Heart valve prosthesis, method for producing a heart valve prosthesis and mould applied thereby

Claim 2

Heart valve prosthesis consisting of a substantially rigid frame with provided therein several synthetic membranes whereby the membrane is a fibre-reinforced matrix material, characterised in that the fibres are arranged parallel in the matrix material and that the fibre material and the matrix material are chemically identical.

Claim 3

Heart valve prosthesis as claimed in claim 1, characterised in that the matrix material and the fibre material consist of polyether urethane.

Claim 4

Heart valve prosthesis as claimed any one of the claims 1-2, characterised in that for the production of the fibre material is used polyether of a lower molecular weight than for the preparation of the matrix material.

Claim 5

Heart valve prosthesis as claimed in claim 3, characterised in that for the preparation of the fibre material is used polyoxy tetramethylene glycol of a relatively low molecular weight relative to the polymer for the matrix material.

Claim 6

Method for producing a heart valve prosthesis as claimed in claim 1, characterised in that in a mould in the shape of the assembly of membranes a solution of the matrix material is applied and dried to form a film of matrix material, the fibres are arranged parallel on the film and the frame is placed and finally a matrix film is formed in one or more operations so that the fibres are embedded and the membrane is adherent to the frame.

Claim 7

Heart valve prosthesis as claimed in claim 1, whereby the heart valve is an aorta valve consisting of three membranes connected to a frame, characterised in that the membranes have been produced according to a method as described in claim 5.

Claim 8

Heart valve prosthesis with a frame and three fibre-reinforced membranes suspended in the frame, said frame being substantially an upright, circular closed strip with three frame legs located along the strip at equal distance in the same direction, whereby the height of the strip is greatest near the frame legs and each time decreases symmetrically, according to a certain curve, from two frame legs along the strip to the centre of the strip portion between the frame legs and whereby each time the coaptation portion of a membrane is connected to two adjacent frame legs and the free membrane portion is connected to the strip portion of the frame enclosed by the frame legs, whereby in the closed position of the heart valve prosthesis the coaptation portions of the membranes lie against each other and the ends of the coaptation portions not connected to the frame legs define a substantially straight line; characterised in that the frame is substantially rigid, that the fibres in the membrane are spaced substantially parallel to each other and are substantially perpendicular to said line in the coaptation portion in the closed position of the heart valve prosthesis, and that the membranes are connected directly to the frame.

Claim 9

Heart valve prosthesis with a frame and three fibre-reinforced membranes suspended in the frame, said frame being substantially an upright, circular closed strip with three frame legs located along the strip at equal distance in the same direction, whereby the height of the strip is greatest near the frame legs and each time decreases symmetrically, according to a certain curve, from two frame legs along the strip to the centre of the strip portion between the frame legs and whereby each time the coaptation portion of a membrane is connected to two adjacent frame legs and the free membrane portion is connected to the strip portion of the frame enclosed by the frame legs, whereby in the closed position of the heart valve prosthesis the coaptation portions of the membranes lie against each other and the ends of the coaptation portions not connected to the frame legs define a substantially straight line; characterised in that the frame is substantially rigid, that the fibres in the membrane are spaced substantially parallel to each other and are substantially perpendicular to said line in the coaptation portion in the closed position of the heart valve prosthesis, and that the membranes are connected directly to the frame.

Claim 10

Heart valve prosthesis as claimed in claim 7, characterised in that the frame is made of steel.

Claim 11

Heart valve prosthesis as claimed in claim 8, characterised in that the thickness of the frame and the diameter of the frame legs are approximately 1 mm.

Claim 12

Heart valve prosthesis as claimed in any one of the claims 7-9, characterised in that the angle α of the free membrane portion to said line ranges from 0 to 20°.

Claim 13

Heart valve prosthesis as claimed in any one of the claims 7-10, characterised in that the modulus of elasticity of the fibres in the membranes ranges from 10 to 50 N/mm 2 .

Claim 14

Heart valve prosthesis as claimed in any one of the claims 7-11, characterised in that the matrix thickness of the membranes ranges from 0.2 to 0.6 mm.

Claim 15

Heart valve prosthesis as claimed in any one of the claims 7-12, characterised in that the fibre thickness of the membranes ranges from 0.2 to 0.3 mm.

Claim 16

Heart valve prosthesis as claimed in any one of the claims 7-13, characterised in that the mean fibre distance in the membranes ranges from 0.8 to 2.7 mm.

Claim 17

Heart valve prosthesis as claimed in claim 14, characterised in that the angle α approximately equals 10°, that the modulus of elasticity is app. 50 N/mm 2 , that the matrix thickness of the nembranes is app. 0.4 mm, that the fibre thickness of the membranes Ls app. 0.25 mm and that the average fibre distance in the membranes is app. 1.5 mm.

Claim 18

Heart valve prosthesis as claimed in any one of the claims 7-15, characterised in that the surface area of the coaptation portion of the membranes ranges from 38 to 152 mm 2 and is preferably 76 mm 2 .

Claim 19

Heart valve prosthesis as claimed in any one of the claims 7-16, characterised in that the modulus of elasticity of the matrix material of the membranes ranges from 1 to 5 N/mm 2 and is preferably app. 1.8 N/mm 2 .

Claim 20

Mould for producing a heart valve prosthesis therein, characterised in that the mould is shaped such that a heart valve prosthesis can be produced as indicated in any one of the claims 7-17.