and changing the flow rate from 0.5 to 14.0 L / min by a valve from a tank maintaining a constant static pressure. A 34% glycerin aqueous solution was used as a fluid to flow through the acrylic tube so as to adapt to the specific gravity of blood (1.08) and the viscosity of blood (2.7 cSt). In addition, aluminum powder was used as a tracer for visualization of the flow. (1-2) Pulsatile flow test In this test, a hydrodynamic valve function evaluation in pulsatile flow, which simulates the left ventricular system circulation in the living body, was performed. This test is based on driving pressure (150 mmHg), arterial compliance (0.015 L / mmHg), peripheral resistance (16.25 m).
mHg min / L) and systole (0.29s)
Is constant and the number of beats is 60, 72, 84 per minute,
The number of times was changed to 96 times.

Then, the flow rate, the effective valve opening area, the energy loss, and the valve closing flow rate (reverse flow rate when the valve was closed) were measured. The Gorlin equation was used to calculate the effective valve opening area. (1-3) Constant Pressure Leakage Test A constant pressure leakage test was performed as an evaluation of the amount of leakage when the valve was closed. In the test, the amount of leak at a constant pressure (100 cmH ₂ O) was measured using an artificial valve (S7009) and converted into the amount per minute.

(2) Test Results (2-1) Results of Steady Flow Test FIGS. 10 and 11 show the test results of the pressure difference before and after the artificial valve when the steady flow is used. FIG. 10 is a comparison according to the axial position. From the result of FIG. 10, S6509 (axial position 6
Except for 5% and curvature 9%), no significant change is observed. Therefore, as shown in the column A of Table 2, the axial position 65% was determined as x, and the axial positions 70%, 75%, and 80% were determined as o.

FIG. 11 is a comparison based on the curvature of the leaflets 2. From the result of FIG. 11, it was observed that the curvature of the leaflets 2 greatly affects the pressure difference before and after the artificial valve. In particular, S7
It was observed that 009 (axial position 70%, curvature 9%) had the smallest pressure difference. If the pressure difference is large, turbulent flow is likely to occur downstream of the valve, which is not preferable. Therefore, as shown in the column A of Table 3, 0% and 9% of curvatures are judged as ◯, and 13% of curvatures are ×.
It was determined.

[0023]

[Table 2]

[0024]

[Table 3] In the visualization test of the flow of the artificial valve in the steady flow, the valve opening 1
The main flow passing through the central region 10h of 0 was not significantly affected by the change in the axial position of the leaflets 2. However, the sidestream was greatly affected by the change in the axial position of the leaflets 2. That is, when the value of the axial position of the leaflet 2 is increased, the side flow becomes smaller,
Therefore, it is presumed that the thrombus prevention effect due to the sidestream is reduced. To effectively reduce the stagnation around the valve, S7
A sidestream flow of about 009 is required. Therefore, B in Table 2
As shown in the column, 70% of the axial position was judged as ◯, and as shown in the column B of Table 3, 9% of curvature was also judged as ◯. (2-2) Results of pulsatile flow test FIGS. 12 and 13 show the relationship between the pulsating flow rate and the pulsation rate when pulsatile flow is used. FIG. 12 is a comparison according to the axial position of the leaflets 2. 12, S7009 and S800
9 has a large flow rate, and S6509 has the smallest flow rate. Therefore, as shown in the column C of Table 2, 70% and 80% of the shaft positions were judged to be ◯, and 65% and 75% of the shaft positions were judged to be Δ. FIG.
Is a comparison based on the curvature of the leaflets 2. In FIG. 13, S
7009 has the highest flow rate, and S7013 has the lowest flow rate. Therefore, as shown in the column C of Table 3, 9% of curvature is judged as ◯, 13% of curvature is judged as ×, and 0% and 11% of curvature are Δ.
It was determined.

14 and 15 show the relationship between the effective valve opening area and the pulsation rate. FIG. 14 is a comparison according to the axial position of the leaflets 2. In FIG. 14, S8009 has the largest effective valve opening area, and S6509 has the smallest effective valve opening area. Therefore, as shown in column D of Table 2, 80% of the shaft positions were judged as ◯, 65% of the shaft positions were judged as x, and 70% and 75% of the shaft positions were judged as Δ. FIG. 15 is a comparison based on the curvature of the leaflets 2. In FIG. 15, S7009 has the largest effective valve opening area, and S7000 has the smallest effective valve opening area. Therefore, as shown in the column D of Table 3, 9% of curvature was judged as ◯, 0% of curvature was judged as ×, and 11% and 13% of curvature were judged as Δ.

16 and 17 show the relationship between the pulse rate and energy loss in each artificial valve. FIG. 16 is a comparison according to the axial position. From the results shown in FIG. 16, although there is no significant difference in energy loss due to the difference in shaft position, S80
09 has the smallest energy loss, and S6509 has the largest energy loss. Therefore, as shown in the E column of Table 2, 80% of the shaft positions were judged as ◯, 65% of the shaft positions were judged as ×, and 70% and 75% of the shaft positions were judged as Δ. FIG. 17 shows leaflet 2
3 is a comparison of energy loss due to a difference in curvature of the. FIG. 17
As shown in, the largest energy loss is observed in S7013, and the energy loss is smallest in S7009. Therefore, as shown in column E of Table 3, a curvature of 13% is judged as x, and a curvature of 9% is determined.
% Was judged as ◯, curvature 0% and 11% were judged as Δ.

18 and 19 show the relationship between the pulse rate and the valve closing flow rate (reverse flow rate when the valve is closed) in each artificial valve. FIG. 18 is a comparison according to the axial position. From the results shown in FIG. 18, it can be seen that S7009 has the smallest valve closing flow rate. Therefore, as shown in column F of Table 2, 70% of the shaft positions were judged to be ◯, and 65%, 75% and 80% of the shaft positions were judged to be Δ.
FIG. 19 is a comparison of valve closing flow rates depending on the curvature of the valve leaf 2. From the results shown in FIG. 19, the valve closing flow rate is small in S7013 and S7009, and the valve closing flow rate is the largest in S7000. Therefore, as shown in the column F of Table 3, the curvatures of 13% and 9% were judged as ◯, the curvature of 0% was judged as ×, and the curvature of 11% was judged as Δ. (2-3) Result of constant pressure leakage test The constant pressure leakage amount of the artificial valve according to S7009 was less than half of the leakage amount of 1.5 L / min determined by the Ministry of Health and Welfare. (2-4) Comprehensive Evaluation In Table 2, there are many ◯ when the axial position is 70%, and in Table 3, there are many ◯ when the curvature is 9%. Therefore, when comprehensively considering from the hydrodynamic characteristic evaluations in the steady flow and the pulsatile flow, S7
009 (70% axial position, 9% curvature) is understood to be the most suitable shape. In particular, as can be understood from FIG. 11, in S7009, since the pressure difference before and after the artificial valve is the smallest, the effect of suppressing turbulence on the downstream side of the artificial valve is great.

[0028]

According to the present invention, not only the main flow but also the sub-flow can be obtained, and the hydrodynamic characteristics are excellent. In particular, the pressure difference before and after the valve can be made small, and the turbulent flow in the downstream of the valve can be suppressed. A bioprosthetic valve having excellent characteristics can be obtained.

[Brief description of drawings]

FIG. 1 is a plan view of a bioprosthetic valve of the present invention.

FIG. 2 is a sectional view taken along line BB ′ in FIG. 1 of the bioprosthetic valve of the present invention.
FIG.

FIG. 3 is a plan view of the valve housing of the bioprosthetic valve of the present invention.

4 is a front view of the stopper portion of the bioprosthetic valve of the present invention as seen from the direction of arrow Y1 in FIG.

FIG. 5 is an explanatory view of the vicinity of the stopper portion of the bioprosthetic valve of the present invention showing a state in which the leaflet is pivotally supported.

FIG. 6 is a plan view of the leaflet of the bioprosthetic valve of the present invention.

FIG. 7 is a front view of the leaflet of the bioprosthetic valve of the present invention viewed from the direction of arrow Y2 in FIG.

8 is a front view of the leaflet of the bioprosthetic valve of the present invention as seen from the direction of the arrow Y3 in FIG.

FIG. 9 is an explanatory diagram of leaflets of the bioprosthetic valve of the present invention for showing L1, L0, C0, and C1.

FIG. 10 is a graph showing a relationship between a steady flow rate and a pressure difference when the axial position is changed.

FIG. 11 is a graph showing the relationship between the flow rate of a steady flow and the pressure difference when the curvature is changed.

FIG. 12 is a graph showing the relationship between the stroke flow rate and the pulsation rate when the axis position is changed.

FIG. 13 is a graph showing the relationship between the ejection flow rate and the pulsation rate when the curvature is changed.

FIG. 14 is a graph showing the relationship between the effective valve opening area and the pulsation rate when the axial position is changed.

FIG. 15 is a graph showing the relationship between the effective valve opening area and the pulsation rate when the curvature is changed.

FIG. 16 is a graph showing the relationship between energy loss and pulse rate when the axis position is changed.

FIG. 17 is a graph showing the relationship between energy loss and pulse rate when the curvature is changed.

FIG. 18 is a graph showing the relationship between the valve closing flow rate and the pulsation rate when the axial position is changed.

FIG. 19 is a graph showing the relationship between the valve closing flow rate and the pulsation rate when the curvature is changed.

[Explanation of symbols]

In the figure, 1 is a valve housing, 10 is a valve opening, 11 is a stopper portion, 11a is a stopper surface, 2 is a valve leaf, 2a is a front edge, and 2b.
Indicates a trailing edge, and P2 indicates an imaginary line.

Claims (1)

[Claims] 1. A centrifuge, comprising a pair of valve housings each having a substantially ring-shaped valve housing having a valve opening, front edges facing each other, and arc-shaped rear edges facing each other and extending along the periphery of the valve opening. The central portion is pivotally supported by the valve housing by the shaft portion so as to be swingable in the axial direction and the centripetal direction, and the respective front edges are separated from each other with the swing in the centrifugal direction, and the central region of the valve opening is opened. Each trailing edge separates from the periphery of the valve opening and opens, and as the centering direction swings, each leading edge approaches and closes the central region of the valve opening, and each trailing edge closes the valve. A valve leaf that closes near the periphery of the mouth and at least one of the valve housing and the leaflet, and each leaflet with respect to an imaginary line that is orthogonal to the axis of the valve mouth when closed. A stopper portion for inclining the valve leaf, and a cross section at the time of valve closing in a direction connecting the front edge and the rear edge of the leaflet, Let L1 be the distance connecting in the direction parallel to the imaginary line, L0 be the distance connecting the leading edge and the trailing edge of the leaflet in the direction parallel to the imaginary line, and let the chord length of the leaflet be C0. When the maximum camper of the leaflet is C1, the axial position of the leaflet (%) = (L1 / L0) × 100, and the curvature (%) of the leaflet = (C1 / C0) × 100 The artificial valve for a living body, wherein the axial position of the leaflets is set to 67 to 73% and the curvature of the leaflets is set to 8 to 10%.